Bumped version to v0.2-beta

Fixes #53

Co-authored-by: kske <kai@kske.dev>
Reviewed-on: https://git.kske.dev/zdm/envoy/pulls/58
Reviewed-by: kske <kai@kske.dev>
Reviewed-by: DieGurke <maxi@kske.dev>

.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 +1,52 @@
+# 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.
+
+## 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.
+
+## 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
+* Databse entities
+* Utility classes to check client version compatability and password validity

client/.classpath

@@ -13,9 +13,9 @@
 	</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">

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

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

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

client/pom.xml

@@ -9,14 +9,14 @@
 	<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>
@@ -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

@@ -9,15 +9,18 @@ import envoy.client.ui.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>
  *
  * @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.
@@ -26,5 +29,12 @@ public class Main {
 	 *             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.*;
-import java.util.Queue;
 import java.util.function.Consumer;
-import java.util.logging.Level;
+import java.util.logging.*;
-import java.util.logging.Logger;
 
 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
@@ -62,4 +56,11 @@ public final class Cache<T> implements Consumer<T>, Serializable {
 		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

@@ -1,16 +1,11 @@
 package envoy.client.data;
 
 import java.io.Serializable;
-import java.util.HashMap;
+import java.util.*;
-import java.util.Map;
 
 /**
  * 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>
  *
  * @author Kai S. K. Engelbart
  * @since Envoy Client v0.1-beta
@@ -52,7 +47,7 @@ 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 +58,11 @@ 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

@@ -1,10 +1,9 @@
 package envoy.client.data;
 
-import java.io.IOException;
+import java.io.*;
-import java.io.Serializable;
+import java.util.*;
-import java.util.ArrayList;
+
-import java.util.List;
+import javafx.collections.*;
-import java.util.Objects;
 
 import envoy.client.net.WriteProxy;
 import envoy.data.*;
@@ -14,10 +13,6 @@ import envoy.event.MessageStatusChange;
 /**
  * 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>
  *
  * @author Maximilian K&auml;fer
  * @author Leon Hofmeister
@@ -26,12 +21,18 @@ import envoy.event.MessageStatusChange;
  */
 public class Chat implements Serializable {
 
-	protected final Contact			recipient;
+	protected final Contact recipient;
-	protected final List<Message>	messages	= new ArrayList<>();
+
+	protected transient ObservableList<Message> messages = FXCollections.observableArrayList();
 
 	protected int unreadAmount;
 
-	private static final long serialVersionUID = 1L;
+	/**
+	 * Stores the last time an {@link envoy.event.IsTyping} event has been sent.
+	 */
+	protected transient long lastWritingEvent;
+
+	private static final long serialVersionUID = 2L;
 
 	/**
 	 * Provides the list of messages that the recipient receives.
@@ -41,12 +42,20 @@ public class Chat implements Serializable {
 	 * @param recipient the user who receives the messages
 	 * @since Envoy Client v0.1-alpha
 	 */
-	public Chat(Contact recipient) {
+	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());
+	}
+
+	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]", getClass().getSimpleName(), recipient, messages.size()); }
 
 	/**
 	 * Generates a hash code based on the recipient.
@@ -65,7 +74,7 @@ public class Chat implements Serializable {
 	public boolean equals(Object obj) {
 		if (this == obj) return true;
 		if (!(obj instanceof Chat)) return false;
-		Chat other = (Chat) obj;
+		final Chat other = (Chat) obj;
 		return Objects.equals(recipient, other.recipient);
 	}
 
@@ -76,11 +85,9 @@ public class Chat implements Serializable {
 	 *
 	 * @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
 	 * @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;
@@ -122,7 +129,7 @@ public class Chat implements Serializable {
 	public void incrementUnreadAmount() { unreadAmount++; }
 
 	/**
-	 * @return the amount of unread mesages in this chat
+	 * @return the amount of unread messages in this chat
 	 * @since Envoy Client v0.1-beta
 	 */
 	public int getUnreadAmount() { return unreadAmount; }
@@ -131,7 +138,7 @@ 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 +147,16 @@ public class Chat implements Serializable {
 	public Contact getRecipient() { return recipient; }
 
 	/**
-	 * @return whether this {@link Chat} points at a {@link User}
+	 * @return the last known time a {@link envoy.event.IsTyping} event has been
-	 * @since Envoy Client v0.1-beta
+	 *         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}
+	 * Sets the {@code lastWritingEvent} to {@code System#currentTimeMillis()}.
-	 * @since Envoy Client v0.1-beta
+	 *
+	 * @since Envoy Client v0.2-beta
 	 */
-	public boolean isGroupChat() { return recipient instanceof Group; }
+	public void lastWritingEventWasNow() { lastWritingEvent = System.currentTimeMillis(); }
 }

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>
  *
  * @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;
 
@@ -35,15 +25,10 @@ public class ClientConfig extends Config {
 	}
 
 	private ClientConfig() {
-		items.put("server", new ConfigItem<>("server", "s", identity(), null, true));
+		super(".envoy");
-		items.put("port", new ConfigItem<>("port", "p", Integer::parseInt, null, true));
+		put("server", "s", identity());
-		items.put("localDB", new ConfigItem<>("localDB", "db", File::new, new File("localDB"), true));
+		put("port", "p", Integer::parseInt);
-		items.put("ignoreLocalDB", new ConfigItem<>("ignoreLocalDB", "nodb", Boolean::parseBoolean, false, false));
+		put("localDBSaveInterval", "db-si", Integer::parseInt);
-		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()));
 	}
 
 	/**
@@ -59,57 +44,8 @@ public class ClientConfig extends Config {
 	public Integer getPort() { return (Integer) items.get("port").get(); }
 
 	/**
-	 * @return the local database specific to the client user
+	 * @return the amount of minutes after which the local database should be saved
-	 * @since Envoy Client v0.1-alpha
+	 * @since Envoy Client v0.2-beta
 	 */
-	public File getLocalDB() { return (File) items.get("localDB").get(); }
+	public Integer getLocalDBSaveInterval() { return (Integer) items.get("localDBSaveInterval").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); }
 }

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

@@ -0,0 +1,93 @@
+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.Instant;
-import java.time.LocalDateTime;
 
 import envoy.client.net.WriteProxy;
-import envoy.data.Contact;
+import envoy.data.*;
-import envoy.data.GroupMessage;
 import envoy.data.Message.MessageStatus;
-import envoy.data.User;
 import envoy.event.GroupMessageStatusChange;
 
 /**
  * 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>
  *
  * @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;
 
@@ -38,16 +31,13 @@ public class GroupChat extends Chat {
 	}
 
 	@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.getSenderID() != sender.getID()) if (gmsg.getMemberStatuses().get(sender.getID()) == MessageStatus.READ) break;
-				if (gmsg.getMemberStatuses().get(sender.getID()) == MessageStatus.READ) break;
+			else {
-				else {
+				gmsg.getMemberStatuses().replace(sender.getID(), MessageStatus.READ);
-					gmsg.getMemberStatuses().replace(sender.getID(), MessageStatus.READ);
+				writeProxy.writeMessageStatusChange(new GroupMessageStatusChange(gmsg.getID(), MessageStatus.READ, Instant.now(), sender.getID()));
-					writeProxy
-						.writeMessageStatusChange(new GroupMessageStatusChange(gmsg.getID(), MessageStatus.READ, LocalDateTime.now(), sender.getID()));
-				}
 			}
 		}
 		unreadAmount = 0;

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

@@ -1,74 +1,147 @@
 package envoy.client.data;
 
+import java.io.*;
+import java.nio.channels.*;
+import java.nio.file.StandardOpenOption;
+import java.time.Instant;
 import java.util.*;
+import java.util.logging.*;
 
+import javafx.collections.*;
+
+import envoy.client.event.*;
 import envoy.data.*;
-import envoy.event.GroupResize;
+import envoy.data.Message.MessageStatus;
-import envoy.event.MessageStatusChange;
+import envoy.event.*;
-import envoy.event.NameChange;
+import envoy.exception.EnvoyException;
+import envoy.util.*;
+
+import dev.kske.eventbus.Event;
+import dev.kske.eventbus.EventBus;
+import dev.kske.eventbus.EventListener;
 
 /**
  * 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>
+ * The managed objects are stored inside a folder in the local file system.
- * File: <strong>LocalDB.java</strong><br>
- * Created: <strong>3 Feb 2020</strong><br>
  *
  * @author Kai S. K. Engelbart
  * @since Envoy Client v0.3-alpha
  */
-public abstract class LocalDB {
+public final class LocalDB implements EventListener {
 
-	protected User					user;
+	// Data
-	protected Map<String, Contact>	users		= new HashMap<>();
+	private User					user;
-	protected List<Chat>			chats		= new ArrayList<>();
+	private Map<String, User>		users		= Collections.synchronizedMap(new HashMap<>());
-	protected IDGenerator			idGenerator;
+	private ObservableList<Chat>	chats		= FXCollections.observableArrayList();
-	protected CacheMap				cacheMap	= new CacheMap();
+	private IDGenerator				idGenerator;
+	private CacheMap				cacheMap	= new CacheMap();
+	private String					authToken;
 
-	{
+	// 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
+	 * Loads the local user registry {@code users.db}, the id generator
-	 * as well. The message id generator will also be saved if present.
+	 * {@code id_gen.db} and last login file {@code last_login.db}.
 	 *
-	 * @throws Exception if the saving process failed
+	 * @since Envoy Client v0.2-beta
-	 * @since Envoy Client v0.3-alpha
 	 */
-	public void save() throws Exception {}
+	private synchronized void loadGlobalData() {
-
+		try {
-	/**
+			try (var in = new ObjectInputStream(new FileInputStream(usersFile))) {
-	 * Loads all user data.
+				users = (Map<String, User>) in.readObject();
-	 *
+			}
-	 * @throws Exception if the loading process failed
+			idGenerator = SerializationUtils.read(idGeneratorFile, IDGenerator.class);
-	 * @since Envoy Client v0.3-alpha
+			try (var in = new ObjectInputStream(new FileInputStream(lastLoginFile))) {
-	 */
+				user		= (User) in.readObject();
-	public void loadUsers() throws Exception {}
+				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");
-	 * Loads the ID generator. Any exception thrown during this process is ignored.
+		try (var in = new ObjectInputStream(new FileInputStream(userFile))) {
-	 *
+			chats		= FXCollections.observableList((List<Chat>) in.readObject());
-	 * @since Envoy Client v0.3-alpha
+			cacheMap	= (CacheMap) in.readObject();
-	 */
+			lastSync	= (Instant) in.readObject();
-	public void loadIDGenerator() {}
+		} finally {
+			synchronize();
+		}
+	}
 
 	/**
 	 * Synchronizes the contact list of the client user with the chat and user
@@ -76,14 +149,13 @@ public abstract class LocalDB {
 	 *
 	 * @since Envoy Client v0.1-beta
 	 */
-	public void synchronize() {
+	private void synchronize() {
-		user.getContacts().stream().filter(u -> u instanceof User && !users.containsKey(u.getName())).forEach(u -> users.put(u.getName(), u));
+		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 : users.values())
-			if (contact instanceof User)
+			if (contact instanceof User) getChat(contact.getID()).ifPresent(chat -> { ((User) chat.getRecipient()).setStatus(contact.getStatus()); });
-				getChat(contact.getID()).ifPresent(chat -> { ((User) chat.getRecipient()).setStatus(((User) contact).getStatus()); });
 
 		// Create missing chats
 		user.getContacts()
@@ -93,24 +165,147 @@ public abstract class LocalDB {
 			.forEach(chats::add);
 	}
 
+	/**
+	 * 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 = 1000)
+	private synchronized void save() {
+		EnvoyLog.getLogger(LocalDB.class).log(Level.INFO, "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 = 150)
+	private void onMessage(Message msg) { if (msg.getStatus() == MessageStatus.SENT) msg.nextStatus(); }
+
+	@Event(priority = 150)
+	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 = 150)
+	private void onMessageStatusChange(MessageStatusChange evt) { getMessage(evt.getID()).ifPresent(msg -> msg.setStatus(evt.get())); }
+
+	@Event(priority = 150)
+	private void onGroupMessageStatusChange(GroupMessageStatusChange evt) {
+		this.<GroupMessage>getMessage(evt.getID()).ifPresent(msg -> msg.getMemberStatuses().replace(evt.getMemberID(), evt.get()));
+	}
+
+	@Event(priority = 150)
+	private void onUserStatusChange(UserStatusChange evt) {
+		this.getChat(evt.getID()).map(Chat::getRecipient).map(User.class::cast).ifPresent(u -> u.setStatus(evt.get()));
+	}
+
+	@Event(priority = 150)
+	private void onGroupResize(GroupResize evt) { getChat(evt.getGroupID()).map(Chat::getRecipient).map(Group.class::cast).ifPresent(evt::apply); }
+
+	@Event(priority = 150)
+	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 = 100)
+	private void onLogout() {
+		autoSaver.cancel();
+		autoSaveRestart = true;
+		lastLoginFile.delete();
+		userFile	= null;
+		user		= null;
+		authToken	= null;
+		chats.clear();
+		lastSync = Instant.EPOCH;
+		cacheMap.clear();
+	}
+
 	/**
 	 * @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; }
+
+	/**
+	 * 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; }
+	public ObservableList<Chat> getChats() { return chats; }
-
-	/**
-	 * @param chats the chats to set
-	 */
-	public void setChats(List<Chat> chats) { this.chats = chats; }
 
 	/**
 	 * @return the {@link User} who initialized the local database
@@ -134,6 +329,7 @@ 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; }
 
 	/**
@@ -149,57 +345,14 @@ public abstract class LocalDB {
 	public CacheMap getCacheMap() { return cacheMap; }
 
 	/**
-	 * Searches for a message by ID.
+	 * @return the time stamp when the database was last saved
-	 *
+	 * @since Envoy Client v0.2-beta
-	 * @param id the ID of the message to search for
-	 * @return an optional containing the message
-	 * @since Envoy Client v0.1-beta
 	 */
-	public Optional<Message> getMessage(long id) {
+	public Instant getLastSync() { return lastSync; }
-		return chats.stream().map(Chat::getMessages).flatMap(List::stream).filter(m -> m.getID() == id).findAny();
-	}
 
 	/**
-	 * Searches for a chat by recipient ID.
+	 * @return the authentication token of the user
-	 * 
+	 * @since Envoy Client v0.2-beta
-	 * @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(); }
+	public String getAuthToken() { return authToken; }
-
-	/**
-	 * 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;
-				}
-			});
-	}
 }

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.*;
-import java.io.IOException;
+import java.util.*;
-import java.util.HashMap;
+import java.util.logging.Level;
-import java.util.Map;
 import java.util.prefs.Preferences;
 
-import envoy.util.SerializationUtils;
+import envoy.client.event.EnvoyCloseEvent;
+import envoy.util.*;
+
+import dev.kske.eventbus.*;
+import dev.kske.eventbus.EventListener;
 
 /**
  * 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>
  *
  * @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;
@@ -44,6 +43,8 @@ public class Settings {
 	 * @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 +68,28 @@ 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, priority = 900)
+	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("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"));
 	}
 
 	/**
@@ -120,19 +133,71 @@ public class Settings {
 	 */
 	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

@@ -8,16 +8,12 @@ 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>
  *
  * @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;

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

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.*;
-import java.nio.file.Path;
 
 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
@@ -27,6 +22,11 @@ public final class AudioRecorder {
 	 */
 	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;
 
@@ -78,7 +78,7 @@ 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 +117,6 @@ 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

@@ -1,9 +1,5 @@
 /**
  * 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/OnCall.java

@@ -0,0 +1,30 @@
+package envoy.client.data.commands;
+
+import java.util.function.Supplier;
+
+/**
+ * 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 OnCall {
+
+	/**
+	 * Performs class specific actions when a {@link SystemCommand} has been called.
+	 *
+	 * @since Envoy Client v0.2-beta
+	 */
+	void onCall();
+
+	/**
+	 * Performs actions that can only be performed by classes that are not
+	 * {@link SystemCommand}s when a SystemCommand has been called.
+	 *
+	 * @param consumer the action to perform when this {@link SystemCommand} has
+	 *                 been called
+	 * @since Envoy Client v0.2-beta
+	 */
+	void onCall(Supplier<Void> consumer);
+}

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

@@ -0,0 +1,128 @@
+package envoy.client.data.commands;
+
+import java.util.*;
+import java.util.function.*;
+
+/**
+ * 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 OnCall {
+
+	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 action that should be performed
+	 * @since Envoy Client v0.2-beta
+	 */
+	public Consumer<List<String>> getAction() { return action; }
+
+	/**
+	 * @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; }
+
+	/**
+	 * Increments the relevance of this {@code SystemCommand}.
+	 */
+	@Override
+	public void onCall() { relevance++; }
+
+	/**
+	 * Increments the relevance of this {@code SystemCommand} and executes the
+	 * supplier.
+	 */
+	@Override
+	public void onCall(Supplier<Void> consumer) {
+		onCall();
+		consumer.get();
+	}
+
+	/**
+	 * @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 SystemCommand other = (SystemCommand) obj;
+		return Objects.equals(action, other.action);
+	}
+
+	@Override
+	public String toString() {
+		return "SystemCommand [relevance=" + relevance + ", numberOfArguments=" + numberOfArguments + ", "
+				+ (action != null ? "action=" + action + ", " : "") + (description != null ? "description=" + description + ", " : "")
+				+ (defaults != null ? "defaults=" + defaults : "") + "]";
+	}
+}

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

@@ -0,0 +1,230 @@
+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 +1,260 @@
+package envoy.client.data.commands;
+
+import java.util.*;
+import java.util.function.Consumer;
+import java.util.logging.*;
+import java.util.regex.Pattern;
+import java.util.stream.Collectors;
+
+import envoy.util.EnvoyLog;
+
+/**
+ * This class stores all {@link SystemCommand}s used.
+ *
+ * @author Leon Hofmeister
+ * @since Envoy Client v0.2-beta
+ */
+public final class SystemCommandMap {
+
+	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);
+
+	/**
+	 * 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.
+	 * It will return an empty optional if the value after the slash is not a key in
+	 * the map, which is a valid case (i.e. input="3/4" and "4" is not a key in the
+	 * map).
+	 * <p>
+	 * Usage example:<br>
+	 * {@code SystemCommandMap systemCommands = new SystemCommandMap();}<br>
+	 * {@code Button button = new  Button();}
+	 * {@code systemCommands.add("example", text -> button.setText(text.get(0), 1);}<br>
+	 * {@code ....}<br>
+	 * user input: {@code "/example xyz ..."}<br>
+	 * {@code systemCommands.get("example xyz ...")} or
+	 * {@code systemCommands.get("/example xyz ...")}
+	 * result: {@code Optional<SystemCommand>}
+	 *
+	 * @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 "/" of a {@link SystemCommand} is stripped.<br>
+	 * It returns the command as (most likely) entered as key in the map for the
+	 * first word of the text.<br>
+	 * It should only be called on strings that contain a "/" at position 0/-1.
+	 *
+	 * @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 slash is not a system command. Only
+	 *          exception: for recommendation purposes.
+	 */
+	public String getCommand(String raw) {
+		final var	trimmed	= raw.stripLeading();
+		final var	index	= trimmed.indexOf(' ');
+		return trimmed.substring(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 boolean valid = commandPattern.matcher(command).matches();
+		if (!valid) logger.log(Level.WARNING,
+				"The command \"" + command
+						+ "\" is not valid. As it will cause problems in execution, 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 "/" is the first visible
+	 * character and then checks if a command is present after that "/". If that is
+	 * the case, it will be executed.
+	 * <p>
+	 *
+	 * @param raw the raw input string
+	 * @return whether a command could be found
+	 * @since Envoy Client v0.2-beta
+	 */
+	public boolean executeIfAnyPresent(String raw) {
+		// possibly a command was detected and could be executed
+		final var	raw2			= raw.stripLeading();
+		final var	commandFound	= raw2.startsWith("/") ? executeIfPresent(raw2) : false;
+		// the command was executed successfully - no further checking needed
+		if (commandFound) logger.log(Level.FINE, "executed system command " + getCommand(raw2));
+		return commandFound;
+	}
+
+	/**
+	 * This method checks if the input String is a key in the map and executes the
+	 * wrapped System command if present.
+	 * Its intended usage is after a "/" has been detected in the input String.
+	 * It will do nothing if the value after the slash is not a key in
+	 * the map, which is a valid case (i.e. input="3/4" and "4" is not a key in the
+	 * map).
+	 * <p>
+	 * Usage example:<br>
+	 * {@code SystemCommandMap systemCommands = new SystemCommandMap();}<br>
+	 * {@code Button button = new Button();}<br>
+	 * {@code systemCommands.add("example", (words)-> button.setText(words.get(0), 1);}<br>
+	 * {@code ....}<br>
+	 * user input: {@code "/example xyz ..."}<br>
+	 * {@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
+	 * @since Envoy Client v0.2-beta
+	 */
+	public boolean executeIfPresent(String input) {
+		final var	command	= getCommand(input);
+		final var	value	= get(command);
+		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.getAction().accept(arguments);
+				systemCommand.onCall();
+			} catch (final Exception e) {
+				logger.log(Level.WARNING, "The system command " + command + " threw an exception: ", e);
+			}
+		});
+		return value.isPresent();
+	}
+
+	/**
+	 * 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;
+	}
+
+	/**
+	 * 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 "/" is at its beginning or not.<br>
+	 * If none are present, nothing will be done.<br>
+	 * Otherwise the given function will be executed on the recommendations.<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);
+	}
+
+	/**
+	 * Recommends commands based upon the currently entered input.<br>
+	 * In the current implementation, all we check 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>
+	 * Will only work for {@code SystemCommand}s whose argument counter is bigger
+	 * than 1.
+	 *
+	 * @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 (int 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; }
+}

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/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/EnvoyCloseEvent.java

@@ -0,0 +1,16 @@
+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/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/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>
+ * Notifies UI components of a theme change.
- * File: <strong>ThemeChangeEvent.java</strong><br>
- * Created: <strong>15 Dec 2019</strong><br>
  *
  * @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 +1,36 @@
+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.setHeight(225);
+		alert.setWidth(400);
+		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 +1,57 @@
+package envoy.client.helper;
+
+import java.util.logging.Level;
+
+import javafx.scene.control.Alert;
+import javafx.scene.control.Alert.AlertType;
+
+import envoy.client.data.*;
+import envoy.client.event.*;
+import envoy.client.ui.SceneContext.SceneInfo;
+import envoy.util.EnvoyLog;
+
+import dev.kske.eventbus.EventBus;
+
+/**
+ * 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()}.
+	 *
+	 * @since Envoy Client v0.2-beta
+	 */
+	public static void exit() {
+		if (Settings.getInstance().isHideOnClose()) Context.getInstance().getStage().setIconified(true);
+		else {
+			EventBus.getInstance().dispatch(new EnvoyCloseEvent());
+			System.exit(0);
+		}
+	}
+
+	/**
+	 * Logs the current user out and reopens
+	 * {@link envoy.client.ui.controller.LoginScene}.
+	 *
+	 * @since Envoy Client v0.2-beta
+	 */
+	public static void logout() {
+		final var alert = new Alert(AlertType.CONFIRMATION);
+		alert.setTitle("Logout?");
+		alert.setContentText("Are you sure you want to log out?");
+
+		AlertHelper.confirmAction(alert, () -> {
+			EnvoyLog.getLogger(ShutdownHelper.class).log(Level.INFO, "A logout was requested");
+			EventBus.getInstance().dispatch(new EnvoyCloseEvent());
+			EventBus.getInstance().dispatch(new Logout());
+			Context.getInstance().getSceneContext().load(SceneInfo.LOGIN_SCENE);
+		});
+	}
+}

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 +1,29 @@
 package envoy.client.net;
 
-import java.io.Closeable;
+import java.io.*;
-import java.io.IOException;
 import java.net.Socket;
 import java.util.concurrent.TimeoutException;
-import java.util.logging.Level;
+import java.util.logging.*;
-import java.util.logging.Logger;
 
 import envoy.client.data.*;
-import envoy.client.event.SendEvent;
+import envoy.client.event.EnvoyCloseEvent;
 import envoy.data.*;
 import envoy.event.*;
-import envoy.event.contact.ContactOperation;
+import envoy.util.*;
-import envoy.event.contact.ContactSearchResult;
+
-import envoy.util.EnvoyLog;
+import dev.kske.eventbus.*;
-import envoy.util.SerializationUtils;
+import dev.kske.eventbus.Event;
 
 /**
  * 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>
  *
  * @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;
@@ -45,6 +39,13 @@ public class Client implements Closeable {
 	private static final Logger			logger		= EnvoyLog.getLogger(Client.class);
 	private static final EventBus		eventBus	= EventBus.getInstance();
 
+	/**
+	 * 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
@@ -69,10 +70,10 @@ public class Client implements Closeable {
 		// 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;
 
@@ -99,7 +100,6 @@ public class Client implements Closeable {
 		}
 
 		online = true;
-
 		logger.log(Level.INFO, "Handshake completed.");
 	}
 
@@ -120,99 +120,86 @@ 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(Message.class).setProcessor(eventBus::dispatch);
-		cacheMap.get(GroupMessage.class).setProcessor(receivedGroupMessageProcessor);
+		cacheMap.get(GroupMessage.class).setProcessor(eventBus::dispatch);
-		cacheMap.get(MessageStatusChange.class).setProcessor(messageStatusChangeProcessor);
+		cacheMap.get(MessageStatusChange.class).setProcessor(eventBus::dispatch);
-		cacheMap.get(GroupMessageStatusChange.class).setProcessor(groupMessageStatusChangeProcessor);
+		cacheMap.get(GroupMessageStatusChange.class).setProcessor(eventBus::dispatch);
-
-		// 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);
-			}
-		});
 
 		// 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 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 (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 {
+	public void sendMessage(Message message) {
-		writeObject(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 = 800)
+	public void close() {
+		if (online) {
+			logger.log(Level.INFO, "Closing connection...");
+			try {
 
-	private void writeObject(Object obj) throws IOException {
+				// The sender must be reset as otherwise the handshake is immediately closed
-		checkOnline();
+				sender	= null;
-		logger.log(Level.FINE, "Sending " + obj);
+				online	= false;
-		SerializationUtils.writeBytesWithLength(obj, socket.getOutputStream());
+				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 +217,7 @@ 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 +1,31 @@
 package envoy.client.net;
 
-import java.io.ByteArrayInputStream;
+import java.io.*;
-import java.io.InputStream;
-import java.io.ObjectInputStream;
 import java.net.SocketException;
-import java.util.HashMap;
+import java.util.*;
-import java.util.Map;
 import java.util.function.Consumer;
-import java.util.logging.Level;
+import java.util.logging.*;
-import java.util.logging.Logger;
 
-import envoy.util.EnvoyLog;
+import envoy.util.*;
-import envoy.util.SerializationUtils;
+
+import dev.kske.eventbus.*;
 
 /**
  * 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>
  *
  * @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}.
@@ -40,6 +36,7 @@ public class Receiver extends Thread {
 	public Receiver(InputStream in) {
 		super("Receiver");
 		this.in = in;
+		setDaemon(true);
 	}
 
 	/**
@@ -51,7 +48,7 @@ public class Receiver extends Thread {
 	@Override
 	public void run() {
 
-		while (true) {
+		while (isAlive)
 			try {
 				// Read object length
 				final byte[] lenBytes = new byte[4];
@@ -66,6 +63,12 @@ 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));
 					continue;
@@ -78,17 +81,22 @@ public class Receiver extends Thread {
 					// 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()));
+					// Dispatch to the processor if present
-					else processor.accept(obj);
+					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);
 			}
-		}
 	}
 
 	/**

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

@@ -1,11 +1,8 @@
 package envoy.client.net;
 
-import java.io.IOException;
+import java.util.logging.*;
-import java.util.logging.Level;
-import java.util.logging.Logger;
 
-import envoy.client.data.Cache;
+import envoy.client.data.*;
-import envoy.client.data.LocalDB;
 import envoy.data.Message;
 import envoy.event.MessageStatusChange;
 import envoy.util.EnvoyLog;
@@ -14,15 +11,11 @@ import envoy.util.EnvoyLog;
  * 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>
  *
  * @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;
@@ -33,10 +26,9 @@ public class WriteProxy {
 	 * 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
+	 * @param client  the client instance used to send messages and events if online
-	 *                events
+	 * @param localDB the local database used to cache messages and events if
-	 * @param localDB the local database used to cache messages and message status
+	 *                offline
-	 *                change events
 	 * @since Envoy Client v0.3-alpha
 	 */
 	public WriteProxy(Client client, LocalDB localDB) {
@@ -45,20 +37,12 @@ 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);
-				logger.log(Level.FINER, "Sending cached " + msg);
+			client.sendMessage(msg);
-				client.sendMessage(msg);
-			} catch (final IOException e) {
-				logger.log(Level.SEVERE, "Could not send cached message: ", e);
-			}
 		});
 		localDB.getCacheMap().get(MessageStatusChange.class).setProcessor(evt -> {
 			logger.log(Level.FINER, "Sending cached " + evt);
-			try {
+			client.send(evt);
-				client.sendEvent(evt);
-			} catch (final IOException e) {
-				logger.log(Level.SEVERE, "Could not send cached message status change event: ", e);
-			}
 		});
 	}
 
@@ -68,19 +52,16 @@ public class WriteProxy {
 	 *
 	 * @since Envoy Client v0.3-alpha
 	 */
-	public void flushCache() {
+	public void flushCache() { localDB.getCacheMap().getMap().values().forEach(Cache::relay); }
-		localDB.getCacheMap().getMap().values().forEach(Cache::relay);
-	}
 
 	/**
 	 * 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 {
+	public void writeMessage(Message message) {
 		if (client.isOnline()) client.sendMessage(message);
 		else localDB.getCacheMap().getApplicable(Message.class).accept(message);
 	}
@@ -90,11 +71,10 @@ public class WriteProxy {
 	 * 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 {
+	public void writeMessageStatusChange(MessageStatusChange evt) {
-		if (client.isOnline()) client.sendEvent(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

@@ -3,10 +3,6 @@ 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>
  *
  * @author Leon Hofmeister
  * @since Envoy Client v0.1-beta

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

@@ -4,16 +4,19 @@ 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.*;
-import javafx.scene.Scene;
+import javafx.scene.input.*;
 import javafx.stage.Stage;
 
 import envoy.client.data.Settings;
-import envoy.client.event.ThemeChangeEvent;
+import envoy.client.event.*;
-import envoy.event.EventBus;
+import envoy.client.helper.ShutdownHelper;
 import envoy.util.EnvoyLog;
 
+import dev.kske.eventbus.*;
+
 /**
  * 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
@@ -21,15 +24,11 @@ import envoy.util.EnvoyLog;
  * <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>
  *
  * @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.
@@ -53,33 +52,12 @@ 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"),
+		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");
 
 		/**
 		 * The path to the FXML resource.
@@ -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);
 	}
 
 	/**
@@ -115,6 +93,7 @@ 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);
 
@@ -125,8 +104,25 @@ public final class SceneContext {
 
 			sceneStack.push(scene);
 			stage.setScene(scene);
-			applyCSS();
+
+			// Add the option to exit Linux-like with "Control" + "Q"
+			scene.getAccelerators().put(new KeyCodeCombination(KeyCode.Q, KeyCombination.CONTROL_DOWN), ShutdownHelper::exit);
+
+			// Add the option to logout using "Control"+"Shift"+"L" if not in login scene
+			if (sceneInfo != SceneInfo.LOGIN_SCENE) scene.getAccelerators()
+				.put(new KeyCodeCombination(KeyCode.L, KeyCombination.CONTROL_DOWN, KeyCombination.SHIFT_DOWN), ShutdownHelper::logout);
+
+			// Add the option to open the settings scene with "Control"+"S", if being in
+			// chat scene
+			if (sceneInfo.equals(SceneInfo.CHAT_SCENE))
+				scene.getAccelerators().put(new KeyCodeCombination(KeyCode.S, KeyCombination.CONTROL_DOWN), () -> load(SceneInfo.SETTINGS_SCENE));
+
+			// 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);
@@ -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);
@@ -164,6 +164,15 @@ public final class SceneContext {
 		}
 	}
 
+	@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 +185,10 @@ 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

@@ -1,10 +1,9 @@
 package envoy.client.ui;
 
-import java.io.File;
+import java.io.*;
-import java.io.IOException;
+import java.time.Instant;
-import java.util.Properties;
+import java.util.concurrent.TimeoutException;
-import java.util.logging.Level;
+import java.util.logging.*;
-import java.util.logging.Logger;
 
 import javafx.application.Application;
 import javafx.scene.control.Alert;
@@ -12,22 +11,19 @@ import javafx.scene.control.Alert.AlertType;
 import javafx.stage.Stage;
 
 import envoy.client.data.*;
+import envoy.client.helper.ShutdownHelper;
 import envoy.client.net.Client;
 import envoy.client.ui.SceneContext.SceneInfo;
 import envoy.client.ui.controller.LoginScene;
-import envoy.data.GroupMessage;
+import envoy.client.util.IconUtil;
-import envoy.data.Message;
+import envoy.data.*;
-import envoy.event.GroupMessageStatusChange;
+import envoy.data.User.UserStatus;
-import envoy.event.MessageStatusChange;
+import envoy.event.*;
 import envoy.exception.EnvoyException;
 import envoy.util.EnvoyLog;
 
 /**
- * Handles application startup and shutdown.
+ * Handles application startup.
- * <p>
- * Project: <strong>envoy-client</strong><br>
- * File: <strong>Startup.java</strong><br>
- * Created: <strong>26.03.2020</strong><br>
  *
  * @author Kai S. K. Engelbart
  * @author Maximilian K&auml;fer
@@ -42,9 +38,10 @@ public final class Startup extends Application {
 	 */
 	public static final String VERSION = "0.1-beta";
 
-	private LocalDB	localDB;
+	private static LocalDB localDB;
-	private Client	client;
 
+	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);
 
@@ -56,80 +53,172 @@ public final class Startup extends Application {
 	 */
 	@Override
 	public void start(Stage stage) throws Exception {
+
+		// Initialize config and logger
 		try {
-			// Load the configuration from client.properties first
+			config.loadAll(Startup.class, "client.properties", getParameters().getRaw().toArray(new String[0]));
-			final Properties properties = new Properties();
+			EnvoyLog.initialize(config);
-			properties.load(Startup.class.getClassLoader().getResourceAsStream("client.properties"));
+		} catch (final IllegalStateException e) {
-			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) {
 			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()) {
+		try {
-			localDB = new TransientLocalDB();
+			final var localDBFile = new File(config.getHomeDirectory(), config.getServer());
-			new Alert(AlertType.WARNING, "Ignoring local database.\nMessages will not be saved!").showAndWait();
+			logger.info("Initializing LocalDB at " + localDBFile);
-		} else try {
+			localDB = new LocalDB(localDBFile);
-			localDB = new PersistentLocalDB(new File(config.getHomeDirectory(), config.getLocalDB().getPath()));
+		} catch (IOException | EnvoyException e) {
-		} catch (final IOException e3) {
+			logger.log(Level.SEVERE, "Could not initialize local database: ", e);
-			logger.log(Level.SEVERE, "Could not initialize local database: ", e3);
+			new Alert(AlertType.ERROR, "Could not initialize local database!\n" + e).showAndWait();
-			new Alert(AlertType.ERROR, "Could not initialize local database!\n" + e3).showAndWait();
 			System.exit(1);
 			return;
 		}
 
-		// Initialize client and unread message cache
+		// Prepare handshake
-		client = new Client();
+		context.setLocalDB(localDB);
 
+		// Configure stage
+		stage.setTitle("Envoy");
+		stage.getIcons().add(IconUtil.loadIcon("envoy_logo"));
+
+		// 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>());
-
+		try {
-		stage.setTitle("Envoy");
+			client.performHandshake(credentials, cacheMap);
-		stage.getIcons().add(IconUtil.loadIcon("envoy_logo"));
+			if (client.isOnline()) {
-
+				loadChatScene();
-		final var sceneContext = new SceneContext(stage);
+				client.initReceiver(localDB, cacheMap);
-		sceneContext.load(SceneInfo.LOGIN_SCENE);
+				return true;
-		sceneContext.<LoginScene>getController().initializeData(client, localDB, cacheMap, sceneContext);
+			} 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 static boolean attemptOfflineMode(String identifier) {
-	public void stop() {
 		try {
-			logger.log(Level.INFO, "Closing connection...");
+			// Try entering offline mode
-			client.close();
+			final User clientUser = localDB.getUsers().get(identifier);
-
+			if (clientUser == null) throw new EnvoyException("Could not enter offline mode: user name unknown");
-			logger.log(Level.INFO, "Saving local database and settings...");
+			client.setSender(clientUser);
-			localDB.save();
+			loadChatScene();
-			Settings.getInstance().save();
+			return true;
-			logger.log(Level.INFO, "Envoy was terminated by its user");
 		} 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
+		localDB.setUser(client.getSender());
+
+		// 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();
+		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();
+
+		if (StatusTrayIcon.isSupported()) {
+
+			// Exit or minimize the stage when a close request occurs
+			stage.setOnCloseRequest(e -> { ShutdownHelper.exit(); if (Settings.getInstance().isHideOnClose()) e.consume(); });
+
+			// Initialize status tray icon
+			final var trayIcon = new StatusTrayIcon(stage);
+			Settings.getInstance().getItems().get("hideOnClose").setChangeHandler(c -> {
+				if ((Boolean) c) trayIcon.show();
+				else trayIcon.hide();
+			});
+		}
+
+		// Start auto save thread
+		localDB.initAutoSave();
+	}
 }

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

@@ -2,25 +2,22 @@ package envoy.client.ui;
 
 import java.awt.*;
 import java.awt.TrayIcon.MessageType;
-import java.awt.event.WindowAdapter;
-import java.awt.event.WindowEvent;
-import java.util.logging.Level;
 
-import envoy.client.event.MessageCreationEvent;
+import javafx.application.Platform;
+import javafx.stage.Stage;
+
+import envoy.client.helper.ShutdownHelper;
+import envoy.client.util.IconUtil;
 import envoy.data.Message;
-import envoy.event.EventBus;
+
-import envoy.exception.EnvoyException;
+import dev.kske.eventbus.*;
-import envoy.util.EnvoyLog;
+import dev.kske.eventbus.Event;
 
 /**
- * Project: <strong>envoy-client</strong><br>
- * File: <strong>StatusTrayIcon.java</strong><br>
- * Created: <strong>3 Dec 2019</strong><br>
- *
  * @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
@@ -33,68 +30,68 @@ public class StatusTrayIcon {
 	 * 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 displayMessages;
+
+	/**
+	 * @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 focusTarget the {@link Window} which focus determines if message
+	 * @param stage the stage whose focus determines if message
-	 *                    notifications are displayed
+	 *              notifications are displayed
-	 * @throws EnvoyException if the currently used OS does not support the System
+	 * @since Envoy Client v0.2-beta
-	 *                        Tray API
-	 * @since Envoy Client v0.2-alpha
 	 */
-	public StatusTrayIcon(Window focusTarget) throws EnvoyException {
+	public StatusTrayIcon(Stage stage) {
-		if (!SystemTray.isSupported()) throw new EnvoyException("The Envoy tray icon is not supported.");
+		trayIcon = new TrayIcon(IconUtil.loadAWTCompatible("/icons/envoy_logo.png"), "Envoy");
-
-		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.");
 
 		final PopupMenu popup = new PopupMenu();
 
 		final MenuItem exitMenuItem = new MenuItem("Exit");
-		exitMenuItem.addActionListener(evt -> System.exit(0));
+		exitMenuItem.addActionListener(evt -> ShutdownHelper.exit());
 		popup.add(exitMenuItem);
 
 		trayIcon.setPopupMenu(popup);
 
-		// Only display messages if the chat window is not focused
+		// Only display messages if the stage is not focused
-		focusTarget.addWindowFocusListener(new WindowAdapter() {
+		stage.focusedProperty().addListener((ov, onHidden, onShown) -> displayMessages = !ov.getValue());
-
-			@Override
-			public void windowGainedFocus(WindowEvent e) { displayMessages = false; }
-
-			@Override
-			public void windowLostFocus(WindowEvent e) { displayMessages = true; }
-		});
 
 		// 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().registerListener(this);
-		EventBus.getInstance()
-			.register(MessageCreationEvent.class,
-					evt -> { if (displayMessages) trayIcon.displayMessage("New message received", evt.get().getText(), MessageType.INFO); });
 	}
 
 	/**
-	 * 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) {
+		} 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);
+
-		}
+	/**
+	 * Removes the icon from the system tray.
+	 *
+	 * @since Envoy Client v0.2-beta
+	 */
+	public void hide() { SystemTray.getSystemTray().remove(trayIcon); }
+
+	@Event
+	private void onMessage(Message message) {
+		if (displayMessages) trayIcon.displayMessage(
+				message.hasAttachment() ? "New " + message.getAttachment().getType().toString().toLowerCase() + " message received" : "New message received",
+				message.getText(),
+				MessageType.INFO);
 	}
 }

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

@@ -1,11 +1,9 @@
-package envoy.client.ui;
+package envoy.client.ui.control;
 
-import java.util.logging.Level;
+import java.util.logging.*;
-import java.util.logging.Logger;
 
-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;
@@ -14,10 +12,6 @@ import envoy.util.EnvoyLog;
 
 /**
  * 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

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

@@ -0,0 +1,69 @@
+package envoy.client.ui.control;
+
+import javafx.geometry.*;
+import javafx.scene.control.Label;
+import javafx.scene.image.*;
+import javafx.scene.layout.*;
+import javafx.scene.shape.Rectangle;
+
+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);
+
+	/**
+	 * @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
+		ImageView	contactProfilePic	= new ImageView(chat instanceof GroupChat ? groupIcon : userIcon);
+		final var clip = new Rectangle();
+		clip.setWidth(32);
+		clip.setHeight(32);
+		clip.setArcHeight(32);
+		clip.setArcWidth(32);
+		contactProfilePic.setClip(clip);
+		getChildren().add(contactProfilePic);
+
+		// Spacing
+		final 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) {
+			final var spacing = new Region();
+			setHgrow(spacing, Priority.ALWAYS);
+			getChildren().add(spacing);
+			final var unreadMessagesLabel = new Label(Integer.toString(chat.getUnreadAmount()));
+			unreadMessagesLabel.setMinSize(15, 15);
+			final var vbox = new VBox();
+			vbox.setAlignment(Pos.CENTER_RIGHT);
+			unreadMessagesLabel.setAlignment(Pos.CENTER);
+			unreadMessagesLabel.getStyleClass().add("unread-messages-amount");
+			vbox.getChildren().add(unreadMessagesLabel);
+			getChildren().add(vbox);
+		}
+		getStyleClass().add("list-element");
+	}
+}

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

@@ -0,0 +1,39 @@
+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 {
+
+	/**
+	 * @param contact the contact to display
+	 * @since Envoy Client v0.2-beta
+	 */
+	public ContactControl(Contact contact) {
+
+		// Name label
+		final var nameLabel = new Label(contact.getName());
+		getChildren().add(nameLabel);
+
+		// Online status (user) or member count (group)
+		if (contact instanceof User) {
+			final var	status		= ((User) contact).getStatus().toString();
+			final var	statusLabel	= new Label(status);
+			statusLabel.getStyleClass().add(status.toLowerCase());
+			getChildren().add(statusLabel);
+		} else {
+			getChildren().add(new Label(contact.getContacts().size() + " members"));
+		}
+		getStyleClass().add("list-element");
+	}
+}

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

@@ -0,0 +1,173 @@
+package envoy.client.ui.control;
+
+import java.awt.Toolkit;
+import java.awt.datatransfer.StringSelection;
+import java.io.*;
+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 javafx.stage.FileChooser;
+
+import envoy.client.data.*;
+import envoy.client.ui.*;
+import envoy.client.util.IconUtil;
+import envoy.data.*;
+import envoy.data.Message.MessageStatus;
+import envoy.util.EnvoyLog;
+
+/**
+ * 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.getInstance().getLocalDB();
+	private final SceneContext	sceneContext	= Context.getInstance().getSceneContext();
+
+	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 Settings					settings		= Settings.getInstance();
+	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 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	copyMenuItem	= new MenuItem("Copy");
+		final var	deleteMenuItem	= new MenuItem("Delete");
+		final var	forwardMenuItem	= new MenuItem("Forward");
+		final var	quoteMenuItem	= new MenuItem("Quote");
+		final var	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
+		// 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 -> saveAttachment(message));
+			contextMenu.getItems().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");
+			ownMessage = true;
+			hbox.setAlignment(Pos.CENTER_RIGHT);
+		} else {
+			getStyleClass().add("received-message");
+			ownMessage = false;
+		}
+		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);
+	}
+
+	// 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) {
+		File		file;
+		final var	fileName			= message.getAttachment().getName();
+		final var	downloadLocation	= settings.getDownloadLocation();
+		// Show save file dialog, if the user did not opt-out
+		if (!settings.isDownloadSavedWithoutAsking()) {
+			final var fileChooser = new FileChooser();
+			fileChooser.setInitialFileName(fileName);
+			fileChooser.setInitialDirectory(downloadLocation);
+			file = fileChooser.showSaveDialog(sceneContext.getStage());
+		} else file = new File(downloadLocation, fileName);
+
+		// A file was selected
+		if (file != null) try (FileOutputStream fos = new FileOutputStream(file)) {
+			fos.write(message.getAttachment().getData());
+			logger.log(Level.FINE, "Attachment of message was saved at " + file.getAbsolutePath());
+		} catch (final IOException e) {
+			logger.log(Level.WARNING, "Could not save attachment of " + message + ": ", e);
+		}
+	}
+
+	/**
+	 * @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 +1,56 @@
+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/TextInputContextMenu.java

@@ -0,0 +1,105 @@
+package envoy.client.ui.control;
+
+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");
+	private final MenuItem	separatorMI	= new SeparatorMenuItem();
+
+	/**
+	 * 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());
+		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(cutMI);
+		getItems().add(copyMI);
+		getItems().add(pasteMI);
+		getItems().add(separatorMI);
+		getItems().add(deleteMI);
+		getItems().add(clearMI);
+		getItems().add(separatorMI);
+		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/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/ChatScene.java

@@ -2,57 +2,57 @@ package envoy.client.ui.controller;
 
 import java.awt.Toolkit;
 import java.awt.datatransfer.StringSelection;
-import java.io.ByteArrayInputStream;
+import java.io.*;
-import java.io.File;
-import java.io.IOException;
 import java.nio.file.Files;
+import java.time.LocalDateTime;
+import java.time.format.DateTimeFormatter;
 import java.util.Random;
-import java.util.logging.Level;
+import java.util.logging.*;
-import java.util.logging.Logger;
 
 import javafx.animation.RotateTransition;
 import javafx.application.Platform;
-import javafx.collections.FXCollections;
+import javafx.collections.ObservableList;
-import javafx.fxml.FXML;
+import javafx.collections.transformation.FilteredList;
-import javafx.scene.Node;
+import javafx.fxml.*;
 import javafx.scene.control.*;
 import javafx.scene.control.Alert.AlertType;
-import javafx.scene.image.Image;
+import javafx.scene.image.*;
-import javafx.scene.image.ImageView;
+import javafx.scene.input.*;
-import javafx.scene.input.KeyCode;
+import javafx.scene.layout.*;
-import javafx.scene.input.KeyEvent;
-import javafx.scene.layout.GridPane;
 import javafx.scene.paint.Color;
+import javafx.scene.shape.Rectangle;
 import javafx.stage.FileChooser;
 import javafx.util.Duration;
 
 import envoy.client.data.*;
 import envoy.client.data.audio.AudioRecorder;
-import envoy.client.event.MessageCreationEvent;
+import envoy.client.data.commands.*;
-import envoy.client.net.Client;
+import envoy.client.event.*;
-import envoy.client.net.WriteProxy;
+import envoy.client.helper.ShutdownHelper;
-import envoy.client.ui.IconUtil;
+import envoy.client.net.*;
-import envoy.client.ui.Restorable;
+import envoy.client.ui.*;
-import envoy.client.ui.SceneContext;
+import envoy.client.ui.SceneContext.SceneInfo;
-import envoy.client.ui.listcell.ContactListCellFactory;
+import envoy.client.ui.control.*;
-import envoy.client.ui.listcell.MessageControl;
+import envoy.client.ui.listcell.*;
-import envoy.client.ui.listcell.MessageListCellFactory;
+import envoy.client.util.*;
 import envoy.data.*;
 import envoy.data.Attachment.AttachmentType;
+import envoy.data.Message.MessageStatus;
 import envoy.event.*;
 import envoy.event.contact.ContactOperation;
 import envoy.exception.EnvoyException;
 import envoy.util.EnvoyLog;
 
+import dev.kske.eventbus.*;
+import dev.kske.eventbus.Event;
+
 /**
- * Project: <strong>envoy-client</strong><br>
+ * Controller for the chat scene.
- * File: <strong>ChatSceneController.java</strong><br>
- * Created: <strong>26.03.2020</strong><br>
  *
  * @author Kai S. K. Engelbart
  * @since Envoy Client v0.1-beta
  */
-public final class ChatScene implements Restorable {
+public final class ChatScene implements EventListener, Restorable {
 
 	@FXML
 	private GridPane scene;
@@ -79,7 +79,13 @@ public final class ChatScene implements Restorable {
 	private Button settingsButton;
 
 	@FXML
-	private Button rotateButton;
+	private Button messageSearchButton;
+
+	@FXML
+	private Button newGroupButton;
+
+	@FXML
+	private Button newContactButton;
 
 	@FXML
 	private TextArea messageTextArea;
@@ -96,24 +102,59 @@ public final class ChatScene implements Restorable {
 	@FXML
 	private ImageView attachmentView;
 
-	private LocalDB			localDB;
+	@FXML
-	private Client			client;
+	private Label topBarContactLabel;
-	private WriteProxy		writeProxy;
-	private SceneContext	sceneContext;
 
-	private Chat			currentChat;
+	@FXML
-	private AudioRecorder	recorder;
+	private Label topBarStatusLabel;
-	private boolean			recording;
-	private Attachment		pendingAttachment;
-	private boolean			postingPermanentlyDisabled;
 
-	private static final Settings	settings	= Settings.getInstance();
+	@FXML
-	private static final EventBus	eventBus	= EventBus.getInstance();
+	private ImageView clientProfilePic;
-	private static final Logger		logger		= EnvoyLog.getLogger(ChatScene.class);
 
-	private static final Image	DEFAULT_ATTACHMENT_VIEW_IMAGE	= IconUtil.loadIconThemeSensitive("attachment_present", 20);
+	@FXML
-	private static final int	MAX_MESSAGE_LENGTH				= 255;
+	private ImageView recipientProfilePic;
-	private static final int	DEFAULT_ICON_SIZE				= 16;
+
+	@FXML
+	private TextArea contactSearch;
+
+	@FXML
+	private VBox contactOperations;
+
+	@FXML
+	private TabPane tabPane;
+
+	@FXML
+	private Tab contactSearchTab;
+
+	@FXML
+	private Tab groupCreationTab;
+
+	@FXML
+	private HBox contactSpecificOnlineOperations;
+
+	private Chat				currentChat;
+	private FilteredList<Chat>	chats;
+	private boolean				recording;
+	private Attachment			pendingAttachment;
+	private boolean				postingPermanentlyDisabled;
+	private boolean				isCustomAttachmentImage;
+
+	private final LocalDB			localDB					= context.getLocalDB();
+	private final Client			client					= context.getClient();
+	private final WriteProxy		writeProxy				= context.getWriteProxy();
+	private final SceneContext		sceneContext			= context.getSceneContext();
+	private final AudioRecorder		recorder				= new AudioRecorder();
+	private final SystemCommandMap	messageTextAreaCommands	= new SystemCommandMap();
+	private final Tooltip			onlyIfOnlineTooltip		= new Tooltip("You need to be online to do this");
+
+	private static Image DEFAULT_ATTACHMENT_VIEW_IMAGE = IconUtil.loadIconThemeSensitive("attachment_present", 20);
+
+	private static final Settings	settings			= Settings.getInstance();
+	private static final EventBus	eventBus			= EventBus.getInstance();
+	private static final Logger		logger				= EnvoyLog.getLogger(ChatScene.class);
+	private static final Context	context				= Context.getInstance();
+	private static final int		MAX_MESSAGE_LENGTH	= 255;
+	private static final int		DEFAULT_ICON_SIZE	= 16;
 
 	/**
 	 * Initializes the appearance of certain visual components.
@@ -122,105 +163,179 @@ public final class ChatScene implements Restorable {
 	 */
 	@FXML
 	private void initialize() {
+		eventBus.registerListener(this);
 
 		// Initialize message and user rendering
-		messageList.setCellFactory(MessageListCellFactory::new);
+		messageList.setCellFactory(MessageListCell::new);
-		chatList.setCellFactory(ContactListCellFactory::new);
+		chatList.setCellFactory(new ListCellFactory<>(ChatControl::new));
 
+		// JavaFX provides an internal way of populating the context menu of a text
+		// area.
+		// We, however, need additional functionality.
+		messageTextArea.setContextMenu(new TextInputContextMenu(messageTextArea, e -> checkKeyCombination(null)));
+
+		// Set the icons of buttons and image views
 		settingsButton.setGraphic(new ImageView(IconUtil.loadIconThemeSensitive("settings", DEFAULT_ICON_SIZE)));
 		voiceButton.setGraphic(new ImageView(IconUtil.loadIconThemeSensitive("microphone", DEFAULT_ICON_SIZE)));
 		attachmentButton.setGraphic(new ImageView(IconUtil.loadIconThemeSensitive("attachment", DEFAULT_ICON_SIZE)));
 		attachmentView.setImage(DEFAULT_ATTACHMENT_VIEW_IMAGE);
-		rotateButton.setGraphic(new ImageView(IconUtil.loadIconThemeSensitive("rotate", (int) (DEFAULT_ICON_SIZE * 1.5))));
+		messageSearchButton.setGraphic(new ImageView(IconUtil.loadIconThemeSensitive("search", DEFAULT_ICON_SIZE)));
+		clientProfilePic.setImage(IconUtil.loadIconThemeSensitive("user_icon", 43));
+		onlyIfOnlineTooltip.setShowDelay(Duration.millis(250));
+		final var clip = new Rectangle();
+		clip.setWidth(43);
+		clip.setHeight(43);
+		clip.setArcHeight(43);
+		clip.setArcWidth(43);
+		clientProfilePic.setClip(clip);
 
-		// Listen to received messages
+		chatList.setItems(chats = new FilteredList<>(localDB.getChats()));
-		eventBus.register(MessageCreationEvent.class, e -> {
+		contactLabel.setText(localDB.getUser().getName());
-			final var message = e.get();
-			localDB.getChat(message instanceof GroupMessage ? message.getRecipientID() : message.getSenderID()).ifPresent(chat -> {
-				chat.insert(message);
-				if (chat.equals(currentChat)) {
-					try {
-						currentChat.read(writeProxy);
-					} catch (final IOException e1) {
-						logger.log(Level.WARNING, "Could not read current chat: ", e1);
-					}
-					Platform.runLater(() -> { messageList.refresh(); scrollToMessageListEnd(); });
-				} else chat.incrementUnreadAmount();
-				// Moving chat with most recent unreadMessages to the top
-				Platform.runLater(() -> {
-					chatList.getItems().remove(chat);
-					chatList.getItems().add(0, chat);
-					if (chat.equals(currentChat)) chatList.getSelectionModel().select(0);
-					localDB.getChats().remove(chat);
-					localDB.getChats().add(0, chat);
-				});
-			});
-		});
 
-		// Listen to message status changes
+		initializeSystemCommandsMap();
-		eventBus.register(MessageStatusChange.class, e -> localDB.getMessage(e.getID()).ifPresent(message -> {
-			message.setStatus(e.get());
-			// Update UI if in current chat
-			if (currentChat != null && message.getSenderID() == currentChat.getRecipient().getID()) Platform.runLater(messageList::refresh);
-		}));
 
-		eventBus.register(GroupMessageStatusChange.class, e -> localDB.getMessage(e.getID()).ifPresent(groupMessage -> {
+		Platform.runLater(() -> {
-			((GroupMessage) groupMessage).getMemberStatuses().replace(e.getMemberID(), e.get());
+			final var online = client.isOnline();
-
+			// no check will be performed in case it has already been disabled - a negative
-			// Update UI if in current chat
+			// GroupCreationResult might have been returned
-			if (currentChat != null && groupMessage.getRecipientID() == currentChat.getRecipient().getID()) Platform.runLater(messageList::refresh);
+			if (!newGroupButton.isDisabled()) newGroupButton.setDisable(!online);
-		}));
+			newContactButton.setDisable(!online);
-
+			if (online) try {
-		// Listen to user status changes
+				Tooltip.uninstall(contactSpecificOnlineOperations, onlyIfOnlineTooltip);
-		eventBus.register(UserStatusChange.class,
+				contactSearchTab.setContent(new FXMLLoader().load(getClass().getResourceAsStream("/fxml/ContactSearchTab.fxml")));
-				e -> chatList.getItems()
+				groupCreationTab.setContent(new FXMLLoader().load(getClass().getResourceAsStream("/fxml/GroupCreationTab.fxml")));
-					.stream()
+			} catch (final IOException e) {
-					.filter(c -> c.getRecipient().getID() == e.getID())
+				logger.log(Level.SEVERE, "An error occurred when attempting to load tabs: ", e);
-					.findAny()
+			}
-					.map(Chat::getRecipient)
+			else {
-					.ifPresent(u -> { ((User) u).setStatus(e.get()); Platform.runLater(chatList::refresh); }));
+				Tooltip.install(contactSpecificOnlineOperations, onlyIfOnlineTooltip);
-
+				updateInfoLabel("You are offline", "info-label-warning");
-		// Listen to contacts changes
-		eventBus.register(ContactOperation.class, e -> {
-			final var contact = e.get();
-			switch (e.getOperationType()) {
-				case ADD:
-					localDB.getUsers().put(contact.getName(), contact);
-					Chat chat = contact instanceof User ? new Chat(contact) : new GroupChat(client.getSender(), contact);
-					localDB.getChats().add(chat);
-					Platform.runLater(() -> chatList.getItems().add(chat));
-					break;
-				case REMOVE:
-					localDB.getUsers().remove(contact.getName());
-					localDB.getChats().removeIf(c -> c.getRecipient().getID() == contact.getID());
-					Platform.runLater(() -> chatList.getItems().removeIf(c -> c.getRecipient().getID() == contact.getID()));
-					break;
 			}
 		});
 	}
 
+	@Event(eventType = BackEvent.class)
+	private void onBackEvent() { tabPane.getSelectionModel().select(Tabs.CONTACT_LIST.ordinal()); }
+
+	@Event(includeSubtypes = true)
+	private void onMessage(Message message) {
+
+		// The sender of the message is the recipient of the chat
+		// Exceptions: this user is the sender (sync) or group message (group is
+		// recipient)
+		final boolean	ownMessage	= message.getSenderID() == localDB.getUser().getID();
+		final var		recipientID	= message instanceof GroupMessage || ownMessage ? message.getRecipientID() : message.getSenderID();
+
+		localDB.getChat(recipientID).ifPresent(chat -> {
+			chat.insert(message);
+
+			// Read current chat or increment unread amount
+			if (chat.equals(currentChat)) {
+				currentChat.read(writeProxy);
+				Platform.runLater(this::scrollToMessageListEnd);
+			} else if (!ownMessage && message.getStatus() != MessageStatus.READ) chat.incrementUnreadAmount();
+
+			// Move chat with most recent unread messages to the top
+			Platform.runLater(() -> {
+				chats.getSource().remove(chat);
+				((ObservableList<Chat>) chats.getSource()).add(0, chat);
+
+				if (chat.equals(currentChat)) chatList.getSelectionModel().select(0);
+			});
+		});
+	}
+
+	@Event
+	private void onMessageStatusChange(MessageStatusChange evt) {
+
+		// Update UI if in current chat and the current user was the sender of the
+		// message
+		if (currentChat != null) localDB.getMessage(evt.getID())
+			.filter(msg -> msg.getSenderID() == client.getSender().getID())
+			.ifPresent(msg -> Platform.runLater(messageList::refresh));
+	}
+
+	@Event(eventType = UserStatusChange.class)
+	private void onUserStatusChange() { Platform.runLater(chatList::refresh); }
+
+	@Event
+	private void onContactOperation(ContactOperation operation) {
+		final var contact = operation.get();
+		switch (operation.getOperationType()) {
+			case ADD:
+				if (contact instanceof User) localDB.getUsers().put(contact.getName(), (User) contact);
+				final var chat = contact instanceof User ? new Chat(contact) : new GroupChat(client.getSender(), contact);
+				Platform.runLater(() -> ((ObservableList<Chat>) chats.getSource()).add(0, chat));
+				break;
+			case REMOVE:
+				Platform.runLater(() -> chats.getSource().removeIf(c -> c.getRecipient().equals(contact)));
+				break;
+		}
+	}
+
+	@Event(eventType = NoAttachments.class)
+	private void onNoAttachments() {
+		Platform.runLater(() -> {
+			attachmentButton.setDisable(true);
+			voiceButton.setDisable(true);
+			final var alert = new Alert(AlertType.ERROR);
+			alert.setTitle("No attachments possible");
+			alert.setHeaderText("Your current server does not support attachments.");
+			alert.setContentText("If this is unplanned, please contact your server administrator.");
+			alert.showAndWait();
+		});
+	}
+
+	@Event
+	private void onGroupCreationResult(GroupCreationResult result) { Platform.runLater(() -> newGroupButton.setDisable(!result.get())); }
+
+	@Event(eventType = ThemeChangeEvent.class)
+	private void onThemeChange() {
+		settingsButton.setGraphic(new ImageView(IconUtil.loadIconThemeSensitive("settings", DEFAULT_ICON_SIZE)));
+		voiceButton.setGraphic(new ImageView(IconUtil.loadIconThemeSensitive("microphone", DEFAULT_ICON_SIZE)));
+		attachmentButton.setGraphic(new ImageView(IconUtil.loadIconThemeSensitive("attachment", DEFAULT_ICON_SIZE)));
+		DEFAULT_ATTACHMENT_VIEW_IMAGE = IconUtil.loadIconThemeSensitive("attachment_present", 20);
+		attachmentView.setImage(isCustomAttachmentImage ? attachmentView.getImage() : DEFAULT_ATTACHMENT_VIEW_IMAGE);
+		messageSearchButton.setGraphic(new ImageView(IconUtil.loadIconThemeSensitive("search", DEFAULT_ICON_SIZE)));
+		clientProfilePic.setImage(IconUtil.loadIconThemeSensitive("user_icon", 43));
+		chatList.setCellFactory(new ListCellFactory<>(ChatControl::new));
+		messageList.setCellFactory(MessageListCell::new);
+		// TODO: cache image
+		if (currentChat.getRecipient() instanceof User) recipientProfilePic.setImage(IconUtil.loadIconThemeSensitive("user_icon", 43));
+		else recipientProfilePic.setImage(IconUtil.loadIconThemeSensitive("group_icon", 43));
+	}
+
+	@Event(eventType = Logout.class, priority = 200)
+	private void onLogout() { eventBus.removeListener(this); }
+
 	/**
-	 * Initializes all necessary data via dependency injection-
+	 * Initializes all {@code SystemCommands} used in {@code ChatScene}.
 	 *
-	 * @param sceneContext the scene context used to load other scenes
+	 * @since Envoy Client v0.2-beta
-	 * @param localDB      the local database form which chats and users are loaded
-	 * @param client       the client used to request ID generators
-	 * @param writeProxy   the write proxy used to send messages and other data to
-	 *                     the server
-	 * @since Envoy Client v0.1-beta
 	 */
-	public void initializeData(SceneContext sceneContext, LocalDB localDB, Client client, WriteProxy writeProxy) {
+	private void initializeSystemCommandsMap() {
-		this.sceneContext	= sceneContext;
+		final var builder = new SystemCommandBuilder(messageTextAreaCommands);
-		this.localDB		= localDB;
-		this.client			= client;
-		this.writeProxy		= writeProxy;
 
-		chatList.setItems(FXCollections.observableList(localDB.getChats()));
+		// Do A Barrel roll initialization
-		contactLabel.setText(localDB.getUser().getName());
+		final var random = new Random();
-		MessageControl.setUser(localDB.getUser());
+		builder.setAction(text -> doABarrelRoll(Integer.parseInt(text.get(0)), Double.parseDouble(text.get(1))))
-		if (!client.isOnline()) updateInfoLabel("You are offline", "infoLabel-info");
+			.setDefaults(Integer.toString(random.nextInt(3) + 1), Double.toString(random.nextDouble() * 3 + 1))
+			.setDescription("See for yourself :)")
+			.setNumberOfArguments(2)
+			.build("dabr");
 
-		recorder = new AudioRecorder();
+		// Logout initialization
+		builder.setAction(text -> ShutdownHelper.logout()).setNumberOfArguments(0).setDescription("Logs you out.").build("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 -> sceneContext.load(SceneInfo.SETTINGS_SCENE))
+			.setNumberOfArguments(0)
+			.setDescription("Opens the settings screen")
+			.build("settings");
 	}
 
 	@Override
@@ -233,7 +348,9 @@ public final class ChatScene implements Restorable {
 	 */
 	@FXML
 	private void chatListClicked() {
-		final Contact user = chatList.getSelectionModel().getSelectedItem().getRecipient();
+		if (chatList.getSelectionModel().isEmpty()) return;
+
+		final var user = chatList.getSelectionModel().getSelectedItem().getRecipient();
 		if (user != null && (currentChat == null || !user.equals(currentChat.getRecipient()))) {
 
 			// LEON: JFC <===> JAVA FRIED CHICKEN <=/=> Java Foundation Classes
@@ -241,18 +358,14 @@ public final class ChatScene implements Restorable {
 			// Load the chat
 			currentChat = localDB.getChat(user.getID()).get();
 
-			messageList.setItems(FXCollections.observableList(currentChat.getMessages()));
+			messageList.setItems(currentChat.getMessages());
-			final var scrollIndex = messageList.getItems().size() - currentChat.getUnreadAmount() - 1;
+			final var scrollIndex = messageList.getItems().size() - currentChat.getUnreadAmount();
 			messageList.scrollTo(scrollIndex);
 			logger.log(Level.FINEST, "Loading chat with " + user + " at index " + scrollIndex);
 			deleteContactMenuItem.setText("Delete " + user.getName());
 
 			// Read the current chat
-			try {
+			currentChat.read(writeProxy);
-				currentChat.read(writeProxy);
-			} catch (final IOException e) {
-				logger.log(Level.WARNING, "Could not read current chat.", e);
-			}
 
 			// Discard the pending attachment
 			if (recorder.isRecording()) {
@@ -270,6 +383,27 @@ public final class ChatScene implements Restorable {
 		voiceButton.setDisable(!recorder.isSupported());
 		attachmentButton.setDisable(false);
 		chatList.refresh();
+
+		if (currentChat != null) {
+			topBarContactLabel.setText(currentChat.getRecipient().getName());
+			if (currentChat.getRecipient() instanceof User) {
+				final String status = ((User) currentChat.getRecipient()).getStatus().toString();
+				topBarStatusLabel.setText(status);
+				topBarStatusLabel.getStyleClass().add(status.toLowerCase());
+				recipientProfilePic.setImage(IconUtil.loadIconThemeSensitive("user_icon", 43));
+			} else {
+				topBarStatusLabel.setText(currentChat.getRecipient().getContacts().size() + " members");
+				recipientProfilePic.setImage(IconUtil.loadIconThemeSensitive("group_icon", 43));
+			}
+			final Rectangle clip = new Rectangle();
+			clip.setWidth(43);
+			clip.setHeight(43);
+			clip.setArcHeight(43);
+			clip.setArcWidth(43);
+			recipientProfilePic.setClip(clip);
+
+			messageSearchButton.setVisible(true);
+		}
 	}
 
 	/**
@@ -278,10 +412,7 @@ public final class ChatScene implements Restorable {
 	 * @since Envoy Client v0.1-beta
 	 */
 	@FXML
-	private void settingsButtonClicked() {
+	private void settingsButtonClicked() { sceneContext.load(SceneContext.SceneInfo.SETTINGS_SCENE); }
-		sceneContext.load(SceneContext.SceneInfo.SETTINGS_SCENE);
-		sceneContext.<SettingsScene>getController().initializeData(sceneContext);
-	}
 
 	/**
 	 * Actions to perform when the "Add Contact" - Button has been clicked.
@@ -289,10 +420,10 @@ public final class ChatScene implements Restorable {
 	 * @since Envoy Client v0.1-beta
 	 */
 	@FXML
-	private void addContactButtonClicked() {
+	private void addContactButtonClicked() { tabPane.getSelectionModel().select(Tabs.CONTACT_SEARCH.ordinal()); }
-		sceneContext.load(SceneContext.SceneInfo.CONTACT_SEARCH_SCENE);
+
-		sceneContext.<ContactSearchScene>getController().initializeData(sceneContext, localDB);
+	@FXML
-	}
+	private void groupCreationButtonClicked() { tabPane.getSelectionModel().select(Tabs.GROUP_CREATION.ordinal()); }
 
 	@FXML
 	private void voiceButtonClicked() {
@@ -306,7 +437,9 @@ public final class ChatScene implements Restorable {
 					});
 					recorder.start();
 				} else {
-					pendingAttachment	= new Attachment(recorder.finish(), AttachmentType.VOICE);
+					pendingAttachment	= new Attachment(recorder.finish(), "Voice_recording_"
+							+ DateTimeFormatter.ofPattern("yyyy_MM_dd-HH_mm_ss").format(LocalDateTime.now()) + "." + AudioRecorder.FILE_FORMAT,
+							AttachmentType.VOICE);
 					recording			= false;
 					Platform.runLater(() -> {
 						voiceButton.setGraphic(new ImageView(IconUtil.loadIconThemeSensitive("microphone", DEFAULT_ICON_SIZE)));
@@ -344,7 +477,7 @@ public final class ChatScene implements Restorable {
 			}
 
 			// Get attachment type (default is document)
-			AttachmentType type = AttachmentType.DOCUMENT;
+			var type = AttachmentType.DOCUMENT;
 			switch (fileChooser.getSelectedExtensionFilter().getDescription()) {
 				case "Pictures":
 					type = AttachmentType.PICTURE;
@@ -357,10 +490,13 @@ public final class ChatScene implements Restorable {
 			// Create the pending attachment
 			try {
 				final var fileBytes = Files.readAllBytes(file.toPath());
-				pendingAttachment = new Attachment(fileBytes, type);
+				pendingAttachment = new Attachment(fileBytes, file.getName(), type);
+				checkPostConditions(false);
 				// Setting the preview image as image of the attachmentView
-				if (type == AttachmentType.PICTURE)
+				if (type == AttachmentType.PICTURE) {
 					attachmentView.setImage(new Image(new ByteArrayInputStream(fileBytes), DEFAULT_ICON_SIZE, DEFAULT_ICON_SIZE, true, true));
+					isCustomAttachmentImage = true;
+				}
 				attachmentView.setVisible(true);
 			} catch (final IOException e) {
 				new Alert(AlertType.ERROR, "The selected file could not be loaded!").showAndWait();
@@ -369,20 +505,27 @@ public final class ChatScene implements Restorable {
 	}
 
 	/**
-	 * Rotates every element in our application by 360° in at most 2.75s.
+	 * Rotates every element in our application by {@code rotations}*360° in
+	 * {@code an}.
 	 *
+	 * @param rotations     the amount of times the scene is rotated by 360°
+	 * @param animationTime the time in seconds that this animation lasts
 	 * @since Envoy Client v0.1-beta
 	 */
-	@FXML
+	private void doABarrelRoll(int rotations, double animationTime) {
-	private void doABarrelRoll() {
+		// Limiting the rotations and duration
-		// contains all Node objects in ChatScene in alphabetical order
+		rotations		= Math.min(rotations, 100000);
-		final var	rotatableNodes	= new Node[] { attachmentButton, attachmentView, contactLabel, infoLabel, messageList, messageTextArea,
+		rotations		= Math.max(rotations, 1);
-				postButton, remainingChars, rotateButton, scene, settingsButton, chatList, voiceButton };
+		animationTime	= Math.min(animationTime, 150);
-		final var	random			= new Random();
+		animationTime	= Math.max(animationTime, 0.25);
+
+		// contains all Node objects in ChatScene
+		final var rotatableNodes = ReflectionUtil.getAllDeclaredNodeVariables(this);
 		for (final var node : rotatableNodes) {
-			// Defines at most four whole rotation in at most 4s
+			// Sets the animation duration to {animationTime}
-			final var rotateTransition = new RotateTransition(Duration.seconds(random.nextDouble() * 3 + 1), node);
+			final var rotateTransition = new RotateTransition(Duration.seconds(animationTime), node);
-			rotateTransition.setByAngle((random.nextInt(3) + 1) * 360);
+			// rotates every element {rotations} times
+			rotateTransition.setByAngle(rotations * 360);
 			rotateTransition.play();
 			// This is needed as for some strange reason objects could stop before being
 			// rotated back to 0°
@@ -400,10 +543,35 @@ public final class ChatScene implements Restorable {
 	 */
 	@FXML
 	private void checkKeyCombination(KeyEvent e) {
+
 		// Checks whether the text is too long
 		messageTextUpdated();
-		// Automatic sending of messages via (ctrl +) enter
+
-		checkPostConditions(e);
+		// Sending an IsTyping event if none has been sent for
+		// IsTyping#millisecondsActive
+		if (client.isOnline() && currentChat.getLastWritingEvent() + IsTyping.millisecondsActive <= System.currentTimeMillis()) {
+			client.send(new IsTyping(getChatID(), currentChat.getRecipient().getID()));
+			currentChat.lastWritingEventWasNow();
+		}
+
+		// KeyPressed will be called before the char has been added to the text, hence
+		// this is needed for the first char
+		if (messageTextArea.getText().length() == 1 && e != null) checkPostConditions(e);
+
+		// This is needed for the messageTA context menu
+		else if (e == null) checkPostConditions(false);
+	}
+
+	/**
+	 * Returns the id that should be used to send things to the server: the id of
+	 * 'our' {@link User} if the recipient of that object is another User, else the
+	 * id of the {@link Group} 'our' user is sending to.
+	 *
+	 * @return an id that can be sent to the server
+	 * @since Envoy Client v0.2-beta
+	 */
+	private long getChatID() {
+		return currentChat.getRecipient() instanceof User ? client.getSender().getID() : currentChat.getRecipient().getID();
 	}
 
 	/**
@@ -412,20 +580,37 @@ public final class ChatScene implements Restorable {
 	 */
 	@FXML
 	private void checkPostConditions(KeyEvent e) {
-		checkPostConditions(settings.isEnterToSend() && e.getCode() == KeyCode.ENTER
+		final var	enterPressed	= e.getCode() == KeyCode.ENTER;
-				|| !settings.isEnterToSend() && e.getCode() == KeyCode.ENTER && e.isControlDown());
+		final var	messagePosted	= enterPressed ? settings.isEnterToSend() ? !e.isControlDown() : e.isControlDown() : false;
+		if (messagePosted) {
+
+			// Removing an inserted line break if added by pressing enter
+			final var	text			= messageTextArea.getText();
+			final var	textPosition	= messageTextArea.getCaretPosition() - 1;
+			if (!e.isControlDown() && !text.isEmpty() && text.charAt(textPosition) == '\n')
+				messageTextArea.setText(new StringBuilder(text).deleteCharAt(textPosition).toString());
+		}
+
+		// if control is pressed, the enter press is originally invalidated. Here it'll
+		// be inserted again
+		else if (enterPressed && e.isControlDown()) {
+			var caretPosition = messageTextArea.getCaretPosition();
+			messageTextArea.setText(new StringBuilder(messageTextArea.getText()).insert(caretPosition, '\n').toString());
+			messageTextArea.positionCaret(++caretPosition);
+		}
+		checkPostConditions(messagePosted);
 	}
 
-	private void checkPostConditions(boolean sendKeyPressed) {
+	private void checkPostConditions(boolean postMessage) {
 		if (!postingPermanentlyDisabled) {
-			if (!postButton.isDisabled() && sendKeyPressed) postMessage();
+			if (!postButton.isDisabled() && postMessage) postMessage();
 			postButton.setDisable(messageTextArea.getText().isBlank() && pendingAttachment == null || currentChat == null);
 		} else {
 			final var noMoreMessaging = "Go online to send messages";
 			if (!infoLabel.getText().equals(noMoreMessaging))
 				// Informing the user that he is a f*cking moron and should use Envoy online
 				// because he ran out of messageIDs to use
-				updateInfoLabel(noMoreMessaging, "infoLabel-error");
+				updateInfoLabel(noMoreMessaging, "info-label-error");
 		}
 	}
 
@@ -451,8 +636,8 @@ public final class ChatScene implements Restorable {
 	 * @since Envoy Client v0.1-beta
 	 */
 	private void updateRemainingCharsLabel() {
-		final int	currentLength	= messageTextArea.getText().length();
+		final var	currentLength	= messageTextArea.getText().length();
-		final int	remainingLength	= MAX_MESSAGE_LENGTH - currentLength;
+		final var	remainingLength	= MAX_MESSAGE_LENGTH - currentLength;
 		remainingChars.setText(String.format("remaining chars: %d/%d", remainingLength, MAX_MESSAGE_LENGTH));
 		remainingChars.setTextFill(Color.rgb(currentLength, remainingLength, 0, 1));
 	}
@@ -470,11 +655,11 @@ public final class ChatScene implements Restorable {
 			postButton.setDisable(true);
 			messageTextArea.setDisable(true);
 			messageTextArea.clear();
-			updateInfoLabel("You need to go online to send more messages", "infoLabel-error");
+			updateInfoLabel("You need to go online to send more messages", "info-label-error");
 			return;
 		}
 		final var text = messageTextArea.getText().strip();
-		try {
+		if (!messageTextAreaCommands.executeIfAnyPresent(text)) {
 			// Creating the message and its metadata
 			final var builder = new MessageBuilder(localDB.getUser().getID(), currentChat.getRecipient().getID(), localDB.getIDGenerator())
 				.setText(text);
@@ -495,27 +680,23 @@ public final class ChatScene implements Restorable {
 			currentChat.insert(message);
 			// Moving currentChat to the top
 			Platform.runLater(() -> {
-				chatList.getItems().remove(currentChat);
+				chats.getSource().remove(currentChat);
-				chatList.getItems().add(0, currentChat);
+				((ObservableList<Chat>) chats.getSource()).add(0, currentChat);
 				chatList.getSelectionModel().select(0);
 				localDB.getChats().remove(currentChat);
 				localDB.getChats().add(0, currentChat);
 			});
-			messageList.refresh();
 			scrollToMessageListEnd();
 
 			// Request a new ID generator if all IDs were used
-			if (!localDB.getIDGenerator().hasNext() && client.isOnline()) client.requestIdGenerator();
+			if (!localDB.getIDGenerator().hasNext() && client.isOnline()) client.requestIDGenerator();
-
-		} catch (final IOException e) {
-			logger.log(Level.SEVERE, "Error while sending message: ", e);
-			new Alert(AlertType.ERROR, "An error occured while sending the message!").showAndWait();
 		}
 
 		// Clear text field and disable post button
 		messageTextArea.setText("");
 		postButton.setDisable(true);
 		updateRemainingCharsLabel();
+		isCustomAttachmentImage = false;
 	}
 
 	/**
@@ -541,9 +722,8 @@ public final class ChatScene implements Restorable {
 
 	/**
 	 * Updates the {@code attachmentView} in terms of visibility.<br>
-	 * Additionally resets the shown image to
+	 * Additionally resets the shown image to {@code DEFAULT_ATTACHMENT_VIEW_IMAGE}
-	 * {@code DEFAULT_ATTACHMENT_VIEW_IMAGE} if another image is currently
+	 * if another image is currently present.
-	 * present.
 	 *
 	 * @param visible whether the {@code attachmentView} should be displayed
 	 * @since Envoy Client v0.1-beta
@@ -562,9 +742,20 @@ public final class ChatScene implements Restorable {
 	private void copyAndPostMessage() {
 		final var messageText = messageTextArea.getText();
 		Toolkit.getDefaultToolkit().getSystemClipboard().setContents(new StringSelection(messageText), null);
+		final var	image				= attachmentView.getImage();
+		final var	messageAttachment	= pendingAttachment;
 		postMessage();
 		messageTextArea.setText(messageText);
 		updateRemainingCharsLabel();
 		postButton.setDisable(messageText.isBlank());
+		attachmentView.setImage(image);
+		if (attachmentView.getImage() != null) attachmentView.setVisible(true);
+		pendingAttachment = messageAttachment;
+	}
+
+	@FXML
+	private void searchContacts() {
+		chats.setPredicate(contactSearch.getText().isBlank() ? c -> true
+				: c -> c.getRecipient().getName().toLowerCase().contains(contactSearch.getText().toLowerCase()));
 	}
 }

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 +1,128 @@
+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 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;
+import envoy.data.User;
+import envoy.event.ElementOperation;
+import envoy.event.contact.*;
+import envoy.util.EnvoyLog;
+
+import dev.kske.eventbus.*;
+
+/**
+ * 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 onContactOperation(ContactOperation 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 ContactOperation} 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 ContactOperation(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() { 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 +1,212 @@
+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.layout.HBox;
+
+import envoy.client.data.*;
+import envoy.client.event.BackEvent;
+import envoy.client.ui.control.ContactControl;
+import envoy.client.ui.listcell.ListCellFactory;
+import envoy.data.*;
+import envoy.event.GroupCreation;
+import envoy.event.contact.ContactOperation;
+import envoy.util.Bounds;
+
+import dev.kske.eventbus.*;
+
+/**
+ * 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;
+
+	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));
+		userList.getSelectionModel().setSelectionMode(SelectionMode.MULTIPLE);
+		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()));
+	}
+
+	/**
+	 * Enables the {@code createButton} if at least one contact is selected.
+	 *
+	 * @since Envoy Client v0.1-beta
+	 */
+	@FXML
+	private void userListClicked() { createButton.setDisable(userList.getSelectionModel().isEmpty() || groupNameField.getText().isBlank()); }
+
+	/**
+	 * 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(userList.getSelectionModel().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();
+		}
+	}
+
+	/**
+	 * 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, userList.getSelectionModel().getSelectedItems().stream().map(User::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);
+	}
+
+	@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 onContactOperation(ContactOperation operation) {
+		if (operation.get() instanceof User) Platform.runLater(() -> {
+			switch (operation.getOperationType()) {
+				case ADD:
+					userList.getItems().add((User) operation.get());
+					break;
+				case REMOVE:
+					userList.getItems().removeIf(operation.get()::equals);
+					break;
+			}
+		});
+	}
+}

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

@@ -1,44 +1,35 @@
 package envoy.client.ui.controller;
 
-import java.io.FileNotFoundException;
+import java.time.Instant;
-import java.io.IOException;
+import java.util.logging.*;
-import java.util.concurrent.TimeoutException;
-import java.util.logging.Level;
-import java.util.logging.Logger;
 
 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 envoy.client.data.*;
+import envoy.client.data.ClientConfig;
-import envoy.client.net.Client;
+import envoy.client.ui.*;
-import envoy.client.net.WriteProxy;
+import envoy.client.util.IconUtil;
-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.*;
-import envoy.util.Bounds;
+
-import envoy.util.EnvoyLog;
+import dev.kske.eventbus.*;
 
 /**
- * Project: <strong>envoy-client</strong><br>
+ * Controller for the login scene.
- * File: <strong>LoginDialog.java</strong><br>
- * Created: <strong>03.04.2020</strong><br>
  *
  * @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 +38,86 @@ public final class LoginScene {
 	private PasswordField repeatPasswordField;
 
 	@FXML
-	private Label repeatPasswordLabel;
+	private Button registerSwitch;
-
-	@FXML
-	private CheckBox registerCheckBox;
 
 	@FXML
 	private Label connectionLabel;
 
-	private Client			client;
+	@FXML
-	private LocalDB			localDB;
+	private Button loginButton;
-	private CacheMap		cacheMap;
-	private SceneContext	sceneContext;
 
-	private static final Logger			logger		= EnvoyLog.getLogger(LoginScene.class);
+	@FXML
-	private static final EventBus		eventBus	= EventBus.getInstance();
+	private CheckBox cbStaySignedIn;
-	private static final ClientConfig	config		= ClientConfig.getInstance();
+
+	@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);
-	}
 
-	/**
+		logo.setImage(IconUtil.loadIcon("envoy_logo"));
-	 * 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();
 
 		// 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())) {
+		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())) {
+		} else if (!Bounds.isValidContactName(user)) {
 			new Alert(AlertType.ERROR, "The entered user name is not valid (" + Bounds.CONTACT_NAME_PATTERN + ")").showAndWait();
-			userTextField.getTextField().clear();
+			userTextField.clear();
-		} else performHandshake(new LoginCredentials(userTextField.getTextField().getText(), passwordField.getText(), registerCheckBox.isSelected(),
+		} else {
-				Startup.VERSION));
+			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() {
+	private void offlineModeButtonPressed() { Startup.attemptOfflineMode(userTextField.getText()); }
-		attemptOfflineMode(new LoginCredentials(userTextField.getTextField().getText(), passwordField.getText(), false, Startup.VERSION));
-	}
 
 	@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());
+		repeatPasswordField.setVisible(registration);
-		repeatPasswordLabel.setVisible(registerCheckBox.isSelected());
+		offlineModeButton.setDisable(registration);
 	}
 
 	@FXML
@@ -130,70 +126,6 @@ public final class LoginScene {
 		System.exit(0);
 	}
 
-	private void performHandshake(LoginCredentials credentials) {
+	@Event
-		try {
+	private void onHandshakeRejection(HandshakeRejection evt) { Platform.runLater(() -> new Alert(AlertType.ERROR, evt.get()).showAndWait()); }
-			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);
-	}
 }

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

@@ -3,19 +3,17 @@ package envoy.client.ui.controller;
 import javafx.fxml.FXML;
 import javafx.scene.control.*;
 
-import envoy.client.ui.SceneContext;
+import envoy.client.data.Context;
-import envoy.client.ui.settings.GeneralSettingsPane;
+import envoy.client.ui.listcell.ListCellFactory;
-import envoy.client.ui.settings.SettingsPane;
+import envoy.client.ui.settings.*;
 
 /**
- * Project: <strong>envoy-client</strong><br>
+ * Controller for the settings scene.
- * File: <strong>SettingsSceneController.java</strong><br>
- * Created: <strong>10.04.2020</strong><br>
  *
  * @author Kai S. K. Engelbart
  * @since Envoy Client v0.1-beta
  */
-public class SettingsScene {
+public final class SettingsScene {
 
 	@FXML
 	private ListView<SettingsPane> settingsList;
@@ -23,26 +21,10 @@ 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<>() {
+		settingsList.setCellFactory(new ListCellFactory<>(pane -> new Label(pane.getTitle())));
-
+		settingsList.getItems().addAll(new GeneralSettingsPane(), new UserSettingsPane(), new DownloadSettingsPane(), new BugReportPane());
-			@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());
 	}
 
 	@FXML
@@ -55,5 +37,5 @@ public class SettingsScene {
 	}
 
 	@FXML
-	private void backButtonClicked() { sceneContext.pop(); }
+	private void backButtonClicked() { Context.getInstance().getSceneContext().pop(); }
 }

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 +1,47 @@
+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);
+		}
+	}
+
+	/**
+	 * 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/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 +1,32 @@
+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 +1,30 @@
+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 +1,37 @@
+package envoy.client.ui.listcell;
+
+import javafx.geometry.*;
+import javafx.scene.control.ListView;
+
+import envoy.client.ui.control.MessageControl;
+import envoy.data.Message;
+
+/**
+ * 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(0, padding, 6, 0) : new Insets(0, 0, 6, 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 +1,9 @@
 /**
  * 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>
  *
  * @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 +1,66 @@
+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 +1,60 @@
+package envoy.client.ui.settings;
+
+import javafx.geometry.Insets;
+import javafx.scene.control.*;
+import javafx.scene.layout.HBox;
+import javafx.stage.DirectoryChooser;
+
+import envoy.client.data.Context;
+
+/**
+ * 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.getInstance().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 +1,69 @@
 package envoy.client.ui.settings;
 
-import java.util.List;
+import javafx.scene.control.*;
 
-import javafx.scene.control.ComboBox;
-import javafx.scene.layout.VBox;
-
-import envoy.client.data.Settings;
 import envoy.client.data.SettingsItem;
 import envoy.client.event.ThemeChangeEvent;
+import envoy.client.helper.ShutdownHelper;
 import envoy.data.User.UserStatus;
-import envoy.event.EventBus;
+
+import dev.kske.eventbus.EventBus;
 
 /**
- * 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 {
+public final class GeneralSettingsPane extends SettingsPane {
-
-	private static final Settings settings = Settings.getInstance();
 
 	/**
 	 * @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")
+		final var	settingsItems		= settings.getItems();
-			.stream()
+		final var	hideOnCloseCheckbox	= new SettingsCheckbox((SettingsItem<Boolean>) settingsItems.get("hideOnClose"));
-			.map(settings.getItems()::get)
+		final var	hideOnCloseTooltip	= new Tooltip("If selected, Envoy will still be present in the task bar when closed.");
-			.map(i -> new SettingsCheckbox((SettingsItem<Boolean>) i))
+		hideOnCloseTooltip.setWrapText(true);
-			.forEach(vbox.getChildren()::add);
+		hideOnCloseCheckbox.setTooltip(hideOnCloseTooltip);
+		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(
+		combobox.setOnAction(e -> { settings.setCurrentTheme(combobox.getValue()); EventBus.getInstance().dispatch(new ThemeChangeEvent()); });
-				e -> { settings.setCurrentTheme(combobox.getValue()); EventBus.getInstance().dispatch(new ThemeChangeEvent(combobox.getValue())); });
+		getChildren().add(combobox);
-		vbox.getChildren().add(combobox);
 
 		final var statusComboBox = new ComboBox<UserStatus>();
 		statusComboBox.getItems().setAll(UserStatus.values());
 		statusComboBox.setValue(UserStatus.ONLINE);
+		statusComboBox.setTooltip(new Tooltip("Change your current status"));
 		// TODO add action when value is changed
 		statusComboBox.setOnAction(e -> {});
-		vbox.getChildren().add(statusComboBox);
+		getChildren().add(statusComboBox);
 
-		getChildren().add(vbox);
+		final var logoutButton = new Button("Logout");
+		logoutButton.setOnAction(e -> ShutdownHelper.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);
 	}
 }

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

@@ -0,0 +1,54 @@
+package envoy.client.ui.settings;
+
+import javafx.geometry.Insets;
+import javafx.scene.control.*;
+import javafx.scene.layout.*;
+import javafx.scene.paint.Color;
+
+import envoy.client.data.Context;
+import envoy.client.net.Client;
+
+/**
+ * Inheriting from this class signifies that options should only be available if
+ * the {@link envoy.data.User} is currently online. If the user is currently
+ * offline, all {@link javafx.scene.Node} variables will be disabled and a
+ * {@link Tooltip} will be displayed for the whole node.
+ *
+ * @author Leon Hofmeister
+ * @author Kai S. K. Engelbart
+ * @since Envoy Client v0.2-beta
+ */
+public abstract class OnlineOnlySettingsPane extends SettingsPane {
+
+	protected final Client client = Context.getInstance().getClient();
+
+	private final Tooltip beOnlineReminder = new Tooltip("You need to be online to modify your account.");
+
+	/**
+	 * @param title the title of this pane
+	 * @since Envoy Client v0.2-beta
+	 */
+	protected OnlineOnlySettingsPane(String title) {
+		super(title);
+
+		setDisable(!client.isOnline());
+
+		if (!client.isOnline()) {
+			final var infoLabel = new Label("You shall not pass!\n(... Unless you would happen to be online)");
+			infoLabel.setId("info-label-warning");
+			infoLabel.setWrapText(true);
+			getChildren().add(infoLabel);
+			setBackground(new Background(new BackgroundFill(Color.grayRgb(100, 0.3), CornerRadii.EMPTY, Insets.EMPTY)));
+
+			Tooltip.install(this, beOnlineReminder);
+		} else Tooltip.uninstall(this, beOnlineReminder);
+	}
+
+	/**
+	 * Sets the text of the tooltip displayed for this pane.
+	 *
+	 * @param text the text to display
+	 * @since Envoy Client v0.2-beta
+	 */
+	protected void setToolTipText(String text) { beOnlineReminder.setText(text); }
+}

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

@@ -6,10 +6,6 @@ import javafx.scene.control.CheckBox;
 import envoy.client.data.SettingsItem;
 
 /**
- * Project: <strong>envoy-client</strong><br>
- * File: <strong>SettingsToggleButton.java</strong><br>
- * Created: <strong>18.04.2020</strong><br>
- *
  * @author Kai S. K. Engelbart
  * @since Envoy Client v0.1-beta
  */

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

@@ -1,19 +1,19 @@
 package envoy.client.ui.settings;
 
-import javafx.scene.layout.Pane;
+import javafx.scene.layout.VBox;
+
+import envoy.client.data.Settings;
 
 /**
- * Project: <strong>envoy-client</strong><br>
- * File: <strong>SettingsPane.java</strong><br>
- * Created: <strong>18.04.2020</strong><br>
- * 
  * @author Kai S. K. Engelbart
  * @since Envoy Client v0.1-beta
  */
-public abstract class SettingsPane extends Pane {
+public abstract class SettingsPane extends VBox {
 
 	protected String title;
 
+	protected static final Settings settings = Settings.getInstance();
+
 	protected SettingsPane(String title) { this.title = title; }
 
 	/**

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

@@ -0,0 +1,177 @@
+package envoy.client.ui.settings;
+
+import java.io.*;
+import java.nio.file.Files;
+import java.util.logging.*;
+
+import javafx.event.EventHandler;
+import javafx.geometry.Pos;
+import javafx.scene.Cursor;
+import javafx.scene.control.*;
+import javafx.scene.control.Alert.AlertType;
+import javafx.scene.image.*;
+import javafx.scene.input.InputEvent;
+import javafx.scene.layout.HBox;
+import javafx.stage.FileChooser;
+
+import envoy.client.data.Context;
+import envoy.client.ui.control.ProfilePicImageView;
+import envoy.client.util.IconUtil;
+import envoy.event.*;
+import envoy.util.*;
+
+import dev.kske.eventbus.EventBus;
+
+/**
+ * @author Leon Hofmeister
+ * @since Envoy Client v0.2-beta
+ */
+public final class UserSettingsPane extends OnlineOnlySettingsPane {
+
+	private boolean	profilePicChanged, usernameChanged, validPassword;
+	private byte[]	currentImageBytes;
+	private String	newUsername, newPassword = "";
+
+	private final ImageView		profilePic				= new ProfilePicImageView(null, 60);
+	private final TextField		usernameTextField		= new TextField();
+	private final PasswordField	currentPasswordField	= new PasswordField();
+	private final PasswordField	newPasswordField		= new PasswordField();
+	private final PasswordField	repeatNewPasswordField	= new PasswordField();
+	private final Button		saveButton				= new Button("Save");
+
+	private static final EventBus	eventBus	= EventBus.getInstance();
+	private static final Logger		logger		= EnvoyLog.getLogger(UserSettingsPane.class);
+
+	/**
+	 * Creates a new {@code UserSettingsPane}.
+	 *
+	 * @since Envoy Client v0.2-beta
+	 */
+	public UserSettingsPane() {
+		super("User");
+		setSpacing(10);
+
+		// Display of profile pic change mechanism
+		final var hbox = new HBox();
+		// TODO: display current profile pic
+		profilePic.setImage(IconUtil.loadIconThemeSensitive("user_icon"));
+		profilePic.setCursor(Cursor.HAND);
+		profilePic.setFitWidth(60);
+		profilePic.setFitHeight(60);
+		profilePic.setOnMouseClicked(e -> {
+			if (!client.isOnline()) return;
+			final var pictureChooser = new FileChooser();
+
+			pictureChooser.setTitle("Select a new profile pic");
+			pictureChooser.setInitialDirectory(new File(System.getProperty("user.home")));
+			pictureChooser.getExtensionFilters().add(new FileChooser.ExtensionFilter("Pictures", "*.png", "*.jpg", "*.bmp", "*.gif"));
+
+			final var file = pictureChooser.showOpenDialog(Context.getInstance().getSceneContext().getStage());
+
+			if (file != null) {
+
+				// Check max file size
+				// TODO: Move to config
+				if (file.length() > 5E6) {
+					new Alert(AlertType.WARNING, "The selected file exceeds the size limit of 5MB!").showAndWait();
+					return;
+				}
+
+				try {
+					currentImageBytes = Files.readAllBytes(file.toPath());
+					profilePic.setImage(new Image(new ByteArrayInputStream(currentImageBytes)));
+					profilePicChanged = true;
+				} catch (final IOException e1) {
+					e1.printStackTrace();
+				}
+			}
+		});
+		hbox.getChildren().add(profilePic);
+
+		// Displaying the username change mechanism
+		final var username = client.getSender().getName();
+		newUsername = username;
+		usernameTextField.setText(username);
+		final EventHandler<? super InputEvent> textChanged = e -> {
+			newUsername = usernameTextField.getText();
+			usernameChanged = newUsername != username;
+		};
+		usernameTextField.setOnInputMethodTextChanged(textChanged);
+		usernameTextField.setOnKeyTyped(textChanged);
+		hbox.getChildren().add(usernameTextField);
+		getChildren().add(hbox);
+
+		// "Displaying" the password change mechanism
+		final HBox[]	passwordHBoxes	= { new HBox(), new HBox(), new HBox() };
+		final Label[]	passwordLabels	= { new Label("Enter current password:"), new Label("Enter new password:"),
+				new Label("Repeat new password:") };
+
+		final PasswordField[]					passwordFields	= { currentPasswordField, newPasswordField, repeatNewPasswordField };
+		final EventHandler<? super InputEvent>	passwordEntered	= e -> {
+																	newPassword		= newPasswordField.getText();
+																	validPassword	= newPassword.equals(repeatNewPasswordField.getText())
+																			&& !newPasswordField.getText().isBlank();
+																};
+		newPasswordField.setOnInputMethodTextChanged(passwordEntered);
+		newPasswordField.setOnKeyTyped(passwordEntered);
+		repeatNewPasswordField.setOnInputMethodTextChanged(passwordEntered);
+		repeatNewPasswordField.setOnKeyTyped(passwordEntered);
+
+		for (int i = 0; i < passwordHBoxes.length; i++) {
+			final var hBox2 = passwordHBoxes[i];
+			passwordLabels[i].setWrapText(true);
+			hBox2.getChildren().add(passwordLabels[i]);
+			hBox2.getChildren().add(passwordFields[i]);
+			getChildren().add(hBox2);
+		}
+
+		// Displaying the save button
+		saveButton.setOnAction(e -> save(client.getSender().getID(), currentPasswordField.getText()));
+		saveButton.setAlignment(Pos.BOTTOM_RIGHT);
+		getChildren().add(saveButton);
+	}
+
+	/**
+	 * Saves the given input and sends the changed input to the server
+	 *
+	 * @param username the new username
+	 * @since Envoy Client v0.2-beta
+	 */
+	private void save(long userID, String oldPassword) {
+
+		// The profile pic was changed
+		if (profilePicChanged) {
+			final var profilePicChangeEvent = new ProfilePicChange(currentImageBytes, userID);
+			eventBus.dispatch(profilePicChangeEvent);
+			client.send(profilePicChangeEvent);
+			logger.log(Level.INFO, "The user just changed his profile pic.");
+		}
+
+		// The username was changed
+		final var validContactName = Bounds.isValidContactName(newUsername);
+		if (usernameChanged && validContactName) {
+			final var nameChangeEvent = new NameChange(userID, newUsername);
+			eventBus.dispatch(nameChangeEvent);
+			client.send(nameChangeEvent);
+			logger.log(Level.INFO, "The user just changed his name to " + newUsername + ".");
+		} else if (!validContactName) {
+			final var alert = new Alert(AlertType.ERROR);
+			alert.setTitle("Invalid username");
+			alert.setContentText("The entered username does not conform with the naming limitations: " + Bounds.CONTACT_NAME_PATTERN);
+			alert.showAndWait();
+			logger.log(Level.INFO, "An invalid username was requested.");
+			return;
+		}
+
+		// The password was changed
+		if (validPassword) {
+			client.send(new PasswordChangeRequest(newPassword, oldPassword, userID));
+			logger.log(Level.INFO, "The user just tried to change his password!");
+		} else if (!(validPassword || newPassword.isBlank())) {
+			final var alert = new Alert(AlertType.ERROR);
+			alert.setTitle("Unequal Password");
+			alert.setContentText("Repeated password is unequal to the chosen new password");
+			alert.showAndWait();
+		}
+	}
+}

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

@@ -1,10 +1,6 @@
 /**
  * This package contains classes used for representing the settings
  * visually.
- * <p>
- * Project: <strong>envoy-client</strong><br>
- * File: <strong>package-info.java</strong><br>
- * Created: <strong>19 Apr 2020</strong><br>
  *
  * @author Leon Hofmeister
  * @author Kai S. K. Engelbart

client/src/main/java/envoy/client/util/IconUtil.java

@@ -1,9 +1,12 @@
-package envoy.client.ui;
+package envoy.client.util;
 
-import java.util.EnumMap;
+import java.awt.image.BufferedImage;
-import java.util.EnumSet;
+import java.io.IOException;
+import java.util.*;
 import java.util.logging.Level;
 
+import javax.imageio.ImageIO;
+
 import javafx.scene.image.Image;
 
 import envoy.client.data.Settings;
@@ -12,15 +15,11 @@ import envoy.util.EnvoyLog;
 /**
  * Provides static utility methods for loading icons from the resource
  * folder.
- * <p>
- * Project: <strong>envoy-client</strong><br>
- * File: <strong>IconUtil.java</strong><br>
- * Created: <strong>16.03.2020</strong><br>
  *
  * @author Kai S. K. Engelbart
  * @since Envoy Client v0.1-beta
  */
-public class IconUtil {
+public final class IconUtil {
 
 	private IconUtil() {}
 
@@ -31,15 +30,7 @@ public class IconUtil {
 	 * @return the loaded image
 	 * @since Envoy Client v0.1-beta
 	 */
-	public static Image load(String path) {
+	public static Image load(String path) { return new Image(IconUtil.class.getResource(path).toExternalForm()); }
-		Image image = null;
-		try {
-			image = new Image(IconUtil.class.getResource(path).toExternalForm());
-		} catch (final NullPointerException e) {
-			EnvoyLog.getLogger(IconUtil.class).log(Level.WARNING, String.format("Could not load image at path %s: ", path), e);
-		}
-		return image;
-	}
 
 	/**
 	 * Loads an image from the resource folder and scales it to the given size.
@@ -50,13 +41,7 @@ public class IconUtil {
 	 * @since Envoy Client v0.1-beta
 	 */
 	public static Image load(String path, int size) {
-		Image image = null;
+		return new Image(IconUtil.class.getResource(path).toExternalForm(), size, size, true, true);
-		try {
-			image = new Image(IconUtil.class.getResource(path).toExternalForm(), size, size, true, true);
-		} catch (final NullPointerException e) {
-			EnvoyLog.getLogger(IconUtil.class).log(Level.WARNING, String.format("Could not load image at path %s: ", path), e);
-		}
-		return image;
 	}
 
 	/**
@@ -145,6 +130,23 @@ public class IconUtil {
 		return icons;
 	}
 
+	/**
+	 * Loads a buffered image from the resource folder which is compatible with AWT.
+	 *
+	 * @param path the path to the icon inside the resource folder
+	 * @return the loaded image
+	 * @since Envoy Client v0.2-beta
+	 */
+	public static BufferedImage loadAWTCompatible(String path) {
+		BufferedImage image = null;
+		try {
+			image = ImageIO.read(IconUtil.class.getResource(path));
+		} catch (final IOException e) {
+			EnvoyLog.getLogger(IconUtil.class).log(Level.WARNING, String.format("Could not load image at path %s: ", path), e);
+		}
+		return image;
+	}
+
 	/**
 	 * This method should be called if the display of an image depends upon the
 	 * currently active theme.<br>
@@ -154,7 +156,7 @@ public class IconUtil {
 	 * @return the theme specific folder
 	 * @since Envoy Client v0.1-beta
 	 */
-	public static String themeSpecificSubFolder() {
+	private static String themeSpecificSubFolder() {
 		return Settings.getInstance().isUsingDefaultTheme() ? Settings.getInstance().getCurrentTheme() + "/" : "";
 	}
 }

client/src/main/java/envoy/client/util/ReflectionUtil.java

@@ -0,0 +1,80 @@
+package envoy.client.util;
+
+import java.util.*;
+import java.util.stream.*;
+
+import javafx.scene.Node;
+
+/**
+ * @author Leon Hofmeister
+ * @since Envoy Client v0.2-beta
+ */
+public final class ReflectionUtil {
+
+	private ReflectionUtil() {}
+
+	/**
+	 * Gets all declared variable values of the given instance that have the
+	 * specified class.
+	 * <p>
+	 * (i.e. can get all {@code JComponents} (Swing) or {@code Nodes} (JavaFX) in a
+	 * GUI class).
+	 * <p>
+	 * <b>Important: If you are using a module, you first need to declare <br>
+	 * "opens {your_package} to envoy.client.util;" in your module-info.java</b>.
+	 *
+	 * @param <T>          the type of the object
+	 * @param <R>          the type to return
+	 * @param instance     the instance of a given class whose values are to be
+	 *                     evaluated
+	 * @param typeToReturn the type of variable to return
+	 * @return all variables in the given instance that have the requested type
+	 * @throws RuntimeException if an exception occurs
+	 * @since Envoy Client v0.2-beta
+	 */
+	public static <T, R> Stream<R> getAllDeclaredVariablesOfTypeAsStream(T instance, Class<R> typeToReturn) {
+		return Arrays.stream(instance.getClass().getDeclaredFields()).filter(field -> typeToReturn.isAssignableFrom(field.getType())).map(field -> {
+			try {
+				field.setAccessible(true);
+				return typeToReturn.cast(field.get(instance));
+			} catch (IllegalArgumentException | IllegalAccessException e) {
+				throw new RuntimeException(e);
+			}
+		});
+	}
+
+	/**
+	 * Gets all declared variables of the given instance that are children of
+	 * {@code Node}.
+	 * <p>
+	 * <b>Important: If you are using a module, you first need to declare <br>
+	 * "opens {your_package} to envoy.client.util;" in your module-info.java</b>.
+	 *
+	 * @param <T>      the type of the instance
+	 * @param instance the instance of a given class whose values are to be
+	 *                 evaluated
+	 * @return all variables of the given object that have the requested type as
+	 *         {@code Stream}
+	 * @since Envoy Client v0.2-beta
+	 */
+	public static <T> Stream<Node> getAllDeclaredNodeVariablesAsStream(T instance) {
+		return getAllDeclaredVariablesOfTypeAsStream(instance, Node.class);
+	}
+
+	/**
+	 * Gets all declared variables of the given instance that are children of
+	 * {@code Node}<br>
+	 * <p>
+	 * <b>Important: If you are using a module, you first need to declare <br>
+	 * "opens {your_package} to envoy.client.util;" in your module-info.java</b>.
+	 *
+	 * @param <T>      the type of the instance
+	 * @param instance the instance of a given class whose values are to be
+	 *                 evaluated
+	 * @return all variables of the given object that have the requested type
+	 * @since Envoy Client v0.2-beta
+	 */
+	public static <T> List<Node> getAllDeclaredNodeVariables(T instance) {
+		return getAllDeclaredNodeVariablesAsStream(instance).collect(Collectors.toList());
+	}
+}

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

@@ -0,0 +1,7 @@
+/**
+ * This package contains utility classes for use in envoy-client.
+ *
+ * @author Leon Hofmeister
+ * @since Envoy Client v0.2-beta
+ */
+package envoy.client.util;

client/src/main/java/module-info.java

@@ -7,17 +7,21 @@
  * @author Maximilian Käfer
  * @since Envoy Client v0.1-beta
  */
-module envoy {
+module envoy.client {
 
-	requires transitive envoy.common;
+	requires envoy.common;
-	requires transitive java.desktop;
+	requires java.desktop;
-	requires transitive java.logging;
+	requires java.logging;
-	requires transitive java.prefs;
+	requires java.prefs;
 	requires javafx.controls;
 	requires javafx.fxml;
 	requires javafx.base;
 	requires javafx.graphics;
 
-	opens envoy.client.ui to javafx.graphics, javafx.fxml;
+	opens envoy.client.ui to javafx.graphics, javafx.fxml, dev.kske.eventbus;
-	opens envoy.client.ui.controller to javafx.graphics, javafx.fxml;
+	opens envoy.client.ui.controller to javafx.graphics, javafx.fxml, envoy.client.util, dev.kske.eventbus;
+	opens envoy.client.ui.control to javafx.graphics, javafx.fxml;
+	opens envoy.client.ui.settings to envoy.client.util;
+	opens envoy.client.net to dev.kske.eventbus;
+	opens envoy.client.data to dev.kske.eventbus;
 }

client/src/main/resources/client.properties

@@ -1,3 +1,6 @@
 server=localhost
 port=8080
-localDB=.\\localDB
+localDB=localDB
+localDBSaveInterval=2
+consoleLevelBarrier=FINER
+fileLevelBarrier=OFF

client/src/main/resources/css/base.css

@@ -1,5 +1,5 @@
 .button, .list-cell, .progress-bar * {
-	-fx-background-radius: 5.0em;
+	-fx-background-radius: 0.3em;
 }
 
 .context-menu, .context-menu > * {
@@ -8,6 +8,28 @@
 	-fx-background-color: transparent;
 }
 
+#text-enter-container, #contact-search-enter-container {
+	-fx-background-radius: 5.0em;
+}
+
+#round-button {
+	-fx-background-radius: 5.0em;
+}
+
+.text-area {
+	-fx-background-color: transparent;
+}
+
+.text-area .scroll-pane {
+    -fx-background-color: transparent;
+}
+.text-area .scroll-pane .viewport{
+    -fx-background-color: transparent;
+}
+.text-area .scroll-pane .content{
+    -fx-background-color: transparent;
+}
+
 .menu-item {
 	-fx-background-radius: 15.0px;
 }
@@ -48,40 +70,75 @@
 
 .received-message {
 	-fx-alignment: center-left;
-	-fx-background-radius: 4.0em;
+	-fx-background-radius: 1.3em;
 	-fx-text-alignment: right;
 }
 
 .own-message {
 	-fx-alignment: center-right;
-	-fx-background-radius: 4.0em;
+	-fx-background-radius: 1.3em;
 	-fx-text-alignment: left;
 }
 
-.unreadMessagesAmount {
+.unread-messages-amount {
 	-fx-alignment: center;
 	-fx-background-color: orange;
 	-fx-background-radius: 4.0em;
 	-fx-text-alignment: center;
 }
 
-#remainingCharsLabel {
+#login-button {
+	-fx-background-radius: 1.0em;
+}
+
+#register-switch {
+	-fx-background-color: transparent;
+	-fx-text-fill: orange;
+}
+
+#login-input-field {
+	-fx-background-color: transparent;
+	-fx-border: solid;
+	-fx-border-width: 0.0 0.0 1.0 0.0;
+}
+
+#remaining-chars-label {
 	-fx-text-fill: #00FF00;
 	-fx-background-color: transparent;
 }
 
-#infoLabel-success {
+#info-label-success {
 	-fx-text-fill: #00FF00;
 }
 
-#infoLabel-info {
+#info-label-info {
 	-fx-text-fill: yellow;
 }
 
-#infoLabel-warning {
+#info-label-warning {
 	-fx-text-fill: orange;
 }
 
-#infoLabel-error {
+#info-label-error {
 	-fx-text-fill: red;
 }
+
+#transparent-background {
+	-fx-background-color: transparent;
+}
+
+#profile-pic {
+	-fx-radius: 1.0em;
+}
+
+.list-element {
+	-fx-background-color: transparent;
+}
+
+.tab-pane {
+    -fx-tab-max-height: 0.0 ;
+} 
+.tab-pane .tab-header-area {
+    visibility: hidden ;
+    -fx-padding: -20.0 0.0 0.0 0.0;
+}

client/src/main/resources/css/dark.css

@@ -7,7 +7,7 @@
 }
 
 .button {
-	-fx-background-color: rgb(105.0,0.0,153.0);
+	-fx-background-color: #690099;
 }
 
 .button:pressed {
@@ -18,12 +18,12 @@
 	-fx-background-color: lightgray;
 }
 
-.list-view, .list-cell, .text-area .content, .text-field, .password-field, .tooltip, .pane, .pane .content, .vbox, .titled-pane > .title, .titled-pane > *.content, .context-menu, .menu-item {
+#message-list, .text-field, .password-field, .tooltip, .pane, .pane .content, .vbox, .titled-pane > .title, .titled-pane > *.content, .context-menu, .menu-item {
-	-fx-background-color: dimgray;
+	-fx-background-color: #222222;
 }
 
 .list-cell:selected, .list-cell:selected > *, .menu-item:hover {
-    -fx-background-color: rgb(105.0,0.0,153.0);
+    -fx-background-color: #690099;
 }
 
 .received-message {
@@ -37,3 +37,53 @@
 .alert.information.dialog-pane, .alert.warning.dialog-pane, .alert.error.dialog-pane {
 	-fx-background-color: black;
 }
+
+#login-input-field {
+	-fx-border-color: white;
+}
+
+#login-background {
+	-fx-background-color: #191919;
+}
+
+#chat-list, #top-bar, #search-panel, #note-background {
+	-fx-background-color: #303030;
+}
+
+#text-enter-container {
+	-fx-background-color: #363636;
+}
+
+#contact-search-enter-container {
+	-fx-background-color: #202020;
+}
+
+#underline {
+	-fx-border: solid;
+	-fx-border-width: 0.0 0.0 1.0 0.0;
+	-fx-border-color: #202020;
+}
+
+.group-member-names {
+	-fx-text-fill: #690099;
+	-fx-font-weight: bold;
+}
+
+.scroll-bar:vertical, .scroll-bar:vertical .track, .scroll-bar:vertical .increment-button , .scroll-bar:vertical .decrement-button {
+	-fx-background-color: transparent;
+}
+
+.scroll-bar:vertical .increment-arrow, .scroll-bar:vertical .decrement-arrow {
+	-fx-background-color: transparent;
+}
+
+.scroll-bar:vertical .thumb {
+	-fx-background-color: #707070;
+	-fx-background-insets : 4.0, 0.0, 0.0;
+	-fx-background-radius : 2.0em;
+}
+
+#proceed-button {
+	-fx-text-fill: white;
+	-fx-background-color: transparent;
+}

client/src/main/resources/css/light.css

@@ -1,16 +1,85 @@
-.button{
+.root {
-	-fx-background-color: orangered;
+	-fx-background-color: #E6E6E6;
 }
 
-.list-cell:selected, .list-cell:selected > * {
+.button {
-	-fx-background-color: orangered;
+	-fx-background-color: #B37D7D;
-	-fx-text-fill: black;
 }
 
-.received-message, .menu-item {
+.button:pressed {
+	-fx-background-color: #808080;
+}
+
+.button:disabled {
+	-fx-background-color: lightgray;
+}
+
+#message-list, .text-field, .password-field, .tooltip, .pane, .pane .content, .vbox, .titled-pane > .title, .titled-pane > *.content, .context-menu, .menu-item {
+	-fx-background-color: #E3E3E3;
+}
+
+.list-cell:selected, .list-cell:selected > *, .menu-item:hover {
+    -fx-background-color: #805959;
+}
+
+.received-message {
 	-fx-background-color: lightgray;
 }
 
 .own-message {
-	-fx-background-color: lightgreen;
+	-fx-background-color: #8FA88F;
+}
+
+.alert.information.dialog-pane, .alert.warning.dialog-pane, .alert.error.dialog-pane {
+	-fx-background-color: black;
+}
+
+#login-input-field {
+	-fx-border-color: black;
+}
+
+#login-background {
+	-fx-background-color: white;
+}
+
+#chat-list, #top-bar, #search-panel, #note-background {
+	-fx-background-color: white;
+}
+
+#text-enter-container {
+	-fx-background-color: #F2F2F2;
+}
+
+#contact-search-enter-container {
+	-fx-background-color: #CCCCCC;
+}
+
+#underline {
+	-fx-border: solid;
+	-fx-border-width: 0.0 0.0 1.0 0.0;
+	-fx-border-color: #CCCCCC;
+}
+
+.group-member-names {
+	-fx-text-fill: #805959;
+	-fx-font-weight: bold;
+}
+
+.scroll-bar:vertical, .scroll-bar:vertical .track, .scroll-bar:vertical .increment-button , .scroll-bar:vertical .decrement-button {
+	-fx-background-color: transparent;
+}
+
+.scroll-bar:vertical .increment-arrow, .scroll-bar:vertical .decrement-arrow {
+	-fx-background-color: transparent;
+}
+
+.scroll-bar:vertical .thumb {
+	-fx-background-color: #707070;
+	-fx-background-insets : 4.0, 0.0, 0.0;
+	-fx-background-radius : 2.0em;
+}
+
+#proceed-button {
+	-fx-text-fill: white;
+	-fx-background-color: transparent;
 }