Creating message notifications only if ChatWindow has lost focus

StatusTray injects a WindowFocusListener into ChatWindow in its
constructor and does only react to received messages if ChatWindow has
currently lost focus.

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

@@ -63,9 +63,9 @@ public class Startup {
 
 		EventQueue.invokeLater(() -> {
 			try {
-				ChatWindow frame = new ChatWindow(client, localDB);
+				ChatWindow chatWindow = new ChatWindow(client, localDB);
-				new StatusTrayIcon().show();
+				new StatusTrayIcon(chatWindow).show();
-				frame.setVisible(true);
+				chatWindow.setVisible(true);
 			} catch (Exception e) {
 				e.printStackTrace();
 			}

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

@@ -8,6 +8,8 @@ import java.awt.SystemTray;
 import java.awt.Toolkit;
 import java.awt.TrayIcon;
 import java.awt.TrayIcon.MessageType;
+import java.awt.event.WindowAdapter;
+import java.awt.event.WindowEvent;
 import java.util.HashSet;
 import java.util.Set;
 
@@ -16,6 +18,7 @@ import envoy.client.event.EventBus;
 import envoy.client.event.EventHandler;
 import envoy.client.event.MessageCreationEvent;
 import envoy.exception.EnvoyException;
+import envoy.schema.Message;
 
 /**
  * Project: <strong>envoy-client</strong><br>
@@ -34,6 +37,12 @@ public class StatusTrayIcon implements EventHandler {
 	 */
 	private TrayIcon trayIcon;
 
+	/**
+	 * A received {@link Message} is only displayed as a system tray notification if
+	 * this variable is set to {@code true}.
+	 */
+	private boolean displayMessages = false;
+
 	/**
 	 * Creates a {@link StatusTrayIcon} with the Envoy logo, a tool tip and a pop-up
 	 * menu.
@@ -41,11 +50,11 @@ public class StatusTrayIcon implements EventHandler {
 	 * @throws EnvoyException if the currently used OS does not support the System
 	 *                        Tray API
 	 */
-	public StatusTrayIcon() throws EnvoyException {
+	public StatusTrayIcon(ChatWindow chatWindow) throws EnvoyException {
 		if (!SystemTray.isSupported()) throw new EnvoyException("The Envoy tray icon is not supported.");
 
-		ClassLoader loader = Thread.currentThread().getContextClassLoader();
+		ClassLoader	loader	= Thread.currentThread().getContextClassLoader();
-		Image img = Toolkit.getDefaultToolkit().createImage(loader.getResource("envoy_logo.png"));
+		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.");
@@ -57,6 +66,22 @@ public class StatusTrayIcon implements EventHandler {
 		popup.add(exitMenuItem);
 
 		trayIcon.setPopupMenu(popup);
+
+		// Only display messages if the chat window is not focused
+		chatWindow.addWindowFocusListener(new WindowAdapter() {
+
+			@Override
+			public void windowGainedFocus(WindowEvent e) {
+				displayMessages = false;
+			}
+
+			@Override
+			public void windowLostFocus(WindowEvent e) {
+				displayMessages = true;
+			}
+		});
+
+		// Start processing message events
 		EventBus.getInstance().register(this);
 	}
 
@@ -83,7 +108,9 @@ public class StatusTrayIcon implements EventHandler {
 	 */
 	@Override
 	public void handle(Event<?> event) {
-		trayIcon.displayMessage("New message received", ((MessageCreationEvent) event).get().getContent().get(0).getText(), MessageType.INFO);
+		System.out.println("Message received. Displaying message: " + displayMessages);
+		if (displayMessages)
+			trayIcon.displayMessage("New message received", ((MessageCreationEvent) event).get().getContent().get(0).getText(), MessageType.INFO);
 	}
 
 	/**