001 | /* |
002 | * WindowEventDemo.java is a 1.4 example that requires |
003 | * no other files. |
004 | */ |
005 |
006 | import javax.swing.*; |
007 | import java.awt.*; |
008 | import java.awt.event.*; |
009 |
010 | public class WindowEventDemo extends JPanel |
011 | implements WindowListener, |
012 | WindowFocusListener, |
013 | WindowStateListener { |
014 | final static String newline = "\n"; |
015 | final static String space = " "; |
016 | static JFrame frame; |
017 | JTextArea display; |
018 |
019 | public WindowEventDemo() { |
020 | super(new BorderLayout()); |
021 | display = new JTextArea(); |
022 | display.setEditable(false); |
023 | JScrollPane scrollPane = new JScrollPane(display); |
024 | scrollPane.setPreferredSize(new Dimension(500, 450)); |
025 | add(scrollPane, BorderLayout.CENTER); |
026 |
027 | frame.addWindowListener(this); |
028 | frame.addWindowFocusListener(this); |
029 | frame.addWindowStateListener(this); |
030 |
031 | checkWM(); |
032 | } |
033 |
034 | //Some window managers don't support all window states. |
035 | //For example, dtwm doesn't support true maximization, |
036 | //but mimics it by resizing the window to be the size |
037 | //of the screen. In this case the window does not fire |
038 | //the MAXIMIZED_ constants on the window's state listener. |
039 | //Microsoft Windows supports MAXIMIZED_BOTH, but not |
040 | //MAXIMIZED_VERT or MAXIMIZED_HORIZ. |
041 | public void checkWM() { |
042 | Toolkit tk = frame.getToolkit(); |
043 | if (!(tk.isFrameStateSupported(Frame.ICONIFIED))) { |
044 | displayMessage( |
045 | "Your window manager doesn't support ICONIFIED."); |
046 | } |
047 | if (!(tk.isFrameStateSupported(Frame.MAXIMIZED_VERT))) { |
048 | displayMessage( |
049 | "Your window manager doesn't support MAXIMIZED_VERT."); |
050 | } |
051 | if (!(tk.isFrameStateSupported(Frame.MAXIMIZED_HORIZ))) { |
052 | displayMessage( |
053 | "Your window manager doesn't support MAXIMIZED_HORIZ."); |
054 | } |
055 | if (!(tk.isFrameStateSupported(Frame.MAXIMIZED_BOTH))) { |
056 | displayMessage( |
057 | "Your window manager doesn't support MAXIMIZED_BOTH."); |
058 | } else { |
059 | displayMessage( |
060 | "Your window manager supports MAXIMIZED_BOTH."); |
061 | } |
062 | } |
063 |
064 | public void windowClosing(WindowEvent e) { |
065 | displayMessage("WindowListener method called: windowClosing."); |
066 |
067 | //A pause so user can see the message before |
068 | //the window actually closes. |
069 | ActionListener task = new ActionListener() { |
070 | boolean alreadyDisposed = false; |
071 | public void actionPerformed(ActionEvent e) { |
072 | if (!alreadyDisposed) { |
073 | alreadyDisposed = true; |
074 | frame.dispose(); |
075 | } else { //make sure the program exits |
076 | System.exit(0); |
077 | } |
078 | } |
079 | }; |
080 | Timer timer = new Timer(500, task); //fire every half second |
081 | timer.setInitialDelay(2000); //first delay 2 seconds |
082 | timer.start(); |
083 | } |
084 |
085 | public void windowClosed(WindowEvent e) { |
086 | //This will only be seen on standard output. |
087 | displayMessage("WindowListener method called: windowClosed."); |
088 | } |
089 |
090 | public void windowOpened(WindowEvent e) { |
091 | displayMessage("WindowListener method called: windowOpened."); |
092 | } |
093 |
094 | public void windowIconified(WindowEvent e) { |
095 | displayMessage("WindowListener method called: windowIconified."); |
096 | } |
097 |
098 | public void windowDeiconified(WindowEvent e) { |
099 | displayMessage("WindowListener method called: windowDeiconified."); |
100 | } |
101 |
102 | public void windowActivated(WindowEvent e) { |
103 | displayMessage("WindowListener method called: windowActivated."); |
104 | } |
105 |
106 | public void windowDeactivated(WindowEvent e) { |
107 | displayMessage("WindowListener method called: windowDeactivated."); |
108 | } |
109 |
110 | public void windowGainedFocus(WindowEvent e) { |
111 | displayMessage("WindowFocusListener method called: windowGainedFocus."); |
112 | } |
113 |
114 | public void windowLostFocus(WindowEvent e) { |
115 | displayMessage("WindowFocusListener method called: windowLostFocus."); |
116 | } |
117 |
118 | public void windowStateChanged(WindowEvent e) { |
119 | displayStateMessage( |
120 | "WindowStateListener method called: windowStateChanged.", e); |
121 | } |
122 |
123 | void displayMessage(String msg) { |
124 | display.append(msg + newline); |
125 | System.out.println(msg); |
126 | } |
127 |
128 | void displayStateMessage(String prefix, WindowEvent e) { |
129 | int state = e.getNewState(); |
130 | int oldState = e.getOldState(); |
131 | String msg = prefix |
132 | + newline + space |
133 | + "New state: " |
134 | + convertStateToString(state) |
135 | + newline + space |
136 | + "Old state: " |
137 | + convertStateToString(oldState); |
138 | display.append(msg + newline); |
139 | System.out.println(msg); |
140 | } |
141 |
142 | String convertStateToString(int state) { |
143 | if (state == Frame.NORMAL) { |
144 | return "NORMAL"; |
145 | } |
146 | if ((state & Frame.ICONIFIED) != 0) { |
147 | return "ICONIFIED"; |
148 | } |
149 | //MAXIMIZED_BOTH is a concatenation of two bits, so |
150 | //we need to test for an exact match. |
151 | if ((state & Frame.MAXIMIZED_BOTH) == Frame.MAXIMIZED_BOTH) { |
152 | return "MAXIMIZED_BOTH"; |
153 | } |
154 | if ((state & Frame.MAXIMIZED_VERT) != 0) { |
155 | return "MAXIMIZED_VERT"; |
156 | } |
157 | if ((state & Frame.MAXIMIZED_HORIZ) != 0) { |
158 | return "MAXIMIZED_HORIZ"; |
159 | } |
160 | return "UNKNOWN"; |
161 | } |
162 |
163 | /** |
164 | * Create the GUI and show it. For thread safety, |
165 | * this method should be invoked from the |
166 | * event-dispatching thread. |
167 | */ |
168 | private static void createAndShowGUI() { |
169 | //Make sure we have nice window decorations. |
170 | JFrame.setDefaultLookAndFeelDecorated(true); |
171 |
172 | //Create and set up the window. |
173 | frame = new JFrame("WindowEventDemo"); |
174 | frame.setDefaultCloseOperation(JFrame.DO_NOTHING_ON_CLOSE); |
175 |
176 | //Create and set up the content pane. |
177 | JComponent newContentPane = new WindowEventDemo(); |
178 | newContentPane.setOpaque(true); //content panes must be opaque |
179 | frame.setContentPane(newContentPane); |
180 |
181 | //Display the window. |
182 | frame.pack(); |
183 | frame.setVisible(true); |
184 | } |
185 |
186 | public static void main(String[] args) { |
187 | //Schedule a job for the event-dispatching thread: |
188 | //creating and showing this application's GUI. |
189 | javax.swing.SwingUtilities.invokeLater(new Runnable() { |
190 | public void run() { |
191 | createAndShowGUI(); |
192 | } |
193 | }); |
194 | } |
195 | } |
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