Implemented settings object and cleaned up ChatWindow

Improvements:
* Settings were implemented
* Light theme support was implemented
* The readability of ChatWindow got improved

src/main/java/envoy/client/Config.java

@@ -63,6 +63,7 @@ public class Config {
 				case "--localDB":
 				case "-db":
 					localDB = new File(args[++i]);
+					break;
 			}
 		if (localDB == null) localDB = new File(".\\localDB");
 		if (syncTimeout == 0) syncTimeout = 1000;
@@ -115,13 +116,24 @@ public class Config {
 	/**
 	 * Changes the default local database.
 	 * Exclusively intended for development purposes.
-	 *
-	 * @param the file containing the local database
+	 * 
+	 * @param localDB the file containing the local database
 	 * @since Envoy v0.1-alpha
 	 **/
 	public void setLocalDB(File localDB) { this.localDB = localDB; }
 
+	/**
+	 * 
+	 * @return the current time (milliseconds) that is waited between Syncs
+	 * @since Envoy v0.1-alpha
+	 */
 	public int getSyncTimeout() { return syncTimeout; }
 
+	/**
+	 * 
+	 * @param syncTimeout sets the time (milliseconds) during which Sync waits
+	 * @since Envoy v0.1-alpha
+	 */
 	public void setSyncTimeout(int syncTimeout) { this.syncTimeout = syncTimeout; }
+
 }

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

@@ -30,8 +30,10 @@ import envoy.schema.User;
  * @since Envoy v0.1-alpha
  */
 public class LocalDB {
+
 	private File			localDB;
 	private User			sender;
+	private final long		id;
 	private List<Chat>		chats			= new ArrayList<>();
 	private ObjectFactory	objectFactory	= new ObjectFactory();
 	private DatatypeFactory	datatypeFactory;
@@ -39,19 +41,19 @@ public class LocalDB {
 	/**
 	 * Constructs an empty local database.
 	 *
-	 * @param client the user that is logged in with this client
+	 * @param sender the user that is logged in with this client
 	 * @since Envoy v0.1-alpha
 	 **/
 
 	public LocalDB(User sender) {
-		this.sender = sender;
+		this.sender	= sender;
+		id			= sender.getID();
 		try {
 			datatypeFactory = DatatypeFactory.newInstance();
 		} catch (DatatypeConfigurationException e) {
 			e.printStackTrace();
 		}
 	}
-    
 
 	/**
 	 * Initializes the local database and fills it with values
@@ -64,14 +66,16 @@ public class LocalDB {
 	public void initializeDBFile(File localDBDir) throws EnvoyException {
 		if (localDBDir.exists() && !localDBDir.isDirectory()) throw new EnvoyException(
 				String.format("LocalDBDir '%s' is not a directory!", localDBDir.getAbsolutePath()));
-		localDB = new File(localDBDir, sender.getID() + ".db");
+		localDB = new File(localDBDir, id + ".db");
 		if (localDB.exists()) loadFromLocalDB();
 	}
 
 	/**
-	 * Saves the database into a file for future use.
+	 * Saves the database into a file for future use.<br>
+	 * It is theoretically possible to fail due to unknown causes.<br>
+	 * In such a case, every message sent/ received during that session will be
+	 * lost.
 	 *
-	 * @throws IOException if something went wrong during saving
 	 * @since Envoy v0.1-alpha
 	 **/
 	public void saveToLocalDB() {
@@ -110,12 +114,13 @@ public class LocalDB {
 	 * Creates a {@link Message} object serializable to XML.
 	 * 
 	 * @param textContent The content (text) of the message
+	 * @param recipientID self explanatory
 	 * @return prepared {@link Message} object
 	 */
-	public Message createMessage(String textContent, User recipient) {
+	public Message createMessage(String textContent, long recipientID) {
 		Message.Metadata metaData = objectFactory.createMessageMetadata();
 		metaData.setSender(sender.getID());
-		metaData.setRecipient(recipient.getID());
+		metaData.setRecipient(recipientID);
 		metaData.setState(MessageState.WAITING);
 		metaData.setDate(datatypeFactory.newXMLGregorianCalendar(Instant.now().toString()));
 
@@ -257,7 +262,7 @@ public class LocalDB {
 	/**
 	 * Adds a message to the "sync" Sync object.
 	 * 
-	 * @param message
+	 * @param message the message to send
 	 * @since Envoy v0.1-alpha
 	 */
 	public void addMessageToSync(Message message) { sync.getMessages().add(message); }
@@ -274,7 +279,6 @@ public class LocalDB {
 	 * Adds the unread messages returned from the server in the latest sync to the
 	 * right chats in the LocalDB.
 	 * 
-	 * @param localDB
 	 * @since Envoy v0.1-alpha
 	 */
 	public void addUnreadMessagesToLocalDB() {
@@ -292,7 +296,6 @@ public class LocalDB {
 	 * Gets all messages with state SENT from the LocalDB and adds them to the
 	 * "sync" Sync object.
 	 * 
-	 * @param localDB
 	 * @since Envoy v0.1-alpha
 	 */
 	public void getSentStateMessagesFromLocalDB() {
@@ -310,7 +313,7 @@ public class LocalDB {
 	 * <br>
 	 * Adds these Messages to the {@code readMessages} {@link Sync} object.
 	 * 
-	 * @param currentChat
+	 * @param currentChat the chat that was just opened
 	 * @since Envoy v0.1-alpha
 	 */
 	public void setMessagesToRead(Chat currentChat) {
@@ -325,8 +328,8 @@ public class LocalDB {
 	/**
 	 * Adds a message with State WAITING to a specific chat in the LocalDB.
 	 * 
-	 * @param message
-	 * @param currentChat
+	 * @param message     the message that is not yet received by the other user
+	 * @param currentChat the chat that is currently open
 	 * @since Envoy v0.1-alpha
 	 */
 	public void addWaitingMessageToLocalDB(Message message, Chat currentChat) { currentChat.appendMessage(message); }
@@ -334,7 +337,6 @@ public class LocalDB {
 	/**
 	 * Adds all messages with State WAITING from the {@link LocalDB} to the Sync.
 	 * 
-	 * @param localDB
 	 * @since Envoy v0.1-alpha
 	 */
 	public void addWaitingMessagesToSync() {
@@ -368,4 +370,11 @@ public class LocalDB {
 	 * @since Envoy v0.1-alpha
 	 */
 	public User getUser() { return sender; }
+
+	/**
+	 * @return the id of the client. Used as shortcut for quicker information
+	 *         retrieval
+	 * @since Envoy v0.2-alpha
+	 */
+	public long getId() { return id; }
 }

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

@@ -0,0 +1,129 @@
+package envoy.client;
+
+import java.util.prefs.Preferences;
+
+/**
+ * Project: <strong>envoy-client</strong><br>
+ * File: <strong>Settings.java</strong><br>
+ * Created: <strong>11 Nov 2019</strong><br>
+ * 
+ * @author Leon Hofmeister
+ * @since Envoy v0.2-alpha
+ */
+public class Settings {
+
+	private String	username;
+	private String	email;
+	private boolean	enterToSend	= true;
+	private boolean	darkMode	= true;
+	// private Image profilePic;
+	private static Settings	settings;
+	private Preferences		prefs	= Preferences.userNodeForPackage(Settings.class);
+
+	/**
+	 * The way to instantiate the settings.
+	 * Is set to private to deny other instances of that object.
+	 * 
+	 * @since Envoy v0.2-alpha
+	 */
+	private Settings() {}
+
+	/**
+	 * This method is used to ensure that there is only one instance of Settings.
+	 * 
+	 * @return the instance of Settings
+	 * @since Envoy v0.2-alpha
+	 */
+	public static Settings getInstance() {
+		if (settings == null) {
+			settings = new Settings();
+		}
+		settings.load();
+		return settings;
+	}
+
+	public void load() {
+		settings.setUsername(prefs.get("username", ""));
+		settings.setEmail(prefs.get("email", ""));
+		settings.setDarkMode(prefs.getBoolean("darkMode", true));
+		settings.setEnterToSend(prefs.getBoolean("enterToSend", true));
+	}
+
+	public void save() {
+		prefs.put("username", settings.getUsername());
+		prefs.put("email", settings.getEmail());
+		prefs.putBoolean("darkMode", settings.isDarkMode());
+		prefs.putBoolean("enterToSend", settings.isEnterToSend());
+	}
+
+	/**
+	 * @return the username
+	 * @since Envoy v0.2-alpha
+	 */
+	public String getUsername() { return username; }
+
+	/**
+	 * @param username the username to set
+	 * @since Envoy v0.2-alpha
+	 */
+	public void setUsername(String username) { this.username = username; }
+
+	/**
+	 * @return the email associated with that user.
+	 * @since Envoy v0.2-alpha
+	 */
+	public String getEmail() { return email; }
+
+	/**
+	 * @param email the email to set
+	 * @since Envoy v0.2-alpha
+	 */
+	public void setEmail(String email) { this.email = email; }
+
+	/**
+	 * @return true, if "enter" suffices to send a message, else it has to be "ctrl"
+	 *         + "enter"
+	 * @since Envoy v0.2-alpha
+	 */
+	public boolean isEnterToSend() { return enterToSend; }
+
+	/**
+	 * Change mode of posting a message via Keystroke.
+	 * 
+	 * @param enterToSend if true, "enter" suffices to send a message, <br>
+	 *                    else it has to be "ctrl" + "enter"
+	 * @since Envoy v0.2-alpha
+	 */
+	public void setEnterToSend(boolean enterToSend) { this.enterToSend = enterToSend; }
+
+	/**
+	 * Describes whether the Envoy GUI should be displayed in dark mode or not.
+	 * 
+	 * @return true, if dark mode display is currently set, else the light theme
+	 *         will be displayed
+	 * @since Envoy v0.2-alpha
+	 */
+	public boolean isDarkMode() { return darkMode; }
+
+	/**
+	 * Change display mode of Envoy GUI.
+	 * 
+	 * @param darkMode true, if dark mode display is currently set, <br>
+	 *                 else the light theme will be displayed
+	 * @since Envoy v0.2-alpha
+	 */
+	public void setDarkMode(boolean darkMode) { this.darkMode = darkMode; }
+
+	// /**
+	// * @return the profilePic
+	// * @since Envoy v0.2-alpha
+	// */
+	// public Image getProfilePic() { return profilePic; }
+	//
+	// /**
+	// * @param profilePic the profilePic to set
+	// * @since Envoy v0.1-alpha
+	// */
+	// public void setProfilePic(Image profilePic) { this.profilePic = profilePic; }
+
+}

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

@@ -1,6 +1,5 @@
 package envoy.client.ui;
 
-import java.awt.Color;
 import java.awt.ComponentOrientation;
 import java.awt.Font;
 import java.awt.GridBagConstraints;
@@ -29,6 +28,7 @@ import envoy.client.Chat;
 import envoy.client.Client;
 import envoy.client.Config;
 import envoy.client.LocalDB;
+import envoy.client.Settings;
 import envoy.schema.Message;
 import envoy.schema.Sync;
 import envoy.schema.User;
@@ -47,19 +47,30 @@ public class ChatWindow extends JFrame {
 
 	private static final long serialVersionUID = 6865098428255463649L;
 
-	private JPanel contentPane = new JPanel();
+	// user specific objects
+	private Client		client;
+	private LocalDB		localDB;
+	private Settings	settings;
+	// used colors in Envoy
+	private UIColors uiColors = UIColors.getInstance(true);
+	// GUI components
+	private JPanel			contentPane				= new JPanel();
+	private JTextArea		messageEnterTextArea	= new JTextArea();
+	private JList<User>		userList				= new JList<>();
+	private Chat			currentChat;
+	private JList<Message>	messageList				= new JList<>();
+	private JScrollPane		scrollPane				= new JScrollPane();
+	private JTextPane		textPane				= new JTextPane();
+	// private JCheckBox jCbChangeMode;
+	private JButton	postButton = new JButton();
+	private JButton	settingsButton = new JButton();
 
-	private Client	client;
-	private LocalDB	localDB;
+	private static int space = 4;
 
-	private JList<User>	userList	= new JList<>();
-	private Chat		currentChat;
-
-	private JTextArea messageEnterTextArea;
-
-	public ChatWindow(Client client, LocalDB localDB) {
+	public ChatWindow(Client client, LocalDB localDB, Settings setting) {
 		this.client		= client;
 		this.localDB	= localDB;
+		this.settings	= setting;
 
 		setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
 		setBounds(100, 100, 600, 800);
@@ -73,9 +84,7 @@ public class ChatWindow extends JFrame {
 			public void windowClosing(WindowEvent e) { localDB.saveToLocalDB(); }
 		});
 
-		contentPane.setBackground(new Color(0, 0, 0));
-		contentPane.setForeground(Color.white);
-		contentPane.setBorder(new EmptyBorder(0, 5, 0, 0));
+		contentPane.setBorder(new EmptyBorder(space, space, space, space));
 		setContentPane(contentPane);
 		GridBagLayout gbl_contentPane = new GridBagLayout();
 		gbl_contentPane.columnWidths	= new int[] { 1, 1, 1 };
@@ -84,25 +93,16 @@ public class ChatWindow extends JFrame {
 		gbl_contentPane.rowWeights		= new double[] { 0.05, 1.0, 0.07 };
 		contentPane.setLayout(gbl_contentPane);
 
-		JList<Message> messageList = new JList<>();
 		messageList.setCellRenderer(new MessageListRenderer());
-
 		messageList.setFocusTraversalKeysEnabled(false);
-		messageList.setSelectionForeground(new Color(255, 255, 255));
-		messageList.setSelectionBackground(new Color(102, 0, 153));
 		messageList.setComponentOrientation(ComponentOrientation.LEFT_TO_RIGHT);
-		messageList.setForeground(new Color(255, 255, 255));
-		messageList.setBackground(new Color(51, 51, 51));
 
 		DefaultListModel<Message> messageListModel = new DefaultListModel<>();
 		messageList.setModel(messageListModel);
 		messageList.setFont(new Font("Arial", Font.PLAIN, 17));
 		messageList.setFixedCellHeight(60);
-		messageList.setBorder(new EmptyBorder(5, 5, 5, 5));
+		messageList.setBorder(new EmptyBorder(space, space, space, space));
 
-		JScrollPane scrollPane = new JScrollPane();
-		scrollPane.setForeground(new Color(0, 0, 0));
-		scrollPane.setBackground(new Color(51, 51, 51));
 		scrollPane.setViewportView(messageList);
 		scrollPane.setBorder(null);
 
@@ -112,18 +112,17 @@ public class ChatWindow extends JFrame {
 		gbc_scrollPane.gridx		= 1;
 		gbc_scrollPane.gridy		= 1;
 
-		gbc_scrollPane.insets = new Insets(0, 10, 10, 10);
+		gbc_scrollPane.insets = new Insets(space, space, space, space);
 
 		contentPane.add(scrollPane, gbc_scrollPane);
 
 		// Message enter field
-		messageEnterTextArea = new JTextArea();
 		messageEnterTextArea.addKeyListener(new KeyAdapter() {
 
 			@Override
 			public void keyReleased(KeyEvent e) {
 
-				if (e.getKeyCode() == KeyEvent.VK_ENTER && ((SettingsScreen.enterToSend && e.getModifiersEx() == 0)
+				if (e.getKeyCode() == KeyEvent.VK_ENTER && ((settings.isEnterToSend() && e.getModifiersEx() == 0)
 						|| (e.getModifiersEx() == KeyEvent.CTRL_DOWN_MASK))) {
 
 					postMessage(messageList);
@@ -133,44 +132,34 @@ public class ChatWindow extends JFrame {
 		});
 		// Checks for changed Message
 		messageEnterTextArea.setWrapStyleWord(true);
-		messageEnterTextArea.setCaretColor(new Color(255, 255, 255));
-		messageEnterTextArea.setForeground(new Color(255, 255, 255));
-		messageEnterTextArea.setBackground(new Color(51, 51, 51));
 		messageEnterTextArea.setLineWrap(true);
 		messageEnterTextArea.setBorder(null);
 		messageEnterTextArea.setFont(new Font("Arial", Font.PLAIN, 17));
-		messageEnterTextArea.setBorder(new EmptyBorder(5, 5, 5, 5));
+		messageEnterTextArea.setBorder(new EmptyBorder(space, space, space, space));
 
 		GridBagConstraints gbc_messageEnterTextfield = new GridBagConstraints();
 		gbc_messageEnterTextfield.fill	= GridBagConstraints.BOTH;
 		gbc_messageEnterTextfield.gridx	= 1;
 		gbc_messageEnterTextfield.gridy	= 2;
 
-		gbc_messageEnterTextfield.insets = new Insets(10, 10, 10, 10);
+		gbc_messageEnterTextfield.insets = new Insets(space, space, space, space);
 
 		contentPane.add(messageEnterTextArea, gbc_messageEnterTextfield);
 
 		// Post Button
-		JButton postButton = new JButton("Post");
-		postButton.setForeground(new Color(255, 255, 255));
-		postButton.setBackground(new Color(102, 51, 153));
 		postButton.setBorderPainted(false);
-
 		GridBagConstraints gbc_moveSelectionPostButton = new GridBagConstraints();
 
 		gbc_moveSelectionPostButton.fill	= GridBagConstraints.BOTH;
 		gbc_moveSelectionPostButton.gridx	= 2;
 		gbc_moveSelectionPostButton.gridy	= 2;
 
-		gbc_moveSelectionPostButton.insets = new Insets(10, 10, 10, 10);
+		gbc_moveSelectionPostButton.insets = new Insets(space, space, space, space);
 
 		postButton.addActionListener((evt) -> { postMessage(messageList); });
 		contentPane.add(postButton, gbc_moveSelectionPostButton);
 
 		// Settings Button
-		JButton settingsButton = new JButton("Settings");
-		settingsButton.setForeground(new Color(255, 255, 255));
-		settingsButton.setBackground(new Color(102, 51, 153));
 		settingsButton.setBorderPainted(false);
 
 		GridBagConstraints gbc_moveSelectionSettingsButton = new GridBagConstraints();
@@ -179,13 +168,12 @@ public class ChatWindow extends JFrame {
 		gbc_moveSelectionSettingsButton.gridx	= 2;
 		gbc_moveSelectionSettingsButton.gridy	= 0;
 
-		gbc_moveSelectionSettingsButton.insets = new Insets(10, 10, 10, 10);
+		gbc_moveSelectionSettingsButton.insets = new Insets(space, space, space, space);
 
 		settingsButton.addActionListener((evt) -> {
 			try {
-				SettingsScreen.open(localDB.getUser().getName());
-			} catch (Exception e) {
 				SettingsScreen.open();
+			} catch (Exception e) {
 				System.err.println("An error occured while opening the settings screen: " + e);
 				e.printStackTrace();
 			}
@@ -193,10 +181,6 @@ public class ChatWindow extends JFrame {
 		contentPane.add(settingsButton, gbc_moveSelectionSettingsButton);
 
 		// Partner name display
-		JTextPane textPane = new JTextPane();
-		textPane.setBackground(new Color(0, 0, 0));
-		textPane.setForeground(new Color(255, 255, 255));
-
 		textPane.setFont(new Font("Arial", Font.PLAIN, 20));
 
 		GridBagConstraints gbc_partnerName = new GridBagConstraints();
@@ -204,7 +188,7 @@ public class ChatWindow extends JFrame {
 		gbc_partnerName.gridx	= 1;
 		gbc_partnerName.gridy	= 0;
 
-		gbc_partnerName.insets = new Insets(0, 10, 0, 10);
+		gbc_partnerName.insets = new Insets(space, space, space, space);
 		contentPane.add(textPane, gbc_partnerName);
 
 		userList.setCellRenderer(new UserListRenderer());
@@ -234,20 +218,18 @@ public class ChatWindow extends JFrame {
 			}
 		});
 
-		userList.setSelectionForeground(new Color(255, 255, 255));
-		userList.setSelectionBackground(new Color(102, 0, 153));
-		userList.setForeground(new Color(255, 255, 255));
-		userList.setBackground(new Color(51, 51, 51));
 		userList.setFont(new Font("Arial", Font.PLAIN, 17));
-		userList.setBorder(new EmptyBorder(5, 5, 5, 5));
+		userList.setBorder(new EmptyBorder(space, space, space, space));
 
 		GridBagConstraints gbc_userList = new GridBagConstraints();
 		gbc_userList.fill	= GridBagConstraints.VERTICAL;
 		gbc_userList.gridx	= 0;
 		gbc_userList.gridy	= 1;
 		gbc_userList.anchor	= GridBagConstraints.PAGE_START;
-		gbc_userList.insets	= new Insets(0, 0, 10, 0);
+		gbc_userList.insets	= new Insets(space, space, space, space);
 
+		changeChatWindowColors();
+		
 		contentPane.add(userList, gbc_userList);
 		contentPane.revalidate();
 
@@ -257,6 +239,46 @@ public class ChatWindow extends JFrame {
 		contentPane.revalidate();
 	}
 
+	/**
+	 * Used to immediately reload the ChatWindow when settings were changed.
+	 * 
+	 * @since Envoy v0.1-alpha
+	 */
+	public void changeChatWindowColors() {
+		uiColors.setDisplayMode(settings.isDarkMode());
+
+		// contentPane
+		contentPane.setBackground(uiColors.getBackgroundColor());
+		contentPane.setForeground(uiColors.getTextColor());
+		// messageList
+		messageList.setSelectionForeground(uiColors.getTextColor());
+		messageList.setSelectionBackground(uiColors.getSpecialUseColor());
+		messageList.setForeground(uiColors.getTextColor());
+		messageList.setBackground(uiColors.getUserInteractionColor());
+		// scrollPane
+		scrollPane.setForeground(uiColors.getBackgroundColor());
+		scrollPane.setBackground(uiColors.getUserInteractionColor());
+		// messageEnterTextArea
+		messageEnterTextArea.setCaretColor(uiColors.getTextColor());
+		messageEnterTextArea.setForeground(uiColors.getTextColor());
+		messageEnterTextArea.setBackground(uiColors.getUserInteractionColor());
+		// postButton
+		postButton.setForeground(uiColors.getTextColor());
+		postButton.setBackground(uiColors.getSpecialUseColor());
+		// settingsButton
+		settingsButton.setForeground(uiColors.getTextColor());
+		settingsButton.setBackground(uiColors.getSpecialUseColor());
+		// textPane
+		textPane.setBackground(uiColors.getBackgroundColor());
+		textPane.setForeground(uiColors.getTextColor());
+		// userList
+		userList.setSelectionForeground(uiColors.getTextColor());
+		userList.setSelectionBackground(uiColors.getSpecialUseColor());
+		userList.setForeground(uiColors.getTextColor());
+		userList.setBackground(uiColors.getUserInteractionColor());
+
+	}
+
 	private void postMessage(JList<Message> messageList) {
 		if (!client.hasRecipient()) {
 			JOptionPane.showMessageDialog(this,
@@ -268,7 +290,7 @@ public class ChatWindow extends JFrame {
 		if (!messageEnterTextArea.getText().isEmpty()) try {
 
 			// Create and send message object
-			final Message message = localDB.createMessage(messageEnterTextArea.getText(), currentChat.getRecipient());
+			final Message message = localDB.createMessage(messageEnterTextArea.getText(), currentChat.getRecipient().getID());
 			localDB.addWaitingMessageToLocalDB(message, currentChat);
 			messageList.setModel(currentChat.getModel());
 

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

@@ -1,15 +1,22 @@
 package envoy.client.ui;
 
 import java.awt.BorderLayout;
-import java.awt.Color;
 import java.awt.FlowLayout;
+import java.awt.GridBagConstraints;
+import java.awt.GridBagLayout;
+import java.awt.Insets;
 
 import javax.swing.JButton;
 import javax.swing.JDialog;
+import javax.swing.JOptionPane;//TODO: temporary
 import javax.swing.JPanel;
 import javax.swing.border.EmptyBorder;
 
+import envoy.client.Settings;
+
 /**
+ * This class provides the GUI to change the user specific settings.
+ * 
  * Project: <strong>envoy-client</strong><br>
  * File: <strong>SettingsScreen.java</strong><br>
  * Created: <strong>31 Oct 2019</strong><br>
@@ -18,139 +25,109 @@ import javax.swing.border.EmptyBorder;
  */
 public class SettingsScreen extends JDialog {
 
-	private static final long	serialVersionUID	= -4476913491263077107L;
-	private final JPanel		contentPanel		= new JPanel();
-	public static boolean		enterToSend			= true;
+	private static final long		serialVersionUID	= -4476913491263077107L;
+	private final JPanel			contentPanel		= new JPanel();
+	private JPanel					buttonPane			= new JPanel();
+	private JButton					okButton			= new JButton("Save");
+	private JButton					cancelButton		= new JButton("Cancel");
+	private static Settings			settings;
+	private static UIColors			uiColors;
+	private static int				space				= 5;
+	private static SettingsScreen	settingsScreen;
 
 	// TODO: Add a JPanel with all the Information necessary:
 	// change (Picture,Username, Email, Password) and toggle(light/dark mode,
 	// "ctrl+enter"/"enter"
 	// to send a message directly)
+
 	/**
-	 * Open the Settings screen.
-	 * Only suited for Dev/Error mode.
-	 * Avoid usage.
+	 * Opens the settings screen.<br>
 	 * 
 	 * @since Envoy v0.1-alpha
 	 */
-	public static void open() { open(new SettingsScreen()); }
+	public static void open() {
 
-	/**
-	 * Opens the Settings screen.<br>
-	 * Use preferably since everyone is already initialised.<br>
-	 * It personalises the screen more.
-	 * 
-	 * @param username The name of the User
-	 * @param Email    The Email that is associated with that Account
-	 * @since Envoy v0.1-alpha
-	 */
-	public static void open(String username) {// , String Email) {AUSKLAMMERN, WENN ANMELDUNG PER
-												// EMAIL IMPLEMENTIERT IST!
-		open(new SettingsScreen(username));
-	}
-
-	public static void open(SettingsScreen dialog) {
-		dialog.setDefaultCloseOperation(JDialog.DISPOSE_ON_CLOSE);
-		dialog.setModal(true);
-		dialog.setVisible(true);
+		settings = Settings.getInstance();
+		uiColors.setDisplayMode(settings.isDarkMode());
+		settingsScreen = new SettingsScreen();
+		settingsScreen.setDefaultCloseOperation(JDialog.DISPOSE_ON_CLOSE);
+		settingsScreen.setModal(true);
+		settingsScreen.setVisible(true);
 	}
 
 	/**
-	 * Builds the Settings screen.<br>
-	 * Use only as Dev/Error Mode.<br>
-	 * Avoid usage.
+	 * Builds the settings screen.<br>
 	 * 
 	 * @since Envoy v0.1-alpha
 	 */
-	public SettingsScreen() {
-		setBackground(Color.BLACK);
+	private SettingsScreen() {
+
 		setBounds(100, 100, 450, 300);
 		getContentPane().setLayout(new BorderLayout());
-		contentPanel.setBackground(Color.BLACK);
-		contentPanel.setBorder(new EmptyBorder(5, 5, 5, 5));
-		getContentPane().add(contentPanel, BorderLayout.CENTER);
-		contentPanel.setLayout(new BorderLayout(0, 0));
-		{
-			JPanel buttonPane = new JPanel();
-			buttonPane.setBackground(Color.BLACK);
-			getContentPane().add(buttonPane, BorderLayout.SOUTH);
-			buttonPane.setLayout(new BorderLayout(0, 0));
-			{
-				JButton okButton = new JButton("Save");
-				okButton.setActionCommand("OK");
-				buttonPane.add(okButton, BorderLayout.EAST);
-				getRootPane().setDefaultButton(okButton);
-				okButton.addActionListener((evt) -> {
-					// Hier später die Daten abspeichern, wenn Datenmodell implementiert ist
-					dispose();
-				});
-			}
-			{
-				JButton cancelButton = new JButton("Cancel");
-				cancelButton.setActionCommand("Cancel");
-				buttonPane.add(cancelButton, BorderLayout.WEST);
-
-				cancelButton.addActionListener((evt) -> { dispose(); });
-			}
-		}
-	}
-
-	/**
-	 * Builds the Settings screen.<br>
-	 * Use preferreably since everyone is already initialised.<br>
-	 * It personalises the screen more.
-	 * 
-	 * @param Username The name of the User
-	 * @param Email    The Email that is associated with that Account
-	 * @since Envoy v0.1-alpha
-	 */
-	public SettingsScreen(String Username) {// , String Email, String hashedPwd) {AUSKLAMMERN, WENN ANMELDUNG PER EMAIL
-											// IMPLEMENTIERT IST!
-		setBackground(Color.BLACK);
-		setBounds(100, 100, 450, 300);
-		getContentPane().setLayout(new BorderLayout());
-		contentPanel.setBackground(Color.BLACK);
 		contentPanel.setLayout(new FlowLayout());
-		contentPanel.setBorder(new EmptyBorder(5, 5, 5, 5));
+		contentPanel.setBorder(new EmptyBorder(space, space, space, space));
 		getContentPane().add(contentPanel, BorderLayout.CENTER);
 		{
-			JPanel buttonPane = new JPanel();
-			buttonPane.setBackground(Color.BLACK);
 			getContentPane().add(buttonPane, BorderLayout.SOUTH);
-			buttonPane.setLayout(new BorderLayout(0, 0));
+			GridBagLayout gbl_buttonPane = new GridBagLayout();
+			gbl_buttonPane.columnWidths		= new int[] { 100, 250, 100, 0 };
+			gbl_buttonPane.rowHeights		= new int[] { 25, 0 };
+			gbl_buttonPane.columnWeights	= new double[] { 0.0, 0.0, 0.0, Double.MIN_VALUE };
+			gbl_buttonPane.rowWeights		= new double[] { 0.0, Double.MIN_VALUE };
+			buttonPane.setLayout(gbl_buttonPane);
 			{
-				JButton okButton = new JButton("Save");
-				okButton.setActionCommand("OK");
-				buttonPane.add(okButton, BorderLayout.EAST);
-				getRootPane().setDefaultButton(okButton);
-				okButton.addActionListener((evt) -> {
-					// Hier später die Daten abspeichern, wenn Datenmodell implementiert ist
-					dispose();
-				});
-			}
-			{
-				JButton cancelButton = new JButton("Cancel");
 				cancelButton.setActionCommand("Cancel");
-				buttonPane.add(cancelButton, BorderLayout.WEST);
+				GridBagConstraints gbc_cancelButton = new GridBagConstraints();
+				gbc_cancelButton.anchor	= GridBagConstraints.NORTHWEST;
+				gbc_cancelButton.insets	= new Insets(space, space, space, space);
+				gbc_cancelButton.gridx	= 0;
+				gbc_cancelButton.gridy	= 0;
+				buttonPane.add(cancelButton, gbc_cancelButton);
 
 				cancelButton.addActionListener((evt) -> { dispose(); });
 			}
+			{
+				okButton.setActionCommand("OK");
+				GridBagConstraints gbc_okButton = new GridBagConstraints();
+				gbc_okButton.anchor	= GridBagConstraints.NORTHEAST;
+				gbc_okButton.fill	= GridBagConstraints.EAST;
+				gbc_okButton.insets	= new Insets(space, space, space, space);
+				gbc_okButton.gridx	= 2;
+				gbc_okButton.gridy	= 0;
+				buttonPane.add(okButton, gbc_okButton);
+				getRootPane().setDefaultButton(okButton);
+				okButton.addActionListener((evt) -> {
+					try {
+						settings.setUsername(settings.getUsername());// still temporary value
+						settings.setEmail(settings.getEmail());// still temporary value
+						settings.setDarkMode(false);// TODO temporary values while no UI is implemented
+						settings.setEnterToSend(settings.isEnterToSend());// still temporary value
+						settings.save();
+					} catch (Exception e) {
+						System.err.println("Something went wrong when changing the setting");
+						settingsScreen.dispose();
+					}
+					JOptionPane.showConfirmDialog(settingsScreen, "Successfully changed settings");
+				});
+			}
 		}
+		changeSettingsScreenColors();
 	}
 
-	/**
-	 * @return true if Enter should be used to send a message instead of ctrl+enter
-	 * @since Envoy v0.1-alpha
-	 */
-	public static boolean isEnterToSend() { return enterToSend; }
+	private void changeSettingsScreenColors() {
+		// whole JDialog
+		setBackground(uiColors.getBackgroundColor());
+		// contentPanel
+		contentPanel.setBackground(uiColors.getBackgroundColor());
+		// buttonPane
+		buttonPane.setBackground(uiColors.getBackgroundColor());
+		// cancelButton
+		cancelButton.setBackground(uiColors.getSpecialUseColor());
+		cancelButton.setForeground(uiColors.getTextColor());
+		// okButton
+		okButton.setBackground(uiColors.getSpecialUseColor());
+		okButton.setForeground(uiColors.getTextColor());
+
+	}
 
-	/**
-	 * @param enterToSend <br>
-	 *                    toggles whether a message should be sent via
-	 *                    <br>
-	 *                    buttonpress "enter" or "ctrl"+"enter"
-	 * @since Envoy v0.1-alpha
-	 */
-	public static void setEnterToSend(boolean enterForSend) { enterToSend = enterForSend; }
-	// TODO: Should be changed to private, but later to avoid warnings
 }

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

@@ -9,6 +9,7 @@ import javax.swing.JOptionPane;
 import envoy.client.Client;
 import envoy.client.Config;
 import envoy.client.LocalDB;
+import envoy.client.Settings;
 import envoy.exception.EnvoyException;
 
 /**
@@ -60,10 +61,11 @@ public class Startup {
 					"Local DB error",
 					JOptionPane.WARNING_MESSAGE);
 		}
+		Settings settings = Settings.getInstance();//TODO delete line
 
 		EventQueue.invokeLater(() -> {
 			try {
-				ChatWindow frame = new ChatWindow(client, localDB);
+				ChatWindow frame = new ChatWindow(client, localDB, settings);
 				frame.setVisible(true);
 			} catch (Exception e) {
 				e.printStackTrace();

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

@@ -0,0 +1,158 @@
+package envoy.client.ui;
+
+import java.awt.Color;
+
+/**
+ * This class stores the colors that are used in Envoy.
+ * <br>
+ * <br>
+ * Project: <strong>envoy-client</strong><br>
+ * File: <strong>EnvoyColors.java</strong><br>
+ * Created: <strong>16 Nov 2019</strong><br>
+ * 
+ * @author Leon Hofmeister
+ * @since Envoy v0.2-alpha
+ */
+public class UIColors {
+
+	private UIColors() {}
+
+	/**
+	 * This color is used for the general background where no other elements
+	 * overlap.
+	 * 
+	 * @since Envoy v0.2-alpha
+	 */
+	private Color backgroundColor;
+
+	/**
+	 * This color is used as background for all areas where a user can interact with
+	 * Envoy.
+	 * (i.e. a JTextArea or JList)
+	 * 
+	 * @since Envoy v0.2-alpha
+	 */
+
+	private Color userInteractionColor;
+
+	/**
+	 * This color is used for any areas that need special attention.
+	 * (i.e. highlighting a selected list column or a button background)
+	 * 
+	 * @since Envoy v0.2-alpha
+	 */
+	private Color specialUseColor;
+
+	/**
+	 * This color is the color in which text will be displayed.
+	 * 
+	 * @since Envoy v0.2-alpha
+	 */
+	private Color textColor;
+
+	/**
+	 * This object ensures that only one {@link UIColors} object exists.
+	 * 
+	 * @since Envoy v0.2-alpha
+	 */
+	private static UIColors uIColors;
+
+	/**
+	 * This method is used to ensure that there is only one instance of EnvoyColors.
+	 * 
+	 * @param darkMode default value how envoyColors should be displayed
+	 * @return the instance of EnvoyColors
+	 * @since Envoy v0.2-alpha
+	 */
+	public static UIColors getInstance(boolean darkMode) {
+		if (uIColors == null) { uIColors = new UIColors(); }
+		uIColors.setDisplayMode(darkMode);
+		return uIColors;
+	}
+
+	/**
+	 * Used to change the appearance of Envoy.
+	 * 
+	 * @param darkMode if true, Envoy will be displayed in dark mode else it will
+	 *                 use bright mode
+	 * @since Envoy v0.2-alpha
+	 */
+	public void setDisplayMode(boolean darkMode) {
+		if (darkMode) {
+			uIColors.setBackgroundColor(Color.black); // TODO: other color suggestions?
+			uIColors.setUserInteractionColor(Color.darkGray); // temporary
+			uIColors.setSpecialUseColor(Color.blue); // temporary
+			uIColors.setTextColor(Color.white); // temporary
+
+		} else {
+			uIColors.setBackgroundColor(Color.white); // temporary
+			uIColors.setUserInteractionColor(Color.lightGray); // temporary
+			uIColors.setSpecialUseColor(Color.green); // temporary
+			uIColors.setTextColor(Color.black); // temporary
+
+		}
+	}
+
+	/**
+	 * @return the {@link UIColors#backgroundColor}
+	 * @since Envoy v0.2-alpha
+	 */
+	public Color getBackgroundColor() { return backgroundColor; }
+
+	/**
+	 * @param backgroundColor the new {@link UIColors#backgroundColor}
+	 * @since Envoy v0.2-alpha
+	 */
+	public void setBackgroundColor(Color backgroundColor) { this.backgroundColor = backgroundColor; }
+
+	/**
+	 * @return the {@link UIColors#userInteractionColor}
+	 * @since Envoy v0.2-alpha
+	 */
+	public Color getUserInteractionColor() { return userInteractionColor; }
+
+	/**
+	 * @param userInteractionColor the new {@link UIColors#userInteractionColor}
+	 * @since Envoy v0.2-alpha
+	 */
+	public void setUserInteractionColor(Color userInteractionColor) {
+		this.userInteractionColor = userInteractionColor;
+	}
+
+	/**
+	 * @return the {@link UIColors#specialUseColor}
+	 * @since Envoy v0.2-alpha
+	 */
+	public Color getSpecialUseColor() { return specialUseColor; }
+
+	/**
+	 * @param specialUseColor the new {@link UIColors#specialUseColor}
+	 * @since Envoy v0.2-alpha
+	 */
+	public void setSpecialUseColor(Color specialUseColor) { this.specialUseColor = specialUseColor; }
+
+	/**
+	 * @return the {@link UIColors#textColor}
+	 * @since Envoy v0.2-alpha
+	 */
+	public Color getTextColor() { return textColor; }
+
+	/**
+	 * @param textColor the new {@link UIColors#textColor}
+	 * @since Envoy v0.2-alpha
+	 */
+	public void setTextColor(Color textColor) { this.textColor = textColor; }
+
+	/**
+	 * @return the {@link UIColors#uIColors}
+	 * @since Envoy v0.2-alpha
+	 */
+	public static UIColors getEnvoyColors() { return uIColors; }
+
+	@Deprecated
+	/**
+	 * @param envoyColors the new {@link EnvoyColors#envoyColors}
+	 * @since Envoy v0.2-alpha
+	 */
+	public static void setEnvoyColors(UIColors uIColors) { UIColors.uIColors = uIColors; }
+}

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

@@ -56,6 +56,12 @@ public class UserListRenderer extends JLabel implements ListCellRenderer<User> {
 						status,
 						name));
 				break;
+			case AFK:
+				break;
+			case DO_NOT_DISTURB:
+				break;
+			default:
+				break;
 		}