Add 'minimize to system tray' toggle

src/main/java/com/jagrosh/jmusicbot/gui/GUI.java

@@ -15,59 +15,123 @@
  */
 package com.jagrosh.jmusicbot.gui;
 
-import java.awt.event.WindowEvent;
-import java.awt.event.WindowListener;
-import javax.swing.JFrame;
-import javax.swing.JTabbedPane;
-import javax.swing.WindowConstants;
+import java.awt.*;
+import java.awt.event.*;
+import javax.swing.*;
+
 import com.jagrosh.jmusicbot.Bot;
 
 
 /**
  *
  * @author John Grosh <john.a.grosh@gmail.com>
  */
-public class GUI extends JFrame 
+public class GUI extends JFrame
 {
     private final ConsolePanel console;
     private final Bot bot;
-
-    public GUI(Bot bot) 
+    private final OptionsPanel optionsPanel;
+
+    public GUI(Bot bot)
     {
         super();
         this.bot = bot;
         console = new ConsolePanel();
+        optionsPanel = new OptionsPanel();
     }
-    
+
     public void init()
     {
         setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
         setTitle("JMusicBot");
         JTabbedPane tabs = new JTabbedPane();
         tabs.add("Console", console);
+        tabs.add("Options", optionsPanel);
         getContentPane().add(tabs);
         pack();
         setLocationRelativeTo(null);
         setVisible(true);
-        addWindowListener(new WindowListener() 
+        addWindowListener(new WindowListener()
         {
             @Override public void windowOpened(WindowEvent e) { /* unused */ }
-            @Override public void windowClosing(WindowEvent e) 
+            @Override public void windowClosing(WindowEvent e)
             {
-                try
-                {
-                    bot.shutdown();
-                }
-                catch(Exception ex)
-                {
-                    System.exit(0);
-                }
+                shutdown();
             }
             @Override public void windowClosed(WindowEvent e) { /* unused */ }
             @Override public void windowIconified(WindowEvent e) { /* unused */ }
             @Override public void windowDeiconified(WindowEvent e) { /* unused */ }
             @Override public void windowActivated(WindowEvent e) { /* unused */ }
             @Override public void windowDeactivated(WindowEvent e) { /* unused */ }
         });
+
+        if (SystemTray.isSupported())
+        {
+            setDefaultCloseOperation(WindowConstants.DO_NOTHING_ON_CLOSE);
+            setupMinimizeToTray();
+        }
+    }
+
+    private void setupMinimizeToTray()
+    {
+        Image icon = Toolkit.getDefaultToolkit().getImage(getClass().getResource("/icon16.png"));
+        MenuItem exit = new MenuItem("Exit");
+        exit.addActionListener(e -> shutdown());
+
+        MenuItem nameLabel = new MenuItem("JMusicBot");
+        nameLabel.setEnabled(false);
+
+        PopupMenu menu = new PopupMenu();
+        menu.add(nameLabel);
+        menu.addSeparator();
+        menu.add(exit);
+
+        SystemTray tray = SystemTray.getSystemTray();
+        TrayIcon trayIcon = new TrayIcon(icon, "JMusicBot", menu);
+
+        // Restore the window when the user clicks the tray icon
+        trayIcon.addMouseListener(new MouseAdapter()
+        {
+            @Override public void mouseClicked(MouseEvent e)
+            {
+                if (e.getButton() != MouseEvent.BUTTON1)
+                {
+                    return;
+                }
+
+                setVisible(true);
+                setExtendedState(JFrame.NORMAL);
+                tray.remove(trayIcon);
+            }
+        });
+
+        // Minimize the window to the system tray when the user clicks the minimize button
+        // and the option "minimize to tray" is active
+        addWindowStateListener(e -> {
+            if (e.getNewState() == JFrame.ICONIFIED && optionsPanel.isMinimizeToTraySelected())
+            {
+                try
+                {
+                    setVisible(false);
+                    tray.add(trayIcon);
+                }
+                catch (AWTException ex)
+                {
+                    System.err.println("TrayIcon could not be added.");
+                }
+            }
+        });
+    }
+
+    private void shutdown()
+    {
+        try
+        {
+            bot.shutdown();
+        }
+        catch(Exception ex)
+        {
+            System.exit(0);
+        }
     }
 }

src/main/java/com/jagrosh/jmusicbot/gui/OptionsPanel.java

@@ -0,0 +1,58 @@
+/*
+ * Copyright 2016 John Grosh <john.a.grosh@gmail.com>.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.jagrosh.jmusicbot.gui;
+
+import javax.swing.*;
+import java.util.prefs.Preferences;
+
+/**
+ * @author Wolfgang Schwendtbauer
+ */
+public class OptionsPanel extends JPanel
+{
+    private static final String KEY_MINIMIZE_TO_SYSTEM_TRAY = "minimizeToSystemTray";
+
+    private final Preferences prefs;
+    private final JCheckBox minimizeToTrayCheckbox;
+
+    public OptionsPanel()
+    {
+        prefs = Preferences.userNodeForPackage(getClass());
+
+        setLayout(new BoxLayout(this, BoxLayout.Y_AXIS));
+
+        minimizeToTrayCheckbox = new JCheckBox("Minimize to system tray");
+        add(minimizeToTrayCheckbox);
+
+        loadPreferences();
+        addListeners();
+    }
+
+    private void loadPreferences()
+    {
+        minimizeToTrayCheckbox.setSelected(prefs.getBoolean(KEY_MINIMIZE_TO_SYSTEM_TRAY, false));
+    }
+
+    private void addListeners()
+    {
+        minimizeToTrayCheckbox.addActionListener(e -> prefs.putBoolean(KEY_MINIMIZE_TO_SYSTEM_TRAY, minimizeToTrayCheckbox.isSelected()));
+    }
+
+    public boolean isMinimizeToTraySelected()
+    {
+        return minimizeToTrayCheckbox.isSelected();
+    }
+}