Add Datamodel

Fixes #105

.github/CODEOWNERS

@@ -1 +0,0 @@
-* @CyB3RC0nN0R

.github/ISSUE_TEMPLATE/bug_report.md

@@ -1,32 +0,0 @@
----
-name: Bug report
-about: Create a report to help us improve
-title: ''
-labels: bug
-assignees: CyB3RC0nN0R, delvh, DieGurke, derharry333
-projects: Envoy
-milestone: Envoy v0.2-beta
----
-
-**Describe the bug**
-A clear and concise description of what the bug is.
-
-**To Reproduce**
-Steps to reproduce the behavior:
-1. Go to '...'
-2. Click on '....'
-3. Scroll down to '....'
-4. See error
-
-**Expected behavior**
-A clear and concise description of what you expected to happen.
-
-**Screenshots**
-If applicable, add screenshots to help explain your problem.
-
-**Desktop (please complete the following information):**
- - OS: [e.g. Debian GNU/Linux, Microsoft Windows 10]
- - Version [e.g. 0.1-beta]
-
-**Additional context**
-Add any other context about the problem here.

.github/ISSUE_TEMPLATE/feature_request.md

@@ -1,21 +0,0 @@
----
-name: Feature request
-about: Suggest an idea for this project
-title: ''
-labels: enhancement, feature
-assignees: CyB3RC0nN0R, delvh, DieGurke
-project: Envoy
-milestones: Envoy v0.2-beta
----
-
-**Is your feature request related to a problem? Please describe.**
-A clear and concise description of what the problem is. Ex. I'm always frustrated when [...]
-
-**Describe the solution you'd like**
-A clear and concise description of what you want to happen.
-
-**Describe alternatives you've considered**
-A clear and concise description of any alternative solutions or features you've considered.
-
-**Additional context**
-Add any other context or screenshots about the feature request here.

.github/PULL_REQUEST_TEMPLATE/bugfix.md

@@ -1,10 +0,0 @@
----
-name: Bug fix
-title: Fixed Bug
-labels: bug
-assignees: CyB3RC0nN0R, delvh, DieGurke
-reviewers: CyB3RC0nN0R, delvh
-projects: Envoy
-milestone: Envoy v0.1-beta
----
-Fixes #{issue}

.github/PULL_REQUEST_TEMPLATE/feature_integration.md

@@ -1,9 +0,0 @@
----
-name: Feature integration
-title: Added feature
-labels: feature
-assignees: CyB3RC0nN0R, delvh, DieGurke
-reviewers: CyB3RC0nN0R, delvh
-projects: Envoy
-milestone: Envoy v0.1-beta
----

.github/PULL_REQUEST_TEMPLATE/javadoc_update.md

@@ -1,10 +0,0 @@
----
-name: Updated Javadoc 
-title: Updated Javadoc
-labels: documentation
-assignees: CyB3RC0nN0R, delvh
-reviewers: CyB3RC0nN0R, delvh
-projects: Envoy
-milestone: Envoy v0.1-beta
-
----

.github/workflows/maven.yml

@@ -1,32 +0,0 @@
-name: Java CI
-
-on: [push]
-
-jobs:
-  build:
-    name: Build & Package
-    runs-on: ${{ matrix.os }}
-    strategy:
-      matrix:
-        os: [ubuntu-latest, windows-latest]
-
-    steps:
-    - uses: actions/checkout@v2
-    - name: Set up JDK 11
-      uses: actions/setup-java@v1
-      with:
-        java-version: 11
-    - name: Cache Maven packages
-      uses: actions/cache@v2
-      with:
-        path: ~/.m2
-        key: ${{ runner.os }}-m2-${{ hashFiles('**/pom.xml') }}
-        restore-keys: ${{ runner.os }}-m2
-    - name: Build with Maven
-      run: mvn -B package
-    - uses: actions/upload-artifact@v2
-      with:
-        name: envoy-${{ matrix.os }}
-        path: |
-          server/target/envoy-server-jar-with-dependencies.jar
-          client/target/envoy-client*shaded.jar

.gitignore

@@ -1 +1,8 @@
+# build folders
 target/
+
+# Eclipse settings
+/.settings
+
+# virtual machine crash logs, see http://www.java.com/en/download/help/error_hotspot.xml
+hs_err_pid*.log

.settings/org.eclipse.core.resources.prefs

@@ -1,2 +0,0 @@
-eclipse.preferences.version=1
-encoding/<project>=UTF-8

README.md

@@ -0,0 +1,69 @@
+# Envoy
+
+<img src="https://git.kske.dev/repo-avatars/33-31e14133097b01b748ab361e3c3adb47" style="display: block" width="150" height="150">
+
+Envoy is a messenger written in Java.
+On this page, the project is explained for different user groups.
+
+## Regular User
+
+To use Envoy to join an existing server, download the client from the [release page](https://git.kske.dev/zdm/envoy/releases).
+
+When starting it for the first time, you can register yourself at a server of your choice.
+After connecting to the server, you can add other users to your contact list and send them messages.
+
+To chat with multiple users at once, you can create a group.
+If you want to transfer a file to another user, you can attach it to a message.
+
+On the settings page some convenience features can be configured, as well as the color theme.
+
+### System requirements
+
+To run Envoy, you have to install a Java Runtime Environment (JRE) of at least version 11.
+You can download an open source implementation from [here](https://jdk.java.net/15/).
+
+If you are running a Linux distribution, make sure that an emoji font like [Noto emoji](https://github.com/googlefonts/noto-emoji) is installed.
+Most major Linux distributions like Debian, Arch and Gentoo have a Noto emoji package available inside their package repositories.
+
+## Server Administrator
+
+To set up an Envoy server, download the package from the release page.
+
+Because the project lacks external documentation for the moment, please refer to the Javadoc inside the source code to configure your Envoy instance.
+
+### System requirements
+
+To run Envoy server, you have to install a JRE as mentioned above, as well as a database.
+In development, PostgreSQL is used, which you can download from [here](https://www.postgresql.org/download/).
+
+Look at the file `META-INF/persistence.xml` inside `envoy-server.jar` for the database configuration.
+
+After creating a database and configuring the credentials, the server will initialize the necessary tables automatically.
+
+## Programmer
+
+Envoy is organized as a Maven project that is split into three modules.
+
+### Client
+
+* Sending and receiving of messages, groups, sending images and voice messages
+* User interface (UI)
+* Client configuration
+* Advanced logging possibilities
+* Tons of Events to interact with
+* Detailed Javadoc to improve readability of code
+
+### Common
+* Basic datatypes
+* Events sent between client and server
+* Configuration API
+* Logging API based on `java.util.logging`
+* Envoy-specific Exception
+* Useful utility classes
+
+### Server
+* Non-blocking connectivity infrastructure based on `java.nio`
+* Processors to handle incoming events
+* Database connectivity
+* Database entities
+* Utility classes to check client version compatability and password validity

client/.classpath

@@ -13,14 +13,15 @@
 	</classpathentry>
 	<classpathentry kind="src" output="target/test-classes" path="src/test/java">
 		<attributes>
+			<attribute name="test" value="true"/>
 			<attribute name="optional" value="true"/>
 			<attribute name="maven.pomderived" value="true"/>
-			<attribute name="test" value="true"/>
 		</attributes>
 	</classpathentry>
 	<classpathentry kind="con" path="org.eclipse.jdt.launching.JRE_CONTAINER/org.eclipse.jdt.internal.debug.ui.launcher.StandardVMType/JavaSE-11">
 		<attributes>
 			<attribute name="maven.pomderived" value="true"/>
+			<attribute name="module" value="true"/>
 		</attributes>
 	</classpathentry>
 	<classpathentry kind="con" path="org.eclipse.m2e.MAVEN2_CLASSPATH_CONTAINER">

client/.gitignore

@@ -1,4 +0,0 @@
-/target/
-
-# virtual machine crash logs, see http://www.java.com/en/download/help/error_hotspot.xml
-hs_err_pid*

client/.project

@@ -1,6 +1,7 @@
 <?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE xml>
 <projectDescription>
-	<name>envoy-client</name>
+	<name>client</name>
 	<comment></comment>
 	<projects>
 	</projects>

client/.settings/org.eclipse.jdt.core.prefs

@@ -18,6 +18,7 @@ org.eclipse.jdt.core.compiler.debug.localVariable=generate
 org.eclipse.jdt.core.compiler.debug.sourceFile=generate
 org.eclipse.jdt.core.compiler.doc.comment.support=enabled
 org.eclipse.jdt.core.compiler.problem.APILeak=warning
+org.eclipse.jdt.core.compiler.problem.annotatedTypeArgumentToUnannotated=info
 org.eclipse.jdt.core.compiler.problem.annotationSuperInterface=warning
 org.eclipse.jdt.core.compiler.problem.assertIdentifier=error
 org.eclipse.jdt.core.compiler.problem.autoboxing=ignore
@@ -128,364 +129,4 @@ org.eclipse.jdt.core.compiler.problem.unusedWarningToken=warning
 org.eclipse.jdt.core.compiler.problem.varargsArgumentNeedCast=warning
 org.eclipse.jdt.core.compiler.release=disabled
 org.eclipse.jdt.core.compiler.source=11
-org.eclipse.jdt.core.formatter.align_assignment_statements_on_columns=true
-org.eclipse.jdt.core.formatter.align_fields_grouping_blank_lines=1
-org.eclipse.jdt.core.formatter.align_type_members_on_columns=true
-org.eclipse.jdt.core.formatter.align_variable_declarations_on_columns=true
-org.eclipse.jdt.core.formatter.align_with_spaces=false
-org.eclipse.jdt.core.formatter.alignment_for_additive_operator=16
-org.eclipse.jdt.core.formatter.alignment_for_arguments_in_allocation_expression=16
-org.eclipse.jdt.core.formatter.alignment_for_arguments_in_annotation=84
-org.eclipse.jdt.core.formatter.alignment_for_arguments_in_enum_constant=16
-org.eclipse.jdt.core.formatter.alignment_for_arguments_in_explicit_constructor_call=16
-org.eclipse.jdt.core.formatter.alignment_for_arguments_in_method_invocation=80
-org.eclipse.jdt.core.formatter.alignment_for_arguments_in_qualified_allocation_expression=20
-org.eclipse.jdt.core.formatter.alignment_for_assignment=0
-org.eclipse.jdt.core.formatter.alignment_for_bitwise_operator=16
-org.eclipse.jdt.core.formatter.alignment_for_compact_if=16
-org.eclipse.jdt.core.formatter.alignment_for_compact_loops=16
-org.eclipse.jdt.core.formatter.alignment_for_conditional_expression=80
-org.eclipse.jdt.core.formatter.alignment_for_conditional_expression_chain=0
-org.eclipse.jdt.core.formatter.alignment_for_enum_constants=16
-org.eclipse.jdt.core.formatter.alignment_for_expressions_in_array_initializer=16
-org.eclipse.jdt.core.formatter.alignment_for_expressions_in_for_loop_header=0
-org.eclipse.jdt.core.formatter.alignment_for_logical_operator=16
-org.eclipse.jdt.core.formatter.alignment_for_method_declaration=0
-org.eclipse.jdt.core.formatter.alignment_for_module_statements=16
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-org.eclipse.jdt.core.formatter.alignment_for_resources_in_try=80
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-org.eclipse.jdt.core.formatter.alignment_for_union_type_in_multicatch=16
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-org.eclipse.jdt.core.formatter.blank_lines_before_first_class_body_declaration=1
-org.eclipse.jdt.core.formatter.blank_lines_before_imports=1
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-org.eclipse.jdt.core.formatter.blank_lines_before_method=1
-org.eclipse.jdt.core.formatter.blank_lines_before_new_chunk=1
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-org.eclipse.jdt.core.formatter.insert_space_after_opening_paren_in_method_invocation=do not insert
-org.eclipse.jdt.core.formatter.insert_space_after_opening_paren_in_parenthesized_expression=do not insert
-org.eclipse.jdt.core.formatter.insert_space_after_opening_paren_in_switch=do not insert
-org.eclipse.jdt.core.formatter.insert_space_after_opening_paren_in_synchronized=do not insert
-org.eclipse.jdt.core.formatter.insert_space_after_opening_paren_in_try=do not insert
-org.eclipse.jdt.core.formatter.insert_space_after_opening_paren_in_while=do not insert
-org.eclipse.jdt.core.formatter.insert_space_after_postfix_operator=do not insert
-org.eclipse.jdt.core.formatter.insert_space_after_prefix_operator=do not insert
-org.eclipse.jdt.core.formatter.insert_space_after_question_in_conditional=insert
-org.eclipse.jdt.core.formatter.insert_space_after_question_in_wildcard=do not insert
-org.eclipse.jdt.core.formatter.insert_space_after_relational_operator=insert
-org.eclipse.jdt.core.formatter.insert_space_after_semicolon_in_for=insert
-org.eclipse.jdt.core.formatter.insert_space_after_semicolon_in_try_resources=insert
-org.eclipse.jdt.core.formatter.insert_space_after_shift_operator=insert
-org.eclipse.jdt.core.formatter.insert_space_after_string_concatenation=insert
-org.eclipse.jdt.core.formatter.insert_space_after_unary_operator=do not insert
-org.eclipse.jdt.core.formatter.insert_space_before_additive_operator=insert
-org.eclipse.jdt.core.formatter.insert_space_before_and_in_type_parameter=insert
-org.eclipse.jdt.core.formatter.insert_space_before_arrow_in_switch_case=insert
-org.eclipse.jdt.core.formatter.insert_space_before_arrow_in_switch_default=insert
-org.eclipse.jdt.core.formatter.insert_space_before_assignment_operator=insert
-org.eclipse.jdt.core.formatter.insert_space_before_at_in_annotation_type_declaration=do not insert
-org.eclipse.jdt.core.formatter.insert_space_before_bitwise_operator=insert
-org.eclipse.jdt.core.formatter.insert_space_before_closing_angle_bracket_in_parameterized_type_reference=do not insert
-org.eclipse.jdt.core.formatter.insert_space_before_closing_angle_bracket_in_type_arguments=do not insert
-org.eclipse.jdt.core.formatter.insert_space_before_closing_angle_bracket_in_type_parameters=do not insert
-org.eclipse.jdt.core.formatter.insert_space_before_closing_brace_in_array_initializer=insert
-org.eclipse.jdt.core.formatter.insert_space_before_closing_bracket_in_array_allocation_expression=do not insert
-org.eclipse.jdt.core.formatter.insert_space_before_closing_bracket_in_array_reference=do not insert
-org.eclipse.jdt.core.formatter.insert_space_before_closing_paren_in_annotation=do not insert
-org.eclipse.jdt.core.formatter.insert_space_before_closing_paren_in_cast=do not insert
-org.eclipse.jdt.core.formatter.insert_space_before_closing_paren_in_catch=do not insert
-org.eclipse.jdt.core.formatter.insert_space_before_closing_paren_in_constructor_declaration=do not insert
-org.eclipse.jdt.core.formatter.insert_space_before_closing_paren_in_enum_constant=do not insert
-org.eclipse.jdt.core.formatter.insert_space_before_closing_paren_in_for=do not insert
-org.eclipse.jdt.core.formatter.insert_space_before_closing_paren_in_if=do not insert
-org.eclipse.jdt.core.formatter.insert_space_before_closing_paren_in_method_declaration=do not insert
-org.eclipse.jdt.core.formatter.insert_space_before_closing_paren_in_method_invocation=do not insert
-org.eclipse.jdt.core.formatter.insert_space_before_closing_paren_in_parenthesized_expression=do not insert
-org.eclipse.jdt.core.formatter.insert_space_before_closing_paren_in_switch=do not insert
-org.eclipse.jdt.core.formatter.insert_space_before_closing_paren_in_synchronized=do not insert
-org.eclipse.jdt.core.formatter.insert_space_before_closing_paren_in_try=do not insert
-org.eclipse.jdt.core.formatter.insert_space_before_closing_paren_in_while=do not insert
-org.eclipse.jdt.core.formatter.insert_space_before_colon_in_assert=insert
-org.eclipse.jdt.core.formatter.insert_space_before_colon_in_case=do not insert
-org.eclipse.jdt.core.formatter.insert_space_before_colon_in_conditional=insert
-org.eclipse.jdt.core.formatter.insert_space_before_colon_in_default=do not insert
-org.eclipse.jdt.core.formatter.insert_space_before_colon_in_for=insert
-org.eclipse.jdt.core.formatter.insert_space_before_colon_in_labeled_statement=do not insert
-org.eclipse.jdt.core.formatter.insert_space_before_comma_in_allocation_expression=do not insert
-org.eclipse.jdt.core.formatter.insert_space_before_comma_in_annotation=do not insert
-org.eclipse.jdt.core.formatter.insert_space_before_comma_in_array_initializer=do not insert
-org.eclipse.jdt.core.formatter.insert_space_before_comma_in_constructor_declaration_parameters=do not insert
-org.eclipse.jdt.core.formatter.insert_space_before_comma_in_constructor_declaration_throws=do not insert
-org.eclipse.jdt.core.formatter.insert_space_before_comma_in_enum_constant_arguments=do not insert
-org.eclipse.jdt.core.formatter.insert_space_before_comma_in_enum_declarations=do not insert
-org.eclipse.jdt.core.formatter.insert_space_before_comma_in_explicitconstructorcall_arguments=do not insert
-org.eclipse.jdt.core.formatter.insert_space_before_comma_in_for_increments=do not insert
-org.eclipse.jdt.core.formatter.insert_space_before_comma_in_for_inits=do not insert
-org.eclipse.jdt.core.formatter.insert_space_before_comma_in_method_declaration_parameters=do not insert
-org.eclipse.jdt.core.formatter.insert_space_before_comma_in_method_declaration_throws=do not insert
-org.eclipse.jdt.core.formatter.insert_space_before_comma_in_method_invocation_arguments=do not insert
-org.eclipse.jdt.core.formatter.insert_space_before_comma_in_multiple_field_declarations=do not insert
-org.eclipse.jdt.core.formatter.insert_space_before_comma_in_multiple_local_declarations=do not insert
-org.eclipse.jdt.core.formatter.insert_space_before_comma_in_parameterized_type_reference=do not insert
-org.eclipse.jdt.core.formatter.insert_space_before_comma_in_superinterfaces=do not insert
-org.eclipse.jdt.core.formatter.insert_space_before_comma_in_switch_case_expressions=do not insert
-org.eclipse.jdt.core.formatter.insert_space_before_comma_in_type_arguments=do not insert
-org.eclipse.jdt.core.formatter.insert_space_before_comma_in_type_parameters=do not insert
-org.eclipse.jdt.core.formatter.insert_space_before_ellipsis=do not insert
-org.eclipse.jdt.core.formatter.insert_space_before_lambda_arrow=insert
-org.eclipse.jdt.core.formatter.insert_space_before_logical_operator=insert
-org.eclipse.jdt.core.formatter.insert_space_before_multiplicative_operator=insert
-org.eclipse.jdt.core.formatter.insert_space_before_opening_angle_bracket_in_parameterized_type_reference=do not insert
-org.eclipse.jdt.core.formatter.insert_space_before_opening_angle_bracket_in_type_arguments=do not insert
-org.eclipse.jdt.core.formatter.insert_space_before_opening_angle_bracket_in_type_parameters=do not insert
-org.eclipse.jdt.core.formatter.insert_space_before_opening_brace_in_annotation_type_declaration=insert
-org.eclipse.jdt.core.formatter.insert_space_before_opening_brace_in_anonymous_type_declaration=insert
-org.eclipse.jdt.core.formatter.insert_space_before_opening_brace_in_array_initializer=insert
-org.eclipse.jdt.core.formatter.insert_space_before_opening_brace_in_block=insert
-org.eclipse.jdt.core.formatter.insert_space_before_opening_brace_in_constructor_declaration=insert
-org.eclipse.jdt.core.formatter.insert_space_before_opening_brace_in_enum_constant=insert
-org.eclipse.jdt.core.formatter.insert_space_before_opening_brace_in_enum_declaration=insert
-org.eclipse.jdt.core.formatter.insert_space_before_opening_brace_in_method_declaration=insert
-org.eclipse.jdt.core.formatter.insert_space_before_opening_brace_in_switch=insert
-org.eclipse.jdt.core.formatter.insert_space_before_opening_brace_in_type_declaration=insert
-org.eclipse.jdt.core.formatter.insert_space_before_opening_bracket_in_array_allocation_expression=do not insert
-org.eclipse.jdt.core.formatter.insert_space_before_opening_bracket_in_array_reference=do not insert
-org.eclipse.jdt.core.formatter.insert_space_before_opening_bracket_in_array_type_reference=do not insert
-org.eclipse.jdt.core.formatter.insert_space_before_opening_paren_in_annotation=do not insert
-org.eclipse.jdt.core.formatter.insert_space_before_opening_paren_in_annotation_type_member_declaration=do not insert
-org.eclipse.jdt.core.formatter.insert_space_before_opening_paren_in_catch=insert
-org.eclipse.jdt.core.formatter.insert_space_before_opening_paren_in_constructor_declaration=do not insert
-org.eclipse.jdt.core.formatter.insert_space_before_opening_paren_in_enum_constant=do not insert
-org.eclipse.jdt.core.formatter.insert_space_before_opening_paren_in_for=insert
-org.eclipse.jdt.core.formatter.insert_space_before_opening_paren_in_if=insert
-org.eclipse.jdt.core.formatter.insert_space_before_opening_paren_in_method_declaration=do not insert
-org.eclipse.jdt.core.formatter.insert_space_before_opening_paren_in_method_invocation=do not insert
-org.eclipse.jdt.core.formatter.insert_space_before_opening_paren_in_parenthesized_expression=do not insert
-org.eclipse.jdt.core.formatter.insert_space_before_opening_paren_in_switch=insert
-org.eclipse.jdt.core.formatter.insert_space_before_opening_paren_in_synchronized=insert
-org.eclipse.jdt.core.formatter.insert_space_before_opening_paren_in_try=insert
-org.eclipse.jdt.core.formatter.insert_space_before_opening_paren_in_while=insert
-org.eclipse.jdt.core.formatter.insert_space_before_parenthesized_expression_in_return=insert
-org.eclipse.jdt.core.formatter.insert_space_before_parenthesized_expression_in_throw=insert
-org.eclipse.jdt.core.formatter.insert_space_before_postfix_operator=do not insert
-org.eclipse.jdt.core.formatter.insert_space_before_prefix_operator=do not insert
-org.eclipse.jdt.core.formatter.insert_space_before_question_in_conditional=insert
-org.eclipse.jdt.core.formatter.insert_space_before_question_in_wildcard=do not insert
-org.eclipse.jdt.core.formatter.insert_space_before_relational_operator=insert
-org.eclipse.jdt.core.formatter.insert_space_before_semicolon=do not insert
-org.eclipse.jdt.core.formatter.insert_space_before_semicolon_in_for=do not insert
-org.eclipse.jdt.core.formatter.insert_space_before_semicolon_in_try_resources=do not insert
-org.eclipse.jdt.core.formatter.insert_space_before_shift_operator=insert
-org.eclipse.jdt.core.formatter.insert_space_before_string_concatenation=insert
-org.eclipse.jdt.core.formatter.insert_space_before_unary_operator=do not insert
-org.eclipse.jdt.core.formatter.insert_space_between_brackets_in_array_type_reference=do not insert
-org.eclipse.jdt.core.formatter.insert_space_between_empty_braces_in_array_initializer=do not insert
-org.eclipse.jdt.core.formatter.insert_space_between_empty_brackets_in_array_allocation_expression=do not insert
-org.eclipse.jdt.core.formatter.insert_space_between_empty_parens_in_annotation_type_member_declaration=do not insert
-org.eclipse.jdt.core.formatter.insert_space_between_empty_parens_in_constructor_declaration=do not insert
-org.eclipse.jdt.core.formatter.insert_space_between_empty_parens_in_enum_constant=do not insert
-org.eclipse.jdt.core.formatter.insert_space_between_empty_parens_in_method_declaration=do not insert
-org.eclipse.jdt.core.formatter.insert_space_between_empty_parens_in_method_invocation=do not insert
-org.eclipse.jdt.core.formatter.join_lines_in_comments=false
-org.eclipse.jdt.core.formatter.join_wrapped_lines=true
-org.eclipse.jdt.core.formatter.keep_annotation_declaration_on_one_line=one_line_if_single_item
-org.eclipse.jdt.core.formatter.keep_anonymous_type_declaration_on_one_line=one_line_never
-org.eclipse.jdt.core.formatter.keep_code_block_on_one_line=one_line_if_empty
-org.eclipse.jdt.core.formatter.keep_else_statement_on_same_line=true
-org.eclipse.jdt.core.formatter.keep_empty_array_initializer_on_one_line=false
-org.eclipse.jdt.core.formatter.keep_enum_constant_declaration_on_one_line=one_line_never
-org.eclipse.jdt.core.formatter.keep_enum_declaration_on_one_line=one_line_if_empty
-org.eclipse.jdt.core.formatter.keep_if_then_body_block_on_one_line=one_line_if_single_item
-org.eclipse.jdt.core.formatter.keep_imple_if_on_one_line=false
-org.eclipse.jdt.core.formatter.keep_lambda_body_block_on_one_line=one_line_always
-org.eclipse.jdt.core.formatter.keep_loop_body_block_on_one_line=one_line_if_empty
-org.eclipse.jdt.core.formatter.keep_method_body_on_one_line=one_line_if_single_item
-org.eclipse.jdt.core.formatter.keep_simple_do_while_body_on_same_line=false
-org.eclipse.jdt.core.formatter.keep_simple_for_body_on_same_line=false
-org.eclipse.jdt.core.formatter.keep_simple_getter_setter_on_one_line=true
-org.eclipse.jdt.core.formatter.keep_simple_while_body_on_same_line=false
-org.eclipse.jdt.core.formatter.keep_then_statement_on_same_line=true
-org.eclipse.jdt.core.formatter.keep_type_declaration_on_one_line=one_line_if_empty
-org.eclipse.jdt.core.formatter.lineSplit=150
-org.eclipse.jdt.core.formatter.never_indent_block_comments_on_first_column=false
-org.eclipse.jdt.core.formatter.never_indent_line_comments_on_first_column=false
-org.eclipse.jdt.core.formatter.number_of_blank_lines_after_code_block=0
-org.eclipse.jdt.core.formatter.number_of_blank_lines_at_beginning_of_code_block=0
-org.eclipse.jdt.core.formatter.number_of_blank_lines_at_beginning_of_method_body=0
-org.eclipse.jdt.core.formatter.number_of_blank_lines_at_end_of_code_block=0
-org.eclipse.jdt.core.formatter.number_of_blank_lines_at_end_of_method_body=0
-org.eclipse.jdt.core.formatter.number_of_blank_lines_before_code_block=0
-org.eclipse.jdt.core.formatter.number_of_empty_lines_to_preserve=1
-org.eclipse.jdt.core.formatter.parentheses_positions_in_annotation=separate_lines_if_wrapped
-org.eclipse.jdt.core.formatter.parentheses_positions_in_catch_clause=common_lines
-org.eclipse.jdt.core.formatter.parentheses_positions_in_enum_constant_declaration=common_lines
-org.eclipse.jdt.core.formatter.parentheses_positions_in_for_statment=common_lines
-org.eclipse.jdt.core.formatter.parentheses_positions_in_if_while_statement=common_lines
-org.eclipse.jdt.core.formatter.parentheses_positions_in_lambda_declaration=common_lines
-org.eclipse.jdt.core.formatter.parentheses_positions_in_method_delcaration=common_lines
-org.eclipse.jdt.core.formatter.parentheses_positions_in_method_invocation=common_lines
-org.eclipse.jdt.core.formatter.parentheses_positions_in_switch_statement=common_lines
-org.eclipse.jdt.core.formatter.parentheses_positions_in_try_clause=common_lines
-org.eclipse.jdt.core.formatter.put_empty_statement_on_new_line=true
-org.eclipse.jdt.core.formatter.tabulation.char=tab
-org.eclipse.jdt.core.formatter.tabulation.size=4
-org.eclipse.jdt.core.formatter.text_block_indentation=0
-org.eclipse.jdt.core.formatter.use_on_off_tags=false
-org.eclipse.jdt.core.formatter.use_tabs_only_for_leading_indentations=false
-org.eclipse.jdt.core.formatter.wrap_before_additive_operator=true
-org.eclipse.jdt.core.formatter.wrap_before_assignment_operator=false
-org.eclipse.jdt.core.formatter.wrap_before_bitwise_operator=true
-org.eclipse.jdt.core.formatter.wrap_before_conditional_operator=true
-org.eclipse.jdt.core.formatter.wrap_before_logical_operator=true
-org.eclipse.jdt.core.formatter.wrap_before_multiplicative_operator=true
-org.eclipse.jdt.core.formatter.wrap_before_or_operator_multicatch=true
-org.eclipse.jdt.core.formatter.wrap_before_relational_operator=true
-org.eclipse.jdt.core.formatter.wrap_before_shift_operator=true
-org.eclipse.jdt.core.formatter.wrap_before_string_concatenation=true
-org.eclipse.jdt.core.formatter.wrap_outer_expressions_when_nested=true
 org.eclipse.jdt.core.javaFormatter=org.eclipse.jdt.core.defaultJavaFormatter

client/.settings/org.hibernate.eclipse.console.prefs

@@ -1,3 +0,0 @@
-default.configuration=
-eclipse.preferences.version=1
-hibernate3.enabled=false

client/pom.xml

@@ -9,24 +9,24 @@
 	<parent>
 		<groupId>informatik-ag-ngl</groupId>
 		<artifactId>envoy</artifactId>
-		<version>0.1-beta</version>
+		<version>0.2-beta</version>
 	</parent>
 
 	<dependencies>
 		<dependency>
 			<groupId>informatik-ag-ngl</groupId>
 			<artifactId>envoy-common</artifactId>
-			<version>0.1-beta</version>
+			<version>0.2-beta</version>
 		</dependency>
 		<dependency>
 			<groupId>org.openjfx</groupId>
 			<artifactId>javafx-controls</artifactId>
-			<version>11.0.2</version>
+			<version>15</version>
 		</dependency>
 		<dependency>
 			<groupId>org.openjfx</groupId>
 			<artifactId>javafx-fxml</artifactId>
-			<version>11.0.2</version>
+			<version>15</version>
 		</dependency>
 	</dependencies>
 
@@ -37,15 +37,6 @@
 				<directory>src/main/resources</directory>
 			</resource>
 		</resources>
-		<pluginManagement>
-			<plugins>
-				<plugin>
-					<groupId>org.apache.maven.plugins</groupId>
-					<artifactId>maven-compiler-plugin</artifactId>
-					<version>3.8.1</version>
-				</plugin>
-			</plugins>
-		</pluginManagement>
 		<plugins>
 			<plugin>
 				<groupId>org.apache.maven.plugins</groupId>

client/src/main/java/envoy/client/Main.java

@@ -7,24 +7,33 @@ import envoy.client.ui.Startup;
 /**
  * Triggers application startup.
  * <p>
- * To allow Maven shading, the main method has to be separated from the
- * {@link Startup} class which extends {@link Application}.
- * <p>
- * Project: <strong>envoy-client</strong><br>
- * File: <strong>Main.java</strong><br>
- * Created: <strong>05.07.2020</strong><br>
+ * To allow Maven shading, the main method has to be separated from the {@link Startup} class which
+ * extends {@link Application}.
  *
  * @author Kai S. K. Engelbart
  * @since Envoy Client v0.1-beta
  */
-public class Main {
+public final class Main {
+
+	/**
+	 * A funny debug switch put in by {@code delvh} to enable easy debugging.
+	 *
+	 * @since Envoy Client v0.2-beta
+	 */
+	private static final boolean debug = false;
 
 	/**
 	 * Starts the application.
 	 *
-	 * @param args the command line arguments are processed by the
-	 *             client configuration
+	 * @param args the command line arguments are processed by the client configuration
 	 * @since Envoy Client v0.1-beta
 	 */
-	public static void main(String[] args) { Application.launch(Startup.class, args); }
+	public static void main(String[] args) {
+		if (debug) {
+			// Put testing code here
+			System.out.println();
+			System.exit(0);
+		}
+		Application.launch(Startup.class, args);
+	}
 }

client/src/main/java/envoy/client/data/Cache.java

@@ -1,20 +1,14 @@
 package envoy.client.data;
 
 import java.io.Serializable;
-import java.util.LinkedList;
-import java.util.Queue;
+import java.util.*;
 import java.util.function.Consumer;
-import java.util.logging.Level;
-import java.util.logging.Logger;
+import java.util.logging.*;
 
 import envoy.util.EnvoyLog;
 
 /**
  * Stores elements in a queue to process them later.
- * <p>
- * Project: <strong>envoy-client</strong><br>
- * File: <strong>Cache.java</strong><br>
- * Created: <strong>6 Feb 2020</strong><br>
  *
  * @param <T> the type of cached elements
  * @author Kai S. K. Engelbart
@@ -41,7 +35,9 @@ public final class Cache<T> implements Consumer<T>, Serializable {
 	}
 
 	@Override
-	public String toString() { return String.format("Cache[elements=" + elements + "]"); }
+	public String toString() {
+		return String.format("Cache[elements=" + elements + "]");
+	}
 
 	/**
 	 * Sets the processor to which cached elements are relayed.
@@ -58,8 +54,18 @@ public final class Cache<T> implements Consumer<T>, Serializable {
 	 * @since Envoy Client v0.3-alpha
 	 */
 	public void relay() {
-		if (processor == null) throw new IllegalStateException("Processor is not defined");
+		if (processor == null)
+			throw new IllegalStateException("Processor is not defined");
 		elements.forEach(processor::accept);
 		elements.clear();
 	}
+
+	/**
+	 * Clears this cache of all stored elements.
+	 *
+	 * @since Envoy Client v0.2-beta
+	 */
+	public void clear() {
+		elements.clear();
+	}
 }

client/src/main/java/envoy/client/data/CacheMap.java

@@ -1,17 +1,11 @@
 package envoy.client.data;
 
 import java.io.Serializable;
-import java.util.HashMap;
-import java.util.Map;
+import java.util.*;
 
 /**
- * Stores a heterogeneous map of {@link Cache} objects with different type
- * parameters.
- * <p>
- * Project: <strong>envoy-client</strong><br>
- * File: <strong>CacheMap.java</strong><br>
- * Created: <strong>09.07.2020</strong><br>
- * 
+ * Stores a heterogeneous map of {@link Cache} objects with different type parameters.
+ *
  * @author Kai S. K. Engelbart
  * @since Envoy Client v0.1-beta
  */
@@ -23,27 +17,31 @@ public final class CacheMap implements Serializable {
 
 	/**
 	 * Adds a cache to the map.
-	 * 
+	 *
 	 * @param <T>   the type accepted by the cache
 	 * @param key   the class that maps to the cache
 	 * @param cache the cache to store
 	 * @since Envoy Client v0.1-beta
 	 */
-	public <T> void put(Class<T> key, Cache<T> cache) { map.put(key, cache); }
+	public <T> void put(Class<T> key, Cache<T> cache) {
+		map.put(key, cache);
+	}
 
 	/**
 	 * Returns a cache mapped by a class.
-	 * 
+	 *
 	 * @param <T> the type accepted by the cache
 	 * @param key the class that maps to the cache
 	 * @return the cache
 	 * @since Envoy Client v0.1-beta
 	 */
-	public <T> Cache<T> get(Class<T> key) { return (Cache<T>) map.get(key); }
+	public <T> Cache<T> get(Class<T> key) {
+		return (Cache<T>) map.get(key);
+	}
 
 	/**
 	 * Returns a cache mapped by a class or any of its subclasses.
-	 * 
+	 *
 	 * @param <T> the type accepted by the cache
 	 * @param key the class that maps to the cache
 	 * @return the cache
@@ -52,7 +50,7 @@ public final class CacheMap implements Serializable {
 	public <T> Cache<? super T> getApplicable(Class<T> key) {
 		Cache<? super T> cache = get(key);
 		if (cache == null)
-			for (var e : map.entrySet())
+			for (final var e : map.entrySet())
 				if (e.getKey().isAssignableFrom(key))
 					cache = (Cache<? super T>) e.getValue();
 		return cache;
@@ -63,4 +61,13 @@ public final class CacheMap implements Serializable {
 	 * @since Envoy Client v0.1-beta
 	 */
 	public Map<Class<?>, Cache<?>> getMap() { return map; }
+
+	/**
+	 * Clears the caches of this map of any values.
+	 *
+	 * @since Envoy Client v0.2-beta
+	 */
+	public void clear() {
+		map.values().forEach(Cache::clear);
+	}
 }

client/src/main/java/envoy/client/data/Chat.java

@@ -1,23 +1,19 @@
 package envoy.client.data;
 
-import java.io.IOException;
-import java.io.Serializable;
-import java.util.ArrayList;
-import java.util.List;
-import java.util.Objects;
+import java.io.*;
+import java.util.*;
+
+import javafx.beans.property.*;
+import javafx.collections.*;
 
-import envoy.client.net.WriteProxy;
 import envoy.data.*;
 import envoy.data.Message.MessageStatus;
 import envoy.event.MessageStatusChange;
 
+import envoy.client.net.WriteProxy;
+
 /**
- * Represents a chat between two {@link User}s
- * as a list of {@link Message} objects.
- * <p>
- * Project: <strong>envoy-client</strong><br>
- * File: <strong>Chat.java</strong><br>
- * Created: <strong>19 Oct 2019</strong><br>
+ * Represents a chat between two {@link User}s as a list of {@link Message} objects.
  *
  * @author Maximilian K&auml;fer
  * @author Leon Hofmeister
@@ -26,12 +22,21 @@ import envoy.event.MessageStatusChange;
  */
 public class Chat implements Serializable {
 
-	protected final Contact			recipient;
-	protected final List<Message>	messages	= new ArrayList<>();
+	protected boolean disabled;
 
-	protected int unreadAmount;
+	/**
+	 * Stores the last time an {@link envoy.event.IsTyping} event has been sent.
+	 */
+	protected transient long lastWritingEvent;
 
-	private static final long serialVersionUID = 1L;
+	protected transient ObservableList<Message> messages = FXCollections.observableArrayList();
+
+	protected int						unreadAmount;
+	protected static IntegerProperty	totalUnreadAmount	= new SimpleIntegerProperty();
+
+	protected final Contact recipient;
+
+	private static final long serialVersionUID = 2L;
 
 	/**
 	 * Provides the list of messages that the recipient receives.
@@ -42,66 +47,91 @@ public class Chat implements Serializable {
 	 * @since Envoy Client v0.1-alpha
 	 */
 	public Chat(Contact recipient) {
-		this.recipient	= recipient;
+		this.recipient = recipient;
+	}
+
+	private void readObject(ObjectInputStream stream) throws ClassNotFoundException, IOException {
+		stream.defaultReadObject();
+		messages = FXCollections.observableList((List<Message>) stream.readObject());
+		totalUnreadAmount.set(totalUnreadAmount.get() + unreadAmount);
+	}
+
+	private void writeObject(ObjectOutputStream stream) throws IOException {
+		stream.defaultWriteObject();
+		stream.writeObject(new ArrayList<>(messages));
 	}
 
 	@Override
-	public String toString() { return String.format("Chat[recipient=%s,messages=%d]", recipient, messages.size()); }
+	public String toString() {
+		return String.format(
+			"%s[recipient=%s,messages=%d,disabled=%b]",
+			getClass().getSimpleName(),
+			recipient,
+			messages.size(),
+			disabled);
+	}
 
 	/**
 	 * Generates a hash code based on the recipient.
-	 * 
+	 *
 	 * @since Envoy Client v0.1-beta
 	 */
 	@Override
-	public int hashCode() { return Objects.hash(recipient); }
+	public int hashCode() {
+		return Objects.hash(recipient);
+	}
 
 	/**
 	 * Tests equality to another object based on the recipient.
-	 * 
+	 *
 	 * @since Envoy Client v0.1-beta
 	 */
 	@Override
 	public boolean equals(Object obj) {
-		if (this == obj) return true;
-		if (!(obj instanceof Chat)) return false;
-		Chat other = (Chat) obj;
+		if (this == obj)
+			return true;
+		if (!(obj instanceof Chat))
+			return false;
+		final var other = (Chat) obj;
 		return Objects.equals(recipient, other.recipient);
 	}
 
 	/**
-	 * Sets the status of all chat messages received from the recipient to
-	 * {@code READ} starting from the bottom and stopping once a read message is
-	 * found.
+	 * Sets the status of all chat messages received from the recipient to {@code READ} starting
+	 * from the bottom and stopping once a read message is found.
 	 *
-	 * @param writeProxy the write proxy instance used to notify the server about
-	 *                   the message status changes
-	 * @throws IOException if a {@link MessageStatusChange} could not be
-	 *                     delivered to the server
+	 * @param writeProxy the write proxy instance used to notify the server about the message status
+	 *                   changes
 	 * @since Envoy Client v0.3-alpha
 	 */
-	public void read(WriteProxy writeProxy) throws IOException {
+	public void read(WriteProxy writeProxy) {
 		for (int i = messages.size() - 1; i >= 0; --i) {
-			final Message m = messages.get(i);
-			if (m.getSenderID() == recipient.getID()) if (m.getStatus() == MessageStatus.READ) break;
-			else {
-				m.setStatus(MessageStatus.READ);
-				writeProxy.writeMessageStatusChange(new MessageStatusChange(m));
-			}
+			final var m = messages.get(i);
+			if (m.getSenderID() == recipient.getID())
+				if (m.getStatus() == MessageStatus.READ)
+					break;
+				else {
+					m.setStatus(MessageStatus.READ);
+					writeProxy.writeMessageStatusChange(new MessageStatusChange(m));
+				}
 		}
+		totalUnreadAmount.set(totalUnreadAmount.get() - unreadAmount);
 		unreadAmount = 0;
 	}
 
 	/**
-	 * @return {@code true} if the newest message received in the chat doesn't have
-	 *         the status {@code READ}
+	 * @return {@code true} if the newest message received in the chat doesn't have the status
+	 *         {@code READ}
 	 * @since Envoy Client v0.3-alpha
 	 */
-	public boolean isUnread() { return !messages.isEmpty() && messages.get(messages.size() - 1).getStatus() != MessageStatus.READ; }
+	public boolean isUnread() {
+		return !messages.isEmpty()
+			&& messages.get(messages.size() - 1).getStatus() != MessageStatus.READ;
+	}
 
 	/**
 	 * Inserts a message at the correct place according to its creation date.
-	 * 
+	 *
 	 * @param message the message to insert
 	 * @since Envoy Client v0.1-beta
 	 */
@@ -115,14 +145,34 @@ public class Chat implements Serializable {
 	}
 
 	/**
-	 * Increments the amount of unread messages.
-	 * 
-	 * @since Envoy Client v0.1-beta
+	 * Removes the message with the given ID.
+	 *
+	 * @param messageID the ID of the message to remove
+	 * @return whether the message has been found and removed
+	 * @since Envoy Client v0.3-beta
 	 */
-	public void incrementUnreadAmount() { unreadAmount++; }
+	public boolean remove(long messageID) {
+		return messages.removeIf(m -> m.getID() == messageID);
+	}
 
 	/**
-	 * @return the amount of unread mesages in this chat
+	 * @return an integer property storing the total amount of unread messages
+	 * @since Envoy Client v0.3-beta
+	 */
+	public static IntegerProperty getTotalUnreadAmount() { return totalUnreadAmount; }
+
+	/**
+	 * Increments the amount of unread messages.
+	 *
+	 * @since Envoy Client v0.1-beta
+	 */
+	public void incrementUnreadAmount() {
+		++unreadAmount;
+		totalUnreadAmount.set(totalUnreadAmount.get() + 1);
+	}
+
+	/**
+	 * @return the amount of unread messages in this chat
 	 * @since Envoy Client v0.1-beta
 	 */
 	public int getUnreadAmount() { return unreadAmount; }
@@ -131,7 +181,7 @@ public class Chat implements Serializable {
 	 * @return all messages in the current chat
 	 * @since Envoy Client v0.1-beta
 	 */
-	public List<Message> getMessages() { return messages; }
+	public ObservableList<Message> getMessages() { return messages; }
 
 	/**
 	 * @return the recipient of a message
@@ -140,14 +190,35 @@ public class Chat implements Serializable {
 	public Contact getRecipient() { return recipient; }
 
 	/**
-	 * @return whether this {@link Chat} points at a {@link User}
-	 * @since Envoy Client v0.1-beta
+	 * @return the last known time a {@link envoy.event.IsTyping} event has been sent
+	 * @since Envoy Client v0.2-beta
 	 */
-	public boolean isUserChat() { return recipient instanceof User; }
+	public long getLastWritingEvent() { return lastWritingEvent; }
 
 	/**
-	 * @return whether this {@link Chat} points at a {@link Group}
-	 * @since Envoy Client v0.1-beta
+	 * Sets the {@code lastWritingEvent} to {@code System#currentTimeMillis()}.
+	 *
+	 * @since Envoy Client v0.2-beta
 	 */
-	public boolean isGroupChat() { return recipient instanceof Group; }
+	public void lastWritingEventWasNow() {
+		lastWritingEvent = System.currentTimeMillis();
+	}
+
+	/**
+	 * Determines whether messages can be sent in this chat. Should be {@code true} i.e. for chats
+	 * whose recipient deleted this client as a contact.
+	 *
+	 * @return whether this chat has been disabled
+	 * @since Envoy Client v0.3-beta
+	 */
+	public boolean isDisabled() { return disabled; }
+
+	/**
+	 * Determines whether messages can be sent in this chat. Should be true i.e. for chats whose
+	 * recipient deleted this client as a contact.
+	 *
+	 * @param disabled whether this chat should be disabled
+	 * @since Envoy Client v0.3-beta
+	 */
+	public void setDisabled(boolean disabled) { this.disabled = disabled; }
 }

client/src/main/java/envoy/client/data/ClientConfig.java

@@ -2,26 +2,16 @@ package envoy.client.data;
 
 import static java.util.function.Function.identity;
 
-import java.io.File;
-import java.util.logging.Level;
-
-import envoy.client.ui.Startup;
 import envoy.data.Config;
-import envoy.data.ConfigItem;
-import envoy.data.LoginCredentials;
 
 /**
- * Implements a configuration specific to the Envoy Client with default values
- * and convenience methods.
- * <p>
- * Project: <strong>envoy-client</strong><br>
- * File: <strong>ClientConfig.java</strong><br>
- * Created: <strong>01.03.2020</strong><br>
+ * Implements a configuration specific to the Envoy Client with default values and convenience
+ * methods.
  *
  * @author Kai S. K. Engelbart
  * @since Envoy Client v0.1-beta
  */
-public class ClientConfig extends Config {
+public final class ClientConfig extends Config {
 
 	private static ClientConfig config;
 
@@ -30,20 +20,16 @@ public class ClientConfig extends Config {
 	 * @since Envoy Client v0.1-beta
 	 */
 	public static ClientConfig getInstance() {
-		if (config == null) config = new ClientConfig();
+		if (config == null)
+			config = new ClientConfig();
 		return config;
 	}
 
 	private ClientConfig() {
-		items.put("server", new ConfigItem<>("server", "s", identity(), null, true));
-		items.put("port", new ConfigItem<>("port", "p", Integer::parseInt, null, true));
-		items.put("localDB", new ConfigItem<>("localDB", "db", File::new, new File("localDB"), true));
-		items.put("ignoreLocalDB", new ConfigItem<>("ignoreLocalDB", "nodb", Boolean::parseBoolean, false, false));
-		items.put("homeDirectory", new ConfigItem<>("homeDirectory", "h", File::new, new File(System.getProperty("user.home"), ".envoy"), true));
-		items.put("fileLevelBarrier", new ConfigItem<>("fileLevelBarrier", "fb", Level::parse, Level.CONFIG, true));
-		items.put("consoleLevelBarrier", new ConfigItem<>("consoleLevelBarrier", "cb", Level::parse, Level.FINEST, true));
-		items.put("user", new ConfigItem<>("user", "u", identity()));
-		items.put("password", new ConfigItem<>("password", "pw", identity()));
+		super(".envoy");
+		put("server", "s", identity());
+		put("port", "p", Integer::parseInt);
+		put("localDBSaveInterval", "db-si", Integer::parseInt);
 	}
 
 	/**
@@ -59,57 +45,10 @@ public class ClientConfig extends Config {
 	public Integer getPort() { return (Integer) items.get("port").get(); }
 
 	/**
-	 * @return the local database specific to the client user
-	 * @since Envoy Client v0.1-alpha
+	 * @return the amount of minutes after which the local database should be saved
+	 * @since Envoy Client v0.2-beta
 	 */
-	public File getLocalDB() { return (File) items.get("localDB").get(); }
-
-	/**
-	 * @return {@code true} if the local database is to be ignored
-	 * @since Envoy Client v0.3-alpha
-	 */
-	public Boolean isIgnoreLocalDB() { return (Boolean) items.get("ignoreLocalDB").get(); }
-
-	/**
-	 * @return the directory in which all local files are saves
-	 * @since Envoy Client v0.2-alpha
-	 */
-	public File getHomeDirectory() { return (File) items.get("homeDirectory").get(); }
-
-	/**
-	 * @return the minimal {@link Level} to log inside the log file
-	 * @since Envoy Client v0.2-alpha
-	 */
-	public Level getFileLevelBarrier() { return (Level) items.get("fileLevelBarrier").get(); }
-
-	/**
-	 * @return the minimal {@link Level} to log inside the console
-	 * @since Envoy Client v0.2-alpha
-	 */
-	public Level getConsoleLevelBarrier() { return (Level) items.get("consoleLevelBarrier").get(); }
-
-	/**
-	 * @return the user name
-	 * @since Envoy Client v0.3-alpha
-	 */
-	public String getUser() { return (String) items.get("user").get(); }
-
-	/**
-	 * @return the password
-	 * @since Envoy Client v0.3-alpha
-	 */
-	public String getPassword() { return (String) items.get("password").get(); }
-
-	/**
-	 * @return {@code true} if user name and password are set
-	 * @since Envoy Client v0.3-alpha
-	 */
-	public boolean hasLoginCredentials() { return getUser() != null && getPassword() != null; }
-
-	/**
-	 * @return login credentials for the specified user name and password, without
-	 *         the registration option
-	 * @since Envoy Client v0.3-alpha
-	 */
-	public LoginCredentials getLoginCredentials() { return new LoginCredentials(getUser(), getPassword(), false, Startup.VERSION); }
+	public Integer getLocalDBSaveInterval() {
+		return (Integer) items.get("localDBSaveInterval").get();
+	}
 }

client/src/main/java/envoy/client/data/Context.java

@@ -0,0 +1,94 @@
+package envoy.client.data;
+
+import javafx.stage.Stage;
+
+import envoy.client.net.*;
+import envoy.client.ui.SceneContext;
+
+/**
+ * Provides access to commonly used objects.
+ *
+ * @author Leon Hofmeister
+ * @since Envoy Client v0.2-beta
+ */
+public class Context {
+
+	private WriteProxy		writeProxy;
+	private LocalDB			localDB;
+	private Stage			stage;
+	private SceneContext	sceneContext;
+
+	private final Client client = new Client();
+
+	private static final Context instance = new Context();
+
+	private Context() {}
+
+	/**
+	 * @return the instance of {@code Context} used throughout Envoy
+	 * @since Envoy Client v0.2-beta
+	 */
+	public static Context getInstance() { return instance; }
+
+	/**
+	 * Initializes the write proxy given that {@code localDB} is initialized.
+	 *
+	 * @since Envoy Client v0.2-beta
+	 */
+	public void initWriteProxy() {
+		if (localDB == null)
+			throw new IllegalStateException("The LocalDB has to be initialized!");
+		writeProxy = new WriteProxy(client, localDB);
+	}
+
+	/**
+	 * @return the localDB
+	 * @since Envoy Client v0.2-beta
+	 */
+	public LocalDB getLocalDB() { return localDB; }
+
+	/**
+	 * @param localDB the localDB to set
+	 * @since Envoy Client v0.2-beta
+	 */
+	public void setLocalDB(LocalDB localDB) { this.localDB = localDB; }
+
+	/**
+	 * @return the sceneContext
+	 * @since Envoy Client v0.2-beta
+	 */
+	public SceneContext getSceneContext() { return sceneContext; }
+
+	/**
+	 * @param sceneContext the sceneContext to set. Additionally sets the stage.
+	 * @since Envoy Client v0.2-beta
+	 */
+	public void setSceneContext(SceneContext sceneContext) {
+		this.sceneContext	= sceneContext;
+		stage				= sceneContext.getStage();
+	}
+
+	/**
+	 * @return the client
+	 * @since Envoy Client v0.2-beta
+	 */
+	public Client getClient() { return client; }
+
+	/**
+	 * @return the writeProxy
+	 * @since Envoy Client v0.2-beta
+	 */
+	public WriteProxy getWriteProxy() { return writeProxy; }
+
+	/**
+	 * @return the stage
+	 * @since Envoy Client v0.2-beta
+	 */
+	public Stage getStage() { return stage; }
+
+	/**
+	 * @param stage the stage to set
+	 * @since Envoy Client v0.2-beta
+	 */
+	public void setStage(Stage stage) { this.stage = stage; }
+}

client/src/main/java/envoy/client/data/GroupChat.java

@@ -1,27 +1,20 @@
 package envoy.client.data;
 
-import java.io.IOException;
-import java.time.LocalDateTime;
+import java.time.Instant;
 
-import envoy.client.net.WriteProxy;
-import envoy.data.Contact;
-import envoy.data.GroupMessage;
+import envoy.data.*;
 import envoy.data.Message.MessageStatus;
-import envoy.data.User;
 import envoy.event.GroupMessageStatusChange;
 
+import envoy.client.net.WriteProxy;
+
 /**
- * Represents a chat between a user and a group
- * as a list of messages.
- * <p>
- * Project: <strong>envoy-client</strong><br>
- * File: <strong>GroupChat.java</strong><br>
- * Created: <strong>05.07.2020</strong><br>
- * 
+ * Represents a chat between a user and a group as a list of messages.
+ *
  * @author Maximilian K&auml;fer
  * @since Envoy Client v0.1-beta
  */
-public class GroupChat extends Chat {
+public final class GroupChat extends Chat {
 
 	private final User sender;
 
@@ -32,23 +25,23 @@ public class GroupChat extends Chat {
 	 * @param recipient the group whose members receive the messages
 	 * @since Envoy Client v0.1-beta
 	 */
-	public GroupChat(User sender, Contact recipient) {
+	public GroupChat(User sender, Group recipient) {
 		super(recipient);
 		this.sender = sender;
 	}
 
 	@Override
-	public void read(WriteProxy writeProxy) throws IOException {
+	public void read(WriteProxy writeProxy) {
 		for (int i = messages.size() - 1; i >= 0; --i) {
 			final GroupMessage gmsg = (GroupMessage) messages.get(i);
-			if (gmsg.getSenderID() != sender.getID()) {
-				if (gmsg.getMemberStatuses().get(sender.getID()) == MessageStatus.READ) break;
+			if (gmsg.getSenderID() != sender.getID())
+				if (gmsg.getMemberStatuses().get(sender.getID()) == MessageStatus.READ)
+					break;
 				else {
 					gmsg.getMemberStatuses().replace(sender.getID(), MessageStatus.READ);
-					writeProxy
-						.writeMessageStatusChange(new GroupMessageStatusChange(gmsg.getID(), MessageStatus.READ, LocalDateTime.now(), sender.getID()));
+					writeProxy.writeMessageStatusChange(new GroupMessageStatusChange(gmsg.getID(),
+						MessageStatus.READ, Instant.now(), sender.getID()));
 				}
-			}
 		}
 		unreadAmount = 0;
 	}

client/src/main/java/envoy/client/data/LocalDB.java

@@ -1,116 +1,443 @@
 package envoy.client.data;
 
+import static java.util.function.Predicate.not;
+
+import java.io.*;
+import java.nio.channels.*;
+import java.nio.file.StandardOpenOption;
+import java.time.Instant;
 import java.util.*;
+import java.util.logging.*;
+import java.util.stream.Stream;
+
+import javafx.application.Platform;
+import javafx.collections.*;
+
+import dev.kske.eventbus.Event;
+import dev.kske.eventbus.EventBus;
+import dev.kske.eventbus.EventListener;
 
 import envoy.data.*;
-import envoy.event.GroupResize;
-import envoy.event.MessageStatusChange;
-import envoy.event.NameChange;
+import envoy.data.Message.MessageStatus;
+import envoy.event.*;
+import envoy.event.contact.*;
+import envoy.exception.EnvoyException;
+import envoy.util.*;
+
+import envoy.client.event.*;
 
 /**
- * Stores information about the current {@link User} and their {@link Chat}s.
- * For message ID generation a {@link IDGenerator} is stored as well.
+ * Stores information about the current {@link User} and their {@link Chat}s. For message ID
+ * generation a {@link IDGenerator} is stored as well.
  * <p>
- * Project: <strong>envoy-client</strong><br>
- * File: <strong>LocalDB.java</strong><br>
- * Created: <strong>3 Feb 2020</strong><br>
+ * The managed objects are stored inside a folder in the local file system.
  *
  * @author Kai S. K. Engelbart
  * @since Envoy Client v0.3-alpha
  */
-public abstract class LocalDB {
+public final class LocalDB implements EventListener {
 
-	protected User					user;
-	protected Map<String, Contact>	users		= new HashMap<>();
-	protected List<Chat>			chats		= new ArrayList<>();
-	protected IDGenerator			idGenerator;
-	protected CacheMap				cacheMap	= new CacheMap();
+	// Data
+	private User					user;
+	private Map<String, User>		users		= Collections.synchronizedMap(new HashMap<>());
+	private ObservableList<Chat>	chats		= FXCollections.observableArrayList();
+	private IDGenerator				idGenerator;
+	private CacheMap				cacheMap	= new CacheMap();
+	private String					authToken;
+	private boolean					contactsChanged;
 
-	{
+	// Auto save timer
+	private Timer	autoSaver;
+	private boolean	autoSaveRestart	= true;
+
+	// State management
+	private Instant lastSync = Instant.EPOCH;
+
+	// Persistence
+	private File		userFile;
+	private FileLock	instanceLock;
+
+	private final File dbDir, idGeneratorFile, lastLoginFile, usersFile;
+
+	private static final Logger logger = EnvoyLog.getLogger(LocalDB.class);
+
+	/**
+	 * Constructs an empty local database.
+	 *
+	 * @param dbDir the directory in which to persist data
+	 * @throws IOException    if {@code dbDir} is a file (and not a directory)
+	 * @throws EnvoyException if {@code dbDir} is in use by another Envoy instance
+	 * @since Envoy Client v0.2-beta
+	 */
+	public LocalDB(File dbDir) throws IOException, EnvoyException {
+		this.dbDir = dbDir;
+		EventBus.getInstance().registerListener(this);
+
+		// Ensure that the database directory exists
+		if (!dbDir.exists())
+			dbDir.mkdirs();
+		else if (!dbDir.isDirectory())
+			throw new IOException(
+				String.format("LocalDBDir '%s' is not a directory!", dbDir.getAbsolutePath()));
+
+		// Lock the directory
+		lock();
+
+		// Initialize global files
+		idGeneratorFile	= new File(dbDir, "id_gen.db");
+		lastLoginFile	= new File(dbDir, "last_login.db");
+		usersFile		= new File(dbDir, "users.db");
+
+		// Load global files
+		loadGlobalData();
+
+		// Initialize offline caches
 		cacheMap.put(Message.class, new Cache<>());
 		cacheMap.put(MessageStatusChange.class, new Cache<>());
 	}
 
 	/**
-	 * Initializes a storage space for a user-specific list of chats.
+	 * Ensured that only one Envoy instance is using this local database by creating a lock file.
+	 * The lock file is deleted on application exit.
 	 *
-	 * @since Envoy Client v0.3-alpha
+	 * @throws EnvoyException if the lock cannot by acquired
+	 * @since Envoy Client v0.2-beta
 	 */
-	public void initializeUserStorage() {}
+	private synchronized void lock() throws EnvoyException {
+		final var file = new File(dbDir, "instance.lock");
+		try {
+			final var fc = FileChannel.open(file.toPath(), StandardOpenOption.CREATE,
+				StandardOpenOption.WRITE);
+			instanceLock = fc.tryLock();
+			if (instanceLock == null)
+				throw new EnvoyException("Another Envoy instance is using this local database!");
+		} catch (final IOException e) {
+			throw new EnvoyException("Could not create lock file!", e);
+		}
+	}
 
 	/**
-	 * Stores all users. If the client user is specified, their chats will be stored
-	 * as well. The message id generator will also be saved if present.
+	 * Loads the local user registry {@code users.db}, the id generator {@code id_gen.db} and last
+	 * login file {@code last_login.db}.
 	 *
-	 * @throws Exception if the saving process failed
-	 * @since Envoy Client v0.3-alpha
+	 * @since Envoy Client v0.2-beta
 	 */
-	public void save() throws Exception {}
-
-	/**
-	 * Loads all user data.
-	 *
-	 * @throws Exception if the loading process failed
-	 * @since Envoy Client v0.3-alpha
-	 */
-	public void loadUsers() throws Exception {}
+	private synchronized void loadGlobalData() {
+		try {
+			try (var in = new ObjectInputStream(new FileInputStream(usersFile))) {
+				users = (Map<String, User>) in.readObject();
+			}
+			idGenerator = SerializationUtils.read(idGeneratorFile, IDGenerator.class);
+			try (var in = new ObjectInputStream(new FileInputStream(lastLoginFile))) {
+				user		= (User) in.readObject();
+				authToken	= (String) in.readObject();
+			}
+		} catch (IOException | ClassNotFoundException e) {}
+	}
 
 	/**
 	 * Loads all data of the client user.
 	 *
-	 * @throws Exception if the loading process failed
+	 * @throws ClassNotFoundException if the loading process failed
+	 * @throws IOException            if the loading process failed
 	 * @since Envoy Client v0.3-alpha
 	 */
-	public void loadUserData() throws Exception {}
+	public synchronized void loadUserData() throws ClassNotFoundException, IOException {
+		if (user == null)
+			throw new IllegalStateException("Client user is null, cannot initialize user storage");
+		userFile = new File(dbDir, user.getID() + ".db");
+		try (var in = new ObjectInputStream(new FileInputStream(userFile))) {
+			Chat.getTotalUnreadAmount().set(0);
+			chats = FXCollections.observableList((List<Chat>) in.readObject());
+
+			// Some chats have changed and should not be overwritten by the saved values
+			if (contactsChanged) {
+				final var contacts = user.getContacts();
+
+				// Mark chats as disabled if a contact is no longer in this users contact list
+				final var changedUserChats = chats.stream()
+					.filter(not(chat -> contacts.contains(chat.getRecipient())))
+					.peek(chat -> {
+						chat.setDisabled(true);
+						logger.log(Level.INFO,
+							String.format("Deleted chat with %s.", chat.getRecipient()));
+					});
+
+				// Also update groups with a different member count
+				final var changedGroupChats =
+					contacts.stream().filter(Group.class::isInstance).flatMap(group -> {
+						final var potentialChat = getChat(group.getID());
+						if (potentialChat.isEmpty())
+							return Stream.empty();
+						final var chat = potentialChat.get();
+						if (group.getContacts().size() != chat.getRecipient().getContacts()
+							.size()) {
+							logger.log(Level.INFO, "Removed one (or more) members from " + group);
+							return Stream.of(chat);
+						} else
+							return Stream.empty();
+					});
+				Stream.concat(changedUserChats, changedGroupChats)
+					.forEach(chat -> chats.set(chats.indexOf(chat), chat));
+
+				// loadUserData can get called two (or more?) times during application lifecycle
+				contactsChanged = false;
+			}
+			cacheMap	= (CacheMap) in.readObject();
+			lastSync	= (Instant) in.readObject();
+		} finally {
+			synchronize();
+		}
+	}
 
 	/**
-	 * Loads the ID generator. Any exception thrown during this process is ignored.
+	 * Synchronizes the contact list of the client user with the chat and user storage.
 	 *
-	 * @since Envoy Client v0.3-alpha
-	 */
-	public void loadIDGenerator() {}
-
-	/**
-	 * Synchronizes the contact list of the client user with the chat and user
-	 * storage.
-	 * 
 	 * @since Envoy Client v0.1-beta
 	 */
-	public void synchronize() {
-		user.getContacts().stream().filter(u -> u instanceof User && !users.containsKey(u.getName())).forEach(u -> users.put(u.getName(), u));
+	private void synchronize() {
+		user.getContacts().stream()
+			.filter(u -> u instanceof User && !users.containsKey(u.getName()))
+			.forEach(u -> users.put(u.getName(), (User) u));
 		users.put(user.getName(), user);
 
 		// Synchronize user status data
-		for (Contact contact : users.values())
+		for (final var contact : user.getContacts())
 			if (contact instanceof User)
-				getChat(contact.getID()).ifPresent(chat -> { ((User) chat.getRecipient()).setStatus(((User) contact).getStatus()); });
+				getChat(contact.getID()).ifPresent(chat -> {
+					((User) chat.getRecipient()).setStatus(((User) contact).getStatus());
+				});
 
 		// Create missing chats
 		user.getContacts()
 			.stream()
 			.filter(c -> !c.equals(user) && getChat(c.getID()).isEmpty())
-			.map(c -> c instanceof User ? new Chat(c) : new GroupChat(user, c))
+			.map(c -> c instanceof User ? new Chat(c) : new GroupChat(user, (Group) c))
 			.forEach(chats::add);
 	}
 
 	/**
-	 * @return a {@code Map<String, User>} of all users stored locally with their
-	 *         user names as keys
+	 * Initializes a timer that automatically saves this local database after a period of time
+	 * specified in the settings.
+	 *
+	 * @since Envoy Client v0.2-beta
+	 */
+	public void initAutoSave() {
+
+		// A logout happened so the timer should be restarted
+		if (autoSaveRestart) {
+			autoSaver		= new Timer("LocalDB Autosave", true);
+			autoSaveRestart	= false;
+		}
+
+		autoSaver.schedule(new TimerTask() {
+
+			@Override
+			public void run() {
+				save();
+			}
+		}, 2000, ClientConfig.getInstance().getLocalDBSaveInterval() * 60000);
+	}
+
+	/**
+	 * Stores all users. If the client user is specified, their chats will be stored as well. The
+	 * message id generator will also be saved if present.
+	 *
+	 * @throws IOException if the saving process failed
+	 * @since Envoy Client v0.3-alpha
+	 */
+	@Event(eventType = EnvoyCloseEvent.class, priority = 500)
+	private synchronized void save() {
+		EnvoyLog.getLogger(LocalDB.class).log(Level.FINER, "Saving local database...");
+
+		// Save users
+		try {
+			SerializationUtils.write(usersFile, users);
+
+			// Save user data and last sync time stamp
+			if (user != null)
+				SerializationUtils
+					.write(userFile, new ArrayList<>(chats), cacheMap,
+						Context.getInstance().getClient().isOnline() ? Instant.now() : lastSync);
+
+			// Save last login information
+			if (authToken != null)
+				SerializationUtils.write(lastLoginFile, user, authToken);
+
+			// Save ID generator
+			if (hasIDGenerator())
+				SerializationUtils.write(idGeneratorFile, idGenerator);
+		} catch (final IOException e) {
+			EnvoyLog.getLogger(LocalDB.class).log(Level.SEVERE, "Unable to save local database: ",
+				e);
+		}
+	}
+
+	@Event(priority = 500)
+	private void onMessage(Message msg) {
+		if (msg.getStatus() == MessageStatus.SENT)
+			msg.nextStatus();
+	}
+
+	@Event(priority = 500)
+	private void onGroupMessage(GroupMessage msg) {
+		// TODO: Cancel event once EventBus is updated
+		if (msg.getStatus() == MessageStatus.WAITING || msg.getStatus() == MessageStatus.READ)
+			logger.warning("The groupMessage has the unexpected status " + msg.getStatus());
+	}
+
+	@Event(priority = 500)
+	private void onMessageStatusChange(MessageStatusChange evt) {
+		getMessage(evt.getID()).ifPresent(msg -> msg.setStatus(evt.get()));
+	}
+
+	@Event(priority = 500)
+	private void onGroupMessageStatusChange(GroupMessageStatusChange evt) {
+		this.<GroupMessage>getMessage(evt.getID())
+			.ifPresent(msg -> msg.getMemberStatuses().replace(evt.getMemberID(), evt.get()));
+	}
+
+	@Event(priority = 500)
+	private void onUserStatusChange(UserStatusChange evt) {
+		getChat(evt.getID()).map(Chat::getRecipient).map(User.class::cast)
+			.ifPresent(u -> u.setStatus(evt.get()));
+	}
+
+	@Event(priority = 500)
+	private void onUserOperation(UserOperation operation) {
+		final var eventUser = operation.get();
+		switch (operation.getOperationType()) {
+			case ADD:
+				Platform.runLater(() -> chats.add(0, new Chat(eventUser)));
+				break;
+			case REMOVE:
+				getChat(eventUser.getID()).ifPresent(chat -> chat.setDisabled(true));
+				break;
+		}
+	}
+
+	@Event
+	private void onGroupCreationResult(GroupCreationResult evt) {
+		final var newGroup = evt.get();
+
+		// The group creation was not successful
+		if (newGroup == null)
+			return;
+
+		// The group was successfully created
+		else
+			Platform.runLater(() -> chats.add(new GroupChat(user, newGroup)));
+	}
+
+	@Event(priority = 500)
+	private void onGroupResize(GroupResize evt) {
+		getChat(evt.getGroupID()).map(Chat::getRecipient).map(Group.class::cast)
+			.ifPresent(evt::apply);
+	}
+
+	@Event(priority = 500)
+	private void onNameChange(NameChange evt) {
+		chats.stream().map(Chat::getRecipient).filter(c -> c.getID() == evt.getID()).findAny()
+			.ifPresent(c -> c.setName(evt.get()));
+	}
+
+	/**
+	 * Stores a new authentication token.
+	 *
+	 * @param evt the event containing the authentication token
+	 * @since Envoy Client v0.2-beta
+	 */
+	@Event
+	private void onNewAuthToken(NewAuthToken evt) {
+		authToken = evt.get();
+	}
+
+	/**
+	 * Deletes all associations to the current user.
+	 *
+	 * @since Envoy Client v0.2-beta
+	 */
+	@Event(eventType = Logout.class, priority = 50)
+	private void onLogout() {
+		autoSaver.cancel();
+		autoSaveRestart = true;
+		lastLoginFile.delete();
+		userFile	= null;
+		user		= null;
+		authToken	= null;
+		chats.clear();
+		lastSync = Instant.EPOCH;
+		cacheMap.clear();
+	}
+
+	/**
+	 * Deletes the message with the given ID, if present.
+	 *
+	 * @param message the event that was
+	 * @since Envoy Client v0.3-beta
+	 */
+	@Event
+	private void onMessageDeletion(MessageDeletion message) {
+		Platform.runLater(() -> {
+
+			// We suppose that messages have unique IDs, hence the search can be stopped
+			// once a message was removed
+			final var messageID = message.get();
+			for (final var chat : chats)
+				if (chat.remove(messageID))
+					break;
+		});
+	}
+
+	@Event(priority = 500)
+	private void onOwnStatusChange(OwnStatusChange statusChange) {
+		user.setStatus(statusChange.get());
+	}
+
+	@Event(eventType = ContactsChangedSinceLastLogin.class, priority = 500)
+	private void onContactsChangedSinceLastLogin() {
+		contactsChanged = true;
+	}
+
+	@Event(priority = 500)
+	private void onContactDisabled(ContactDisabled event) {
+		getChat(event.get().getID()).ifPresent(chat -> chat.setDisabled(true));
+	}
+
+	/**
+	 * @return a {@code Map<String, User>} of all users stored locally with their user names as keys
 	 * @since Envoy Client v0.2-alpha
 	 */
-	public Map<String, Contact> getUsers() { return users; }
+	public Map<String, User> getUsers() { return users; }
 
 	/**
-	 * @return all saved {@link Chat} objects that list the client user as the
-	 *         sender
+	 * Searches for a message by ID.
+	 *
+	 * @param id the ID of the message to search for
+	 * @return an optional containing the message
+	 * @since Envoy Client v0.1-beta
+	 */
+	public <T extends Message> Optional<T> getMessage(long id) {
+		return (Optional<T>) chats.stream().map(Chat::getMessages).flatMap(List::stream)
+			.filter(m -> m.getID() == id).findAny();
+	}
+
+	/**
+	 * Searches for a chat by recipient ID.
+	 *
+	 * @param recipientID the ID of the chat's recipient
+	 * @return an optional containing the chat
+	 * @since Envoy Client v0.1-beta
+	 */
+	public Optional<Chat> getChat(long recipientID) {
+		return chats.stream().filter(c -> c.getRecipient().getID() == recipientID).findAny();
+	}
+
+	/**
+	 * @return all saved {@link Chat} objects that list the client user as the sender
 	 * @since Envoy Client v0.1-alpha
 	 **/
-	public List<Chat> getChats() { return chats; }
-
-	/**
-	 * @param chats the chats to set
-	 */
-	public void setChats(List<Chat> chats) { this.chats = chats; }
+	public ObservableList<Chat> getChats() { return chats; }
 
 	/**
 	 * @return the {@link User} who initialized the local database
@@ -134,13 +461,16 @@ public abstract class LocalDB {
 	 * @param idGenerator the message ID generator to set
 	 * @since Envoy Client v0.3-alpha
 	 */
+	@Event(priority = 150)
 	public void setIDGenerator(IDGenerator idGenerator) { this.idGenerator = idGenerator; }
 
 	/**
 	 * @return {@code true} if an {@link IDGenerator} is present
 	 * @since Envoy Client v0.3-alpha
 	 */
-	public boolean hasIDGenerator() { return idGenerator != null; }
+	public boolean hasIDGenerator() {
+		return idGenerator != null;
+	}
 
 	/**
 	 * @return the cache map for messages and message status changes
@@ -149,57 +479,14 @@ public abstract class LocalDB {
 	public CacheMap getCacheMap() { return cacheMap; }
 
 	/**
-	 * Searches for a message by ID.
-	 *
-	 * @param id the ID of the message to search for
-	 * @return an optional containing the message
-	 * @since Envoy Client v0.1-beta
+	 * @return the time stamp when the database was last saved
+	 * @since Envoy Client v0.2-beta
 	 */
-	public Optional<Message> getMessage(long id) {
-		return chats.stream().map(Chat::getMessages).flatMap(List::stream).filter(m -> m.getID() == id).findAny();
-	}
+	public Instant getLastSync() { return lastSync; }
 
 	/**
-	 * Searches for a chat by recipient ID.
-	 * 
-	 * @param recipientID the ID of the chat's recipient
-	 * @return an optional containing the chat
-	 * @since Envoy Client v0.1-beta
+	 * @return the authentication token of the user
+	 * @since Envoy Client v0.2-beta
 	 */
-	public Optional<Chat> getChat(long recipientID) { return chats.stream().filter(c -> c.getRecipient().getID() == recipientID).findAny(); }
-
-	/**
-	 * Performs a contact name change if the corresponding contact is present.
-	 *
-	 * @param event the {@link NameChange} to process
-	 * @since Envoy Client v0.1-beta
-	 */
-	public void replaceContactName(NameChange event) {
-		chats.stream().map(Chat::getRecipient).filter(c -> c.getID() == event.getID()).findAny().ifPresent(c -> c.setName(event.get()));
-	}
-
-	/**
-	 * Performs a group resize operation if the corresponding group is present.
-	 *
-	 * @param event the {@link GroupResize} to process
-	 * @since Envoy Client v0.1-beta
-	 */
-	public void updateGroup(GroupResize event) {
-		chats.stream()
-			.map(Chat::getRecipient)
-			.filter(Group.class::isInstance)
-			.filter(g -> g.getID() == event.getGroupID() && g.getID() != user.getID())
-			.map(Group.class::cast)
-			.findAny()
-			.ifPresent(group -> {
-				switch (event.getOperation()) {
-					case ADD:
-						group.getContacts().add(event.get());
-						break;
-					case REMOVE:
-						group.getContacts().remove(event.get());
-						break;
-				}
-			});
-	}
+	public String getAuthToken() { return authToken; }
 }

client/src/main/java/envoy/client/data/PersistentLocalDB.java

@@ -1,88 +0,0 @@
-package envoy.client.data;
-
-import java.io.*;
-import java.util.ArrayList;
-import java.util.HashMap;
-
-import envoy.data.IDGenerator;
-import envoy.util.SerializationUtils;
-
-/**
- * Implements a {@link LocalDB} in a way that stores all information inside a
- * folder on the local file system.
- * <p>
- * Project: <strong>envoy-client</strong><br>
- * File: <strong>PersistentLocalDB.java</strong><br>
- * Created: <strong>27.10.2019</strong><br>
- *
- * @author Kai S. K. Engelbart
- * @author Maximilian K&auml;fer
- * @since Envoy Client v0.1-alpha
- */
-public final class PersistentLocalDB extends LocalDB {
-
-	private File dbDir, userFile, idGeneratorFile, usersFile;
-
-	/**
-	 * Constructs an empty local database. To serialize any user-specific data to
-	 * the file system, call {@link PersistentLocalDB#initializeUserStorage()} first
-	 * and then {@link PersistentLocalDB#save()}.
-	 *
-	 * @param dbDir the directory in which to persist data
-	 * @throws IOException if {@code dbDir} is a file (and not a directory)
-	 * @since Envoy Client v0.1-alpha
-	 */
-	public PersistentLocalDB(File dbDir) throws IOException {
-		this.dbDir = dbDir;
-
-		// Test if the database directory is actually a directory
-		if (dbDir.exists() && !dbDir.isDirectory())
-			throw new IOException(String.format("LocalDBDir '%s' is not a directory!", dbDir.getAbsolutePath()));
-
-		// Initialize global files
-		idGeneratorFile	= new File(dbDir, "id_gen.db");
-		usersFile		= new File(dbDir, "users.db");
-	}
-
-	/**
-	 * Creates a database file for a user-specific list of chats.
-	 *
-	 * @throws IllegalStateException if the client user is not specified
-	 * @since Envoy Client v0.1-alpha
-	 */
-	@Override
-	public void initializeUserStorage() {
-		if (user == null) throw new IllegalStateException("Client user is null, cannot initialize user storage");
-		userFile = new File(dbDir, user.getID() + ".db");
-	}
-
-	@Override
-	public void save() throws IOException {
-		// Save users
-		SerializationUtils.write(usersFile, users);
-
-		// Save user data
-		if (user != null) SerializationUtils.write(userFile, chats, cacheMap);
-
-		// Save id generator
-		if (hasIDGenerator()) SerializationUtils.write(idGeneratorFile, idGenerator);
-	}
-
-	@Override
-	public void loadUsers() throws ClassNotFoundException, IOException { users = SerializationUtils.read(usersFile, HashMap.class); }
-
-	@Override
-	public void loadUserData() throws ClassNotFoundException, IOException {
-		try (var in = new ObjectInputStream(new FileInputStream(userFile))) {
-			chats		= (ArrayList<Chat>) in.readObject();
-			cacheMap	= (CacheMap) in.readObject();
-		}
-	}
-
-	@Override
-	public void loadIDGenerator() {
-		try {
-			idGenerator = SerializationUtils.read(idGeneratorFile, IDGenerator.class);
-		} catch (ClassNotFoundException | IOException e) {}
-	}
-}

client/src/main/java/envoy/client/data/Settings.java

@@ -1,28 +1,27 @@
 package envoy.client.data;
 
-import java.io.File;
-import java.io.IOException;
-import java.util.HashMap;
-import java.util.Map;
+import java.io.*;
+import java.util.*;
+import java.util.logging.Level;
 import java.util.prefs.Preferences;
 
-import envoy.util.SerializationUtils;
+import dev.kske.eventbus.*;
+import dev.kske.eventbus.EventListener;
+
+import envoy.util.*;
+
+import envoy.client.event.EnvoyCloseEvent;
 
 /**
- * Manages all application settings, which are different objects that can be
- * changed during runtime and serialized them by using either the file system or
- * the {@link Preferences} API.
- * <p>
- * Project: <strong>envoy-client</strong><br>
- * File: <strong>Settings.java</strong><br>
- * Created: <strong>11 Nov 2019</strong><br>
+ * Manages all application settings, which are different objects that can be changed during runtime
+ * and serialized them by using either the file system or the {@link Preferences} API.
  *
  * @author Leon Hofmeister
  * @author Maximilian K&auml;fer
  * @author Kai S. K. Engelbart
  * @since Envoy Client v0.2-alpha
  */
-public class Settings {
+public final class Settings implements EventListener {
 
 	// Actual settings accessible by the rest of the application
 	private Map<String, SettingsItem<?>> items;
@@ -30,7 +29,8 @@ public class Settings {
 	/**
 	 * Settings are stored in this file.
 	 */
-	private static final File settingsFile = new File(ClientConfig.getInstance().getHomeDirectory(), "settings.ser");
+	private static final File settingsFile =
+		new File(ClientConfig.getInstance().getHomeDirectory(), "settings.ser");
 
 	/**
 	 * Singleton instance of this class.
@@ -38,12 +38,14 @@ public class Settings {
 	private static Settings settings = new Settings();
 
 	/**
-	 * The way to instantiate the settings. Is set to private to deny other
-	 * instances of that object.
+	 * The way to instantiate the settings. Is set to private to deny other instances of that
+	 * object.
 	 *
 	 * @since Envoy Client v0.2-alpha
 	 */
 	private Settings() {
+		EventBus.getInstance().registerListener(this);
+
 		// Load settings from settings file
 		try {
 			items = SerializationUtils.read(settingsFile, HashMap.class);
@@ -67,16 +69,35 @@ public class Settings {
 	 * @throws IOException if an error occurs while saving the themes
 	 * @since Envoy Client v0.2-alpha
 	 */
-	public void save() throws IOException {
+	@Event(eventType = EnvoyCloseEvent.class)
+	private void save() {
+		EnvoyLog.getLogger(Settings.class).log(Level.INFO, "Saving settings...");
 
 		// Save settings to settings file
-		SerializationUtils.write(settingsFile, items);
+		try {
+			SerializationUtils.write(settingsFile, items);
+		} catch (final IOException e) {
+			EnvoyLog.getLogger(Settings.class).log(Level.SEVERE, "Unable to save settings file: ",
+				e);
+		}
 	}
 
 	private void supplementDefaults() {
-		items.putIfAbsent("enterToSend", new SettingsItem<>(true, "Enter to send", "Sends a message by pressing the enter key."));
-		items.putIfAbsent("onCloseMode", new SettingsItem<>(true, "Hide on close", "Hides the chat window when it is closed."));
-		items.putIfAbsent("currentTheme", new SettingsItem<>("dark", "Current Theme Name", "The name of the currently selected theme."));
+		items.putIfAbsent("enterToSend", new SettingsItem<>(true, "Enter to send",
+			"Sends a message by pressing the enter key."));
+		items.putIfAbsent("hideOnClose",
+			new SettingsItem<>(false, "Hide on close", "Hides the chat window when it is closed."));
+		items.putIfAbsent("currentTheme", new SettingsItem<>("dark", "Current Theme Name",
+			"The name of the currently selected theme."));
+		items.putIfAbsent("downloadLocation",
+			new SettingsItem<>(new File(System.getProperty("user.home") + "/Downloads/"),
+				"Download location",
+				"The location where files will be saved to"));
+		items.putIfAbsent("autoSaveDownloads", new SettingsItem<>(false, "Save without asking?",
+			"Should downloads be saved without asking?"));
+		items.putIfAbsent("askForConfirmation",
+			new SettingsItem<>(true, "Ask for confirmation",
+				"Will ask for confirmation before doing certain things"));
 	}
 
 	/**
@@ -91,7 +112,9 @@ public class Settings {
 	 * @param themeName the name to set
 	 * @since Envoy Client v0.2-alpha
 	 */
-	public void setCurrentTheme(String themeName) { ((SettingsItem<String>) items.get("currentTheme")).set(themeName); }
+	public void setCurrentTheme(String themeName) {
+		((SettingsItem<String>) items.get("currentTheme")).set(themeName);
+	}
 
 	/**
 	 * @return true if the currently used theme is one of the default themes
@@ -103,9 +126,8 @@ public class Settings {
 	}
 
 	/**
-	 * @return {@code true}, if pressing the {@code Enter} key suffices to send a
-	 *         message. Otherwise it has to be pressed in conjunction with the
-	 *         {@code Control} key.
+	 * @return {@code true}, if pressing the {@code Enter} key suffices to send a message. Otherwise
+	 *         it has to be pressed in conjunction with the {@code Control} key.
 	 * @since Envoy Client v0.2-alpha
 	 */
 	public Boolean isEnterToSend() { return (Boolean) items.get("enterToSend").get(); }
@@ -113,26 +135,84 @@ public class Settings {
 	/**
 	 * Changes the keystrokes performed by the user to send a message.
 	 *
-	 * @param enterToSend If set to {@code true} a message can be sent by pressing
-	 *                    the {@code Enter} key. Otherwise it has to be pressed in
-	 *                    conjunction with the {@code Control} key.
+	 * @param enterToSend If set to {@code true} a message can be sent by pressing the {@code Enter}
+	 *                    key. Otherwise it has to be pressed in conjunction with the
+	 *                    {@code Control} key.
 	 * @since Envoy Client v0.2-alpha
 	 */
-	public void setEnterToSend(boolean enterToSend) { ((SettingsItem<Boolean>) items.get("enterToSend")).set(enterToSend); }
+	public void setEnterToSend(boolean enterToSend) {
+		((SettingsItem<Boolean>) items.get("enterToSend")).set(enterToSend);
+	}
+
+	/**
+	 * @return whether Envoy will prompt a dialogue before saving an {@link envoy.data.Attachment}
+	 * @since Envoy Client v0.2-beta
+	 */
+	public Boolean isDownloadSavedWithoutAsking() {
+		return (Boolean) items.get("autoSaveDownloads").get();
+	}
+
+	/**
+	 * Sets whether Envoy will prompt a dialogue before saving an {@link envoy.data.Attachment}.
+	 *
+	 * @param autosaveDownload whether a download should be saved without asking before
+	 * @since Envoy Client v0.2-beta
+	 */
+	public void setDownloadSavedWithoutAsking(boolean autosaveDownload) {
+		((SettingsItem<Boolean>) items.get("autoSaveDownloads")).set(autosaveDownload);
+	}
+
+	/**
+	 * @return the path where downloads should be saved
+	 * @since Envoy Client v0.2-beta
+	 */
+	public File getDownloadLocation() { return (File) items.get("downloadLocation").get(); }
+
+	/**
+	 * Sets the path where downloads should be saved.
+	 *
+	 * @param downloadLocation the path to set
+	 * @since Envoy Client v0.2-beta
+	 */
+	public void setDownloadLocation(File downloadLocation) {
+		((SettingsItem<File>) items.get("downloadLocation")).set(downloadLocation);
+	}
 
 	/**
 	 * @return the current on close mode.
 	 * @since Envoy Client v0.3-alpha
 	 */
-	public Boolean getCurrentOnCloseMode() { return (Boolean) items.get("onCloseMode").get(); }
+	public Boolean isHideOnClose() { return (Boolean) items.get("hideOnClose").get(); }
 
 	/**
 	 * Sets the current on close mode.
 	 *
-	 * @param currentOnCloseMode the on close mode that should be set.
+	 * @param hideOnClose whether the application should be minimized on close
 	 * @since Envoy Client v0.3-alpha
 	 */
-	public void setCurrentOnCloseMode(boolean currentOnCloseMode) { ((SettingsItem<Boolean>) items.get("onCloseMode")).set(currentOnCloseMode); }
+	public void setHideOnClose(boolean hideOnClose) {
+		((SettingsItem<Boolean>) items.get("hideOnClose")).set(hideOnClose);
+	}
+
+	/**
+	 * @return whether a confirmation dialog should be displayed before certain actions
+	 * @since Envoy Client v0.2-alpha
+	 */
+	public Boolean isAskForConfirmation() {
+		return (Boolean) items.get("askForConfirmation").get();
+	}
+
+	/**
+	 * Changes the behavior of calling certain functionality by displaying a confirmation dialog
+	 * before executing it.
+	 *
+	 * @param askForConfirmation whether confirmation dialogs should be displayed before certain
+	 *                           actions
+	 * @since Envoy Client v0.2-alpha
+	 */
+	public void setAskForConfirmation(boolean askForConfirmation) {
+		((SettingsItem<Boolean>) items.get("askForConfirmation")).set(askForConfirmation);
+	}
 
 	/**
 	 * @return the items

client/src/main/java/envoy/client/data/SettingsItem.java

@@ -1,35 +1,26 @@
 package envoy.client.data;
 
 import java.io.Serializable;
-import java.util.function.Consumer;
 
 import javax.swing.JComponent;
 
 /**
- * Encapsulates a persistent value that is directly or indirectly mutable by the
- * user.
- * <p>
- * Project: <strong>envoy-client</strong><br>
- * File: <strong>SettingsItem.java</strong><br>
- * Created: <strong>23.12.2019</strong><br>
+ * Encapsulates a persistent value that is directly or indirectly mutable by the user.
  *
  * @param <T> the type of this {@link SettingsItem}'s value
  * @author Kai S. K. Engelbart
  * @since Envoy Client v0.3-alpha
  */
-public class SettingsItem<T> implements Serializable {
+public final class SettingsItem<T> implements Serializable {
 
 	private T		value;
 	private String	userFriendlyName, description;
 
-	private transient Consumer<T> changeHandler;
-
 	private static final long serialVersionUID = 1L;
 
 	/**
-	 * Initializes a {@link SettingsItem}. The default value's class will be mapped
-	 * to a {@link JComponent} that can be used to display this {@link SettingsItem}
-	 * to the user.
+	 * Initializes a {@link SettingsItem}. The default value's class will be mapped to a
+	 * {@link JComponent} that can be used to display this {@link SettingsItem} to the user.
 	 *
 	 * @param value            the default value
 	 * @param userFriendlyName the user friendly name (short)
@@ -46,17 +37,18 @@ public class SettingsItem<T> implements Serializable {
 	 * @return the value
 	 * @since Envoy Client v0.3-alpha
 	 */
-	public T get() { return value; }
+	public T get() {
+		return value;
+	}
 
 	/**
-	 * Changes the value of this {@link SettingsItem}. If a {@code ChangeHandler} if
-	 * defined, it will be invoked with this value.
+	 * Changes the value of this {@link SettingsItem}. If a {@code ChangeHandler} if defined, it
+	 * will be invoked with this value.
 	 *
 	 * @param value the value to set
 	 * @since Envoy Client v0.3-alpha
 	 */
 	public void set(T value) {
-		if (changeHandler != null && value != this.value) changeHandler.accept(value);
 		this.value = value;
 	}
 
@@ -70,7 +62,9 @@ public class SettingsItem<T> implements Serializable {
 	 * @param userFriendlyName the userFriendlyName to set
 	 * @since Envoy Client v0.3-alpha
 	 */
-	public void setUserFriendlyName(String userFriendlyName) { this.userFriendlyName = userFriendlyName; }
+	public void setUserFriendlyName(String userFriendlyName) {
+		this.userFriendlyName = userFriendlyName;
+	}
 
 	/**
 	 * @return the description
@@ -83,17 +77,4 @@ public class SettingsItem<T> implements Serializable {
 	 * @since Envoy Client v0.3-alpha
 	 */
 	public void setDescription(String description) { this.description = description; }
-
-	/**
-	 * Sets a {@code ChangeHandler} for this {@link SettingsItem}. It will be
-	 * invoked with the current value once during the registration and every time
-	 * when the value changes.
-	 *
-	 * @param changeHandler the changeHandler to set
-	 * @since Envoy Client v0.3-alpha
-	 */
-	public void setChangeHandler(Consumer<T> changeHandler) {
-		this.changeHandler = changeHandler;
-		changeHandler.accept(value);
-	}
 }

client/src/main/java/envoy/client/data/TransientLocalDB.java

@@ -1,15 +0,0 @@
-package envoy.client.data;
-
-/**
- * Implements a {@link LocalDB} in a way that does not persist any information
- * after application shutdown.
- * <p>
- * Project: <strong>envoy-client</strong><br>
- * File: <strong>TransientLocalDB.java</strong><br>
- * Created: <strong>3 Feb 2020</strong><br>
- *
- * @author Kai S. K. Engelbart
- * @since Envoy Client v0.3-alpha
- */
-public final class TransientLocalDB extends LocalDB {
-}

client/src/main/java/envoy/client/data/audio/AudioPlayer.java

@@ -6,10 +6,6 @@ import envoy.exception.EnvoyException;
 
 /**
  * Plays back audio from a byte array.
- * <p>
- * Project: <strong>envoy-client</strong><br>
- * File: <strong>AudioPlayer.java</strong><br>
- * Created: <strong>05.07.2020</strong><br>
  *
  * @author Kai S. K. Engelbart
  * @since Envoy Client v0.1-beta
@@ -26,7 +22,9 @@ public final class AudioPlayer {
 	 *
 	 * @since Envoy Client v0.1-beta
 	 */
-	public AudioPlayer() { this(AudioRecorder.DEFAULT_AUDIO_FORMAT); }
+	public AudioPlayer() {
+		this(AudioRecorder.DEFAULT_AUDIO_FORMAT);
+	}
 
 	/**
 	 * Initializes the player with a given audio format.

client/src/main/java/envoy/client/data/audio/AudioRecorder.java

@@ -1,8 +1,7 @@
 package envoy.client.data.audio;
 
 import java.io.IOException;
-import java.nio.file.Files;
-import java.nio.file.Path;
+import java.nio.file.*;
 
 import javax.sound.sampled.*;
 
@@ -10,10 +9,6 @@ import envoy.exception.EnvoyException;
 
 /**
  * Records audio and exports it as a byte array.
- * <p>
- * Project: <strong>envoy-client</strong><br>
- * File: <strong>AudioRecorder.java</strong><br>
- * Created: <strong>02.07.2020</strong><br>
  *
  * @author Kai S. K. Engelbart
  * @since Envoy Client v0.1-beta
@@ -25,7 +20,13 @@ public final class AudioRecorder {
 	 *
 	 * @since Envoy Client v0.1-beta
 	 */
-	public static final AudioFormat DEFAULT_AUDIO_FORMAT = new AudioFormat(16000, 16, 1, true, false);
+	public static final AudioFormat DEFAULT_AUDIO_FORMAT =
+		new AudioFormat(16000, 16, 1, true, false);
+
+	/**
+	 * The format in which audio files will be saved.
+	 */
+	public static final String FILE_FORMAT = "wav";
 
 	private final AudioFormat	format;
 	private final DataLine.Info	info;
@@ -38,7 +39,9 @@ public final class AudioRecorder {
 	 *
 	 * @since Envoy Client v0.1-beta
 	 */
-	public AudioRecorder() { this(DEFAULT_AUDIO_FORMAT); }
+	public AudioRecorder() {
+		this(DEFAULT_AUDIO_FORMAT);
+	}
 
 	/**
 	 * Initializes the recorder with a given audio format.
@@ -78,7 +81,7 @@ public final class AudioRecorder {
 			line.start();
 
 			// Prepare temp file
-			tempFile = Files.createTempFile("recording", "wav");
+			tempFile = Files.createTempFile("recording", FILE_FORMAT);
 
 			// Start the recording
 			final var ais = new AudioInputStream(line);
@@ -117,6 +120,6 @@ public final class AudioRecorder {
 		line.close();
 		try {
 			Files.deleteIfExists(tempFile);
-		} catch (IOException e) {}
+		} catch (final IOException e) {}
 	}
 }

client/src/main/java/envoy/client/data/audio/package-info.java

@@ -1,10 +1,6 @@
 /**
  * Contains classes related to recording and playing back audio clips.
- * <p>
- * Project: <strong>envoy-client</strong><br>
- * File: <strong>package-info.java</strong><br>
- * Created: <strong>05.07.2020</strong><br>
- * 
+ *
  * @author Kai S. K. Engelbart
  * @since Envoy Client v0.1-beta
  */

client/src/main/java/envoy/client/data/commands/Callable.java

@@ -0,0 +1,20 @@
+package envoy.client.data.commands;
+
+import java.util.List;
+
+/**
+ * This interface defines an action that should be performed when a system command gets called.
+ *
+ * @author Leon Hofmeister
+ * @since Envoy Client v0.2-beta
+ */
+public interface Callable {
+
+	/**
+	 * Performs the instance specific action when a {@link SystemCommand} has been called.
+	 *
+	 * @param arguments the arguments that should be passed to the {@link SystemCommand}
+	 * @since Envoy Client v0.2-beta
+	 */
+	void call(List<String> arguments);
+}

client/src/main/java/envoy/client/data/commands/SystemCommand.java

@@ -0,0 +1,116 @@
+package envoy.client.data.commands;
+
+import java.util.*;
+import java.util.function.Consumer;
+
+/**
+ * This class is the base class of all {@code SystemCommands} and contains an action and a number of
+ * arguments that should be used as input for this function. No {@code SystemCommand} can return
+ * anything. Every {@code SystemCommand} must have as argument type {@code List<String>} so that the
+ * words following the indicator String can be used as input of the function. This approach has one
+ * limitation:<br>
+ * <b>Order matters!</b> Changing the order of arguments will likely result in unexpected behavior.
+ *
+ * @author Leon Hofmeister
+ * @since Envoy Client v0.2-beta
+ */
+public final class SystemCommand implements Callable {
+
+	protected int relevance;
+
+	/**
+	 * The argument count of the command.
+	 */
+	protected final int numberOfArguments;
+
+	/**
+	 * This function takes a {@code List<String>} as argument because automatically
+	 * {@code SystemCommand#numberOfArguments} words following the necessary command will be put
+	 * into this list.
+	 *
+	 * @see String#split(String)
+	 */
+	protected final Consumer<List<String>> action;
+
+	protected final String description;
+
+	protected final List<String> defaults;
+
+	/**
+	 * Constructs a new {@code SystemCommand}.
+	 *
+	 * @param action            the action performed by the command
+	 * @param numberOfArguments the argument count accepted by the action
+	 * @param defaults          the default values for the corresponding arguments
+	 * @param description       the description of this {@code SystemCommand}
+	 * @since Envoy Client v0.2-beta
+	 */
+	public SystemCommand(Consumer<List<String>> action, int numberOfArguments,
+		List<String> defaults, String description) {
+		this.numberOfArguments	= numberOfArguments;
+		this.action				= action;
+		this.defaults			= defaults == null ? new ArrayList<>() : defaults;
+		this.description		= description;
+	}
+
+	/**
+	 * @return the argument count of the command
+	 * @since Envoy Client v0.2-beta
+	 */
+	public int getNumberOfArguments() { return numberOfArguments; }
+
+	/**
+	 * @return the description
+	 * @since Envoy Client v0.2-beta
+	 */
+	public String getDescription() { return description; }
+
+	/**
+	 * @return the relevance
+	 * @since Envoy Client v0.2-beta
+	 */
+	public int getRelevance() { return relevance; }
+
+	/**
+	 * @param relevance the relevance to set
+	 * @since Envoy Client v0.2-beta
+	 */
+	public void setRelevance(int relevance) { this.relevance = relevance; }
+
+	@Override
+	public void call(List<String> arguments) {
+		action.accept(arguments);
+		++relevance;
+	}
+
+	/**
+	 * @return the defaults
+	 * @since Envoy Client v0.2-beta
+	 */
+	public List<String> getDefaults() { return defaults; }
+
+	@Override
+	public int hashCode() {
+		return Objects.hash(action);
+	}
+
+	@Override
+	public boolean equals(Object obj) {
+		if (this == obj)
+			return true;
+		if (obj == null)
+			return false;
+		if (getClass() != obj.getClass())
+			return false;
+		final var other = (SystemCommand) obj;
+		return Objects.equals(action, other.action);
+	}
+
+	@Override
+	public String toString() {
+		return "SystemCommand [relevance=" + relevance + ", numberOfArguments=" + numberOfArguments
+			+ ", "
+			+ (description != null ? "description=" + description + ", " : "")
+			+ (defaults != null ? "defaults=" + defaults : "") + "]";
+	}
+}

client/src/main/java/envoy/client/data/commands/SystemCommandBuilder.java

@@ -0,0 +1,232 @@
+package envoy.client.data.commands;
+
+import java.util.*;
+import java.util.function.Consumer;
+
+/**
+ * This class acts as a builder for {@link SystemCommand}s.
+ *
+ * @author Leon Hofmeister
+ * @since Envoy Client v0.2-beta
+ */
+public final class SystemCommandBuilder {
+
+	private int						numberOfArguments;
+	private Consumer<List<String>>	action;
+	private List<String>			defaults;
+	private String					description;
+	private int						relevance;
+
+	private final SystemCommandMap commandsMap;
+
+	/**
+	 * Creates a new {@code SystemCommandsBuilder} without underlying {@link SystemCommandMap}.
+	 *
+	 * @since Envoy Client v0.2-beta
+	 */
+	public SystemCommandBuilder() {
+		this(null);
+	}
+
+	/**
+	 * @param commandsMap the map to use when calling build (optional)
+	 * @since Envoy Client v0.2-beta
+	 */
+	public SystemCommandBuilder(SystemCommandMap commandsMap) {
+		this.commandsMap = commandsMap;
+	}
+
+	/**
+	 * @param numberOfArguments the numberOfArguments to set
+	 * @return this {@code SystemCommandBuilder}
+	 * @since Envoy Client v0.2-beta
+	 */
+	public SystemCommandBuilder setNumberOfArguments(int numberOfArguments) {
+		this.numberOfArguments = numberOfArguments;
+		return this;
+	}
+
+	/**
+	 * @param action the action to set
+	 * @return this {@code SystemCommandBuilder}
+	 * @since Envoy Client v0.2-beta
+	 */
+	public SystemCommandBuilder setAction(Consumer<List<String>> action) {
+		this.action = action;
+		return this;
+	}
+
+	/**
+	 * @param description the description to set
+	 * @return this {@code SystemCommandBuilder}
+	 * @since Envoy Client v0.2-beta
+	 */
+	public SystemCommandBuilder setDescription(String description) {
+		this.description = description;
+		return this;
+	}
+
+	/**
+	 * @param relevance the relevance to set
+	 * @return this {@code SystemCommandBuilder}
+	 * @since Envoy Client v0.2-beta
+	 */
+	public SystemCommandBuilder setRelevance(int relevance) {
+		this.relevance = relevance;
+		return this;
+	}
+
+	/**
+	 * @param defaults the defaults to set
+	 * @return this {@code SystemCommandBuilder}
+	 * @since Envoy Client v0.2-beta
+	 */
+	public SystemCommandBuilder setDefaults(String... defaults) {
+		this.defaults = List.of(defaults);
+		return this;
+	}
+
+	/**
+	 * Resets all values stored.
+	 *
+	 * @return this {@code SystemCommandBuilder}
+	 * @since Envoy Client v0.2-beta
+	 */
+	public SystemCommandBuilder reset() {
+		numberOfArguments	= 0;
+		action				= null;
+		defaults			= new ArrayList<>();
+		description			= "";
+		relevance			= 0;
+		return this;
+	}
+
+	/**
+	 * Builds a {@code SystemCommand} based upon the previously entered data.
+	 *
+	 * @return the built {@code SystemCommand}
+	 * @since Envoy Client v0.2-beta
+	 */
+	public SystemCommand build() {
+		return build(true);
+	}
+
+	/**
+	 * Builds a {@code SystemCommand} based upon the previously entered data.<br>
+	 * {@code SystemCommand#numberOfArguments} will be set to 0, regardless of the previous
+	 * value.<br>
+	 * At the end, this {@code SystemCommandBuilder} will be reset.
+	 *
+	 * @return the built {@code SystemCommand}
+	 * @since Envoy Client v0.2-beta
+	 */
+	public SystemCommand buildNoArg() {
+		numberOfArguments = 0;
+		return build(true);
+	}
+
+	/**
+	 * Builds a {@code SystemCommand} based upon the previously entered data.<br>
+	 * {@code SystemCommand#numberOfArguments} will be set to use the rest of the string as
+	 * argument, regardless of the previous value.<br>
+	 * At the end, this {@code SystemCommandBuilder} will be reset.
+	 *
+	 * @return the built {@code SystemCommand}
+	 * @since Envoy Client v0.2-beta
+	 */
+	public SystemCommand buildRemainingArg() {
+		numberOfArguments = -1;
+		return build(true);
+	}
+
+	/**
+	 * Builds a {@code SystemCommand} based upon the previously entered data.<br>
+	 * Automatically adds the built object to the given map. At the end, this
+	 * {@code SystemCommandBuilder} <b>can</b> be reset but must not be.
+	 *
+	 * @param reset whether this {@code SystemCommandBuilder} should be reset afterwards.<br>
+	 *              This can be useful if another command wants to execute something similar
+	 * @return the built {@code SystemCommand}
+	 * @since Envoy Client v0.2-beta
+	 */
+	public SystemCommand build(boolean reset) {
+		final var sc = new SystemCommand(action, numberOfArguments, defaults, description);
+		sc.setRelevance(relevance);
+		if (reset)
+			reset();
+		return sc;
+	}
+
+	/**
+	 * Builds a {@code SystemCommand} based upon the previously entered data. Automatically adds the
+	 * built object to the given map.
+	 *
+	 * @param command the command under which to store the SystemCommand in the
+	 *                {@link SystemCommandMap}
+	 * @return the built {@code SystemCommand}
+	 * @throws NullPointerException if no map has been assigned to this builder
+	 * @since Envoy Client v0.2-beta
+	 */
+	public SystemCommand build(String command) {
+		return build(command, true);
+	}
+
+	/**
+	 * Builds a {@code SystemCommand} based upon the previously entered data.<br>
+	 * Automatically adds the built object to the given map. {@code SystemCommand#numberOfArguments}
+	 * will be set to 0, regardless of the previous value.<br>
+	 * At the end, this {@code SystemCommandBuilder} will be reset.
+	 *
+	 * @param command the command under which to store the SystemCommand in the
+	 *                {@link SystemCommandMap}
+	 * @return the built {@code SystemCommand}
+	 * @throws NullPointerException if no map has been assigned to this builder
+	 * @since Envoy Client v0.2-beta
+	 */
+	public SystemCommand buildNoArg(String command) {
+		numberOfArguments = 0;
+		return build(command, true);
+	}
+
+	/**
+	 * Builds a {@code SystemCommand} based upon the previously entered data.<br>
+	 * Automatically adds the built object to the given map. {@code SystemCommand#numberOfArguments}
+	 * will be set to use the rest of the string as argument, regardless of the previous value.<br>
+	 * At the end, this {@code SystemCommandBuilder} will be reset.
+	 *
+	 * @param command the command under which to store the SystemCommand in the
+	 *                {@link SystemCommandMap}
+	 * @return the built {@code SystemCommand}
+	 * @throws NullPointerException if no map has been assigned to this builder
+	 * @since Envoy Client v0.2-beta
+	 */
+	public SystemCommand buildRemainingArg(String command) {
+		numberOfArguments = -1;
+		return build(command, true);
+	}
+
+	/**
+	 * Builds a {@code SystemCommand} based upon the previously entered data.<br>
+	 * Automatically adds the built object to the given map. At the end, this
+	 * {@code SystemCommandBuilder} <b>can</b> be reset but must not be.
+	 *
+	 * @param command the command under which to store the SystemCommand in the
+	 *                {@link SystemCommandMap}
+	 * @param reset   whether this {@code SystemCommandBuilder} should be reset afterwards.<br>
+	 *                This can be useful if another command wants to execute something similar
+	 * @return the built {@code SystemCommand}
+	 * @throws NullPointerException if no map has been assigned to this builder
+	 * @since Envoy Client v0.2-beta
+	 */
+	public SystemCommand build(String command, boolean reset) {
+		final var sc = new SystemCommand(action, numberOfArguments, defaults, description);
+		sc.setRelevance(relevance);
+		if (commandsMap != null)
+			commandsMap.add(command, sc);
+		else
+			throw new NullPointerException("No map in SystemCommandsBuilder present");
+		if (reset)
+			reset();
+		return sc;
+	}
+}

client/src/main/java/envoy/client/data/commands/SystemCommandMap.java

@@ -0,0 +1,336 @@
+package envoy.client.data.commands;
+
+import java.util.*;
+import java.util.concurrent.atomic.AtomicBoolean;
+import java.util.function.Consumer;
+import java.util.logging.*;
+import java.util.regex.Pattern;
+import java.util.stream.Collectors;
+
+import javafx.application.Platform;
+import javafx.scene.control.Alert;
+import javafx.scene.control.Alert.AlertType;
+
+import envoy.util.EnvoyLog;
+
+/**
+ * Stores all {@link SystemCommand}s used. SystemCommands can be called using an activator char and
+ * the text that needs to be present behind the activator. Additionally offers the option to request
+ * recommendations for a partial input String.
+ *
+ * @author Leon Hofmeister
+ * @since Envoy Client v0.2-beta
+ */
+public final class SystemCommandMap {
+
+	private final Character						activator;
+	private final Map<String, SystemCommand>	systemCommands	= new HashMap<>();
+	private final Pattern						commandPattern	=
+		Pattern.compile("^[a-zA-Z0-9_:!/\\(\\)\\?\\.\\,\\;\\-]+$");
+
+	private static final Logger logger = EnvoyLog.getLogger(SystemCommandMap.class);
+
+	/**
+	 * Creates a new {@code SystemCommandMap} with the given char as activator. If this Character is
+	 * null, any text used as input will be treated as a system command.
+	 *
+	 * @param activator the char to use as activator for commands
+	 * @since Envoy Client v0.3-beta
+	 */
+	public SystemCommandMap(Character activator) {
+		this.activator = activator;
+	}
+
+	/**
+	 * Creates a new {@code SystemCommandMap} with '/' as activator.
+	 *
+	 * @since Envoy Client v0.3-beta
+	 */
+	public SystemCommandMap() {
+		activator = '/';
+	}
+
+	/**
+	 * Adds a new command to the map if the command name is valid.
+	 *
+	 * @param command       the input string to execute the given action
+	 * @param systemCommand the command to add - can be built using {@link SystemCommandBuilder}
+	 * @see SystemCommandMap#isValidKey(String)
+	 * @since Envoy Client v0.2-beta
+	 */
+	public void add(String command, SystemCommand systemCommand) {
+		if (isValidKey(command))
+			systemCommands.put(command.toLowerCase(), systemCommand);
+	}
+
+	/**
+	 * This method checks if the input String is a key in the map and returns the wrapped System
+	 * command if present.
+	 * <p>
+	 * Usage example:<br>
+	 * {@code SystemCommandMap systemCommands = new SystemCommandMap('*');}<br>
+	 * {@code systemCommands.add("example", new SystemCommand(text -> {}, 1, null, ""));}<br>
+	 * {@code ....}<br>
+	 * user input: {@code "*example xyz ..."}<br>
+	 * {@code systemCommands.get("example xyz ...")} or
+	 * {@code systemCommands.get("*example xyz ...")} result:
+	 * {@code Optional<SystemCommand>.get() != null}
+	 *
+	 * @param input the input string given by the user
+	 * @return the wrapped system command, if present
+	 * @since Envoy Client v0.2-beta
+	 */
+	public Optional<SystemCommand> get(String input) {
+		return Optional.ofNullable(systemCommands.get(getCommand(input.toLowerCase())));
+	}
+
+	/**
+	 * This method ensures that the activator of a {@link SystemCommand} is stripped.<br>
+	 * It only checks the word beginning from the first non-blank position in the input. It returns
+	 * the command as (most likely) entered as key in the map for the first word of the text.<br>
+	 * Activators in the middle of the word will be disregarded.
+	 *
+	 * @param raw the input
+	 * @return the command as entered in the map
+	 * @since Envoy Client v0.2-beta
+	 * @apiNote this method will (most likely) not return anything useful if whatever is entered
+	 *          after the activator is not a system command. Only exception: for recommendation
+	 *          purposes.
+	 */
+	public String getCommand(String raw) {
+		final var trimmed = raw.stripLeading();
+
+		// Entering only the activator should not throw an error
+		if (trimmed.length() == 1 && activator != null && activator.equals(trimmed.charAt(0)))
+			return "";
+		else {
+			final var index = trimmed.indexOf(' ');
+			return trimmed.substring(
+				activator != null && activator.equals(trimmed.charAt(0)) ? 1 : 0,
+				index < 1 ? trimmed.length() : index);
+		}
+	}
+
+	/**
+	 * Examines whether a key can be put in the map and logs it with {@code Level.WARNING} if that
+	 * key violates API constrictions.<br>
+	 * (allowed chars are <b>a-zA-Z0-9_:!/()?.,;-</b>)
+	 * <p>
+	 * The approach to not throw an exception was taken so that an ugly try-catch block for every
+	 * addition to the system commands map could be avoided, an error that should only occur during
+	 * implementation and not in production.
+	 *
+	 * @param command the key to examine
+	 * @return whether this key can be used in the map
+	 * @since Envoy Client v0.2-beta
+	 */
+	public boolean isValidKey(String command) {
+		final var valid = commandPattern.matcher(command).matches();
+		if (!valid)
+			logger.log(Level.WARNING,
+				"The command \"" + command
+					+ "\" is not valid. As it might cause problems when executed, it will not be entered into the map. Only the characters "
+					+ commandPattern + "are allowed");
+		return valid;
+	}
+
+	/**
+	 * Takes a 'raw' string (the whole input) and checks if the activator is the first visible
+	 * character and then checks if a command is present after that activator. If that is the case,
+	 * it will be executed.
+	 *
+	 * @param raw the raw input string
+	 * @return whether a command could be found and successfully executed
+	 * @since Envoy Client v0.2-beta
+	 */
+	public boolean executeIfPresent(String raw) {
+
+		// possibly a command was detected and could be executed
+		final var	raw2			= raw.stripLeading();
+		final var	commandFound	= activator == null || raw2.startsWith(activator.toString())
+			? executeAvailableCommand(raw2)
+			: false;
+
+		// the command was executed successfully - no further checking needed
+		if (commandFound)
+			logger.log(Level.FINE, "executed system command " + getCommand(raw2));
+		return commandFound;
+	}
+
+	/**
+	 * Retrieves the recommendations based on the current input entered.<br>
+	 * The first word is used for the recommendations and it does not matter if the activator is at
+	 * its beginning or not.<br>
+	 * If recommendations are present, the given function will be executed on the
+	 * recommendations.<br>
+	 * Otherwise nothing will be done.<br>
+	 *
+	 * @param input  the input string
+	 * @param action the action that should be taken for the recommendations, if any are present
+	 * @since Envoy Client v0.2-beta
+	 */
+	public void requestRecommendations(String input, Consumer<Set<String>> action) {
+		final var partialCommand = getCommand(input);
+
+		// Get the expected commands
+		final var recommendations = recommendCommands(partialCommand);
+		if (recommendations.isEmpty())
+			return;
+
+		// Execute the given action
+		else
+			action.accept(recommendations);
+	}
+
+	/**
+	 * This method checks if the input String is a key in the map and executes the wrapped System
+	 * command if present.
+	 * <p>
+	 * Usage example:<br>
+	 * {@code SystemCommandMap systemCommands = new SystemCommandMap('*');}<br>
+	 * {@code Button button = new Button();}<br>
+	 * {@code systemCommands.add("example", new SystemCommand(text -> {button.setText(text.get(0))},
+	 * 1, null, ""));}<br>
+	 * {@code ....}<br>
+	 * user input: {@code "*example xyz ..."}<br>
+	 * {@code systemCommands.executeIfPresent("example xyz ...")} or
+	 * {@code systemCommands.executeIfPresent("*example xyz ...")} result:
+	 * {@code button.getText()=="xyz"}
+	 *
+	 * @param input the input string given by the user
+	 * @return whether a command could be found and successfully executed
+	 * @since Envoy Client v0.2-beta
+	 */
+	private boolean executeAvailableCommand(String input) {
+		final var	command			= getCommand(input);
+		final var	value			= get(command);
+		final var	commandExecuted	= new AtomicBoolean(value.isPresent());
+		value.ifPresent(systemCommand -> {
+
+			// Splitting the String so that the leading command including the first " " is
+			// removed and only as many following words as allowed by the system command
+			// persist
+			final var arguments = extractArguments(input, systemCommand);
+
+			// Executing the function
+			try {
+				systemCommand.call(arguments);
+			} catch (final NumberFormatException e) {
+				logger.log(Level.INFO,
+					String.format(
+						"System command %s could not be performed correctly because the user is a dumbass and could not write a parseable number.",
+						command));
+				Platform.runLater(() -> {
+					final var alert = new Alert(AlertType.ERROR);
+					alert.setContentText("Please enter a readable number as argument.");
+					alert.showAndWait();
+				});
+				commandExecuted.set(false);
+			} catch (final Exception e) {
+				logger.log(Level.WARNING, "System command " + command + " threw an exception: ", e);
+				Platform.runLater(() -> {
+					final var alert = new Alert(AlertType.ERROR);
+					alert.setContentText(
+						"Could not execute system command: Internal error. Please insult the responsible programmer.");
+					alert.showAndWait();
+				});
+				commandExecuted.set(false);
+			}
+		});
+		return commandExecuted.get();
+	}
+
+	/**
+	 * Supplies missing values with default values.
+	 *
+	 * @param input         the input String
+	 * @param systemCommand the command that is expected
+	 * @return the list of arguments that can be used to parse the systemCommand
+	 * @since Envoy Client v0.2-beta
+	 */
+	private List<String> extractArguments(String input, SystemCommand systemCommand) {
+
+		// no more arguments follow after the command (e.g. text = "/DABR")
+		final var indexOfSpace = input.indexOf(" ");
+		if (indexOfSpace < 0)
+			return supplementDefaults(new String[] {}, systemCommand);
+
+		// the arguments behind a system command
+		final var	remainingString		= input.substring(indexOfSpace + 1);
+		final var	numberOfArguments	= systemCommand.getNumberOfArguments();
+
+		// splitting those arguments and supplying default values
+		final var	textArguments		= remainingString.split(" ", -1);
+		final var	originalArguments	=
+			numberOfArguments >= 0 ? Arrays.copyOfRange(textArguments, 0, numberOfArguments)
+				: textArguments;
+		final var	arguments			= supplementDefaults(originalArguments, systemCommand);
+		return arguments;
+	}
+
+	/**
+	 * Recommends commands based upon the currently entered input.<br>
+	 * In the current implementation, all that gets checked is whether a key contains this input.
+	 * This might be updated later on.
+	 *
+	 * @param partialCommand the partially entered command
+	 * @return a set of all commands that match this input
+	 * @since Envoy Client v0.2-beta
+	 */
+	private Set<String> recommendCommands(String partialCommand) {
+
+		// current implementation only looks if input is contained within a command,
+		// might be updated
+		return systemCommands.keySet()
+			.stream()
+			.filter(command -> command.contains(partialCommand))
+			.sorted(
+				(command1, command2) -> Integer.compare(systemCommands.get(command1).getRelevance(),
+					systemCommands.get(command2).getRelevance()))
+			.collect(Collectors.toSet());
+	}
+
+	/**
+	 * Supplies the default values for arguments if none are present in the text for any argument.
+	 * <br>
+	 *
+	 * @param textArguments the arguments that were parsed from the text
+	 * @param toEvaluate    the system command whose default values should be used
+	 * @return the final argument list
+	 * @since Envoy Client v0.2-beta
+	 * @apiNote this method will insert an empty String if the size of the list given to the
+	 *          {@code SystemCommand} is smaller than its argument counter and no more text
+	 *          arguments could be found.
+	 */
+	private List<String> supplementDefaults(String[] textArguments, SystemCommand toEvaluate) {
+		final var			defaults			= toEvaluate.getDefaults();
+		final var			numberOfArguments	= toEvaluate.getNumberOfArguments();
+		final List<String>	result				= new ArrayList<>();
+
+		if (toEvaluate.getNumberOfArguments() > 0)
+			for (var index = 0; index < numberOfArguments; index++) {
+				String textArg = null;
+				if (index < textArguments.length)
+					textArg = textArguments[index];
+
+				// Set the argument at position index to the current argument of the text, if it
+				// is present. Otherwise the default for that argument will be taken if present.
+				// In the worst case, an empty String will be used.
+				result.add(!(textArg == null) && !textArg.isBlank() ? textArg
+					: index < defaults.size() ? defaults.get(index) : "");
+			}
+		return result;
+	}
+
+	/**
+	 * @return all {@link SystemCommand}s used with the underlying command as key
+	 * @since Envoy Client v0.2-beta
+	 */
+	public Map<String, SystemCommand> getSystemCommands() { return systemCommands; }
+
+	/**
+	 * @return the activator of any command in this map. Can be null.
+	 * @since Envoy Client v0.3-beta
+	 */
+	public Character getActivator() { return activator; }
+}

client/src/main/java/envoy/client/data/commands/package-info.java

@@ -0,0 +1,8 @@
+/**
+ * This package contains all classes that can be used as system commands.<br>
+ * Every system command can be called using a specific syntax:"/&lt;command&gt;"
+ *
+ * @author Leon Hofmeister
+ * @since Envoy Client v0.2-beta
+ */
+package envoy.client.data.commands;

client/src/main/java/envoy/client/data/shortcuts/EnvoyShortcutConfig.java

@@ -0,0 +1,77 @@
+package envoy.client.data.shortcuts;
+
+import javafx.scene.input.*;
+
+import envoy.data.User.UserStatus;
+
+import envoy.client.data.Context;
+import envoy.client.helper.ShutdownHelper;
+import envoy.client.ui.SceneContext.SceneInfo;
+import envoy.client.util.UserUtil;
+
+/**
+ * Envoy-specific implementation of the keyboard-shortcut interaction offered by
+ * {@link GlobalKeyShortcuts}.
+ *
+ * @author Leon Hofmeister
+ * @since Envoy Client v0.3-beta
+ */
+public class EnvoyShortcutConfig {
+
+	private EnvoyShortcutConfig() {}
+
+	/**
+	 * Supplies the default shortcuts for {@link GlobalKeyShortcuts}.
+	 *
+	 * @since Envoy Client v0.3-beta
+	 */
+	public static void initializeEnvoyShortcuts() {
+		final var instance = GlobalKeyShortcuts.getInstance();
+
+		// Add the option to exit with "Control" + "Q" or "Alt" + "F4" as offered by
+		// some desktop environments
+		instance.add(new KeyCodeCombination(KeyCode.Q, KeyCombination.CONTROL_DOWN),
+			ShutdownHelper::exit);
+
+		// Add the option to logout using "Control"+"Shift"+"L" if not in login scene
+		instance.addForNotExcluded(
+			new KeyCodeCombination(KeyCode.L, KeyCombination.CONTROL_DOWN,
+				KeyCombination.SHIFT_DOWN),
+			UserUtil::logout,
+			SceneInfo.LOGIN_SCENE);
+
+		// Add option to open settings scene with "Control"+"S", if not in login scene
+		instance.addForNotExcluded(new KeyCodeCombination(KeyCode.S, KeyCombination.CONTROL_DOWN),
+			() -> Context.getInstance().getSceneContext().load(SceneInfo.SETTINGS_SCENE),
+			SceneInfo.SETTINGS_SCENE,
+			SceneInfo.LOGIN_SCENE);
+
+		// Add option to change to status away
+		instance.addForNotExcluded(
+			new KeyCodeCombination(KeyCode.A, KeyCombination.CONTROL_DOWN,
+				KeyCombination.SHIFT_DOWN),
+			() -> UserUtil.changeStatus(UserStatus.AWAY),
+			SceneInfo.LOGIN_SCENE);
+
+		// Add option to change to status busy
+		instance.addForNotExcluded(
+			new KeyCodeCombination(KeyCode.B, KeyCombination.CONTROL_DOWN,
+				KeyCombination.SHIFT_DOWN),
+			() -> UserUtil.changeStatus(UserStatus.BUSY),
+			SceneInfo.LOGIN_SCENE);
+
+		// Add option to change to status offline
+		instance.addForNotExcluded(
+			new KeyCodeCombination(KeyCode.F, KeyCombination.CONTROL_DOWN,
+				KeyCombination.SHIFT_DOWN),
+			() -> UserUtil.changeStatus(UserStatus.OFFLINE),
+			SceneInfo.LOGIN_SCENE);
+
+		// Add option to change to status online
+		instance.addForNotExcluded(
+			new KeyCodeCombination(KeyCode.N, KeyCombination.CONTROL_DOWN,
+				KeyCombination.SHIFT_DOWN),
+			() -> UserUtil.changeStatus(UserStatus.ONLINE),
+			SceneInfo.LOGIN_SCENE);
+	}
+}

client/src/main/java/envoy/client/data/shortcuts/GlobalKeyShortcuts.java

@@ -0,0 +1,79 @@
+package envoy.client.data.shortcuts;
+
+import java.util.*;
+
+import javafx.scene.input.KeyCombination;
+
+import envoy.client.ui.SceneContext.SceneInfo;
+
+/**
+ * Contains all keyboard shortcuts used throughout the application.
+ *
+ * @author Leon Hofmeister
+ * @since Envoy Client v0.3-beta
+ */
+public final class GlobalKeyShortcuts {
+
+	private final EnumMap<SceneInfo, Map<KeyCombination, Runnable>> shortcuts =
+		new EnumMap<>(SceneInfo.class);
+
+	private static GlobalKeyShortcuts instance = new GlobalKeyShortcuts();
+
+	private GlobalKeyShortcuts() {
+		for (final var sceneInfo : SceneInfo.values())
+			shortcuts.put(sceneInfo, new HashMap<KeyCombination, Runnable>());
+	}
+
+	/**
+	 * @return the instance of global keyboard shortcuts.
+	 * @since Envoy Client v0.3-beta
+	 */
+	public static GlobalKeyShortcuts getInstance() { return instance; }
+
+	/**
+	 * Adds the given keyboard shortcut and its action to all scenes.
+	 *
+	 * @param keys   the keys to press to perform the given action
+	 * @param action the action to perform
+	 * @since Envoy Client v0.3-beta
+	 */
+	public void add(KeyCombination keys, Runnable action) {
+		shortcuts.values().forEach(collection -> collection.put(keys, action));
+	}
+
+	/**
+	 * Adds the given keyboard shortcut and its action to all scenes that are not part of exclude.
+	 *
+	 * @param keys    the keys to press to perform the given action
+	 * @param action  the action to perform
+	 * @param exclude the scenes that should be excluded from receiving this keyboard shortcut
+	 * @since Envoy Client v0.3-beta
+	 */
+	public void addForNotExcluded(KeyCombination keys, Runnable action, SceneInfo... exclude) {
+
+		// Computing the remaining sceneInfos
+		final var	include	= new SceneInfo[SceneInfo.values().length - exclude.length];
+		int			index	= 0;
+		outer: for (final var sceneInfo : SceneInfo.values()) {
+			for (final var excluded : exclude)
+				if (sceneInfo.equals(excluded))
+					continue outer;
+			include[index++] = sceneInfo;
+		}
+
+		// Adding the action to the remaining sceneInfos
+		for (final var sceneInfo : include)
+			shortcuts.get(sceneInfo).put(keys, action);
+	}
+
+	/**
+	 * Returns all stored keyboard shortcuts for the given scene constant.
+	 *
+	 * @param sceneInfo the currently loading scene
+	 * @return all stored keyboard shortcuts for this scene
+	 * @since Envoy Client v0.3-beta
+	 */
+	public Map<KeyCombination, Runnable> getKeyboardShortcuts(SceneInfo sceneInfo) {
+		return shortcuts.get(sceneInfo);
+	}
+}

client/src/main/java/envoy/client/data/shortcuts/KeyboardMapping.java

@@ -0,0 +1,24 @@
+package envoy.client.data.shortcuts;
+
+import java.util.Map;
+
+import javafx.scene.input.KeyCombination;
+
+import envoy.client.ui.SceneContext;
+
+/**
+ * Provides methods to set the keyboard shortcuts for a specific scene. Should only be implemented
+ * by controllers of scenes so that these methods can automatically be called inside
+ * {@link SceneContext} as soon as the underlying FXML file has been loaded.
+ *
+ * @author Leon Hofmeister
+ * @since Envoy Client v0.3-beta
+ */
+public interface KeyboardMapping {
+
+	/**
+	 * @return all keyboard shortcuts of a scene
+	 * @since Envoy Client v0.3-beta
+	 */
+	Map<KeyCombination, Runnable> getKeyboardShortcuts();
+}

client/src/main/java/envoy/client/data/shortcuts/package-info.java

@@ -0,0 +1,7 @@
+/**
+ * Contains the necessary classes to enable using keyboard shortcuts in Envoy.
+ *
+ * @author Leon Hofmeister
+ * @since Envoy Client v0.3-beta
+ */
+package envoy.client.data.shortcuts;

client/src/main/java/envoy/client/event/BackEvent.java

@@ -0,0 +1,15 @@
+package envoy.client.event;
+
+import envoy.event.Event.Valueless;
+
+/**
+ * This event serves the purpose of triggering the tab change to tab 0 in
+ * {@link envoy.client.ui.controller.ChatScene}.
+ *
+ * @author Maximilian Käfer
+ * @since Envoy Client v0.2-beta
+ */
+public class BackEvent extends Valueless {
+
+	private static final long serialVersionUID = 0L;
+}

client/src/main/java/envoy/client/event/ContactDisabled.java

@@ -0,0 +1,23 @@
+package envoy.client.event;
+
+import envoy.data.Contact;
+import envoy.event.Event;
+
+/**
+ * Signifies that the chat of a contact should be disabled.
+ *
+ * @author Leon Hofmeister
+ * @since Envoy Client v0.3-beta
+ */
+public class ContactDisabled extends Event<Contact> {
+
+	private static final long serialVersionUID = 1L;
+
+	/**
+	 * @param contact the contact that should be disabled
+	 * @since Envoy Client v0.3-beta
+	 */
+	public ContactDisabled(Contact contact) {
+		super(contact);
+	}
+}

client/src/main/java/envoy/client/event/EnvoyCloseEvent.java

@@ -0,0 +1,15 @@
+package envoy.client.event;
+
+import envoy.event.Event.Valueless;
+
+/**
+ * This event notifies various Envoy components of the application being about to shut down. This
+ * allows the graceful closing of connections, persisting local data etc.
+ *
+ * @author Leon Hofmeister
+ * @since Envoy Client v0.2-beta
+ */
+public class EnvoyCloseEvent extends Valueless {
+
+	private static final long serialVersionUID = 1L;
+}

client/src/main/java/envoy/client/event/Logout.java

@@ -0,0 +1,14 @@
+package envoy.client.event;
+
+import envoy.event.Event.Valueless;
+
+/**
+ * Indicates that a logout has been requested.
+ *
+ * @author Leon Hofmeister
+ * @since Envoy Client v0.2-beta
+ */
+public final class Logout extends Valueless {
+
+	private static final long serialVersionUID = 1L;
+}

client/src/main/java/envoy/client/event/MessageCreationEvent.java

@@ -1,22 +0,0 @@
-package envoy.client.event;
-
-import envoy.data.Message;
-import envoy.event.Event;
-
-/**
- * Project: <strong>envoy-client</strong><br>
- * File: <strong>MessageCreationEvent.java</strong><br>
- * Created: <strong>4 Dec 2019</strong><br>
- *
- * @author Kai S. K. Engelbart
- * @since Envoy Client v0.2-alpha
- */
-public class MessageCreationEvent extends Event<Message> {
-
-	private static final long serialVersionUID = 0L;
-
-	/**
-	 * @param message the {@link Message} that has been created
-	 */
-	public MessageCreationEvent(Message message) { super(message); }
-}

client/src/main/java/envoy/client/event/MessageDeletion.java

@@ -0,0 +1,22 @@
+package envoy.client.event;
+
+import envoy.event.Event;
+
+/**
+ * Conveys the deletion of a message.
+ *
+ * @author Leon Hofmeister
+ * @since Envoy Common v0.3-beta
+ */
+public class MessageDeletion extends Event<Long> {
+
+	private static final long serialVersionUID = 1L;
+
+	/**
+	 * @param messageID the ID of the deleted message
+	 * @since Envoy Common v0.3-beta
+	 */
+	public MessageDeletion(long messageID) {
+		super(messageID);
+	}
+}

client/src/main/java/envoy/client/event/MessageModificationEvent.java

@@ -1,22 +0,0 @@
-package envoy.client.event;
-
-import envoy.data.Message;
-import envoy.event.Event;
-
-/**
- * Project: <strong>envoy-client</strong><br>
- * File: <strong>MessageModificationEvent.java</strong><br>
- * Created: <strong>4 Dec 2019</strong><br>
- *
- * @author Kai S. K. Engelbart
- * @since Envoy Client v0.2-alpha
- */
-public class MessageModificationEvent extends Event<Message> {
-
-	private static final long serialVersionUID = 0L;
-
-	/**
-	 * @param message the {@link Message} that has been modified
-	 */
-	public MessageModificationEvent(Message message) { super(message); }
-}

client/src/main/java/envoy/client/event/OwnStatusChange.java

@@ -0,0 +1,23 @@
+package envoy.client.event;
+
+import envoy.data.User.UserStatus;
+import envoy.event.Event;
+
+/**
+ * Signifies a manual status change of the client user.
+ *
+ * @author Leon Hofmeister
+ * @since Envoy Client v0.3-beta
+ */
+public class OwnStatusChange extends Event<UserStatus> {
+
+	private static final long serialVersionUID = 1L;
+
+	/**
+	 * @param value the new user status of the client user
+	 * @since Envoy Client v0.3-beta
+	 */
+	public OwnStatusChange(UserStatus value) {
+		super(value);
+	}
+}

client/src/main/java/envoy/client/event/SendEvent.java

@@ -1,22 +0,0 @@
-package envoy.client.event;
-
-import envoy.event.Event;
-
-/**
- * Project: <strong>envoy-client</strong><br>
- * File: <strong>SendEvent.java</strong><br>
- * Created: <strong>11.02.2020</strong><br>
- *
- * @author: Maximilian K&aumlfer
- * @since Envoy Client v0.3-alpha
- */
-public class SendEvent extends Event<Event<?>> {
-
-	private static final long serialVersionUID = 0L;
-
-	/**
-	 * @param value the event to send to the server
-	 */
-	public SendEvent(Event<?> value) { super(value); }
-
-}

client/src/main/java/envoy/client/event/ThemeChangeEvent.java

@@ -3,23 +3,12 @@ package envoy.client.event;
 import envoy.event.Event;
 
 /**
- * Project: <strong>envoy-client</strong><br>
- * File: <strong>ThemeChangeEvent.java</strong><br>
- * Created: <strong>15 Dec 2019</strong><br>
+ * Notifies UI components of a theme change.
  *
  * @author Kai S. K. Engelbart
  * @since Envoy Client v0.2-alpha
  */
-public class ThemeChangeEvent extends Event<String> {
+public final class ThemeChangeEvent extends Event.Valueless {
 
 	private static final long serialVersionUID = 0L;
-
-	/**
-	 * Initializes a {@link ThemeChangeEvent} conveying information about the change
-	 * of the theme currently in use.
-	 *
-	 * @param theme the name of the new theme
-	 * @since Envoy Client v0.2-alpha
-	 */
-	public ThemeChangeEvent(String theme) { super(theme); }
 }

client/src/main/java/envoy/client/helper/AlertHelper.java

@@ -0,0 +1,33 @@
+package envoy.client.helper;
+
+import javafx.scene.control.*;
+
+import envoy.client.data.Settings;
+
+/**
+ * Provides methods that are commonly used for alerts.
+ *
+ * @author Leon Hofmeister
+ * @since Envoy Client v0.2-beta
+ */
+public final class AlertHelper {
+
+	private AlertHelper() {}
+
+	/**
+	 * Asks for a confirmation dialog if {@link Settings#isAskForConfirmation()} returns
+	 * {@code true}. Immediately executes the action if no dialog was requested or the dialog was
+	 * exited with a confirmation. Does nothing if the dialog was closed without clicking on OK.
+	 *
+	 * @param alert  the (customized) alert to show. <strong>Should not be shown already</strong>
+	 * @param action the action to perform in case of success
+	 * @since Envoy Client v0.2-beta
+	 */
+	public static void confirmAction(Alert alert, Runnable action) {
+		alert.setHeaderText("");
+		if (Settings.getInstance().isAskForConfirmation())
+			alert.showAndWait().filter(ButtonType.OK::equals).ifPresent(bu -> action.run());
+		else
+			action.run();
+	}
+}

client/src/main/java/envoy/client/helper/ShutdownHelper.java

@@ -0,0 +1,45 @@
+package envoy.client.helper;
+
+import dev.kske.eventbus.EventBus;
+
+import envoy.client.data.*;
+import envoy.client.event.EnvoyCloseEvent;
+import envoy.client.ui.StatusTrayIcon;
+
+/**
+ * Simplifies shutdown actions.
+ *
+ * @author Leon Hofmeister
+ * @since Envoy Client v0.2-beta
+ */
+public final class ShutdownHelper {
+
+	private ShutdownHelper() {}
+
+	/**
+	 * Exits Envoy or minimizes it, depending on the current state of
+	 * {@link Settings#isHideOnClose()} and {@link StatusTrayIcon#isSupported()}.
+	 *
+	 * @since Envoy Client v0.2-beta
+	 */
+	public static void exit() {
+		exit(false);
+	}
+
+	/**
+	 * Exits Envoy immediately if {@code force = true}, else it can exit or minimize Envoy,
+	 * depending on the current state of {@link Settings#isHideOnClose()} and
+	 * {@link StatusTrayIcon#isSupported()}.
+	 *
+	 * @param force whether to close in any case.
+	 * @since Envoy Client v0.2-beta
+	 */
+	public static void exit(boolean force) {
+		if (!force && Settings.getInstance().isHideOnClose() && StatusTrayIcon.isSupported())
+			Context.getInstance().getStage().setIconified(true);
+		else {
+			EventBus.getInstance().dispatch(new EnvoyCloseEvent());
+			System.exit(0);
+		}
+	}
+}

client/src/main/java/envoy/client/helper/package-info.java

@@ -0,0 +1,9 @@
+/**
+ * Provides helper methods that reduce boilerplate code.
+ *
+ * @author Leon Hofmeister
+ * @author Kai S. K. Engelbert
+ * @author Maximilian Käfer
+ * @since Envoy Client v0.2-beta
+ */
+package envoy.client.helper;

client/src/main/java/envoy/client/net/Client.java

@@ -1,35 +1,30 @@
 package envoy.client.net;
 
-import java.io.Closeable;
-import java.io.IOException;
+import java.io.*;
 import java.net.Socket;
 import java.util.concurrent.TimeoutException;
-import java.util.logging.Level;
-import java.util.logging.Logger;
+import java.util.logging.*;
+
+import dev.kske.eventbus.*;
+import dev.kske.eventbus.Event;
 
-import envoy.client.data.*;
-import envoy.client.event.SendEvent;
 import envoy.data.*;
 import envoy.event.*;
-import envoy.event.contact.ContactOperation;
-import envoy.event.contact.ContactSearchResult;
-import envoy.util.EnvoyLog;
-import envoy.util.SerializationUtils;
+import envoy.util.*;
+
+import envoy.client.data.*;
+import envoy.client.event.EnvoyCloseEvent;
 
 /**
- * Establishes a connection to the server, performs a handshake and delivers
- * certain objects to the server.
- * <p>
- * Project: <strong>envoy-client</strong><br>
- * File: <strong>Client.java</strong><br>
- * Created: <strong>28 Sep 2019</strong><br>
+ * Establishes a connection to the server, performs a handshake and delivers certain objects to the
+ * server.
  *
  * @author Kai S. K. Engelbart
  * @author Maximilian K&auml;fer
  * @author Leon Hofmeister
  * @since Envoy Client v0.1-alpha
  */
-public class Client implements Closeable {
+public final class Client implements EventListener, Closeable {
 
 	// Connection handling
 	private Socket		socket;
@@ -46,35 +41,45 @@ public class Client implements Closeable {
 	private static final EventBus		eventBus	= EventBus.getInstance();
 
 	/**
-	 * Enters the online mode by acquiring a user ID from the server. As a
-	 * connection has to be established and a handshake has to be made, this method
-	 * will block for up to 5 seconds. If the handshake does exceed this time limit,
-	 * an exception is thrown.
+	 * Constructs a client and registers it as an event listener.
+	 *
+	 * @since Envoy Client v0.2-beta
+	 */
+	public Client() {
+		eventBus.registerListener(this);
+	}
+
+	/**
+	 * Enters the online mode by acquiring a user ID from the server. As a connection has to be
+	 * established and a handshake has to be made, this method will block for up to 5 seconds. If
+	 * the handshake does exceed this time limit, an exception is thrown.
 	 *
 	 * @param credentials the login credentials of the user
 	 * @param cacheMap    the map of all caches needed
 	 * @throws TimeoutException     if the server could not be reached
 	 * @throws IOException          if the login credentials could not be written
-	 * @throws InterruptedException if the current thread is interrupted while
-	 *                              waiting for the handshake response
+	 * @throws InterruptedException if the current thread is interrupted while waiting for the
+	 *                              handshake response
 	 */
-	public void performHandshake(LoginCredentials credentials, CacheMap cacheMap) throws TimeoutException, IOException, InterruptedException {
-		if (online) throw new IllegalStateException("Handshake has already been performed successfully");
+	public void performHandshake(LoginCredentials credentials, CacheMap cacheMap)
+		throws TimeoutException, IOException, InterruptedException {
+		if (online)
+			throw new IllegalStateException("Handshake has already been performed successfully");
+		rejected = false;
 
 		// Establish TCP connection
-		logger.log(Level.FINER, String.format("Attempting connection to server %s:%d...", config.getServer(), config.getPort()));
+		logger.log(Level.FINER, String.format("Attempting connection to server %s:%d...",
+			config.getServer(), config.getPort()));
 		socket = new Socket(config.getServer(), config.getPort());
 		logger.log(Level.FINE, "Successfully established TCP connection to server");
 
 		// Create object receiver
 		receiver = new Receiver(socket.getInputStream());
 
-		// Register user creation processor, contact list processor and message cache
+		// Register user creation processor, contact list processor, message cache and
+		// authentication token
 		receiver.registerProcessor(User.class, sender -> this.sender = sender);
 		receiver.registerProcessors(cacheMap.getMap());
-		receiver.registerProcessor(HandshakeRejection.class, evt -> { rejected = true; eventBus.dispatch(evt); });
-
-		rejected = false;
 
 		// Start receiver
 		receiver.start();
@@ -94,24 +99,24 @@ public class Client implements Closeable {
 				return;
 			}
 
-			if (System.currentTimeMillis() - start > 5000) throw new TimeoutException("Did not log in after 5 seconds");
+			if (System.currentTimeMillis() - start > 5000) {
+				rejected = true;
+				throw new TimeoutException("Did not log in after 5 seconds");
+			}
 			Thread.sleep(500);
 		}
 
 		online = true;
-
 		logger.log(Level.INFO, "Handshake completed.");
 	}
 
 	/**
-	 * Initializes the {@link Receiver} used to process data sent from the server to
-	 * this client.
+	 * Initializes the {@link Receiver} used to process data sent from the server to this client.
 	 *
-	 * @param localDB  the local database used to persist the current
-	 *                 {@link IDGenerator}
+	 * @param localDB  the local database used to persist the current {@link IDGenerator}
 	 * @param cacheMap the map of all caches needed
-	 * @throws IOException if no {@link IDGenerator} is present and none could be
-	 *                     requested from the server
+	 * @throws IOException if no {@link IDGenerator} is present and none could be requested from the
+	 *                     server
 	 * @since Envoy Client v0.2-alpha
 	 */
 	public void initReceiver(LocalDB localDB, CacheMap cacheMap) throws IOException {
@@ -120,99 +125,92 @@ public class Client implements Closeable {
 		// Remove all processors as they are only used during the handshake
 		receiver.removeAllProcessors();
 
-		// Process incoming messages
-		final var	receivedMessageProcessor			= new ReceivedMessageProcessor();
-		final var	receivedGroupMessageProcessor		= new ReceivedGroupMessageProcessor();
-		final var	messageStatusChangeProcessor		= new MessageStatusChangeProcessor();
-		final var	groupMessageStatusChangeProcessor	= new GroupMessageStatusChangeProcessor();
-
-		receiver.registerProcessor(GroupMessage.class, receivedGroupMessageProcessor);
-		receiver.registerProcessor(Message.class, receivedMessageProcessor);
-		receiver.registerProcessor(MessageStatusChange.class, messageStatusChangeProcessor);
-		receiver.registerProcessor(GroupMessageStatusChange.class, groupMessageStatusChangeProcessor);
-
 		// Relay cached messages and message status changes
-		cacheMap.get(Message.class).setProcessor(receivedMessageProcessor);
-		cacheMap.get(GroupMessage.class).setProcessor(receivedGroupMessageProcessor);
-		cacheMap.get(MessageStatusChange.class).setProcessor(messageStatusChangeProcessor);
-		cacheMap.get(GroupMessageStatusChange.class).setProcessor(groupMessageStatusChangeProcessor);
-
-		// Process user status changes
-		receiver.registerProcessor(UserStatusChange.class, eventBus::dispatch);
-
-		// Process message ID generation
-		receiver.registerProcessor(IDGenerator.class, localDB::setIDGenerator);
-
-		// Process name changes
-		receiver.registerProcessor(NameChange.class, evt -> { localDB.replaceContactName(evt); eventBus.dispatch(evt); });
-
-		// Process contact searches
-		receiver.registerProcessor(ContactSearchResult.class, eventBus::dispatch);
-
-		// Process contact operations
-		receiver.registerProcessor(ContactOperation.class, eventBus::dispatch);
-
-		// Process group size changes
-		receiver.registerProcessor(GroupResize.class, evt -> { localDB.updateGroup(evt); eventBus.dispatch(evt); });
-
-		// Send event
-		eventBus.register(SendEvent.class, evt -> {
-			try {
-				sendEvent(evt.get());
-			} catch (final IOException e) {
-				logger.log(Level.WARNING, "An error occurred when trying to send " + evt, e);
-			}
-		});
+		cacheMap.get(Message.class).setProcessor(eventBus::dispatch);
+		cacheMap.get(GroupMessage.class).setProcessor(eventBus::dispatch);
+		cacheMap.get(MessageStatusChange.class).setProcessor(eventBus::dispatch);
+		cacheMap.get(GroupMessageStatusChange.class).setProcessor(eventBus::dispatch);
 
 		// Request a generator if none is present or the existing one is consumed
-		if (!localDB.hasIDGenerator() || !localDB.getIDGenerator().hasNext()) requestIdGenerator();
+		if (!localDB.hasIDGenerator() || !localDB.getIDGenerator().hasNext())
+			requestIDGenerator();
 
 		// Relay caches
 		cacheMap.getMap().values().forEach(Cache::relay);
 	}
 
 	/**
-	 * Sends a message to the server. The message's status will be incremented once
-	 * it was delivered successfully.
+	 * Sends an object to the server.
+	 *
+	 * @param obj the object to send
+	 * @throws IllegalStateException if the client is not online
+	 * @throws RuntimeException      if the object serialization failed
+	 * @since Envoy Client v0.2-beta
+	 */
+	public void send(Serializable obj) throws IllegalStateException, RuntimeException {
+		checkOnline();
+		logger.log(Level.FINE, "Sending " + obj);
+		try {
+			SerializationUtils.writeBytesWithLength(obj, socket.getOutputStream());
+		} catch (final IOException e) {
+			throw new RuntimeException(e);
+		}
+	}
+
+	/**
+	 * Sends a message to the server. The message's status will be incremented once it was delivered
+	 * successfully.
 	 *
 	 * @param message the message to send
-	 * @throws IOException if the message does not reach the server
 	 * @since Envoy Client v0.3-alpha
 	 */
-	public void sendMessage(Message message) throws IOException {
-		writeObject(message);
+	public void sendMessage(Message message) {
+		send(message);
 		message.nextStatus();
 	}
 
-	/**
-	 * Sends an event to the server.
-	 *
-	 * @param evt the event to send
-	 * @throws IOException if the event did not reach the server
-	 */
-	public void sendEvent(Event<?> evt) throws IOException { writeObject(evt); }
-
 	/**
 	 * Requests a new {@link IDGenerator} from the server.
 	 *
-	 * @throws IOException if the request does not reach the server
 	 * @since Envoy Client v0.3-alpha
 	 */
-	public void requestIdGenerator() throws IOException {
+	public void requestIDGenerator() {
 		logger.log(Level.INFO, "Requesting new id generator...");
-		writeObject(new IDGeneratorRequest());
+		send(new IDGeneratorRequest());
+	}
+
+	@Event(eventType = HandshakeRejection.class, priority = 1000)
+	private void onHandshakeRejection() {
+		rejected = true;
 	}
 
 	@Override
-	public void close() throws IOException { if (online) socket.close(); }
+	@Event(eventType = EnvoyCloseEvent.class, priority = 50)
+	public void close() {
+		if (online) {
+			logger.log(Level.INFO, "Closing connection...");
+			try {
 
-	private void writeObject(Object obj) throws IOException {
-		checkOnline();
-		logger.log(Level.FINE, "Sending " + obj);
-		SerializationUtils.writeBytesWithLength(obj, socket.getOutputStream());
+				// The sender must be reset as otherwise the handshake is immediately closed
+				sender	= null;
+				online	= false;
+				socket.close();
+			} catch (final IOException e) {
+				logger.log(Level.WARNING, "Failed to close socket: ", e);
+			}
+		}
 	}
 
-	private void checkOnline() { if (!online) throw new IllegalStateException("Client is not online"); }
+	/**
+	 * Ensured that the client is online.
+	 *
+	 * @throws IllegalStateException if the client is not online
+	 * @since Envoy Client v0.3-alpha
+	 */
+	private void checkOnline() throws IllegalStateException {
+		if (!online)
+			throw new IllegalStateException("Client is not online");
+	}
 
 	/**
 	 * @return the {@link User} as which this client is logged in
@@ -230,6 +228,7 @@ public class Client implements Closeable {
 
 	/**
 	 * @return the {@link Receiver} used by this {@link Client}
+	 * @since v0.2-alpha
 	 */
 	public Receiver getReceiver() { return receiver; }
 

client/src/main/java/envoy/client/net/GroupMessageStatusChangeProcessor.java

@@ -1,29 +0,0 @@
-package envoy.client.net;
-
-import java.util.function.Consumer;
-import java.util.logging.Logger;
-
-import envoy.data.Message.MessageStatus;
-import envoy.event.EventBus;
-import envoy.event.GroupMessageStatusChange;
-import envoy.util.EnvoyLog;
-
-/**
- * Project: <strong>envoy-client</strong><br>
- * File: <strong>GroupMessageStatusChangePocessor.java</strong><br>
- * Created: <strong>03.07.2020</strong><br>
- * 
- * @author Maximilian K&auml;fer
- * @since Envoy Client v0.1-beta
- */
-public class GroupMessageStatusChangeProcessor implements Consumer<GroupMessageStatusChange> {
-
-	private static final Logger logger = EnvoyLog.getLogger(GroupMessageStatusChangeProcessor.class);
-	
-	@Override
-	public void accept(GroupMessageStatusChange evt) {
-		if (evt.get().ordinal() < MessageStatus.RECEIVED.ordinal()) logger.warning("Received invalid group message status change " + evt);
-		else EventBus.getInstance().dispatch(evt);
-	}
-
-}

client/src/main/java/envoy/client/net/MessageStatusChangeProcessor.java

@@ -1,35 +0,0 @@
-package envoy.client.net;
-
-import java.util.function.Consumer;
-import java.util.logging.Logger;
-
-import envoy.data.Message.MessageStatus;
-import envoy.event.EventBus;
-import envoy.event.MessageStatusChange;
-import envoy.util.EnvoyLog;
-
-/**
- * Project: <strong>envoy-client</strong><br>
- * File: <strong>MessageStatusChangeProcessor.java</strong><br>
- * Created: <strong>4 Feb 2020</strong><br>
- *
- * @author Kai S. K. Engelbart
- * @since Envoy Client v0.3-alpha
- */
-public class MessageStatusChangeProcessor implements Consumer<MessageStatusChange> {
-
-	private static final Logger logger = EnvoyLog.getLogger(MessageStatusChangeProcessor.class);
-
-	/**
-	 * Dispatches a {@link MessageStatusChange} if the status is
-	 * {@code RECEIVED} or {@code READ}.
-	 *
-	 * @param evt the status change event
-	 * @since Envoy Client v0.3-alpha
-	 */
-	@Override
-	public void accept(MessageStatusChange evt) {
-		if (evt.get().ordinal() < MessageStatus.RECEIVED.ordinal()) logger.warning("Received invalid message status change " + evt);
-		else EventBus.getInstance().dispatch(evt);
-	}
-}

client/src/main/java/envoy/client/net/ReceivedGroupMessageProcessor.java

@@ -1,33 +0,0 @@
-package envoy.client.net;
-
-import java.util.function.Consumer;
-import java.util.logging.Logger;
-
-import envoy.client.event.MessageCreationEvent;
-import envoy.data.GroupMessage;
-import envoy.data.Message.MessageStatus;
-import envoy.event.EventBus;
-import envoy.util.EnvoyLog;
-
-/**
- * Project: <strong>envoy-client</strong><br>
- * File: <strong>ReceivedGroupMessageProcessor.java</strong><br>
- * Created: <strong>13.06.2020</strong><br>
- * 
- * @author Maximilian K&auml;fer
- * @since Envoy Client v0.1-beta
- */
-public class ReceivedGroupMessageProcessor implements Consumer<GroupMessage> {
-
-	private static final Logger logger = EnvoyLog.getLogger(ReceivedGroupMessageProcessor.class);
-
-	@Override
-	public void accept(GroupMessage groupMessage) {
-		if (groupMessage.getStatus() == MessageStatus.WAITING || groupMessage.getStatus() == MessageStatus.READ)
-			logger.warning("The groupMessage has the unexpected status " + groupMessage.getStatus());
-
-		// Dispatch event
-		EventBus.getInstance().dispatch(new MessageCreationEvent(groupMessage));
-	}
-
-}

client/src/main/java/envoy/client/net/ReceivedMessageProcessor.java

@@ -1,36 +0,0 @@
-package envoy.client.net;
-
-import java.util.function.Consumer;
-import java.util.logging.Level;
-import java.util.logging.Logger;
-
-import envoy.client.event.MessageCreationEvent;
-import envoy.data.Message;
-import envoy.data.Message.MessageStatus;
-import envoy.event.EventBus;
-import envoy.util.EnvoyLog;
-
-/**
- * Project: <strong>envoy-client</strong><br>
- * File: <strong>ReceivedMessageProcessor.java</strong><br>
- * Created: <strong>31.12.2019</strong><br>
- *
- * @author Kai S. K. Engelbart
- * @since Envoy Client v0.3-alpha
- */
-public class ReceivedMessageProcessor implements Consumer<Message> {
-
-	private static final Logger logger = EnvoyLog.getLogger(ReceivedMessageProcessor.class);
-
-	@Override
-	public void accept(Message message) {
-		if (message.getStatus() != MessageStatus.SENT) logger.log(Level.WARNING, "The message has the unexpected status " + message.getStatus());
-		else {
-			// Update status to RECEIVED
-			message.nextStatus();
-
-			// Dispatch event
-			EventBus.getInstance().dispatch(new MessageCreationEvent(message));
-		}
-	}
-}

client/src/main/java/envoy/client/net/Receiver.java

@@ -1,35 +1,30 @@
 package envoy.client.net;
 
-import java.io.ByteArrayInputStream;
-import java.io.InputStream;
-import java.io.ObjectInputStream;
+import java.io.*;
 import java.net.SocketException;
-import java.util.HashMap;
-import java.util.Map;
+import java.util.*;
 import java.util.function.Consumer;
-import java.util.logging.Level;
-import java.util.logging.Logger;
+import java.util.logging.*;
 
-import envoy.util.EnvoyLog;
-import envoy.util.SerializationUtils;
+import dev.kske.eventbus.*;
+
+import envoy.util.*;
 
 /**
- * Receives objects from the server and passes them to processor objects based
- * on their class.
- * <p>
- * Project: <strong>envoy-client</strong><br>
- * File: <strong>Receiver.java</strong><br>
- * Created: <strong>30.12.2019</strong><br>
+ * Receives objects from the server and passes them to processor objects based on their class.
  *
  * @author Kai S. K. Engelbart
  * @since Envoy Client v0.3-alpha
  */
-public class Receiver extends Thread {
+public final class Receiver extends Thread {
+
+	private boolean isAlive = true;
 
 	private final InputStream					in;
 	private final Map<Class<?>, Consumer<?>>	processors	= new HashMap<>();
 
-	private static final Logger logger = EnvoyLog.getLogger(Receiver.class);
+	private static final EventBus	eventBus	= EventBus.getInstance();
+	private static final Logger		logger		= EnvoyLog.getLogger(Receiver.class);
 
 	/**
 	 * Creates an instance of {@link Receiver}.
@@ -40,18 +35,18 @@ public class Receiver extends Thread {
 	public Receiver(InputStream in) {
 		super("Receiver");
 		this.in = in;
+		setDaemon(true);
 	}
 
 	/**
-	 * Starts the receiver loop. When an object is read, it is passed to the
-	 * appropriate processor.
+	 * Starts the receiver loop. When an object is read, it is passed to the appropriate processor.
 	 *
 	 * @since Envoy Client v0.3-alpha
 	 */
 	@Override
 	public void run() {
 
-		while (true) {
+		while (isAlive)
 			try {
 				// Read object length
 				final byte[] lenBytes = new byte[4];
@@ -66,53 +61,79 @@ public class Receiver extends Thread {
 
 				// Catch LV encoding errors
 				if (len != bytesRead) {
+					// Server has stopped sending, i.e. because he went offline
+					if (bytesRead == -1) {
+						isAlive = false;
+						logger.log(Level.INFO,
+							"Lost connection to the server. Exiting receiver...");
+						continue;
+					}
 					logger.log(Level.WARNING,
-							String.format("LV encoding violated: expected %d bytes, received %d bytes. Discarding object...", len, bytesRead));
+						String.format(
+							"LV encoding violated: expected %d bytes, received %d bytes. Discarding object...",
+							len, bytesRead));
 					continue;
 				}
 
-				try (ObjectInputStream oin = new ObjectInputStream(new ByteArrayInputStream(objBytes))) {
+				try (ObjectInputStream oin =
+					new ObjectInputStream(new ByteArrayInputStream(objBytes))) {
 					final Object obj = oin.readObject();
 					logger.log(Level.FINE, "Received " + obj);
 
 					// Get appropriate processor
 					@SuppressWarnings("rawtypes")
 					final Consumer processor = processors.get(obj.getClass());
-					if (processor == null)
-						logger.log(Level.WARNING, String.format("The received object has the %s for which no processor is defined.", obj.getClass()));
-					else processor.accept(obj);
+
+					// Dispatch to the processor if present
+					if (processor != null)
+						processor.accept(obj);
+					// Dispatch to the event bus if the object is an event without a processor
+					else if (obj instanceof IEvent)
+						eventBus.dispatch((IEvent) obj);
+					// Notify if no processor could be located
+					else
+						logger.log(Level.WARNING,
+							String.format(
+								"The received object has the %s for which no processor is defined.",
+								obj.getClass()));
 				}
-			} catch (final SocketException e) {
+			} catch (final SocketException | EOFException e) {
 				// Connection probably closed by client.
+				logger.log(Level.INFO, "Exiting receiver...");
 				return;
 			} catch (final Exception e) {
 				logger.log(Level.SEVERE, "Error on receiver thread", e);
 			}
-		}
 	}
 
 	/**
-	 * Adds an object processor to this {@link Receiver}. It will be called once an
-	 * object of the accepted class has been received.
+	 * Adds an object processor to this {@link Receiver}. It will be called once an object of the
+	 * accepted class has been received.
 	 *
 	 * @param processorClass the object class accepted by the processor
 	 * @param processor      the object processor
 	 * @since Envoy Client v0.3-alpha
 	 */
-	public <T> void registerProcessor(Class<T> processorClass, Consumer<T> processor) { processors.put(processorClass, processor); }
+	public <T> void registerProcessor(Class<T> processorClass, Consumer<T> processor) {
+		processors.put(processorClass, processor);
+	}
 
 	/**
 	 * Adds a map of object processors to this {@link Receiver}.
-	 * 
+	 *
 	 * @param processors the processors to add the processors to add
 	 * @since Envoy Client v0.1-beta
 	 */
-	public void registerProcessors(Map<Class<?>, ? extends Consumer<?>> processors) { this.processors.putAll(processors); }
+	public void registerProcessors(Map<Class<?>, ? extends Consumer<?>> processors) {
+		this.processors.putAll(processors);
+	}
 
 	/**
 	 * Removes all object processors registered at this {@link Receiver}.
 	 *
 	 * @since Envoy Client v0.3-alpha
 	 */
-	public void removeAllProcessors() { processors.clear(); }
+	public void removeAllProcessors() {
+		processors.clear();
+	}
 }

client/src/main/java/envoy/client/net/WriteProxy.java

@@ -1,28 +1,21 @@
 package envoy.client.net;
 
-import java.io.IOException;
-import java.util.logging.Level;
-import java.util.logging.Logger;
+import java.util.logging.*;
 
-import envoy.client.data.Cache;
-import envoy.client.data.LocalDB;
 import envoy.data.Message;
 import envoy.event.MessageStatusChange;
 import envoy.util.EnvoyLog;
 
+import envoy.client.data.*;
+
 /**
- * Implements methods to send {@link Message}s and
- * {@link MessageStatusChange}s to the server or cache them inside a
- * {@link LocalDB} depending on the online status.
- * <p>
- * Project: <strong>envoy-client</strong><br>
- * File: <strong>WriteProxy.java</strong><br>
- * Created: <strong>6 Feb 2020</strong><br>
+ * Implements methods to send {@link Message}s and {@link MessageStatusChange}s to the server or
+ * cache them inside a {@link LocalDB} depending on the online status.
  *
  * @author Kai S. K. Engelbart
  * @since Envoy Client v0.3-alpha
  */
-public class WriteProxy {
+public final class WriteProxy {
 
 	private final Client	client;
 	private final LocalDB	localDB;
@@ -30,13 +23,11 @@ public class WriteProxy {
 	private static final Logger logger = EnvoyLog.getLogger(WriteProxy.class);
 
 	/**
-	 * Initializes a write proxy using a client and a local database. The
-	 * corresponding cache processors are injected into the caches.
+	 * Initializes a write proxy using a client and a local database. The corresponding cache
+	 * processors are injected into the caches.
 	 *
-	 * @param client  the client used to send messages and message status change
-	 *                events
-	 * @param localDB the local database used to cache messages and message status
-	 *                change events
+	 * @param client  the client instance used to send messages and events if online
+	 * @param localDB the local database used to cache messages and events if offline
 	 * @since Envoy Client v0.3-alpha
 	 */
 	public WriteProxy(Client client, LocalDB localDB) {
@@ -45,26 +36,17 @@ public class WriteProxy {
 
 		// Initialize cache processors for messages and message status change events
 		localDB.getCacheMap().get(Message.class).setProcessor(msg -> {
-			try {
-				logger.log(Level.FINER, "Sending cached " + msg);
-				client.sendMessage(msg);
-			} catch (final IOException e) {
-				logger.log(Level.SEVERE, "Could not send cached message: ", e);
-			}
+			logger.log(Level.FINER, "Sending cached " + msg);
+			client.sendMessage(msg);
 		});
 		localDB.getCacheMap().get(MessageStatusChange.class).setProcessor(evt -> {
 			logger.log(Level.FINER, "Sending cached " + evt);
-			try {
-				client.sendEvent(evt);
-			} catch (final IOException e) {
-				logger.log(Level.SEVERE, "Could not send cached message status change event: ", e);
-			}
+			client.send(evt);
 		});
 	}
 
 	/**
-	 * Sends cached {@link Message}s and {@link MessageStatusChange}s to the
-	 * server.
+	 * Sends cached {@link Message}s and {@link MessageStatusChange}s to the server.
 	 *
 	 * @since Envoy Client v0.3-alpha
 	 */
@@ -73,28 +55,30 @@ public class WriteProxy {
 	}
 
 	/**
-	 * Delivers a message to the server if online. Otherwise the message is cached
-	 * inside the local database.
+	 * Delivers a message to the server if online. Otherwise the message is cached inside the local
+	 * database.
 	 *
 	 * @param message the message to send
-	 * @throws IOException if the message could not be sent
 	 * @since Envoy Client v0.3-alpha
 	 */
-	public void writeMessage(Message message) throws IOException {
-		if (client.isOnline()) client.sendMessage(message);
-		else localDB.getCacheMap().getApplicable(Message.class).accept(message);
+	public void writeMessage(Message message) {
+		if (client.isOnline())
+			client.sendMessage(message);
+		else
+			localDB.getCacheMap().getApplicable(Message.class).accept(message);
 	}
 
 	/**
-	 * Delivers a message status change event to the server if online. Otherwise the
-	 * event is cached inside the local database.
+	 * Delivers a message status change event to the server if online. Otherwise the event is cached
+	 * inside the local database.
 	 *
 	 * @param evt the event to send
-	 * @throws IOException if the event could not be sent
 	 * @since Envoy Client v0.3-alpha
 	 */
-	public void writeMessageStatusChange(MessageStatusChange evt) throws IOException {
-		if (client.isOnline()) client.sendEvent(evt);
-		else localDB.getCacheMap().getApplicable(MessageStatusChange.class).accept(evt);
+	public void writeMessageStatusChange(MessageStatusChange evt) {
+		if (client.isOnline())
+			client.send(evt);
+		else
+			localDB.getCacheMap().getApplicable(MessageStatusChange.class).accept(evt);
 	}
 }

client/src/main/java/envoy/client/ui/ClearableTextField.java

@@ -1,169 +0,0 @@
-package envoy.client.ui;
-
-import javafx.beans.property.BooleanProperty;
-import javafx.beans.property.ObjectProperty;
-import javafx.beans.property.StringProperty;
-import javafx.event.ActionEvent;
-import javafx.event.EventHandler;
-import javafx.scene.control.*;
-import javafx.scene.image.ImageView;
-import javafx.scene.layout.Background;
-import javafx.scene.layout.ColumnConstraints;
-import javafx.scene.layout.GridPane;
-
-/**
- * This class offers a text field that is automatically equipped with a clear
- * button.
- * <p>
- * Project: <strong>envoy-client</strong><br>
- * File: <strong>ClearableTextField.java</strong><br>
- * Created: <strong>25.06.2020</strong><br>
- *
- * @author Leon Hofmeister
- * @since Envoy Client v0.1-beta
- */
-public class ClearableTextField extends GridPane {
-
-	private final TextField textField;
-
-	private final Button clearButton;
-
-	/**
-	 * Constructs a new {@code ClearableTextField} with no initial text and icon
-	 * size 16.
-	 *
-	 * @since Envoy Client v0.1-beta
-	 */
-	public ClearableTextField() { this("", 16); }
-
-	/**
-	 * Constructs a new {@code ClearableTextField} with initial text and a
-	 * predetermined icon size.
-	 *
-	 * @param text the text that should be displayed by default
-	 * @param size the size of the icon
-	 * @since Envoy Client v0.1-beta
-	 */
-	public ClearableTextField(String text, int size) {
-		// initializing the textField and the button
-		textField	= new TextField(text);
-		clearButton	= new Button("", new ImageView(IconUtil.loadIconThemeSensitive("clear_button", size)));
-		clearButton.setOnAction(e -> textField.clear());
-		clearButton.setFocusTraversable(false);
-		clearButton.getStyleClass().clear();
-		clearButton.setBackground(Background.EMPTY);
-		// Adding the two elements to the GridPane
-		add(textField, 0, 0, 2, 1);
-		add(clearButton, 1, 0, 1, 1);
-		// Setting the percent - widths of the two columns.
-		// Used to locate the button on the right.
-		final var columnConstraints = new ColumnConstraints();
-		columnConstraints.setPercentWidth(90);
-		getColumnConstraints().add(columnConstraints);
-		final var columnConstraints2 = new ColumnConstraints();
-		columnConstraints2.setPercentWidth(10);
-		getColumnConstraints().add(columnConstraints2);
-	}
-
-	/**
-	 * @return the underlying {@code textField}
-	 * @since Envoy Client v0.1-beta
-	 */
-	public TextField getTextField() { return textField; }
-
-	/**
-	 * This method offers the freedom to perform custom actions when the
-	 * {@code clearButton} has been pressed.
-	 * <p>
-	 * The default is
-	 * <b><code>  e -> {clearableTextField.getTextField().clear();}</code></b>
-	 *
-	 * @param onClearButtonAction the action that should be performed
-	 * @since Envoy Client v0.1-beta
-	 */
-	public void setClearButtonListener(EventHandler<ActionEvent> onClearButtonAction) { clearButton.setOnAction(onClearButtonAction); }
-
-	/**
-	 * @return the current property of the prompt text
-	 * @see javafx.scene.control.TextInputControl#promptTextProperty()
-	 * @since Envoy Client v0.1-beta
-	 */
-	public final StringProperty promptTextProperty() { return textField.promptTextProperty(); }
-
-	/**
-	 * @return the current prompt text
-	 * @see javafx.scene.control.TextInputControl#getPromptText()
-	 * @since Envoy Client v0.1-beta
-	 */
-	public final String getPromptText() { return textField.getPromptText(); }
-
-	/**
-	 * @param value the prompt text to display
-	 * @see javafx.scene.control.TextInputControl#setPromptText(java.lang.String)
-	 * @since Envoy Client v0.1-beta
-	 */
-	public final void setPromptText(String value) { textField.setPromptText(value); }
-
-	/**
-	 * @return the current property of the tooltip
-	 * @see javafx.scene.control.Control#tooltipProperty()
-	 * @since Envoy Client v0.1-beta
-	 */
-	public final ObjectProperty<Tooltip> tooltipProperty() { return textField.tooltipProperty(); }
-
-	/**
-	 * @param value the new tooltip
-	 * @see javafx.scene.control.Control#setTooltip(javafx.scene.control.Tooltip)
-	 * @since Envoy Client v0.1-beta
-	 */
-	public final void setTooltip(Tooltip value) { textField.setTooltip(value); }
-
-	/**
-	 * @return the current tooltip
-	 * @see javafx.scene.control.Control#getTooltip()
-	 * @since Envoy Client v0.1-beta
-	 */
-	public final Tooltip getTooltip() { return textField.getTooltip(); }
-
-	/**
-	 * @return the current property of the context menu
-	 * @see javafx.scene.control.Control#contextMenuProperty()
-	 * @since Envoy Client v0.1-beta
-	 */
-	public final ObjectProperty<ContextMenu> contextMenuProperty() { return textField.contextMenuProperty(); }
-
-	/**
-	 * @param value the new context menu
-	 * @see javafx.scene.control.Control#setContextMenu(javafx.scene.control.ContextMenu)
-	 * @since Envoy Client v0.1-beta
-	 */
-	public final void setContextMenu(ContextMenu value) { textField.setContextMenu(value); }
-
-	/**
-	 * @return the current context menu
-	 * @see javafx.scene.control.Control#getContextMenu()
-	 * @since Envoy Client v0.1-beta
-	 */
-	public final ContextMenu getContextMenu() { return textField.getContextMenu(); }
-
-	/**
-	 * @param value whether this ClearableTextField should be editable
-	 * @see javafx.scene.control.TextInputControl#setEditable(boolean)
-	 * @since Envoy Client v0.1-beta
-	 */
-	public final void setEditable(boolean value) { textField.setEditable(value); }
-
-	/**
-	 * @return the current property whether this ClearableTextField is editable
-	 * @see javafx.scene.control.TextInputControl#editableProperty()
-	 * @since Envoy Client v0.1-beta
-	 */
-	public final BooleanProperty editableProperty() { return textField.editableProperty(); }
-
-	/**
-	 * @return whether this {@code ClearableTextField} is editable
-	 * @see javafx.scene.control.TextInputControl#isEditable()
-	 * @since Envoy Client v0.1-beta
-	 */
-	public final boolean isEditable() { return textField.isEditable(); }
-}

client/src/main/java/envoy/client/ui/Restorable.java

@@ -1,12 +1,8 @@
 package envoy.client.ui;
 
 /**
- * This interface defines an action that should be performed when a scene gets
- * restored from the scene stack in {@link SceneContext}.
- * <p>
- * Project: <strong>envoy-client</strong><br>
- * File: <strong>Restorable.java</strong><br>
- * Created: <strong>03.07.2020</strong><br>
+ * This interface defines an action that should be performed when a scene gets restored from the
+ * scene stack in {@link SceneContext}.
  *
  * @author Leon Hofmeister
  * @since Envoy Client v0.1-beta
@@ -16,8 +12,7 @@ public interface Restorable {
 
 	/**
 	 * This method is getting called when a scene gets restored.<br>
-	 * Hence, it can contain anything that should be done when the underlying scene
-	 * gets restored.
+	 * Hence, it can contain anything that should be done when the underlying scene gets restored.
 	 *
 	 * @since Envoy Client v0.1-beta
 	 */

client/src/main/java/envoy/client/ui/SceneContext.java

@@ -4,32 +4,29 @@ import java.io.IOException;
 import java.util.Stack;
 import java.util.logging.Level;
 
+import javafx.application.Platform;
 import javafx.fxml.FXMLLoader;
-import javafx.scene.Parent;
-import javafx.scene.Scene;
+import javafx.scene.*;
 import javafx.stage.Stage;
 
-import envoy.client.data.Settings;
-import envoy.client.event.ThemeChangeEvent;
-import envoy.event.EventBus;
+import dev.kske.eventbus.*;
+
 import envoy.util.EnvoyLog;
 
+import envoy.client.data.Settings;
+import envoy.client.data.shortcuts.*;
+import envoy.client.event.*;
+
 /**
- * Manages a stack of scenes. The most recently added scene is displayed inside
- * a stage. When a scene is removed from the stack, its predecessor is
- * displayed.
+ * Manages a stack of scenes. The most recently added scene is displayed inside a stage. When a
+ * scene is removed from the stack, its predecessor is displayed.
  * <p>
- * When a scene is loaded, the style sheet for the current theme is applied to
- * it.
- * <p>
- * Project: <strong>envoy-client</strong><br>
- * File: <strong>SceneContext.java</strong><br>
- * Created: <strong>06.06.2020</strong><br>
+ * When a scene is loaded, the style sheet for the current theme is applied to it.
  *
  * @author Kai S. K. Engelbart
  * @since Envoy Client v0.1-beta
  */
-public final class SceneContext {
+public final class SceneContext implements EventListener {
 
 	/**
 	 * Contains information about different scenes and their FXML resource files.
@@ -53,40 +50,21 @@ public final class SceneContext {
 		 */
 		SETTINGS_SCENE("/fxml/SettingsScene.fxml"),
 
-		/**
-		 * The scene in which the contact search screen is displayed.
-		 *
-		 * @since Envoy Client v0.1-beta
-		 */
-		CONTACT_SEARCH_SCENE("/fxml/ContactSearchScene.fxml"),
-
-		/**
-		 * The scene in which the group creation screen is displayed.
-		 *
-		 * @since Envoy Client v0.1-beta
-		 */
-		GROUP_CREATION_SCENE("/fxml/GroupCreationScene.fxml"),
-
 		/**
 		 * The scene in which the login screen is displayed.
 		 *
 		 * @since Envoy Client v0.1-beta
 		 */
-		LOGIN_SCENE("/fxml/LoginScene.fxml"),
-
-		/**
-		 * The scene in which the info screen is displayed.
-		 *
-		 * @since Envoy Client v0.1-beta
-		 */
-		MESSAGE_INFO_SCENE("/fxml/MessageInfoScene.fxml");
+		LOGIN_SCENE("/fxml/LoginScene.fxml");
 
 		/**
 		 * The path to the FXML resource.
 		 */
 		public final String path;
 
-		SceneInfo(String path) { this.path = path; }
+		SceneInfo(String path) {
+			this.path = path;
+		}
 	}
 
 	private final Stage			stage;
@@ -104,7 +82,7 @@ public final class SceneContext {
 	 */
 	public SceneContext(Stage stage) {
 		this.stage = stage;
-		EventBus.getInstance().register(ThemeChangeEvent.class, theme -> applyCSS());
+		EventBus.getInstance().registerListener(this);
 	}
 
 	/**
@@ -115,21 +93,39 @@ public final class SceneContext {
 	 * @since Envoy Client v0.1-beta
 	 */
 	public void load(SceneInfo sceneInfo) {
+		EnvoyLog.getLogger(SceneContext.class).log(Level.FINER, "Loading scene " + sceneInfo);
 		loader.setRoot(null);
 		loader.setController(null);
 
 		try {
-			final var	rootNode	= (Parent) loader.load(getClass().getResourceAsStream(sceneInfo.path));
+			final var	rootNode	=
+				(Parent) loader.load(getClass().getResourceAsStream(sceneInfo.path));
 			final var	scene		= new Scene(rootNode);
-			controllerStack.push(loader.getController());
+			final var	controller	= loader.getController();
+			controllerStack.push(controller);
 
 			sceneStack.push(scene);
 			stage.setScene(scene);
-			applyCSS();
+
+			// Supply the global custom keyboard shortcuts for that scene
+			scene.getAccelerators()
+				.putAll(GlobalKeyShortcuts.getInstance().getKeyboardShortcuts(sceneInfo));
+
+			// Supply the scene specific keyboard shortcuts
+			if (controller instanceof KeyboardMapping)
+				scene.getAccelerators()
+					.putAll(((KeyboardMapping) controller).getKeyboardShortcuts());
+
+			// The LoginScene is the only scene not intended to be resized
+			// As strange as it seems, this is needed as otherwise the LoginScene won't be
+			// displayed on some OS (...Debian...)
 			stage.sizeToScene();
+			Platform.runLater(() -> stage.setResizable(sceneInfo != SceneInfo.LOGIN_SCENE));
+			applyCSS();
 			stage.show();
 		} catch (final IOException e) {
-			EnvoyLog.getLogger(SceneContext.class).log(Level.SEVERE, String.format("Could not load scene for %s: ", sceneInfo), e);
+			EnvoyLog.getLogger(SceneContext.class).log(Level.SEVERE,
+				String.format("Could not load scene for %s: ", sceneInfo), e);
 			throw new RuntimeException(e);
 		}
 	}
@@ -140,8 +136,12 @@ public final class SceneContext {
 	 * @since Envoy Client v0.1-beta
 	 */
 	public void pop() {
+
+		// Pop scene and controller
 		sceneStack.pop();
 		controllerStack.pop();
+
+		// Apply new scene if present
 		if (!sceneStack.isEmpty()) {
 			final var newScene = sceneStack.peek();
 			stage.setScene(newScene);
@@ -150,7 +150,8 @@ public final class SceneContext {
 			// If the controller implements the Restorable interface,
 			// the actions to perform on restoration will be executed here
 			final var controller = controllerStack.peek();
-			if (controller instanceof Restorable) ((Restorable) controller).onRestore();
+			if (controller instanceof Restorable)
+				((Restorable) controller).onRestore();
 		}
 		stage.show();
 	}
@@ -160,10 +161,22 @@ public final class SceneContext {
 			final var	styleSheets	= stage.getScene().getStylesheets();
 			final var	themeCSS	= "/css/" + settings.getCurrentTheme() + ".css";
 			styleSheets.clear();
-			styleSheets.addAll(getClass().getResource("/css/base.css").toExternalForm(), getClass().getResource(themeCSS).toExternalForm());
+			styleSheets.addAll(getClass().getResource("/css/base.css").toExternalForm(),
+				getClass().getResource(themeCSS).toExternalForm());
 		}
 	}
 
+	@Event(eventType = Logout.class, priority = 150)
+	private void onLogout() {
+		sceneStack.clear();
+		controllerStack.clear();
+	}
+
+	@Event(priority = 150, eventType = ThemeChangeEvent.class)
+	private void onThemeChange() {
+		applyCSS();
+	}
+
 	/**
 	 * @param <T> the type of the controller
 	 * @return the controller used by the current scene
@@ -176,4 +189,10 @@ public final class SceneContext {
 	 * @since Envoy Client v0.1-beta
 	 */
 	public Stage getStage() { return stage; }
+
+	/**
+	 * @return whether the scene stack is empty
+	 * @since Envoy Client v0.2-beta
+	 */
+	public boolean isEmpty() { return sceneStack.isEmpty(); }
 }

client/src/main/java/envoy/client/ui/Startup.java

@@ -1,33 +1,31 @@
 package envoy.client.ui;
 
-import java.io.File;
-import java.io.IOException;
-import java.util.Properties;
-import java.util.logging.Level;
-import java.util.logging.Logger;
+import java.io.*;
+import java.time.Instant;
+import java.util.concurrent.TimeoutException;
+import java.util.logging.*;
 
 import javafx.application.Application;
 import javafx.scene.control.Alert;
 import javafx.scene.control.Alert.AlertType;
 import javafx.stage.Stage;
 
-import envoy.client.data.*;
-import envoy.client.net.Client;
-import envoy.client.ui.SceneContext.SceneInfo;
-import envoy.client.ui.controller.LoginScene;
-import envoy.data.GroupMessage;
-import envoy.data.Message;
-import envoy.event.GroupMessageStatusChange;
-import envoy.event.MessageStatusChange;
+import envoy.data.*;
+import envoy.data.User.UserStatus;
+import envoy.event.*;
 import envoy.exception.EnvoyException;
 import envoy.util.EnvoyLog;
 
+import envoy.client.data.*;
+import envoy.client.data.shortcuts.EnvoyShortcutConfig;
+import envoy.client.helper.ShutdownHelper;
+import envoy.client.net.Client;
+import envoy.client.ui.SceneContext.SceneInfo;
+import envoy.client.ui.controller.LoginScene;
+import envoy.client.util.IconUtil;
+
 /**
- * Handles application startup and shutdown.
- * <p>
- * Project: <strong>envoy-client</strong><br>
- * File: <strong>Startup.java</strong><br>
- * Created: <strong>26.03.2020</strong><br>
+ * Handles application startup.
  *
  * @author Kai S. K. Engelbart
  * @author Maximilian K&auml;fer
@@ -40,96 +38,210 @@ public final class Startup extends Application {
 	 *
 	 * @since Envoy Client v0.1-beta
 	 */
-	public static final String VERSION = "0.1-beta";
+	public static final String VERSION = "0.2-beta";
 
-	private LocalDB	localDB;
-	private Client	client;
+	private static LocalDB localDB;
 
+	private static final Context		context	= Context.getInstance();
+	private static final Client			client	= context.getClient();
 	private static final ClientConfig	config	= ClientConfig.getInstance();
 	private static final Logger			logger	= EnvoyLog.getLogger(Startup.class);
 
 	/**
-	 * Loads the configuration, initializes the client and the local database and
-	 * delegates the rest of the startup process to {@link LoginScene}.
+	 * Loads the configuration, initializes the client and the local database and delegates the rest
+	 * of the startup process to {@link LoginScene}.
 	 *
 	 * @since Envoy Client v0.1-beta
 	 */
 	@Override
 	public void start(Stage stage) throws Exception {
+
+		// Initialize config and logger
 		try {
-			// Load the configuration from client.properties first
-			final Properties properties = new Properties();
-			properties.load(Startup.class.getClassLoader().getResourceAsStream("client.properties"));
-			config.load(properties);
-
-			// Override configuration values with command line arguments
-			final String[] args = getParameters().getRaw().toArray(new String[0]);
-			if (args.length > 0) config.load(args);
-
-			// Check if all mandatory configuration values have been initialized
-			if (!config.isInitialized()) throw new EnvoyException("Configuration is not fully initialized");
-		} catch (final Exception e) {
+			config.loadAll(Startup.class, "client.properties",
+				getParameters().getRaw().toArray(new String[0]));
+			EnvoyLog.initialize(config);
+		} catch (final IllegalStateException e) {
 			new Alert(AlertType.ERROR, "Error loading configuration values:\n" + e);
 			logger.log(Level.SEVERE, "Error loading configuration values: ", e);
-			e.printStackTrace();
 			System.exit(1);
 		}
-
-		// Setup logger for the envoy package
-		EnvoyLog.initialize(config);
-		EnvoyLog.attach("envoy");
-		EnvoyLog.setFileLevelBarrier(config.getFileLevelBarrier());
-		EnvoyLog.setConsoleLevelBarrier(config.getConsoleLevelBarrier());
-
 		logger.log(Level.INFO, "Envoy starting...");
 
 		// Initialize the local database
-		if (config.isIgnoreLocalDB()) {
-			localDB = new TransientLocalDB();
-			new Alert(AlertType.WARNING, "Ignoring local database.\nMessages will not be saved!").showAndWait();
-		} else try {
-			localDB = new PersistentLocalDB(new File(config.getHomeDirectory(), config.getLocalDB().getPath()));
-		} catch (final IOException e3) {
-			logger.log(Level.SEVERE, "Could not initialize local database: ", e3);
-			new Alert(AlertType.ERROR, "Could not initialize local database!\n" + e3).showAndWait();
+		try {
+			final var localDBFile = new File(config.getHomeDirectory(), config.getServer());
+			logger.info("Initializing LocalDB at " + localDBFile);
+			localDB = new LocalDB(localDBFile);
+		} catch (IOException | EnvoyException e) {
+			logger.log(Level.SEVERE, "Could not initialize local database: ", e);
+			new Alert(AlertType.ERROR, "Could not initialize local database!\n" + e).showAndWait();
 			System.exit(1);
 			return;
 		}
 
-		// Initialize client and unread message cache
-		client = new Client();
+		// Prepare handshake
+		context.setLocalDB(localDB);
 
+		// Configure stage
+		stage.setTitle("Envoy");
+		stage.getIcons().add(IconUtil.loadIcon("envoy_logo"));
+
+		// Configure global shortcuts
+		EnvoyShortcutConfig.initializeEnvoyShortcuts();
+
+		// Create scene context
+		final var sceneContext = new SceneContext(stage);
+		context.setSceneContext(sceneContext);
+
+		// Authenticate with token if present
+		if (localDB.getAuthToken() != null) {
+			logger.info("Attempting authentication with token...");
+			localDB.loadUserData();
+			if (!performHandshake(
+				LoginCredentials.loginWithToken(localDB.getUser().getName(), localDB.getAuthToken(),
+					VERSION, localDB.getLastSync())))
+				sceneContext.load(SceneInfo.LOGIN_SCENE);
+		} else
+			// Load login scene
+			sceneContext.load(SceneInfo.LOGIN_SCENE);
+	}
+
+	/**
+	 * Tries to perform a Handshake with the server.
+	 *
+	 * @param credentials the credentials to use for the handshake
+	 * @return whether the handshake was successful or offline mode could be entered
+	 * @since Envoy Client v0.2-beta
+	 */
+	public static boolean performHandshake(LoginCredentials credentials) {
 		final var cacheMap = new CacheMap();
 		cacheMap.put(Message.class, new Cache<Message>());
 		cacheMap.put(GroupMessage.class, new Cache<GroupMessage>());
 		cacheMap.put(MessageStatusChange.class, new Cache<MessageStatusChange>());
 		cacheMap.put(GroupMessageStatusChange.class, new Cache<GroupMessageStatusChange>());
+		final var originalStatus =
+			localDB.getUser() == null ? UserStatus.ONLINE : localDB.getUser().getStatus();
+		try {
+			client.performHandshake(credentials, cacheMap);
+			if (client.isOnline()) {
 
-		stage.setTitle("Envoy");
-		stage.getIcons().add(IconUtil.loadIcon("envoy_logo"));
-
-		final var sceneContext = new SceneContext(stage);
-		sceneContext.load(SceneInfo.LOGIN_SCENE);
-		sceneContext.<LoginScene>getController().initializeData(client, localDB, cacheMap, sceneContext);
+				// Restore the original status as the server automatically returns status ONLINE
+				client.getSender().setStatus(originalStatus);
+				loadChatScene();
+				client.initReceiver(localDB, cacheMap);
+				return true;
+			} else
+				return false;
+		} catch (IOException | InterruptedException | TimeoutException e) {
+			logger.log(Level.INFO, "Could not connect to server. Entering offline mode...");
+			return attemptOfflineMode(credentials.getIdentifier());
+		}
 	}
 
 	/**
-	 * Closes the client connection and saves the local database and settings.
+	 * Attempts to load {@link envoy.client.ui.controller.ChatScene} in offline mode for a given
+	 * user.
 	 *
-	 * @since Envoy Client v0.1-beta
+	 * @param identifier the identifier of the user - currently his username
+	 * @return whether the offline mode could be entered
+	 * @since Envoy Client v0.2-beta
 	 */
-	@Override
-	public void stop() {
+	public static boolean attemptOfflineMode(String identifier) {
 		try {
-			logger.log(Level.INFO, "Closing connection...");
-			client.close();
-
-			logger.log(Level.INFO, "Saving local database and settings...");
-			localDB.save();
-			Settings.getInstance().save();
-			logger.log(Level.INFO, "Envoy was terminated by its user");
+			// Try entering offline mode
+			final User clientUser = localDB.getUsers().get(identifier);
+			if (clientUser == null)
+				throw new EnvoyException("Could not enter offline mode: user name unknown");
+			client.setSender(clientUser);
+			loadChatScene();
+			return true;
 		} catch (final Exception e) {
-			logger.log(Level.SEVERE, "Unable to save local files: ", e);
+			new Alert(AlertType.ERROR, "Client error: " + e).showAndWait();
+			logger.log(Level.SEVERE, "Offline mode could not be loaded: ", e);
+			System.exit(1);
+			return false;
 		}
 	}
+
+	/**
+	 * Loads the last known time a user has been online.
+	 *
+	 * @param identifier the identifier of this user - currently his name
+	 * @return the last {@code Instant} at which he has been online
+	 * @since Envoy Client v0.2-beta
+	 */
+	public static Instant loadLastSync(String identifier) {
+		try {
+			localDB.setUser(localDB.getUsers().get(identifier));
+			localDB.loadUserData();
+		} catch (final Exception e) {
+			// User storage empty, wrong user name etc. -> default lastSync
+		}
+		return localDB.getLastSync();
+	}
+
+	private static void loadChatScene() {
+
+		// Set client user in local database
+		final var user = client.getSender();
+		localDB.setUser(user);
+
+		// Initialize chats in local database
+		try {
+			localDB.loadUserData();
+		} catch (final FileNotFoundException e) {
+			// The local database file has not yet been created, probably first login
+		} catch (final Exception e) {
+			new Alert(AlertType.ERROR,
+				"Error while loading local database: " + e + "\nChats will not be stored locally.")
+					.showAndWait();
+			logger.log(Level.WARNING, "Could not load local database: ", e);
+		}
+
+		context.initWriteProxy();
+
+		if (client.isOnline()) {
+			context.getWriteProxy().flushCache();
+
+			// Inform the server that this user has a different user status than expected
+			if (!user.getStatus().equals(UserStatus.ONLINE))
+				client.send(new UserStatusChange(user));
+		} else
+
+			// Set all contacts to offline mode
+			localDB.getChats()
+				.stream()
+				.map(Chat::getRecipient)
+				.filter(User.class::isInstance)
+				.map(User.class::cast)
+				.forEach(u -> u.setStatus(UserStatus.OFFLINE));
+
+		final var stage = context.getStage();
+
+		// Pop LoginScene if present
+		if (!context.getSceneContext().isEmpty())
+			context.getSceneContext().pop();
+
+		// Load ChatScene
+		stage.setMinHeight(400);
+		stage.setMinWidth(843);
+		context.getSceneContext().load(SceneContext.SceneInfo.CHAT_SCENE);
+		stage.centerOnScreen();
+
+		// Exit or minimize the stage when a close request occurs
+		stage.setOnCloseRequest(
+			e -> {
+				ShutdownHelper.exit();
+				if (Settings.getInstance().isHideOnClose() && StatusTrayIcon.isSupported())
+					e.consume();
+			});
+
+		// Initialize status tray icon
+		if (StatusTrayIcon.isSupported())
+			new StatusTrayIcon(stage).show();
+
+		// Start auto save thread
+		localDB.initAutoSave();
+	}
 }

client/src/main/java/envoy/client/ui/StatusTrayIcon.java

@@ -1,100 +1,224 @@
 package envoy.client.ui;
 
+import static java.awt.Image.SCALE_SMOOTH;
+
 import java.awt.*;
 import java.awt.TrayIcon.MessageType;
-import java.awt.event.WindowAdapter;
-import java.awt.event.WindowEvent;
-import java.util.logging.Level;
+import java.awt.image.BufferedImage;
+
+import javafx.application.Platform;
+import javafx.stage.Stage;
+
+import dev.kske.eventbus.*;
+import dev.kske.eventbus.Event;
 
-import envoy.client.event.MessageCreationEvent;
 import envoy.data.Message;
-import envoy.event.EventBus;
-import envoy.exception.EnvoyException;
-import envoy.util.EnvoyLog;
+import envoy.data.User.UserStatus;
+
+import envoy.client.data.*;
+import envoy.client.event.*;
+import envoy.client.helper.ShutdownHelper;
+import envoy.client.util.*;
 
 /**
- * Project: <strong>envoy-client</strong><br>
- * File: <strong>StatusTrayIcon.java</strong><br>
- * Created: <strong>3 Dec 2019</strong><br>
+ * A tray icon with the Envoy logo, an "Envoy" tool tip and a pop-up menu with menu items for
+ * <ul>
+ * <li>Changing the user status</li>
+ * <li>Logging out</li>
+ * <li>Quitting Envoy</li>
+ * </ul>
  *
  * @author Kai S. K. Engelbart
  * @since Envoy Client v0.2-alpha
  */
-public class StatusTrayIcon {
+public final class StatusTrayIcon implements EventListener {
 
 	/**
-	 * The {@link TrayIcon} provided by the System Tray API for controlling the
-	 * system tray. This includes displaying the icon, but also creating
-	 * notifications when new messages are received.
+	 * The {@link TrayIcon} provided by the System Tray API for controlling the system tray. This
+	 * includes displaying the icon, but also creating notifications when new messages are received.
 	 */
 	private final TrayIcon trayIcon;
 
 	/**
-	 * A received {@link Message} is only displayed as a system tray notification if
-	 * this variable is set to {@code true}.
+	 * A received {@link Message} is only displayed as a system tray notification if this variable
+	 * is set to {@code true}.
 	 */
-	private boolean displayMessages = false;
+	private boolean displayMessageNotification;
 
 	/**
-	 * Creates a {@link StatusTrayIcon} with the Envoy logo, a tool tip and a pop-up
-	 * menu.
-	 *
-	 * @param focusTarget the {@link Window} which focus determines if message
-	 *                    notifications are displayed
-	 * @throws EnvoyException if the currently used OS does not support the System
-	 *                        Tray API
-	 * @since Envoy Client v0.2-alpha
+	 * The size of the tray icon's image.
 	 */
-	public StatusTrayIcon(Window focusTarget) throws EnvoyException {
-		if (!SystemTray.isSupported()) throw new EnvoyException("The Envoy tray icon is not supported.");
+	private final Dimension size;
 
-		final ClassLoader	loader	= Thread.currentThread().getContextClassLoader();
-		final Image			img		= Toolkit.getDefaultToolkit().createImage(loader.getResource("envoy_logo.png"));
-		trayIcon = new TrayIcon(img, "Envoy Client");
-		trayIcon.setImageAutoSize(true);
-		trayIcon.setToolTip("You are notified if you have unread messages.");
+	/**
+	 * The Envoy logo on which the current user status and unread message count will be drawn to
+	 * compose the tray icon.
+	 */
+	private final Image logo;
 
-		final PopupMenu popup = new PopupMenu();
+	private static final Font unreadMessageFont = new Font("sans-serif", Font.PLAIN, 8);
 
-		final MenuItem exitMenuItem = new MenuItem("Exit");
-		exitMenuItem.addActionListener(evt -> System.exit(0));
+	/**
+	 * @return {@code true} if the status tray icon is supported on this platform
+	 * @since Envoy Client v0.2-beta
+	 */
+	public static boolean isSupported() { return SystemTray.isSupported(); }
+
+	/**
+	 * Creates a {@link StatusTrayIcon} with the Envoy logo, a tool tip and a pop-up menu.
+	 *
+	 * @param stage the stage whose focus determines if message notifications are displayed
+	 * @since Envoy Client v0.2-beta
+	 */
+	public StatusTrayIcon(Stage stage) {
+		size	= SystemTray.getSystemTray().getTrayIconSize();
+		logo	= IconUtil.loadAWTCompatible("/icons/envoy_logo.png").getScaledInstance(size.width,
+			size.height, SCALE_SMOOTH);
+
+		final var popup = new PopupMenu();
+
+		// Adding the exit menu item
+		final var exitMenuItem = new MenuItem("Exit");
+		exitMenuItem.addActionListener(evt -> ShutdownHelper.exit(true));
 		popup.add(exitMenuItem);
 
-		trayIcon.setPopupMenu(popup);
+		// Adding the logout menu item
+		final var logoutMenuItem = new MenuItem("Logout");
+		logoutMenuItem.addActionListener(evt -> Platform.runLater(UserUtil::logout));
+		popup.add(logoutMenuItem);
 
-		// Only display messages if the chat window is not focused
-		focusTarget.addWindowFocusListener(new WindowAdapter() {
+		// Adding the status change items
+		final var statusSubMenu = new Menu("Change status");
+		for (final var status : UserStatus.values()) {
+			final var statusMenuItem = new MenuItem(status.toString().toLowerCase());
+			statusMenuItem
+				.addActionListener(evt -> Platform.runLater(() -> UserUtil.changeStatus(status)));
+			statusSubMenu.add(statusMenuItem);
+		}
+		popup.add(statusSubMenu);
 
-			@Override
-			public void windowGainedFocus(WindowEvent e) { displayMessages = false; }
+		// Initialize the icon
+		trayIcon = new TrayIcon(createImage(), "Envoy", popup);
 
-			@Override
-			public void windowLostFocus(WindowEvent e) { displayMessages = true; }
-		});
+		// Only display messages if the stage is not focused and the current user status
+		// is not BUSY (if BUSY, displayMessageNotification will be false)
+		stage.focusedProperty()
+			.addListener((ov, wasFocused, isFocused) -> displayMessageNotification =
+				!displayMessageNotification && wasFocused ? false : !isFocused);
+
+		// Listen to changes in the total unread message amount
+		Chat.getTotalUnreadAmount().addListener((ov, oldValue, newValue) -> updateImage());
 
 		// Show the window if the user clicks on the icon
-		trayIcon.addActionListener(evt -> { focusTarget.setVisible(true); focusTarget.requestFocus(); });
+		trayIcon.addActionListener(evt -> Platform.runLater(() -> {
+			stage.setIconified(false);
+			stage.toFront();
+			stage.requestFocus();
+		}));
 
 		// Start processing message events
-		// TODO: Handle other message types
-		EventBus.getInstance()
-			.register(MessageCreationEvent.class,
-					evt -> { if (displayMessages) trayIcon.displayMessage("New message received", evt.get().getText(), MessageType.INFO); });
+		EventBus.getInstance().registerListener(this);
 	}
 
 	/**
-	 * Makes this {@link StatusTrayIcon} appear in the system tray.
+	 * Makes the icon appear in the system tray.
 	 *
-	 * @throws EnvoyException if the status icon could not be attaches to the system
-	 *                        tray for system-internal reasons
 	 * @since Envoy Client v0.2-alpha
 	 */
-	public void show() throws EnvoyException {
+	public void show() {
 		try {
 			SystemTray.getSystemTray().add(trayIcon);
-		} catch (final AWTException e) {
-			EnvoyLog.getLogger(StatusTrayIcon.class).log(Level.INFO, "Could not display StatusTrayIcon: ", e);
-			throw new EnvoyException("Could not attach Envoy tray icon to system tray.", e);
+		} catch (AWTException e) {}
+	}
+
+	/**
+	 * Removes the icon from the system tray.
+	 *
+	 * @since Envoy Client v0.2-beta
+	 */
+	@Event(eventType = Logout.class)
+	public void hide() {
+		SystemTray.getSystemTray().remove(trayIcon);
+	}
+
+	@Event
+	private void onOwnStatusChange(OwnStatusChange statusChange) {
+		displayMessageNotification = !statusChange.get().equals(UserStatus.BUSY);
+		trayIcon.getImage().flush();
+		trayIcon.setImage(createImage());
+	}
+
+	@Event
+	private void onMessage(Message message) {
+		if (displayMessageNotification)
+			trayIcon
+				.displayMessage(message.hasAttachment()
+					? "New " + message.getAttachment().getType().toString().toLowerCase()
+						+ " message received"
+					: "New message received", message.getText(), MessageType.INFO);
+	}
+
+	/**
+	 * Updates the tray icon's image by first releasing the resources held by the current image and
+	 * then setting a new one generated by the {@link StatusTrayIcon#createImage()} method.
+	 *
+	 * @since Envoy Client v0.3-beta
+	 */
+	private void updateImage() {
+		trayIcon.getImage().flush();
+		trayIcon.setImage(createImage());
+	}
+
+	/**
+	 * Composes an icon that displays the current user status and the amount of unread messages, if
+	 * any are present.
+	 *
+	 * @since Envoy Client v0.3-beta
+	 */
+	private BufferedImage createImage() {
+
+		// Create a new image with the dimensions of the logo
+		var img = new BufferedImage(size.width, size.height, BufferedImage.TYPE_INT_ARGB);
+
+		// Obtain the draw graphics of the image and copy the logo
+		var g = img.createGraphics();
+		g.drawImage(logo, 0, 0, null);
+
+		// Draw the current user status
+		switch (Context.getInstance().getLocalDB().getUser().getStatus()) {
+			case ONLINE:
+				g.setColor(Color.GREEN);
+				break;
+			case AWAY:
+				g.setColor(Color.ORANGE);
+				break;
+			case BUSY:
+				g.setColor(Color.RED);
+				break;
+			case OFFLINE:
+				g.setColor(Color.GRAY);
 		}
+		g.fillOval(size.width / 2, size.height / 2, size.width / 2, size.height / 2);
+
+		// Draw total amount of unread messages, if any are present
+		if (Chat.getTotalUnreadAmount().get() > 0) {
+
+			// Draw black background circle
+			g.setColor(Color.BLACK);
+			g.fillOval(size.width / 2, 0, size.width / 2, size.height / 2);
+
+			// Unread amount in white
+			String unreadAmount = Chat.getTotalUnreadAmount().get() > 9 ? "9+"
+				: String.valueOf(Chat.getTotalUnreadAmount().get());
+			g.setColor(Color.WHITE);
+			g.setFont(unreadMessageFont);
+			g.drawString(unreadAmount,
+				3 * size.width / 4 - g.getFontMetrics().stringWidth(unreadAmount) / 2,
+				size.height / 2);
+		}
+
+		// Finish drawing
+		g.dispose();
+		return img;
 	}
 }

client/src/main/java/envoy/client/ui/chatscene/ChatSceneCommands.java

@@ -0,0 +1,194 @@
+package envoy.client.ui.chatscene;
+
+import java.util.Random;
+import java.util.function.*;
+import java.util.logging.Level;
+
+import javafx.scene.control.*;
+import javafx.scene.control.Alert.AlertType;
+import javafx.scene.control.skin.VirtualFlow;
+
+import envoy.data.Message;
+import envoy.data.User.UserStatus;
+import envoy.util.EnvoyLog;
+
+import envoy.client.data.Context;
+import envoy.client.data.commands.*;
+import envoy.client.helper.ShutdownHelper;
+import envoy.client.ui.SceneContext.SceneInfo;
+import envoy.client.ui.controller.ChatScene;
+import envoy.client.util.*;
+
+/**
+ * Contains all {@link SystemCommand}s used for {@link envoy.client.ui.controller.ChatScene}.
+ *
+ * @author Leon Hofmeister
+ * @since Envoy Client v0.3-beta
+ */
+public final class ChatSceneCommands {
+
+	private final ListView<Message>		messageList;
+	private final SystemCommandMap		messageTextAreaCommands	= new SystemCommandMap();
+	private final SystemCommandBuilder	builder					=
+		new SystemCommandBuilder(messageTextAreaCommands);
+
+	private static final String messageDependantCommandDescription =
+		" the given message. Use s/S to use the selected message. Otherwise expects a number relative to the uppermost completely visible message.";
+
+	/**
+	 * @param messageList the message list to use for some commands
+	 * @param chatScene   the instance of {@code ChatScene} that uses this object
+	 * @since Envoy Client v0.3-beta
+	 */
+	public ChatSceneCommands(ListView<Message> messageList, ChatScene chatScene) {
+		this.messageList = messageList;
+
+		// Error message initialization
+		builder.setAction(text -> { throw new RuntimeException(); })
+			.setDescription("Shows an error message.").buildNoArg("error");
+
+		// Do A Barrel roll initialization
+		final var random = new Random();
+		builder
+			.setAction(text -> chatScene.doABarrelRoll(Integer.parseInt(text.get(0)),
+				Double.parseDouble(text.get(1))))
+			.setDefaults(Integer.toString(random.nextInt(3) + 1),
+				Double.toString(random.nextDouble() * 3 + 1))
+			.setDescription("See for yourself :)")
+			.setNumberOfArguments(2)
+			.build("dabr");
+
+		// Logout initialization
+		builder.setAction(text -> UserUtil.logout()).setDescription("Logs you out.")
+			.buildNoArg("logout");
+
+		// Exit initialization
+		builder.setAction(text -> ShutdownHelper.exit()).setNumberOfArguments(0)
+			.setDescription("Exits the program.").build("exit", false);
+		builder.build("q");
+
+		// Open settings scene initialization
+		builder
+			.setAction(
+				text -> Context.getInstance().getSceneContext().load(SceneInfo.SETTINGS_SCENE))
+			.setDescription("Opens the settings screen")
+			.buildNoArg("settings");
+
+		// Status change initialization
+		builder.setAction(text -> {
+			try {
+				UserUtil.changeStatus(Enum.valueOf(UserStatus.class, text.get(0).toUpperCase()));
+			} catch (final IllegalArgumentException e) {
+				final var alert = new Alert(AlertType.ERROR);
+				alert.setContentText("Please provide an existing status");
+				alert.showAndWait();
+			}
+		}).setDescription("Changes your status to the given status.").setNumberOfArguments(1)
+			.setDefaults("").build("status");
+
+		// Selection of a new message initialization
+		messageDependantAction("s",
+			m -> {
+				messageList.getSelectionModel().clearSelection();
+				messageList.getSelectionModel().select(m);
+			},
+			m -> true,
+			"Selects");
+
+		// Copy text of selection initialization
+		messageDependantAction("cp", MessageUtil::copyMessageText, m -> !m.getText().isEmpty(),
+			"Copies the text of");
+
+		// Delete selection initialization
+		messageDependantAction("del", MessageUtil::deleteMessage, m -> true, "Deletes");
+
+		// Save attachment of selection initialization
+		messageDependantAction("save-att", MessageUtil::saveAttachment, Message::hasAttachment,
+			"Saves the attachment of");
+	}
+
+	private void messageDependantAction(String command, Consumer<Message> action,
+		Predicate<Message> additionalCheck, String description) {
+		builder.setAction(text -> {
+			final var positionalArgument = text.get(0).toLowerCase();
+
+			// the currently selected message was requested
+			if (positionalArgument.startsWith("s")) {
+				final var relativeString =
+					positionalArgument.length() == 1 ? "" : positionalArgument.substring(1);
+
+				// Only s has been used as input
+				if (positionalArgument.length() == 1) {
+					final var selectedMessage = messageList.getSelectionModel().getSelectedItem();
+					if (selectedMessage != null && additionalCheck.test(selectedMessage))
+						action.accept(selectedMessage);
+					return;
+
+					// Either s++ or s-- has been requested
+				} else if (relativeString.equals("++") || relativeString.equals("--"))
+					selectionNeighbor(action, additionalCheck, positionalArgument);
+
+				// A message relative to the currently selected message should be used (i.e.
+				// s+4)
+				else
+					useRelativeMessage(command, action, additionalCheck, relativeString, true);
+
+				// Either ++s or --s has been requested
+			} else if (positionalArgument.equals("--s") || positionalArgument.equals("++s"))
+				selectionNeighbor(action, additionalCheck, positionalArgument);
+
+			// Just a number is expected: ((+)4)
+			else
+				useRelativeMessage(command, action, additionalCheck, positionalArgument, false);
+		}).setDefaults("s").setNumberOfArguments(1)
+			.setDescription(description.concat(messageDependantCommandDescription)).build(command);
+	}
+
+	private void selectionNeighbor(Consumer<Message> action, Predicate<Message> additionalCheck,
+		final String positionalArgument) {
+		final var wantedIndex = messageList.getSelectionModel().getSelectedIndex()
+			+ (positionalArgument.contains("+") ? 1 : -1);
+		messageList.getSelectionModel().clearAndSelect(wantedIndex);
+		final var selectedMessage = messageList.getItems().get(wantedIndex);
+		if (selectedMessage != null && additionalCheck.test(selectedMessage))
+			action.accept(selectedMessage);
+	}
+
+	private void useRelativeMessage(String command, Consumer<Message> action,
+		Predicate<Message> additionalCheck, final String positionalArgument,
+		boolean useSelectedMessage) throws NumberFormatException {
+		final var	stripPlus	=
+			positionalArgument.startsWith("+") ? positionalArgument.substring(1)
+				: positionalArgument;
+		final var	incDec		= Integer.valueOf(stripPlus);
+		try {
+
+			// The currently selected message is the base message
+			if (useSelectedMessage) {
+				final var messageToUse = messageList.getItems()
+					.get(messageList.getSelectionModel().getSelectedIndex() + incDec);
+				if (messageToUse != null && additionalCheck.test(messageToUse))
+					action.accept(messageToUse);
+
+				// The currently upmost completely visible message is the base message
+			} else {
+				final var messageToUse = messageList.getItems()
+					.get(((VirtualFlow<?>) messageList.lookup(".virtual-flow"))
+						.getFirstVisibleCell().getIndex() + 1 + incDec);
+				if (messageToUse != null && additionalCheck.test(messageToUse))
+					action.accept(messageToUse);
+			}
+		} catch (final IndexOutOfBoundsException e) {
+			EnvoyLog.getLogger(ChatSceneCommands.class)
+				.log(Level.INFO,
+					" A non-existing message was requested by the user for System command "
+						+ command);
+		}
+	}
+
+	/**
+	 * @return the map used by this {@code ChatSceneCommands}
+	 * @since Envoy Client v0.3-beta
+	 */
+	public SystemCommandMap getChatSceneCommands() { return messageTextAreaCommands; }
+}

client/src/main/java/envoy/client/ui/chatscene/TextInputContextMenu.java

@@ -0,0 +1,107 @@
+package envoy.client.ui.chatscene;
+
+import java.util.function.Consumer;
+
+import javafx.event.*;
+import javafx.scene.control.*;
+import javafx.scene.input.Clipboard;
+
+/**
+ * Displays a context menu that offers an additional option when one of its menu items has been
+ * clicked.
+ * <p>
+ * Current options are:
+ * <ul>
+ * <li>undo</li>
+ * <li>redo</li>
+ * <li>cut</li>
+ * <li>copy</li>
+ * <li>paste</li>
+ * <li>delete</li>
+ * <li>clear</li>
+ * <li>Select all</li>
+ * </ul>
+ *
+ * @author Leon Hofmeister
+ * @since Envoy Client v0.2-beta
+ * @apiNote please refrain from using {@link ContextMenu#setOnShowing(EventHandler)} as this is
+ *          already used by this component
+ */
+public class TextInputContextMenu extends ContextMenu {
+
+	private final MenuItem	undoMI		= new MenuItem("Undo");
+	private final MenuItem	redoMI		= new MenuItem("Redo");
+	private final MenuItem	cutMI		= new MenuItem("Cut");
+	private final MenuItem	copyMI		= new MenuItem("Copy");
+	private final MenuItem	pasteMI		= new MenuItem("Paste");
+	private final MenuItem	deleteMI	= new MenuItem("Delete selection");
+	private final MenuItem	clearMI		= new MenuItem("Clear");
+	private final MenuItem	selectAllMI	= new MenuItem("Select all");
+
+	/**
+	 * Creates a new {@code TextInputContextMenu} with an optional action when this menu was
+	 * clicked. Currently shows:
+	 * <ul>
+	 * <li>undo</li>
+	 * <li>redo</li>
+	 * <li>cut</li>
+	 * <li>copy</li>
+	 * <li>paste</li>
+	 * <li>delete</li>
+	 * <li>clear</li>
+	 * <li>Select all</li>
+	 * </ul>
+	 *
+	 * @param control         the text input component to display this {@code ContextMenu}
+	 * @param menuItemClicked the second action to perform when a menu item of this context menu has
+	 *                        been clicked
+	 * @since Envoy Client v0.2-beta
+	 * @apiNote please refrain from using {@link ContextMenu#setOnShowing(EventHandler)} as this is
+	 *          already used by this component
+	 */
+	public TextInputContextMenu(TextInputControl control, Consumer<ActionEvent> menuItemClicked) {
+
+		// Define the actions when clicked
+		undoMI.setOnAction(addAction(e -> control.undo(), menuItemClicked));
+		redoMI.setOnAction(addAction(e -> control.redo(), menuItemClicked));
+		cutMI.setOnAction(addAction(e -> control.cut(), menuItemClicked));
+		copyMI.setOnAction(addAction(e -> control.copy(), menuItemClicked));
+		pasteMI.setOnAction(addAction(e -> control.paste(), menuItemClicked));
+		deleteMI.setOnAction(addAction(e -> control.replaceSelection(""), menuItemClicked));
+		clearMI.setOnAction(addAction(e -> control.setText(""), menuItemClicked));
+		selectAllMI.setOnAction(addAction(e -> control.selectAll(), menuItemClicked));
+
+		// Define the times it will be disabled
+		undoMI.disableProperty().bind(control.undoableProperty().not());
+		redoMI.disableProperty().bind(control.redoableProperty().not());
+		cutMI.disableProperty().bind(control.selectedTextProperty().isEmpty());
+		copyMI.disableProperty().bind(control.selectedTextProperty().isEmpty());
+		deleteMI.disableProperty().bind(control.selectedTextProperty().isEmpty());
+		clearMI.disableProperty().bind(control.textProperty().isEmpty());
+		selectAllMI.disableProperty().bind(control.textProperty().isEmpty());
+		setOnShowing(e -> pasteMI.setDisable(!Clipboard.getSystemClipboard().hasString()));
+
+		selectAllMI.getProperties().put("refreshMenu", Boolean.TRUE);
+
+		// Add all items to the ContextMenu
+		getItems().add(undoMI);
+		getItems().add(redoMI);
+		getItems().add(new SeparatorMenuItem());
+		getItems().add(cutMI);
+		getItems().add(copyMI);
+		getItems().add(pasteMI);
+		getItems().add(new SeparatorMenuItem());
+		getItems().add(deleteMI);
+		getItems().add(clearMI);
+		getItems().add(new SeparatorMenuItem());
+		getItems().add(selectAllMI);
+	}
+
+	private EventHandler<ActionEvent> addAction(Consumer<ActionEvent> originalAction,
+		Consumer<ActionEvent> additionalAction) {
+		return e -> {
+			originalAction.accept(e);
+			additionalAction.accept(e);
+		};
+	}
+}

client/src/main/java/envoy/client/ui/chatscene/package-info.java

@@ -0,0 +1,7 @@
+/**
+ * Contains classes that influence the appearance and behavior of ChatScene.
+ *
+ * @author Leon Hofmeister
+ * @since Envoy Client v0.3-beta
+ */
+package envoy.client.ui.chatscene;

client/src/main/java/envoy/client/ui/control/AudioControl.java

@@ -1,30 +1,25 @@
-package envoy.client.ui;
+package envoy.client.ui.control;
 
-import java.util.logging.Level;
-import java.util.logging.Logger;
+import java.util.logging.*;
 
-import javafx.scene.control.Alert;
+import javafx.scene.control.*;
 import javafx.scene.control.Alert.AlertType;
-import javafx.scene.control.Button;
 import javafx.scene.layout.HBox;
 
-import envoy.client.data.audio.AudioPlayer;
 import envoy.exception.EnvoyException;
 import envoy.util.EnvoyLog;
 
+import envoy.client.data.audio.AudioPlayer;
+
 /**
  * Enables the play back of audio clips through a button.
- * <p>
- * Project: <strong>envoy-client</strong><br>
- * File: <strong>AudioControl.java</strong><br>
- * Created: <strong>05.07.2020</strong><br>
  *
  * @author Kai S. K. Engelbart
  * @since Envoy Client v0.1-beta
  */
 public final class AudioControl extends HBox {
 
-	private AudioPlayer player = new AudioPlayer();
+	private final AudioPlayer player = new AudioPlayer();
 
 	private static final Logger logger = EnvoyLog.getLogger(AudioControl.class);
 

client/src/main/java/envoy/client/ui/control/ChatControl.java

@@ -0,0 +1,63 @@
+package envoy.client.ui.control;
+
+import javafx.geometry.*;
+import javafx.scene.control.Label;
+import javafx.scene.image.Image;
+import javafx.scene.layout.*;
+
+import envoy.client.data.*;
+import envoy.client.util.IconUtil;
+
+/**
+ * Displays a chat using a contact control for the recipient and a label for the unread message
+ * count.
+ *
+ * @see ContactControl
+ * @author Leon Hofmeister
+ * @since Envoy Client v0.1-beta
+ */
+public final class ChatControl extends HBox {
+
+	private static final Image userIcon = IconUtil.loadIconThemeSensitive("user_icon", 32),
+		groupIcon = IconUtil.loadIconThemeSensitive("group_icon", 32);
+
+	/**
+	 * Creates a new {@code ChatControl}.
+	 *
+	 * @param chat the chat to display
+	 * @since Envoy Client v0.1-beta
+	 */
+	public ChatControl(Chat chat) {
+		setAlignment(Pos.CENTER_LEFT);
+		setPadding(new Insets(0, 0, 3, 0));
+
+		// Profile picture
+		var contactProfilePic =
+			new ProfilePicImageView(chat instanceof GroupChat ? groupIcon : userIcon, 32);
+		getChildren().add(contactProfilePic);
+
+		// Spacing
+		var leftSpacing = new Region();
+		leftSpacing.setPrefSize(8, 0);
+		leftSpacing.setMinSize(8, 0);
+		leftSpacing.setMaxSize(8, 0);
+		getChildren().add(leftSpacing);
+
+		// Contact control
+		getChildren().add(new ContactControl(chat.getRecipient()));
+
+		// Unread messages
+		if (chat.getUnreadAmount() != 0) {
+			var spacing = new Region();
+			setHgrow(spacing, Priority.ALWAYS);
+			getChildren().add(spacing);
+			var unreadMessagesLabel = new Label(
+				chat.getUnreadAmount() > 99 ? "99+" : String.valueOf(chat.getUnreadAmount()));
+			unreadMessagesLabel.setMinSize(15, 15);
+			unreadMessagesLabel.setAlignment(Pos.CENTER_RIGHT);
+			unreadMessagesLabel.getStyleClass().add("unread-messages-amount");
+			getChildren().add(unreadMessagesLabel);
+		}
+		getStyleClass().add("list-element");
+	}
+}

client/src/main/java/envoy/client/ui/control/ContactControl.java

@@ -0,0 +1,51 @@
+package envoy.client.ui.control;
+
+import javafx.scene.control.Label;
+import javafx.scene.layout.VBox;
+
+import envoy.data.*;
+
+/**
+ * Displays information about a contact in two rows. The first row contains the name. The second row
+ * contains the online status (user) or the member count (group).
+ *
+ * @author Kai S. K. Engelbart
+ * @since Envoy Client v0.2-beta
+ */
+public final class ContactControl extends VBox {
+
+	private final Contact contact;
+
+	/**
+	 * @param contact the contact to display
+	 * @since Envoy Client v0.2-beta
+	 */
+	public ContactControl(Contact contact) {
+		this.contact = contact;
+
+		// Name label
+		final var nameLabel = new Label(contact.getName());
+		getChildren().add(nameLabel);
+
+		// Online status (user) or member count (group)
+		getChildren().add(contact instanceof User ? new UserStatusLabel((User) contact)
+			: new GroupSizeLabel((Group) contact));
+
+		getStyleClass().add("list-element");
+	}
+
+	/**
+	 * Replaces the info label of this {@code ContactControl} with an updated version.
+	 * <p>
+	 * This method should be called when the status of the underlying user or the size of the
+	 * underlying group has changed.
+	 *
+	 * @since Envoy Client v0.3-beta
+	 * @apiNote will produce buggy results if contact control gets updated so that the info label is
+	 *          no longer on index 1.
+	 */
+	public void replaceInfoLabel() {
+		getChildren().set(1, contact instanceof User ? new UserStatusLabel((User) contact)
+			: new GroupSizeLabel((Group) contact));
+	}
+}

client/src/main/java/envoy/client/ui/control/GroupSizeLabel.java

@@ -0,0 +1,23 @@
+package envoy.client.ui.control;
+
+import javafx.scene.control.Label;
+
+import envoy.data.Group;
+
+/**
+ * Displays the amount of members in a {@link Group}.
+ *
+ * @author Leon Hofmeister
+ * @since Envoy Client v0.3-beta
+ */
+public final class GroupSizeLabel extends Label {
+
+	/**
+	 * @param recipient the group whose members to show
+	 * @since Envoy Client v0.3-beta
+	 */
+	public GroupSizeLabel(Group recipient) {
+		super(recipient.getContacts().size() + " member"
+			+ (recipient.getContacts().size() != 1 ? "s" : ""));
+	}
+}

client/src/main/java/envoy/client/ui/control/MessageControl.java

@@ -0,0 +1,165 @@
+package envoy.client.ui.control;
+
+import java.io.ByteArrayInputStream;
+import java.time.ZoneId;
+import java.time.format.DateTimeFormatter;
+import java.util.Map;
+import java.util.logging.*;
+
+import javafx.geometry.*;
+import javafx.scene.control.*;
+import javafx.scene.image.*;
+import javafx.scene.layout.*;
+
+import envoy.data.*;
+import envoy.data.Message.MessageStatus;
+import envoy.util.EnvoyLog;
+
+import envoy.client.data.*;
+import envoy.client.net.Client;
+import envoy.client.util.*;
+
+/**
+ * This class transforms a single {@link Message} into a UI component.
+ *
+ * @author Leon Hofmeister
+ * @author Maximilian Käfer
+ * @since Envoy Client v0.1-beta
+ */
+public final class MessageControl extends Label {
+
+	private final boolean ownMessage;
+
+	private final LocalDB	localDB	= context.getLocalDB();
+	private final Client	client	= context.getClient();
+
+	private static final Context					context			= Context.getInstance();
+	private static final DateTimeFormatter			dateFormat		=
+		DateTimeFormatter.ofPattern("dd.MM.yyyy HH:mm:ss")
+			.withZone(ZoneId.systemDefault());
+	private static final Map<MessageStatus, Image>	statusImages	=
+		IconUtil.loadByEnum(MessageStatus.class, 16);
+	private static final Logger						logger			=
+		EnvoyLog.getLogger(MessageControl.class);
+
+	/**
+	 * @param message the message that should be formatted
+	 * @since Envoy Client v0.1-beta
+	 */
+	public MessageControl(Message message) {
+		ownMessage = message.getSenderID() == localDB.getUser().getID();
+
+		// Creating the underlying VBox and the dateLabel
+		final var hbox = new HBox();
+		if (message.getSenderID() != localDB.getUser().getID() && message instanceof GroupMessage) {
+			// Displaying the name of the sender in a group
+			final var label = new Label();
+			label.getStyleClass().add("group-member-names");
+			label.setText(localDB.getUsers()
+				.values()
+				.stream()
+				.filter(c -> c.getID() == message.getSenderID())
+				.findFirst()
+				.map(User::getName)
+				.orElse("Unknown User"));
+			label.setPadding(new Insets(0, 5, 0, 0));
+			hbox.getChildren().add(label);
+		}
+		hbox.getChildren().add(new Label(dateFormat.format(message.getCreationDate())));
+		final var vbox = new VBox(hbox);
+
+		// Creating the actions for the MenuItems
+		final var	contextMenu	= new ContextMenu();
+		final var	items		= contextMenu.getItems();
+
+		// Copy message action
+		if (!message.getText().isEmpty()) {
+			final var copyMenuItem = new MenuItem("Copy Text");
+			copyMenuItem.setOnAction(e -> MessageUtil.copyMessageText(message));
+			items.add(copyMenuItem);
+		}
+
+		// Delete message
+		final var deleteMenuItem = new MenuItem("Delete locally");
+		deleteMenuItem.setOnAction(e -> MessageUtil.deleteMessage(message));
+		items.add(deleteMenuItem);
+
+		// As long as these types of messages are not implemented and no caches are
+		// defined for them, we only want them to appear when being online
+		if (client.isOnline()) {
+
+			// Forward menu item
+			final var forwardMenuItem = new MenuItem("Forward");
+			forwardMenuItem.setOnAction(e -> MessageUtil.forwardMessage(message));
+			items.add(forwardMenuItem);
+
+			// Quote menu item
+			final var quoteMenuItem = new MenuItem("Quote");
+			quoteMenuItem.setOnAction(e -> MessageUtil.quoteMessage(message));
+			items.add(quoteMenuItem);
+		}
+
+		// Info actions
+		final var infoMenuItem = new MenuItem("Info");
+		infoMenuItem.setOnAction(e -> loadMessageInfoScene(message));
+		items.add(infoMenuItem);
+
+		// Handling message attachment display
+		// TODO: Add missing attachment types
+		if (message.hasAttachment()) {
+			switch (message.getAttachment().getType()) {
+				case PICTURE:
+					vbox.getChildren()
+						.add(new ImageView(
+							new Image(new ByteArrayInputStream(message.getAttachment().getData()),
+								256, 256, true, true)));
+					break;
+				case VIDEO:
+					break;
+				case VOICE:
+					vbox.getChildren().add(new AudioControl(message.getAttachment().getData()));
+					break;
+				case DOCUMENT:
+					break;
+			}
+			final var saveAttachment = new MenuItem("Save attachment");
+			saveAttachment.setOnAction(e -> MessageUtil.saveAttachment(message));
+			items.add(saveAttachment);
+		}
+		// Creating the textLabel
+		final var textLabel = new Label(message.getText());
+		textLabel.setMaxWidth(430);
+		textLabel.setWrapText(true);
+		final var hBoxBottom = new HBox();
+		hBoxBottom.getChildren().add(textLabel);
+		// Setting the message status icon and background color
+		if (message.getSenderID() == localDB.getUser().getID()) {
+			final var statusIcon = new ImageView(statusImages.get(message.getStatus()));
+			statusIcon.setPreserveRatio(true);
+			final var space = new Region();
+			HBox.setHgrow(space, Priority.ALWAYS);
+			hBoxBottom.getChildren().add(space);
+			hBoxBottom.getChildren().add(statusIcon);
+			hBoxBottom.setAlignment(Pos.BOTTOM_RIGHT);
+			getStyleClass().add("own-message");
+			hbox.setAlignment(Pos.CENTER_RIGHT);
+		} else
+			getStyleClass().add("received-message");
+		vbox.getChildren().add(hBoxBottom);
+		// Adjusting height and weight of the cell to the corresponding ListView
+		paddingProperty().setValue(new Insets(5, 20, 5, 20));
+		setContextMenu(contextMenu);
+		setGraphic(vbox);
+	}
+
+	private void loadMessageInfoScene(Message message) {
+		logger.log(Level.FINEST, "message info scene was requested for " + message);
+	}
+
+	/**
+	 * @return whether the message stored by this {@code MessageControl} has been sent by this user
+	 *         of Envoy
+	 * @since Envoy Client v0.1-beta
+	 */
+	public boolean isOwnMessage() { return ownMessage; }
+}

client/src/main/java/envoy/client/ui/control/ProfilePicImageView.java

@@ -0,0 +1,61 @@
+package envoy.client.ui.control;
+
+import javafx.scene.image.*;
+import javafx.scene.shape.Rectangle;
+
+/**
+ * Provides a set of convenience constructors for images that are displayed as profile pictures.
+ *
+ * @author Leon Hofmeister
+ * @since Envoy Client v0.2-beta
+ */
+public final class ProfilePicImageView extends ImageView {
+
+	/**
+	 * Creates a new {@code ProfilePicImageView} without a default image.
+	 *
+	 * @since Envoy Client v0.2-beta
+	 */
+	public ProfilePicImageView() {
+		this(null);
+	}
+
+	/**
+	 * Creates a new {@code ProfilePicImageView}.
+	 *
+	 * @param image the image to display
+	 * @since Envoy Client v0.2-beta
+	 */
+	public ProfilePicImageView(Image image) {
+		this(image, 40);
+	}
+
+	/**
+	 * Creates a new {@code ProfilePicImageView}.
+	 *
+	 * @param image           the image to display
+	 * @param sizeAndRounding the size and rounding for a circular {@code ProfilePicImageView}
+	 * @since Envoy Client v0.2-beta
+	 */
+	public ProfilePicImageView(Image image, double sizeAndRounding) {
+		this(image, sizeAndRounding, sizeAndRounding);
+	}
+
+	/**
+	 * Creates a new {@code ProfilePicImageView}.
+	 *
+	 * @param image    the image to display
+	 * @param size     the size of this {@code ProfilePicImageView}
+	 * @param rounding how rounded this {@code ProfilePicImageView} should be
+	 * @since Envoy Client v0.2-beta
+	 */
+	public ProfilePicImageView(Image image, double size, double rounding) {
+		super(image);
+		final var clip = new Rectangle();
+		clip.setWidth(size);
+		clip.setHeight(size);
+		clip.setArcHeight(rounding);
+		clip.setArcWidth(rounding);
+		setClip(clip);
+	}
+}

client/src/main/java/envoy/client/ui/control/QuickSelectControl.java

@@ -0,0 +1,94 @@
+package envoy.client.ui.control;
+
+import java.util.function.Consumer;
+
+import javafx.geometry.*;
+import javafx.scene.control.*;
+import javafx.scene.image.ImageView;
+import javafx.scene.layout.*;
+import javafx.scene.shape.Rectangle;
+
+import envoy.data.User;
+
+import envoy.client.util.IconUtil;
+
+/**
+ * Displays an {@link User} as a quick select control which is used in the quick select list.
+ *
+ * @author Maximilian Käfer
+ * @since Envoy Client v0.3-beta
+ */
+public class QuickSelectControl extends VBox {
+
+	private final User user;
+
+	/**
+	 * Creates an instance of the {@code QuickSelectControl}.
+	 *
+	 * @param user   the contact whose data is used to create this instance.
+	 * @param action the action to perform when a contact is removed with this control as a
+	 *               parameter
+	 * @since Envoy Client v0.3-beta
+	 */
+	public QuickSelectControl(User user, Consumer<QuickSelectControl> action) {
+		this.user = user;
+		setPadding(new Insets(1, 0, 0, 0));
+		setPrefWidth(37);
+		setMaxWidth(37);
+		setMinWidth(37);
+		var stackPane = new StackPane();
+		stackPane.setAlignment(Pos.TOP_CENTER);
+
+		// Profile picture
+		var picHold = new VBox();
+		picHold.setPadding(new Insets(2, 0, 0, 0));
+		picHold.setPrefHeight(35);
+		picHold.setMaxHeight(35);
+		picHold.setMinHeight(35);
+		var			contactProfilePic	=
+			new ImageView(IconUtil.loadIconThemeSensitive("user_icon", 32));
+		final var	clip				= new Rectangle();
+		clip.setWidth(32);
+		clip.setHeight(32);
+		clip.setArcHeight(32);
+		clip.setArcWidth(32);
+		contactProfilePic.setClip(clip);
+		picHold.getChildren().add(contactProfilePic);
+		stackPane.getChildren().add(picHold);
+
+		var hBox = new HBox();
+		hBox.setPrefHeight(12);
+		hBox.setMaxHeight(12);
+		hBox.setMinHeight(12);
+		var region = new Region();
+		hBox.getChildren().add(region);
+		HBox.setHgrow(region, Priority.ALWAYS);
+
+		var removeBtn = new Button();
+		removeBtn.setPrefSize(12, 12);
+		removeBtn.setMaxSize(12, 12);
+		removeBtn.setMinSize(12, 12);
+		removeBtn.setOnMouseClicked(evt -> action.accept(this));
+		removeBtn.setId("remove-button");
+		hBox.getChildren().add(removeBtn);
+		stackPane.getChildren().add(hBox);
+		getChildren().add(stackPane);
+
+		var nameLabel = new Label();
+		nameLabel.setPrefSize(35, 20);
+		nameLabel.setMaxSize(35, 20);
+		nameLabel.setMinSize(35, 20);
+		nameLabel.setText(user.getName());
+		nameLabel.setAlignment(Pos.TOP_CENTER);
+		nameLabel.setPadding(new Insets(0, 5, 0, 0));
+		getChildren().add(nameLabel);
+
+		getStyleClass().add("quick-select");
+	}
+
+	/**
+	 * @return the user whose data is used in this instance
+	 * @since Envoy Client v0.3-beta
+	 */
+	public User getUser() { return user; }
+}

client/src/main/java/envoy/client/ui/control/UserStatusLabel.java

@@ -0,0 +1,23 @@
+package envoy.client.ui.control;
+
+import javafx.scene.control.Label;
+
+import envoy.data.User;
+
+/**
+ * Displays the status of a {@link User}.
+ *
+ * @author Leon Hofmeister
+ * @since Envoy Client v0.3-beta
+ */
+public final class UserStatusLabel extends Label {
+
+	/**
+	 * @param user the user whose status to display
+	 * @since Envoy Client v0.3-beta
+	 */
+	public UserStatusLabel(User user) {
+		super(user.getStatus().toString());
+		getStyleClass().add(user.getStatus().toString().toLowerCase());
+	}
+}

client/src/main/java/envoy/client/ui/control/package-info.java

@@ -0,0 +1,9 @@
+/**
+ * Defines custom UI controls.
+ *
+ * @author Kai S. K. Engelbart
+ * @author Leon Hofmeister
+ * @author Maximilian Käfer
+ * @since Envoy Client v0.2-beta
+ */
+package envoy.client.ui.control;

client/src/main/java/envoy/client/ui/controller/ContactSearchScene.java

@@ -1,130 +0,0 @@
-package envoy.client.ui.controller;
-
-import java.util.logging.Level;
-import java.util.logging.Logger;
-import java.util.stream.Collectors;
-
-import javafx.application.Platform;
-import javafx.fxml.FXML;
-import javafx.scene.control.Alert;
-import javafx.scene.control.Alert.AlertType;
-import javafx.scene.control.ButtonType;
-import javafx.scene.control.ListView;
-
-import envoy.client.data.Chat;
-import envoy.client.data.LocalDB;
-import envoy.client.event.SendEvent;
-import envoy.client.ui.ClearableTextField;
-import envoy.client.ui.SceneContext;
-import envoy.client.ui.listcell.ContactListCellFactory;
-import envoy.event.ElementOperation;
-import envoy.event.EventBus;
-import envoy.event.contact.ContactOperation;
-import envoy.event.contact.ContactSearchRequest;
-import envoy.event.contact.ContactSearchResult;
-import envoy.util.EnvoyLog;
-
-/**
- * Project: <strong>envoy-client</strong><br>
- * File: <strong>ContactSearchSceneController.java</strong><br>
- * Created: <strong>07.06.2020</strong><br>
- *
- * @author Leon Hofmeister
- * @since Envoy Client v0.1-beta
- */
-public class ContactSearchScene {
-
-	@FXML
-	private ClearableTextField searchBar;
-
-	@FXML
-	private ListView<Chat> chatList;
-
-	private SceneContext sceneContext;
-
-	private LocalDB localDB;
-
-	private static EventBus		eventBus	= EventBus.getInstance();
-	private static final Logger	logger		= EnvoyLog.getLogger(ChatScene.class);
-
-	/**
-	 * @param sceneContext enables the user to return to the chat scene
-	 * @param localDB      the local database to which new contacts are added
-	 * @since Envoy Client v0.1-beta
-	 */
-	public void initializeData(SceneContext sceneContext, LocalDB localDB) {
-		this.sceneContext	= sceneContext;
-		this.localDB		= localDB;
-	}
-
-	@FXML
-	private void initialize() {
-		chatList.setCellFactory(ContactListCellFactory::new);
-		searchBar.setClearButtonListener(e -> { searchBar.getTextField().clear(); chatList.getItems().clear(); });
-		eventBus.register(ContactSearchResult.class,
-				response -> Platform.runLater(() -> {
-					chatList.getItems().clear();
-					chatList.getItems().addAll(response.get().stream().map(Chat::new).collect(Collectors.toList()));
-				}));
-	}
-
-	/**
-	 * Disables the clear and search button if no text is present in the search bar.
-	 *
-	 * @since Envoy Client v0.1-beta
-	 */
-	@FXML
-	private void sendRequest() {
-		final var text = searchBar.getTextField().getText().strip();
-		if (!text.isBlank()) eventBus.dispatch(new SendEvent(new ContactSearchRequest(text)));
-		else chatList.getItems().clear();
-	}
-
-	/**
-	 * Clears the text in the search bar and the items shown in the list.
-	 * Additionally disables both clear and search button.
-	 *
-	 * @since Envoy Client v0.1-beta
-	 */
-	@FXML
-	private void clear() {
-		searchBar.getTextField().setText(null);
-		chatList.getItems().clear();
-	}
-
-	/**
-	 * Sends an {@link ContactOperation} for every selected contact to the
-	 * server.
-	 *
-	 * @since Envoy Client v0.1-beta
-	 */
-	@FXML
-	private void chatListClicked() {
-		final var chat = chatList.getSelectionModel().getSelectedItem();
-		if (chat != null) {
-			final var alert = new Alert(AlertType.CONFIRMATION);
-			alert.setTitle("Add Contact to Contact List");
-			alert.setHeaderText("Add the user " + chat.getRecipient().getName() + " to your contact list?");
-			// Normally, this would be total BS (we are already on the FX Thread), however
-			// it could be proven that the creation of this dialog wrapped in
-			// Platform.runLater is less error-prone than without it
-			Platform.runLater(() -> alert.showAndWait().filter(btn -> btn == ButtonType.OK).ifPresent(btn -> {
-				final var event = new ContactOperation(chat.getRecipient(), ElementOperation.ADD);
-				// Sends the event to the server
-				eventBus.dispatch(new SendEvent(event));
-				// Updates the UI
-				eventBus.dispatch(event);
-				logger.log(Level.INFO, "Added contact " + chat.getRecipient());
-			}));
-		}
-	}
-
-	@FXML
-	private void newGroupButtonClicked() {
-		sceneContext.load(SceneContext.SceneInfo.GROUP_CREATION_SCENE);
-		sceneContext.<GroupCreationScene>getController().initializeData(sceneContext, localDB);
-	}
-
-	@FXML
-	private void backButtonClicked() { sceneContext.pop(); }
-}

client/src/main/java/envoy/client/ui/controller/ContactSearchTab.java

@@ -0,0 +1,139 @@
+package envoy.client.ui.controller;
+
+import java.util.logging.*;
+
+import javafx.application.Platform;
+import javafx.fxml.FXML;
+import javafx.scene.control.*;
+import javafx.scene.control.Alert.AlertType;
+
+import dev.kske.eventbus.*;
+
+import envoy.data.User;
+import envoy.event.ElementOperation;
+import envoy.event.contact.*;
+import envoy.util.EnvoyLog;
+
+import envoy.client.data.Context;
+import envoy.client.event.BackEvent;
+import envoy.client.helper.AlertHelper;
+import envoy.client.net.Client;
+import envoy.client.ui.control.ContactControl;
+import envoy.client.ui.listcell.ListCellFactory;
+
+/**
+ * Provides a search bar in which a user name (substring) can be entered. The users with a matching
+ * name are then displayed inside a list view. A {@link UserSearchRequest} is sent on every
+ * keystroke.
+ * <p>
+ * <i>The actual search algorithm is implemented on the server.
+ * <p>
+ * To create a group, a button is available that loads the {@link GroupCreationTab}.
+ *
+ * @author Leon Hofmeister
+ * @author Maximilian K&auml;fer
+ * @since Envoy Client v0.1-beta
+ */
+public class ContactSearchTab implements EventListener {
+
+	@FXML
+	private TextArea searchBar;
+
+	@FXML
+	private ListView<User> userList;
+
+	private User currentlySelectedUser;
+
+	private final Alert alert = new Alert(AlertType.CONFIRMATION);
+
+	private static final Client		client		= Context.getInstance().getClient();
+	private static final EventBus	eventBus	= EventBus.getInstance();
+	private static final Logger		logger		= EnvoyLog.getLogger(ChatScene.class);
+
+	@FXML
+	private void initialize() {
+		eventBus.registerListener(this);
+		userList.setCellFactory(new ListCellFactory<>(ContactControl::new));
+		alert.setTitle("Add User?");
+	}
+
+	@Event
+	private void onUserSearchResult(UserSearchResult result) {
+		Platform.runLater(() -> {
+			userList.getItems().clear();
+			userList.getItems().addAll(result.get());
+		});
+	}
+
+	@Event
+	private void onUserOperation(UserOperation operation) {
+		final var contact = operation.get();
+		if (operation.getOperationType() == ElementOperation.ADD)
+			Platform.runLater(() -> {
+				userList.getItems().remove(contact);
+				if (currentlySelectedUser != null && currentlySelectedUser.equals(contact)
+					&& alert.isShowing())
+					alert.close();
+			});
+	}
+
+	/**
+	 * If text is present, sends a request to the server.
+	 *
+	 * @since Envoy Client v0.1-beta
+	 */
+	@FXML
+	private void sendRequest() {
+		final var text = searchBar.getText().strip();
+		if (!text.isBlank())
+			client.send(new UserSearchRequest(text));
+		else
+			userList.getItems().clear();
+	}
+
+	/**
+	 * Clears the text in the search bar and the items shown in the list. Additionally disables both
+	 * clear and search button.
+	 *
+	 * @since Envoy Client v0.1-beta
+	 */
+	@FXML
+	private void clear() {
+		searchBar.setText(null);
+		userList.getItems().clear();
+	}
+
+	/**
+	 * Sends an {@link UserOperation} for the selected user to the server.
+	 *
+	 * @since Envoy Client v0.1-beta
+	 */
+	@FXML
+	private void userListClicked() {
+		final var user = userList.getSelectionModel().getSelectedItem();
+		if (user != null) {
+			currentlySelectedUser = user;
+			alert.setContentText(
+				"Add user " + currentlySelectedUser.getName() + " to your contacts?");
+			AlertHelper.confirmAction(alert, this::addAsContact);
+		}
+	}
+
+	private void addAsContact() {
+
+		// Sends the event to the server
+		final var event = new UserOperation(currentlySelectedUser, ElementOperation.ADD);
+		client.send(event);
+
+		// Removes the chosen user and updates the UI
+		userList.getItems().remove(currentlySelectedUser);
+		eventBus.dispatch(event);
+		logger.log(Level.INFO, "Added user " + currentlySelectedUser);
+	}
+
+	@FXML
+	private void backButtonClicked() {
+		searchBar.setText("");
+		eventBus.dispatch(new BackEvent());
+	}
+}

client/src/main/java/envoy/client/ui/controller/GroupCreationScene.java

@@ -1,109 +0,0 @@
-package envoy.client.ui.controller;
-
-import java.util.stream.Collectors;
-
-import javafx.application.Platform;
-import javafx.fxml.FXML;
-import javafx.scene.control.*;
-import javafx.scene.control.Alert.AlertType;
-
-import envoy.client.data.Chat;
-import envoy.client.data.LocalDB;
-import envoy.client.event.SendEvent;
-import envoy.client.ui.ClearableTextField;
-import envoy.client.ui.SceneContext;
-import envoy.client.ui.listcell.ContactListCellFactory;
-import envoy.data.Group;
-import envoy.event.EventBus;
-import envoy.event.GroupCreation;
-import envoy.util.Bounds;
-
-/**
- * Project: <strong>envoy-client</strong><br>
- * File: <strong>ContactSearchSceneController.java</strong><br>
- * Created: <strong>07.06.2020</strong><br>
- *
- * @author Maximilian K&auml;fer
- * @since Envoy Client v0.1-beta
- */
-public class GroupCreationScene {
-
-	@FXML
-	private Button createButton;
-
-	@FXML
-	private ClearableTextField groupNameField;
-
-	@FXML
-	private ListView<Chat> chatList;
-
-	private SceneContext sceneContext;
-
-	private static final EventBus eventBus = EventBus.getInstance();
-
-	@FXML
-	private void initialize() {
-		chatList.setCellFactory(ContactListCellFactory::new);
-		chatList.getSelectionModel().setSelectionMode(SelectionMode.MULTIPLE);
-		groupNameField.setClearButtonListener(e -> { groupNameField.getTextField().clear(); createButton.setDisable(true); });
-	}
-
-	/**
-	 * @param sceneContext enables the user to return to the chat scene
-	 * @param localDB      the local database from which potential group members can
-	 *                     be selected
-	 * @since Envoy Client v0.1-beta
-	 */
-	public void initializeData(SceneContext sceneContext, LocalDB localDB) {
-		this.sceneContext = sceneContext;
-		Platform.runLater(() -> chatList.getItems()
-			.addAll(localDB.getChats()
-				.stream()
-				.filter(c -> !(c.getRecipient() instanceof Group))
-				.filter(c -> c.getRecipient().getID() != localDB.getUser().getID())
-				.collect(Collectors.toList())));
-	}
-
-	/**
-	 * Enables the {@code createButton} if at least one contact is selected.
-	 *
-	 * @since Envoy Client v0.1-beta
-	 */
-	@FXML
-	private void chatListClicked() {
-		createButton.setDisable(chatList.getSelectionModel().isEmpty() || groupNameField.getTextField().getText().isBlank());
-	}
-
-	/**
-	 * Checks, whether the {@code createButton} can be enabled because text is
-	 * present in the textfield.
-	 *
-	 * @since Envoy Client v0.1-beta
-	 */
-	@FXML
-	private void textUpdated() { createButton.setDisable(groupNameField.getTextField().getText().isBlank()); }
-
-	/**
-	 * Sends a {@link GroupCreation} to the server and closes this scene.
-	 * <p>
-	 * If the given group name is not valid, an error is displayed instead.
-	 *
-	 * @since Envoy Client v0.1-beta
-	 */
-	@FXML
-	private void createButtonClicked() {
-		final var name = groupNameField.getTextField().getText();
-		if (!Bounds.isValidContactName(name)) {
-			new Alert(AlertType.ERROR, "The entered group name is not valid (" + Bounds.CONTACT_NAME_PATTERN + ")").showAndWait();
-			groupNameField.getTextField().clear();
-		} else {
-			eventBus.dispatch(new SendEvent(new GroupCreation(name,
-					chatList.getSelectionModel().getSelectedItems().stream().map(c -> c.getRecipient().getID()).collect(Collectors.toSet()))));
-			new Alert(AlertType.INFORMATION, String.format("Group '%s' successfully created.", name)).showAndWait();
-			sceneContext.pop();
-		}
-	}
-
-	@FXML
-	private void backButtonClicked() { sceneContext.pop(); }
-}

client/src/main/java/envoy/client/ui/controller/GroupCreationTab.java

@@ -0,0 +1,255 @@
+package envoy.client.ui.controller;
+
+import static java.util.function.Predicate.not;
+
+import java.util.stream.Collectors;
+
+import javafx.application.Platform;
+import javafx.fxml.FXML;
+import javafx.scene.control.*;
+import javafx.scene.input.MouseEvent;
+import javafx.scene.layout.HBox;
+
+import dev.kske.eventbus.*;
+
+import envoy.data.*;
+import envoy.event.GroupCreation;
+import envoy.event.contact.UserOperation;
+import envoy.util.Bounds;
+
+import envoy.client.data.*;
+import envoy.client.event.BackEvent;
+import envoy.client.ui.control.*;
+import envoy.client.ui.listcell.ListCellFactory;
+
+/**
+ * Provides a group creation interface. A group name can be entered in the text field at the top.
+ * Available users (local chat recipients) are displayed inside a list and can be selected (multiple
+ * selection available).
+ * <p>
+ * When the group creation button is pressed, a {@link GroupCreation} is sent to the server. This
+ * controller enforces a valid group name and a non-empty member list (excluding the client user).
+ *
+ * @author Maximilian K&auml;fer
+ * @since Envoy Client v0.1-beta
+ */
+public class GroupCreationTab implements EventListener {
+
+	@FXML
+	private Button createButton;
+
+	@FXML
+	private Button cancelButton;
+
+	@FXML
+	private TextArea groupNameField;
+
+	@FXML
+	private ListView<User> userList;
+
+	@FXML
+	private Label errorMessageLabel;
+
+	@FXML
+	private Button proceedDuplicateButton;
+
+	@FXML
+	private Button cancelDuplicateButton;
+
+	@FXML
+	private HBox errorProceedBox;
+
+	@FXML
+	private ListView<QuickSelectControl> quickSelectList;
+
+	private String name;
+
+	private final LocalDB localDB = Context.getInstance().getLocalDB();
+
+	private static final EventBus eventBus = EventBus.getInstance();
+
+	@FXML
+	private void initialize() {
+		userList.setCellFactory(new ListCellFactory<>(ContactControl::new));
+		createButton.setDisable(true);
+		eventBus.registerListener(this);
+		userList.getItems()
+			.addAll(localDB.getChats()
+				.stream()
+				.map(Chat::getRecipient)
+				.filter(User.class::isInstance)
+				.filter(not(localDB.getUser()::equals))
+				.map(User.class::cast)
+				.collect(Collectors.toList()));
+		resizeQuickSelectSpace(0);
+		quickSelectList.addEventFilter(MouseEvent.MOUSE_PRESSED, MouseEvent::consume);
+	}
+
+	/**
+	 * Enables the {@code createButton} if at least one contact is selected.
+	 *
+	 * @since Envoy Client v0.1-beta
+	 */
+	@FXML
+	private void userListClicked() {
+		if (userList.getSelectionModel().getSelectedItem() != null) {
+			quickSelectList.getItems().add(new QuickSelectControl(
+				userList.getSelectionModel().getSelectedItem(), this::removeFromQuickSelection));
+			createButton.setDisable(
+				quickSelectList.getItems().isEmpty() || groupNameField.getText().isBlank());
+			resizeQuickSelectSpace(60);
+			userList.getItems().remove(userList.getSelectionModel().getSelectedItem());
+			userList.getSelectionModel().clearSelection();
+		}
+	}
+
+	/**
+	 * Checks, whether the {@code createButton} can be enabled because text is present in the text
+	 * field.
+	 *
+	 * @since Envoy Client v0.1-beta
+	 */
+	@FXML
+	private void textUpdated() {
+		createButton
+			.setDisable(quickSelectList.getItems().isEmpty() || groupNameField.getText().isBlank());
+	}
+
+	/**
+	 * Sends a {@link GroupCreation} to the server and closes this scene.
+	 * <p>
+	 * If the given group name is not valid, an error is displayed instead.
+	 *
+	 * @since Envoy Client v0.1-beta
+	 */
+	@FXML
+	private void createButtonClicked() {
+		name = groupNameField.getText();
+		if (!Bounds.isValidContactName(name)) {
+			setErrorMessageLabelSize(30);
+			errorMessageLabel.setText("The group name is not valid!");
+			groupNameField.clear();
+		} else if (groupNameAlreadyPresent(name)) {
+			setErrorMessageLabelSize(30);
+			errorMessageLabel.setText("Name does already exist! Proceed anyways?");
+			setProcessPaneSize(30);
+			createButton.setDisable(true);
+			cancelButton.setDisable(true);
+		} else {
+			createGroup(name);
+			eventBus.dispatch(new BackEvent());
+			// Restoring the original design as tabs will always be reused
+			setErrorMessageLabelSize(0);
+			groupNameField.clear();
+			quickSelectList.getItems().forEach(q -> userList.getItems().add(q.getUser()));
+			quickSelectList.getItems().clear();
+			resizeQuickSelectSpace(0);
+		}
+	}
+
+	/**
+	 * Creates a new group with the given name and all selected members.<br>
+	 * Additionally pops the scene automatically.
+	 *
+	 * @param name the chosen group name
+	 * @since Envoy Client v0.1-beta
+	 */
+	private void createGroup(String name) {
+		Context.getInstance()
+			.getClient()
+			.send(new GroupCreation(name, quickSelectList.getItems().stream()
+				.map(q -> q.getUser().getID()).collect(Collectors.toSet())));
+	}
+
+	/**
+	 * Returns true if the proposed group name is already present in the users {@code LocalDB}.
+	 *
+	 * @param newName the chosen group name
+	 * @return true if this name is already present
+	 * @since Envoy Client v0.1-beta
+	 */
+	public boolean groupNameAlreadyPresent(String newName) {
+		return localDB.getChats().stream().map(Chat::getRecipient).filter(Group.class::isInstance)
+			.map(Contact::getName).anyMatch(newName::equals);
+	}
+
+	/**
+	 * Removes an element from the quickSelectList.
+	 *
+	 * @param element the element to be removed.
+	 * @since Envoy Client v0.3-beta
+	 */
+	public void removeFromQuickSelection(QuickSelectControl element) {
+		quickSelectList.getItems().remove(element);
+		userList.getItems().add(element.getUser());
+		if (quickSelectList.getItems().isEmpty()) {
+			resizeQuickSelectSpace(0);
+			createButton.setDisable(true);
+		}
+	}
+
+	private void resizeQuickSelectSpace(int value) {
+		quickSelectList.setPrefHeight(value);
+		quickSelectList.setMaxHeight(value);
+		quickSelectList.setMinHeight(value);
+	}
+
+	@FXML
+	private void backButtonClicked() {
+		eventBus.dispatch(new BackEvent());
+		setErrorMessageLabelSize(0);
+		setProcessPaneSize(0);
+	}
+
+	@FXML
+	private void proceedOnNameDuplication() {
+		createButton.setDisable(false);
+		cancelButton.setDisable(false);
+		createGroup(name);
+		eventBus.dispatch(new BackEvent());
+		setErrorMessageLabelSize(0);
+		setProcessPaneSize(0);
+		groupNameField.clear();
+	}
+
+	@FXML
+	private void cancelOnNameDuplication() {
+		createButton.setDisable(false);
+		cancelButton.setDisable(false);
+		setErrorMessageLabelSize(0);
+		setProcessPaneSize(0);
+		groupNameField.clear();
+	}
+
+	private void setErrorMessageLabelSize(int value) {
+		errorMessageLabel.setPrefHeight(value);
+		errorMessageLabel.setMinHeight(value);
+		errorMessageLabel.setMaxHeight(value);
+	}
+
+	private void setProcessPaneSize(int value) {
+		proceedDuplicateButton.setPrefHeight(value);
+		proceedDuplicateButton.setMinHeight(value);
+		proceedDuplicateButton.setMaxHeight(value);
+		cancelDuplicateButton.setPrefHeight(value);
+		cancelDuplicateButton.setMinHeight(value);
+		cancelDuplicateButton.setMaxHeight(value);
+		errorProceedBox.setPrefHeight(value);
+		errorProceedBox.setMinHeight(value);
+		errorProceedBox.setMaxHeight(value);
+	}
+
+	@Event
+	private void onUserOperation(UserOperation operation) {
+		Platform.runLater(() -> {
+			switch (operation.getOperationType()) {
+				case ADD:
+					userList.getItems().add(operation.get());
+					break;
+				case REMOVE:
+					userList.getItems().removeIf(operation.get()::equals);
+					break;
+			}
+		});
+	}
+}

client/src/main/java/envoy/client/ui/controller/LoginScene.java

@@ -1,44 +1,36 @@
 package envoy.client.ui.controller;
 
-import java.io.FileNotFoundException;
-import java.io.IOException;
-import java.util.concurrent.TimeoutException;
-import java.util.logging.Level;
-import java.util.logging.Logger;
+import java.time.Instant;
+import java.util.logging.*;
 
 import javafx.application.Platform;
 import javafx.fxml.FXML;
+import javafx.geometry.Insets;
 import javafx.scene.control.*;
 import javafx.scene.control.Alert.AlertType;
+import javafx.scene.image.ImageView;
+
+import dev.kske.eventbus.*;
 
-import envoy.client.data.*;
-import envoy.client.net.Client;
-import envoy.client.net.WriteProxy;
-import envoy.client.ui.ClearableTextField;
-import envoy.client.ui.SceneContext;
-import envoy.client.ui.Startup;
 import envoy.data.LoginCredentials;
-import envoy.data.User;
-import envoy.data.User.UserStatus;
-import envoy.event.EventBus;
 import envoy.event.HandshakeRejection;
-import envoy.exception.EnvoyException;
-import envoy.util.Bounds;
-import envoy.util.EnvoyLog;
+import envoy.util.*;
+
+import envoy.client.data.ClientConfig;
+import envoy.client.ui.Startup;
+import envoy.client.util.IconUtil;
 
 /**
- * Project: <strong>envoy-client</strong><br>
- * File: <strong>LoginDialog.java</strong><br>
- * Created: <strong>03.04.2020</strong><br>
+ * Controller for the login scene.
  *
  * @author Kai S. K. Engelbart
  * @author Maximilian K&auml;fer
  * @since Envoy Client v0.1-beta
  */
-public final class LoginScene {
+public final class LoginScene implements EventListener {
 
 	@FXML
-	private ClearableTextField userTextField;
+	private TextField userTextField;
 
 	@FXML
 	private PasswordField passwordField;
@@ -47,81 +39,93 @@ public final class LoginScene {
 	private PasswordField repeatPasswordField;
 
 	@FXML
-	private Label repeatPasswordLabel;
-
-	@FXML
-	private CheckBox registerCheckBox;
+	private Button registerSwitch;
 
 	@FXML
 	private Label connectionLabel;
 
-	private Client			client;
-	private LocalDB			localDB;
-	private CacheMap		cacheMap;
-	private SceneContext	sceneContext;
+	@FXML
+	private Button loginButton;
 
-	private static final Logger			logger		= EnvoyLog.getLogger(LoginScene.class);
-	private static final EventBus		eventBus	= EventBus.getInstance();
-	private static final ClientConfig	config		= ClientConfig.getInstance();
+	@FXML
+	private CheckBox cbStaySignedIn;
+
+	@FXML
+	private Button offlineModeButton;
+
+	@FXML
+	private Label registerTextLabel;
+
+	@FXML
+	private ImageView logo;
+
+	private boolean registration;
+
+	private static final Logger			logger	= EnvoyLog.getLogger(LoginScene.class);
+	private static final ClientConfig	config	= ClientConfig.getInstance();
 
 	@FXML
 	private void initialize() {
 		connectionLabel.setText("Server: " + config.getServer() + ":" + config.getPort());
 
 		// Show an alert after an unsuccessful handshake
-		eventBus.register(HandshakeRejection.class, e -> Platform.runLater(() -> { new Alert(AlertType.ERROR, e.get()).showAndWait(); }));
-	}
+		EventBus.getInstance().registerListener(this);
 
-	/**
-	 * Loads the login dialog using the FXML file {@code LoginDialog.fxml}.
-	 *
-	 * @param client       the client used to perform the handshake
-	 * @param localDB      the local database used for offline login
-	 * @param cacheMap     the map of all caches needed
-	 * @param sceneContext the scene context used to initialize the chat scene
-	 * @since Envoy Client v0.1-beta
-	 */
-	public void initializeData(Client client, LocalDB localDB, CacheMap cacheMap, SceneContext sceneContext) {
-		this.client			= client;
-		this.localDB		= localDB;
-		this.cacheMap		= cacheMap;
-		this.sceneContext	= sceneContext;
-
-		// Prepare handshake
-		localDB.loadIDGenerator();
+		logo.setImage(IconUtil.loadIcon("envoy_logo"));
 
 		// Set initial cursor
 		userTextField.requestFocus();
-
-		// Perform automatic login if configured
-		if (config.hasLoginCredentials()) performHandshake(config.getLoginCredentials());
 	}
 
 	@FXML
 	private void loginButtonPressed() {
+		final String	user			= userTextField.getText(), pass = passwordField.getText(),
+			repeatPass = repeatPasswordField.getText();
+		final boolean	requestToken	= cbStaySignedIn.isSelected();
 
 		// Prevent registration with unequal passwords
-		if (registerCheckBox.isSelected() && !passwordField.getText().equals(repeatPasswordField.getText())) {
-			new Alert(AlertType.ERROR, "The entered password is unequal to the repeated one").showAndWait();
+		if (registration && !pass.equals(repeatPass)) {
+			new Alert(AlertType.ERROR, "The entered password is unequal to the repeated one")
+				.showAndWait();
 			repeatPasswordField.clear();
-		} else if (!Bounds.isValidContactName(userTextField.getTextField().getText())) {
-			new Alert(AlertType.ERROR, "The entered user name is not valid (" + Bounds.CONTACT_NAME_PATTERN + ")").showAndWait();
-			userTextField.getTextField().clear();
-		} else performHandshake(new LoginCredentials(userTextField.getTextField().getText(), passwordField.getText(), registerCheckBox.isSelected(),
-				Startup.VERSION));
+		} else if (!Bounds.isValidContactName(user)) {
+			new Alert(AlertType.ERROR,
+				"The entered user name is not valid (" + Bounds.CONTACT_NAME_PATTERN + ")")
+					.showAndWait();
+			userTextField.clear();
+		} else {
+			Instant lastSync = Startup.loadLastSync(userTextField.getText());
+			Startup.performHandshake(registration
+				? LoginCredentials.registration(user, pass, requestToken, Startup.VERSION, lastSync)
+				: LoginCredentials.login(user, pass, requestToken, Startup.VERSION, lastSync));
+		}
 	}
 
 	@FXML
 	private void offlineModeButtonPressed() {
-		attemptOfflineMode(new LoginCredentials(userTextField.getTextField().getText(), passwordField.getText(), false, Startup.VERSION));
+		Startup.attemptOfflineMode(userTextField.getText());
 	}
 
 	@FXML
-	private void registerCheckboxChanged() {
+	private void registerSwitchPressed() {
+
+		// Update button text and register switch
+		if (!registration) {
+			loginButton.setText("Register");
+			loginButton.setPadding(new Insets(2, 116, 2, 116));
+			registerTextLabel.setText("Already an account?");
+			registerSwitch.setText("Login");
+		} else {
+			loginButton.setText("Login");
+			loginButton.setPadding(new Insets(2, 125, 2, 125));
+			registerTextLabel.setText("No account yet?");
+			registerSwitch.setText("Register");
+		}
+		registration = !registration;
 
 		// Make repeat password field and label visible / invisible
-		repeatPasswordField.setVisible(registerCheckBox.isSelected());
-		repeatPasswordLabel.setVisible(registerCheckBox.isSelected());
+		repeatPasswordField.setVisible(registration);
+		offlineModeButton.setDisable(registration);
 	}
 
 	@FXML
@@ -130,70 +134,8 @@ public final class LoginScene {
 		System.exit(0);
 	}
 
-	private void performHandshake(LoginCredentials credentials) {
-		try {
-			client.performHandshake(credentials, cacheMap);
-			if (client.isOnline()) {
-				loadChatScene();
-				client.initReceiver(localDB, cacheMap);
-			}
-		} catch (IOException | InterruptedException | TimeoutException e) {
-			logger.log(Level.INFO, "Could not connect to server. Entering offline mode...");
-			attemptOfflineMode(credentials);
-		}
-	}
-
-	private void attemptOfflineMode(LoginCredentials credentials) {
-		try {
-			// Try entering offline mode
-			localDB.loadUsers();
-			final User clientUser = (User) localDB.getUsers().get(credentials.getIdentifier());
-			if (clientUser == null) throw new EnvoyException("Could not enter offline mode: user name unknown");
-			client.setSender(clientUser);
-			loadChatScene();
-		} catch (final Exception e) {
-			new Alert(AlertType.ERROR, "Client error: " + e).showAndWait();
-			logger.log(Level.SEVERE, "Offline mode could not be loaded: ", e);
-			System.exit(1);
-		}
-	}
-
-	private void loadChatScene() {
-
-		// Set client user in local database
-		localDB.setUser(client.getSender());
-
-		// Initialize chats in local database
-		try {
-			localDB.initializeUserStorage();
-			localDB.loadUserData();
-		} catch (final FileNotFoundException e) {
-			// The local database file has not yet been created, probably first login
-		} catch (final Exception e) {
-			new Alert(AlertType.ERROR, "Error while loading local database: " + e + "\nChats will not be stored locally.").showAndWait();
-			logger.log(Level.WARNING, "Could not load local database: ", e);
-		}
-
-		// Initialize write proxy
-		final var writeProxy = new WriteProxy(client, localDB);
-
-		localDB.synchronize();
-
-		if (client.isOnline()) writeProxy.flushCache();
-		else
-			// Set all contacts to offline mode
-			localDB.getChats()
-				.stream()
-				.map(Chat::getRecipient)
-				.filter(User.class::isInstance)
-				.map(User.class::cast)
-				.forEach(u -> u.setStatus(UserStatus.OFFLINE));
-
-		// Load ChatScene
-		sceneContext.pop();
-		sceneContext.getStage().setMinHeight(400);
-		sceneContext.getStage().setMinWidth(350);
-		sceneContext.load(SceneContext.SceneInfo.CHAT_SCENE);
-		sceneContext.<ChatScene>getController().initializeData(sceneContext, localDB, client, writeProxy);
+	@Event
+	private void onHandshakeRejection(HandshakeRejection evt) {
+		Platform.runLater(() -> new Alert(AlertType.ERROR, evt.get()).showAndWait());
 	}
 }

client/src/main/java/envoy/client/ui/controller/SettingsScene.java

@@ -1,21 +1,23 @@
 package envoy.client.ui.controller;
 
+import java.util.Map;
+
 import javafx.fxml.FXML;
 import javafx.scene.control.*;
+import javafx.scene.input.*;
 
-import envoy.client.ui.SceneContext;
-import envoy.client.ui.settings.GeneralSettingsPane;
-import envoy.client.ui.settings.SettingsPane;
+import envoy.client.data.Context;
+import envoy.client.data.shortcuts.KeyboardMapping;
+import envoy.client.ui.listcell.ListCellFactory;
+import envoy.client.ui.settings.*;
 
 /**
- * Project: <strong>envoy-client</strong><br>
- * File: <strong>SettingsSceneController.java</strong><br>
- * Created: <strong>10.04.2020</strong><br>
+ * Controller for the settings scene.
  *
  * @author Kai S. K. Engelbart
  * @since Envoy Client v0.1-beta
  */
-public class SettingsScene {
+public final class SettingsScene implements KeyboardMapping {
 
 	@FXML
 	private ListView<SettingsPane> settingsList;
@@ -23,26 +25,11 @@ public class SettingsScene {
 	@FXML
 	private TitledPane titledPane;
 
-	private SceneContext sceneContext;
-
-	/**
-	 * @param sceneContext enables the user to return to the chat scene
-	 * @since Envoy Client v0.1-beta
-	 */
-	public void initializeData(SceneContext sceneContext) { this.sceneContext = sceneContext; }
-
 	@FXML
 	private void initialize() {
-		settingsList.setCellFactory(listView -> new ListCell<>() {
-
-			@Override
-			protected void updateItem(SettingsPane item, boolean empty) {
-				super.updateItem(item, empty);
-				if (!empty && item != null) setGraphic(new Label(item.getTitle()));
-			}
-		});
-
-		settingsList.getItems().add(new GeneralSettingsPane());
+		settingsList.setCellFactory(new ListCellFactory<>(pane -> new Label(pane.getTitle())));
+		settingsList.getItems().addAll(new GeneralSettingsPane(), new UserSettingsPane(),
+			new DownloadSettingsPane(), new BugReportPane());
 	}
 
 	@FXML
@@ -55,5 +42,13 @@ public class SettingsScene {
 	}
 
 	@FXML
-	private void backButtonClicked() { sceneContext.pop(); }
+	private void backButtonClicked() {
+		Context.getInstance().getSceneContext().pop();
+	}
+
+	@Override
+	public Map<KeyCombination, Runnable> getKeyboardShortcuts() {
+		return Map.of(new KeyCodeCombination(KeyCode.B, KeyCombination.CONTROL_DOWN),
+			this::backButtonClicked);
+	}
 }

client/src/main/java/envoy/client/ui/controller/Tabs.java

@@ -0,0 +1,25 @@
+package envoy.client.ui.controller;
+
+/**
+ * Provides options to select different tabs.
+ *
+ * @author Maximilian Käfer
+ * @since Envoy Client v0.2-beta
+ */
+public enum Tabs {
+
+	/**
+	 * Selects the {@code contact list} tab.
+	 */
+	CONTACT_LIST,
+
+	/**
+	 * Selects the {@code contact search} tab.
+	 */
+	CONTACT_SEARCH,
+
+	/**
+	 * Selects the {@code group creation} tab.
+	 */
+	GROUP_CREATION
+}

client/src/main/java/envoy/client/ui/controller/package-info.java

@@ -1,11 +1,9 @@
 /**
  * Contains JavaFX scene controllers.
- * <p>
- * Project: <strong>envoy-client</strong><br>
- * File: <strong>package-info.java</strong><br>
- * Created: <strong>08.06.2020</strong><br>
  *
  * @author Kai S. K. Engelbart
+ * @author Leon Hofmeister
+ * @author Maximilian K&auml;fer
  * @since Envoy Client v0.1-beta
  */
 package envoy.client.ui.controller;

client/src/main/java/envoy/client/ui/listcell/AbstractListCell.java

@@ -0,0 +1,48 @@
+package envoy.client.ui.listcell;
+
+import javafx.scene.*;
+import javafx.scene.control.*;
+
+/**
+ * Provides a convenience frame for list cell creation.
+ *
+ * @author Kai S. K. Engelbart
+ * @param <T> the type of element displayed by the list cell
+ * @param <U> the type of node as which the list element will be displayed
+ * @since Envoy Client v0.1-beta
+ */
+public abstract class AbstractListCell<T, U extends Node> extends ListCell<T> {
+
+	protected ListView<? extends T> listView;
+
+	/**
+	 * @param listView the list view inside of which the cell will be displayed
+	 * @since Envoy Client v0.1-beta
+	 */
+	public AbstractListCell(ListView<? extends T> listView) {
+		this.listView = listView;
+		setContentDisplay(ContentDisplay.GRAPHIC_ONLY);
+		getStyleClass().add("list-element");
+	}
+
+	@Override
+	protected final void updateItem(T item, boolean empty) {
+		super.updateItem(item, empty);
+		if (!(empty || item == null)) {
+			setCursor(Cursor.HAND);
+			setGraphic(renderItem(item));
+		} else {
+			setGraphic(null);
+			setCursor(Cursor.DEFAULT);
+		}
+	}
+
+	/**
+	 * Converts a list item to a node. This can have side effects on the list cell.
+	 *
+	 * @param item the item to render
+	 * @return a node representing the item
+	 * @since Envoy Client v0.1-beta
+	 */
+	protected abstract U renderItem(T item);
+}

client/src/main/java/envoy/client/ui/listcell/ChatControl.java

@@ -1,58 +0,0 @@
-package envoy.client.ui.listcell;
-
-import javafx.geometry.Pos;
-import javafx.scene.control.Label;
-import javafx.scene.layout.*;
-
-import envoy.client.data.Chat;
-import envoy.data.Contact;
-import envoy.data.Group;
-import envoy.data.User;
-
-/**
- * This class formats a single {@link Contact} into a UI component.
- * <p>
- * Project: <strong>envoy-client</strong><br>
- * File: <strong>ContactControl.java</strong><br>
- * Created: <strong>01.07.2020</strong><br>
- *
- * @author Leon Hofmeister
- * @since Envoy Client v0.1-beta
- */
-public class ChatControl extends HBox {
-
-	/**
-	 * @param chat the chat to display
-	 * @since Envoy Client v0.1-beta
-	 */
-	public ChatControl(Chat chat) {
-		// Container with contact name
-		final var	vBox		= new VBox();
-		final var	nameLabel	= new Label(chat.getRecipient().getName());
-		nameLabel.setWrapText(true);
-		vBox.getChildren().add(nameLabel);
-		if (chat.getRecipient() instanceof User) {
-			// Online status
-			final var	user		= (User) chat.getRecipient();
-			final var	statusLabel	= new Label(user.getStatus().toString());
-			statusLabel.getStyleClass().add(user.getStatus().toString().toLowerCase());
-			vBox.getChildren().add(statusLabel);
-		} else // Member count
-			vBox.getChildren().add(new Label(((Group) chat.getRecipient()).getContacts().size() + " members"));
-				
-		getChildren().add(vBox);
-		if (chat.getUnreadAmount() != 0) {
-			Region spacing = new Region();
-			setHgrow(spacing, Priority.ALWAYS);
-			getChildren().add(spacing);
-			final var unreadMessagesLabel = new Label(Integer.toString(chat.getUnreadAmount()));
-			unreadMessagesLabel.setMinSize(15, 15);
-			var vBox2 = new VBox();
-			vBox2.setAlignment(Pos.CENTER_RIGHT);
-			unreadMessagesLabel.setAlignment(Pos.CENTER);
-			unreadMessagesLabel.getStyleClass().add("unreadMessagesAmount");
-			vBox2.getChildren().add(unreadMessagesLabel);
-			getChildren().add(vBox2);
-		}
-	}
-}

client/src/main/java/envoy/client/ui/listcell/ChatListCell.java

@@ -0,0 +1,55 @@
+package envoy.client.ui.listcell;
+
+import javafx.scene.control.*;
+
+import envoy.data.User;
+
+import envoy.client.data.*;
+import envoy.client.net.Client;
+import envoy.client.ui.control.ChatControl;
+import envoy.client.util.UserUtil;
+
+/**
+ * A list cell containing chats represented as chat controls.
+ *
+ * @author Leon Hofmeister
+ * @since Envoy Client v0.3-beta
+ */
+public class ChatListCell extends AbstractListCell<Chat, ChatControl> {
+
+	private static final Client client = Context.getInstance().getClient();
+
+	/**
+	 * @param listView the list view inside of which the cell will be displayed
+	 * @since Envoy Client v0.3-beta
+	 */
+	public ChatListCell(ListView<? extends Chat> listView) {
+		super(listView);
+	}
+
+	@Override
+	protected ChatControl renderItem(Chat chat) {
+		if (client.isOnline()) {
+			final var	menu		= new ContextMenu();
+			final var	removeMI	= new MenuItem();
+			removeMI.setText(
+				chat.isDisabled() ? "Delete "
+					: chat.getRecipient() instanceof User ? "Block "
+						: "Leave group " + chat.getRecipient().getName());
+			removeMI.setOnAction(
+				chat.isDisabled() ? e -> UserUtil.deleteContact(chat.getRecipient())
+					: e -> UserUtil.disableContact(chat.getRecipient()));
+			menu.getItems().add(removeMI);
+			setContextMenu(menu);
+		} else
+			setContextMenu(null);
+
+		// TODO: replace with icon in ChatControl
+		final var chatControl = new ChatControl(chat);
+		if (chat.isDisabled())
+			chatControl.getStyleClass().add("disabled-chat");
+		else
+			chatControl.getStyleClass().remove("disabled-chat");
+		return chatControl;
+	}
+}

client/src/main/java/envoy/client/ui/listcell/ContactListCellFactory.java

@@ -1,44 +0,0 @@
-package envoy.client.ui.listcell;
-
-import javafx.scene.control.ListCell;
-import javafx.scene.control.ListView;
-
-import envoy.client.data.Chat;
-
-/**
- * Project: <strong>envoy-client</strong><br>
- * File: <strong>UserListCell.java</strong><br>
- * Created: <strong>28.03.2020</strong><br>
- *
- * @author Kai S. K. Engelbart
- * @since Envoy Client v0.1-beta
- */
-public class ContactListCellFactory extends ListCell<Chat> {
-
-	private final ListView<Chat> listView;
-
-	/**
-	 * @param listView the list view inside which this cell is contained
-	 * @since Envoy Client v0.1-beta
-	 */
-	public ContactListCellFactory(ListView<Chat> listView) { this.listView = listView; }
-
-	/**
-	 * Displays the name of a contact. If the contact is a user, their online status
-	 * is displayed as well.
-	 *
-	 * @since Envoy Client v0.1-beta
-	 */
-	@Override
-	protected void updateItem(Chat chat, boolean empty) {
-		super.updateItem(chat, empty);
-		if (empty || chat.getRecipient() == null) {
-			setText(null);
-			setGraphic(null);
-		} else {
-			final var control = new ChatControl(chat);
-			prefWidthProperty().bind(listView.widthProperty().subtract(40));
-			setGraphic(control);
-		}
-	}
-}

client/src/main/java/envoy/client/ui/listcell/GenericListCell.java

@@ -0,0 +1,34 @@
+package envoy.client.ui.listcell;
+
+import java.util.function.Function;
+
+import javafx.scene.Node;
+import javafx.scene.control.ListView;
+
+/**
+ * A generic list cell rendering an item using a provided render function.
+ *
+ * @author Kai S. K. Engelbart
+ * @param <T> the type of element displayed by the list cell
+ * @param <U> the type of node as which the list element will be displayed
+ * @since Envoy Client v0.2-beta
+ */
+public final class GenericListCell<T, U extends Node> extends AbstractListCell<T, U> {
+
+	private final Function<? super T, U> renderer;
+
+	/**
+	 * @param listView the list view inside of which the cell will be displayed
+	 * @param renderer a function converting a list item to a node
+	 * @since Envoy Client v0.1-beta
+	 */
+	public GenericListCell(ListView<? extends T> listView, Function<? super T, U> renderer) {
+		super(listView);
+		this.renderer = renderer;
+	}
+
+	@Override
+	protected U renderItem(T item) {
+		return renderer.apply(item);
+	}
+}

client/src/main/java/envoy/client/ui/listcell/ListCellFactory.java

@@ -0,0 +1,34 @@
+package envoy.client.ui.listcell;
+
+import java.util.function.Function;
+
+import javafx.scene.Node;
+import javafx.scene.control.*;
+import javafx.util.Callback;
+
+/**
+ * Provides a creation mechanism for generic list cells given a list view and a conversion function.
+ *
+ * @author Kai S. K. Engelbart
+ * @param <T> the type of object to display
+ * @param <U> the type of node displayed
+ * @since Envoy Client v0.1-beta
+ */
+public final class ListCellFactory<T, U extends Node>
+	implements Callback<ListView<T>, ListCell<T>> {
+
+	private final Function<? super T, U> renderer;
+
+	/**
+	 * @param renderer a function converting the type to display into a node
+	 * @since Envoy Client v0.1-beta
+	 */
+	public ListCellFactory(Function<? super T, U> renderer) {
+		this.renderer = renderer;
+	}
+
+	@Override
+	public ListCell<T> call(ListView<T> listView) {
+		return new GenericListCell<>(listView, renderer);
+	}
+}

client/src/main/java/envoy/client/ui/listcell/MessageControl.java

@@ -1,123 +0,0 @@
-package envoy.client.ui.listcell;
-
-import java.awt.Toolkit;
-import java.awt.datatransfer.StringSelection;
-import java.io.ByteArrayInputStream;
-import java.time.format.DateTimeFormatter;
-import java.util.Map;
-import java.util.logging.Level;
-import java.util.logging.Logger;
-
-import javafx.geometry.Insets;
-import javafx.scene.control.ContextMenu;
-import javafx.scene.control.Label;
-import javafx.scene.control.MenuItem;
-import javafx.scene.image.Image;
-import javafx.scene.image.ImageView;
-import javafx.scene.layout.VBox;
-
-import envoy.client.ui.AudioControl;
-import envoy.client.ui.IconUtil;
-import envoy.data.Message;
-import envoy.data.Message.MessageStatus;
-import envoy.data.User;
-import envoy.util.EnvoyLog;
-
-/**
- * This class formats a single {@link Message} into a UI component.
- * <p>
- * Project: <strong>envoy-client</strong><br>
- * File: <strong>MessageControl.java</strong><br>
- * Created: <strong>01.07.2020</strong><br>
- *
- * @author Leon Hofmeister
- * @since Envoy Client v0.1-beta
- */
-public class MessageControl extends Label {
-
-	private static User								client;
-	private static final DateTimeFormatter			dateFormat		= DateTimeFormatter.ofPattern("dd.MM.yyyy HH:mm");
-	private static final Map<MessageStatus, Image>	statusImages	= IconUtil.loadByEnum(MessageStatus.class, 16);
-
-	private static final Logger logger = EnvoyLog.getLogger(MessageControl.class);
-
-	/**
-	 *
-	 * @param message the message that should be formatted
-	 * @since Envoy Client v0.1-beta
-	 */
-	public MessageControl(Message message) {
-		// Creating the underlying VBox and the dateLabel
-		final var vbox = new VBox(new Label(dateFormat.format(message.getCreationDate())));
-
-		// Creating the actions for the MenuItems
-		final ContextMenu	contextMenu		= new ContextMenu();
-		final MenuItem		copyMenuItem	= new MenuItem("Copy");
-		final MenuItem		deleteMenuItem	= new MenuItem("Delete");
-		final MenuItem		forwardMenuItem	= new MenuItem("Forward");
-		final MenuItem		quoteMenuItem	= new MenuItem("Quote");
-		final MenuItem		infoMenuItem	= new MenuItem("Info");
-		copyMenuItem.setOnAction(e -> copyMessage(message));
-		deleteMenuItem.setOnAction(e -> deleteMessage(message));
-		forwardMenuItem.setOnAction(e -> forwardMessage(message));
-		quoteMenuItem.setOnAction(e -> quoteMessage(message));
-		infoMenuItem.setOnAction(e -> loadMessageInfoScene(message));
-		contextMenu.getItems().addAll(copyMenuItem, deleteMenuItem, forwardMenuItem, quoteMenuItem, infoMenuItem);
-
-		// Handling message attachment display
-		if (message.hasAttachment()) {
-			switch (message.getAttachment().getType()) {
-				case PICTURE:
-					vbox.getChildren().add(new ImageView(new Image(new ByteArrayInputStream(message.getAttachment().getData()), 256, 256, true, true)));
-					break;
-				case VIDEO:
-					break;
-				case VOICE:
-					vbox.getChildren().add(new AudioControl(message.getAttachment().getData()));
-					break;
-				case DOCUMENT:
-					break;
-			}
-			final var saveAttachment = new MenuItem("Save attachment");
-			saveAttachment.setOnAction(e -> saveAttachment(message));
-			contextMenu.getItems().add(saveAttachment);
-		}
-		// Creating the textLabel
-		final var textLabel = new Label(message.getText());
-		textLabel.setWrapText(true);
-		vbox.getChildren().add(textLabel);
-		// Setting the message status icon and background color
-		if (message.getSenderID() == client.getID()) {
-			final var statusIcon = new ImageView(statusImages.get(message.getStatus()));
-			statusIcon.setPreserveRatio(true);
-			vbox.getChildren().add(statusIcon);
-			getStyleClass().add("own-message");
-		} else getStyleClass().add("received-message");
-		// Adjusting height and weight of the cell to the corresponding ListView
-		paddingProperty().setValue(new Insets(5, 20, 5, 20));
-		setContextMenu(contextMenu);
-		setGraphic(vbox);
-	}
-
-	// Context Menu actions
-
-	private void copyMessage(Message message) {
-		Toolkit.getDefaultToolkit().getSystemClipboard().setContents(new StringSelection(message.getText()), null);
-	}
-
-	private void deleteMessage(Message message) { logger.log(Level.FINEST, "message deletion was requested for " + message); }
-
-	private void forwardMessage(Message message) { logger.log(Level.FINEST, "message forwarding was requested for " + message); }
-
-	private void quoteMessage(Message message) { logger.log(Level.FINEST, "message quotation was requested for " + message); }
-
-	private void loadMessageInfoScene(Message message) { logger.log(Level.FINEST, "message info scene was requested for " + message); }
-
-	private void saveAttachment(Message message) { logger.log(Level.FINEST, "attachment saving was requested for " + message); }
-
-	/**
-	 * @param client the user who has logged in
-	 * @since Envoy Client v0.1-beta
-	 */
-	public static void setUser(User client) { MessageControl.client = client; }
-}

client/src/main/java/envoy/client/ui/listcell/MessageListCell.java

@@ -0,0 +1,43 @@
+package envoy.client.ui.listcell;
+
+import javafx.geometry.*;
+import javafx.scene.control.ListView;
+
+import envoy.data.Message;
+
+import envoy.client.ui.control.MessageControl;
+
+/**
+ * A list cell containing messages represented as message controls.
+ *
+ * @author Kai S. K. Engelbart
+ * @since Envoy Client v0.1-beta
+ */
+public final class MessageListCell extends AbstractListCell<Message, MessageControl> {
+
+	/**
+	 * @param listView the list view inside of which the cell will be displayed
+	 * @since Envoy Client v0.1-beta
+	 */
+	public MessageListCell(ListView<? extends Message> listView) {
+		super(listView);
+	}
+
+	@Override
+	protected MessageControl renderItem(Message message) {
+		final var control = new MessageControl(message);
+		listView.widthProperty().addListener((observable, oldValue,
+			newValue) -> adjustPadding(newValue.intValue(), control.isOwnMessage()));
+		adjustPadding((int) listView.getWidth(), control.isOwnMessage());
+		if (control.isOwnMessage())
+			setAlignment(Pos.CENTER_RIGHT);
+		else
+			setAlignment(Pos.CENTER_LEFT);
+		return control;
+	}
+
+	private void adjustPadding(int listWidth, boolean ownMessage) {
+		int padding = 10 + Math.max((listWidth - 1000) / 2, 0);
+		setPadding(ownMessage ? new Insets(3, padding, 3, 0) : new Insets(3, 0, 3, padding));
+	}
+}

client/src/main/java/envoy/client/ui/listcell/MessageListCellFactory.java

@@ -1,52 +0,0 @@
-package envoy.client.ui.listcell;
-
-import javafx.scene.control.ListCell;
-import javafx.scene.control.ListView;
-import javafx.scene.control.Tooltip;
-import javafx.stage.PopupWindow.AnchorLocation;
-
-import envoy.data.Message;
-
-/**
- * Displays a single message inside the message list.
- * <p>
- * Project: <strong>envoy-client</strong><br>
- * File: <strong>MessageListCellFactory.java</strong><br>
- * Created: <strong>28.03.2020</strong><br>
- *
- * @author Kai S. K. Engelbart
- * @since Envoy Client v0.1-beta
- */
-public class MessageListCellFactory extends ListCell<Message> {
-
-	private final ListView<Message> listView;
-
-	/**
-	 * @param listView the list view inside which this cell is contained
-	 * @since Envoy Client v0.1-beta
-	 */
-	public MessageListCellFactory(ListView<Message> listView) { this.listView = listView; }
-
-	/**
-	 * Displays the text, the data of creation and the status of a message.
-	 *
-	 * @since Envoy v0.1-beta
-	 */
-	@Override
-	protected void updateItem(Message message, boolean empty) {
-		super.updateItem(message, empty);
-		if (empty || message == null) {
-			setText(null);
-			setGraphic(null);
-		} else {
-			final var control = new MessageControl(message);
-			control.prefWidthProperty().bind(listView.widthProperty().subtract(40));
-			// Creating the Tooltip to deselect a message
-			final var tooltip = new Tooltip("You can select a message by clicking on it \nand deselect it by pressing \"ctrl\" and clicking on it");
-			tooltip.setWrapText(true);
-			tooltip.setAnchorLocation(AnchorLocation.WINDOW_TOP_LEFT);
-			setTooltip(tooltip);
-			setGraphic(control);
-		}
-	}
-}

client/src/main/java/envoy/client/ui/listcell/package-info.java

@@ -1,12 +1,8 @@
 /**
- * This package contains custom list cells that are used to display certain
- * things.
- * <p>
- * Project: <strong>envoy-client</strong><br>
- * File: <strong>package-info.java</strong><br>
- * Created: <strong>30.06.2020</strong><br>
+ * This package contains custom list cells that are used to display certain things.
  *
  * @author Leon Hofmeister
+ * @author Kai S. K. Engelbart
  * @since Envoy Client v0.1-beta
  */
 package envoy.client.ui.listcell;

client/src/main/java/envoy/client/ui/settings/BugReportPane.java

@@ -0,0 +1,71 @@
+package envoy.client.ui.settings;
+
+import javafx.event.EventHandler;
+import javafx.scene.control.*;
+import javafx.scene.input.InputEvent;
+
+import envoy.event.IssueProposal;
+
+/**
+ * This class offers the option for users to submit a bug report. Only the title of a bug is needed
+ * to be sent.
+ *
+ * @author Leon Hofmeister
+ * @since Envoy Client v0.2-beta
+ */
+public final class BugReportPane extends OnlineOnlySettingsPane {
+
+	private final Label		titleLabel				= new Label("Suggest a title for the bug:");
+	private final TextField	titleTextField			= new TextField();
+	private final Label		pleaseExplainLabel		=
+		new Label("Paste here the log of what went wrong and/ or explain what went wrong:");
+	private final TextArea	errorDetailArea			= new TextArea();
+	private final CheckBox	showUsernameInBugReport	=
+		new CheckBox("Show your username in the bug report?");
+	private final Button	submitReportButton		= new Button("Submit report");
+
+	private final EventHandler<? super InputEvent> inputEventHandler =
+		e -> submitReportButton.setDisable(titleTextField.getText().isBlank());
+
+	/**
+	 * Creates a new {@code BugReportPane}.
+	 *
+	 * @since Envoy Client v0.2-beta
+	 */
+	public BugReportPane() {
+		super("Report a bug");
+		setSpacing(10);
+		setToolTipText("A bug can only be reported while being online");
+
+		// Displaying the label to ask for a title
+		titleLabel.setWrapText(true);
+		getChildren().add(titleLabel);
+
+		// Displaying the TextField where to enter the title of this bug
+		titleTextField.setOnKeyTyped(inputEventHandler);
+		titleTextField.setOnInputMethodTextChanged(inputEventHandler);
+		getChildren().add(titleTextField);
+
+		// Displaying the label to ask for clarification
+		pleaseExplainLabel.setWrapText(true);
+		getChildren().add(pleaseExplainLabel);
+
+		// Displaying the TextArea where to enter the log and/or own description
+		errorDetailArea.setWrapText(true);
+		getChildren().add(errorDetailArea);
+
+		// Displaying the consent button that your user name will be shown
+		showUsernameInBugReport.setSelected(true);
+		getChildren().add(showUsernameInBugReport);
+
+		// Displaying the submitReportButton
+		submitReportButton.setDisable(true);
+		submitReportButton.setOnAction(e -> {
+			String title = titleTextField.getText(), description = errorDetailArea.getText();
+			client.send(
+				showUsernameInBugReport.isSelected() ? new IssueProposal(title, description, true)
+					: new IssueProposal(title, description, client.getSender().getName(), true));
+		});
+		getChildren().add(submitReportButton);
+	}
+}

client/src/main/java/envoy/client/ui/settings/DownloadSettingsPane.java

@@ -0,0 +1,63 @@
+package envoy.client.ui.settings;
+
+import javafx.geometry.Insets;
+import javafx.scene.control.*;
+import javafx.scene.layout.HBox;
+import javafx.stage.DirectoryChooser;
+
+/**
+ * Displays options for downloading {@link envoy.data.Attachment}s.
+ *
+ * @author Leon Hofmeister
+ * @since Envoy Client v0.2-beta
+ */
+public final class DownloadSettingsPane extends SettingsPane {
+
+	/**
+	 * Constructs a new {@code DownloadSettingsPane}.
+	 *
+	 * @since Envoy Client v0.2-beta
+	 */
+	public DownloadSettingsPane() {
+		super("Download");
+		setSpacing(15);
+		setPadding(new Insets(15));
+
+		// Checkbox to disable asking
+		final var checkBox =
+			new CheckBox(settings.getItems().get("autoSaveDownloads").getUserFriendlyName());
+		checkBox.setSelected(settings.isDownloadSavedWithoutAsking());
+		checkBox.setTooltip(new Tooltip(
+			"Determines whether a \"Select save location\" - dialogue will be shown when saving attachments."));
+		checkBox.setOnAction(e -> settings.setDownloadSavedWithoutAsking(checkBox.isSelected()));
+		getChildren().add(checkBox);
+
+		// Displaying the default path to save to
+		final var pathLabel =
+			new Label(settings.getItems().get("downloadLocation").getDescription() + ":");
+		pathLabel.setWrapText(true);
+		getChildren().add(pathLabel);
+		final var hbox = new HBox(20);
+		Tooltip.install(hbox,
+			new Tooltip("Determines the location where attachments will be saved to."));
+		final var currentPath = new Label(settings.getDownloadLocation().getAbsolutePath());
+		hbox.getChildren().add(currentPath);
+
+		// Setting the default path
+		final var button = new Button("Select");
+		button.setOnAction(e -> {
+			final var directoryChooser = new DirectoryChooser();
+			directoryChooser.setTitle("Select the directory where attachments should be saved to");
+			directoryChooser.setInitialDirectory(settings.getDownloadLocation());
+			final var selectedDirectory =
+				directoryChooser.showDialog(context.getSceneContext().getStage());
+
+			if (selectedDirectory != null) {
+				currentPath.setText(selectedDirectory.getAbsolutePath());
+				settings.setDownloadLocation(selectedDirectory);
+			}
+		});
+		hbox.getChildren().add(button);
+		getChildren().add(hbox);
+	}
+}

client/src/main/java/envoy/client/ui/settings/GeneralSettingsPane.java

@@ -1,57 +1,83 @@
 package envoy.client.ui.settings;
 
-import java.util.List;
+import javafx.scene.control.*;
 
-import javafx.scene.control.ComboBox;
-import javafx.scene.layout.VBox;
+import dev.kske.eventbus.EventBus;
+
+import envoy.data.User.UserStatus;
 
-import envoy.client.data.Settings;
 import envoy.client.data.SettingsItem;
 import envoy.client.event.ThemeChangeEvent;
-import envoy.data.User.UserStatus;
-import envoy.event.EventBus;
+import envoy.client.ui.StatusTrayIcon;
+import envoy.client.util.UserUtil;
 
 /**
- * Project: <strong>envoy-client</strong><br>
- * File: <strong>GeneralSettingsPane.java</strong><br>
- * Created: <strong>18.04.2020</strong><br>
- *
  * @author Kai S. K. Engelbart
  * @since Envoy Client v0.1-beta
  */
-public class GeneralSettingsPane extends SettingsPane {
-
-	private static final Settings settings = Settings.getInstance();
+public final class GeneralSettingsPane extends SettingsPane {
 
 	/**
 	 * @since Envoy Client v0.1-beta
 	 */
 	public GeneralSettingsPane() {
 		super("General");
-		final var vbox = new VBox();
+		setSpacing(10);
 
-		// TODO: Support other value types
-		List.of("onCloseMode", "enterToSend")
-			.stream()
-			.map(settings.getItems()::get)
-			.map(i -> new SettingsCheckbox((SettingsItem<Boolean>) i))
-			.forEach(vbox.getChildren()::add);
+		final var settingsItems = settings.getItems();
+
+		// Add hide on close if supported
+		final var	hideOnCloseCheckbox	=
+			new SettingsCheckbox((SettingsItem<Boolean>) settingsItems.get("hideOnClose"));
+		final var	hideOnCloseTooltip	= new Tooltip(StatusTrayIcon.isSupported()
+			? "If selected, Envoy will still be present in the task bar when closed."
+			: "status tray icon is not supported on your system.");
+		hideOnCloseTooltip.setWrapText(true);
+		hideOnCloseCheckbox.setTooltip(hideOnCloseTooltip);
+		hideOnCloseCheckbox.setDisable(!StatusTrayIcon.isSupported());
+		getChildren().add(hideOnCloseCheckbox);
+
+		final var	enterToSendCheckbox	=
+			new SettingsCheckbox((SettingsItem<Boolean>) settingsItems.get("enterToSend"));
+		final var	enterToSendTooltip	= new Tooltip(
+			"When selected, messages can be sent pressing \"Enter\". A line break can be inserted by pressing \"Ctrl\" + \"Enter\". Else it will be the other way around.");
+		enterToSendTooltip.setWrapText(true);
+		enterToSendCheckbox.setTooltip(enterToSendTooltip);
+		getChildren().add(enterToSendCheckbox);
+
+		final var	askForConfirmationCheckbox	=
+			new SettingsCheckbox((SettingsItem<Boolean>) settingsItems.get("askForConfirmation"));
+		final var	askForConfirmationTooltip	=
+			new Tooltip("When selected, nothing will prompt a confirmation dialog");
+		askForConfirmationTooltip.setWrapText(true);
+		askForConfirmationCheckbox.setTooltip(askForConfirmationTooltip);
+		getChildren().add(askForConfirmationCheckbox);
 
 		final var combobox = new ComboBox<String>();
 		combobox.getItems().add("dark");
 		combobox.getItems().add("light");
+		combobox
+			.setTooltip(new Tooltip("Determines the current theme Envoy will be displayed in."));
 		combobox.setValue(settings.getCurrentTheme());
-		combobox.setOnAction(
-				e -> { settings.setCurrentTheme(combobox.getValue()); EventBus.getInstance().dispatch(new ThemeChangeEvent(combobox.getValue())); });
-		vbox.getChildren().add(combobox);
+		combobox.setOnAction(e -> {
+			settings.setCurrentTheme(combobox.getValue());
+			EventBus.getInstance().dispatch(new ThemeChangeEvent());
+		});
+		getChildren().add(combobox);
 
 		final var statusComboBox = new ComboBox<UserStatus>();
 		statusComboBox.getItems().setAll(UserStatus.values());
-		statusComboBox.setValue(UserStatus.ONLINE);
-		// TODO add action when value is changed
-		statusComboBox.setOnAction(e -> {});
-		vbox.getChildren().add(statusComboBox);
+		statusComboBox.setValue(context.getLocalDB().getUser().getStatus());
+		statusComboBox.setTooltip(new Tooltip("Change your current status"));
+		statusComboBox.setOnAction(e -> UserUtil.changeStatus(statusComboBox.getValue()));
+		getChildren().add(statusComboBox);
 
-		getChildren().add(vbox);
+		final var logoutButton = new Button("Logout");
+		logoutButton.setOnAction(e -> UserUtil.logout());
+		final var logoutTooltip = new Tooltip(
+			"Brings you back to the login screen and removes \"remember me\" status from this account");
+		logoutTooltip.setWrapText(true);
+		logoutButton.setTooltip(logoutTooltip);
+		getChildren().add(logoutButton);
 	}
 }