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25 
26 package java.awt.event;
27 
28 import java.awt.Window;
29 import java.lang.annotation.Native;
30 import sun.awt.AppContext;
31 import sun.awt.SunToolkit;
32 
33 /**
34  * A low-level event that indicates that a window has changed its status. This
35  * low-level event is generated by a Window object when it is opened, closed,
36  * activated, deactivated, iconified, or deiconified, or when focus is
37  * transferred into or out of the Window.
38  * <P>
39  * The event is passed to every {@code WindowListener}
40  * or {@code WindowAdapter} object which registered to receive such
41  * events using the window's {@code addWindowListener} method.
42  * ({@code WindowAdapter} objects implement the
43  * {@code WindowListener} interface.) Each such listener object
44  * gets this {@code WindowEvent} when the event occurs.
45  * <p>
46  * An unspecified behavior will be caused if the {@code id} parameter
47  * of any particular {@code WindowEvent} instance is not
48  * in the range from {@code WINDOW_FIRST} to {@code WINDOW_LAST}.
49  *
50  * @author Carl Quinn
51  * @author Amy Fowler
52  *
53  * @see WindowAdapter
54  * @see WindowListener
55  * @see <a href="http://docs.oracle.com/javase/tutorial/uiswing/events/windowlistener.html">Tutorial: Writing a Window Listener</a>
56  *
57  * @since 1.1
58  */
59 public class WindowEvent extends ComponentEvent {
60 
61     /**
62      * The first number in the range of ids used for window events.
63      */
64     public static final int WINDOW_FIRST        = 200;
65 
66     /**
67      * The window opened event.  This event is delivered only
68      * the first time a window is made visible.
69      */
70     @Native public static final int WINDOW_OPENED       = WINDOW_FIRST; // 200
71 
72     /**
73      * The "window is closing" event. This event is delivered when
74      * the user attempts to close the window from the window's system menu.
75      * If the program does not explicitly hide or dispose the window
76      * while processing this event, the window close operation will be
77      * cancelled.
78      */
79     @Native public static final int WINDOW_CLOSING      = 1 + WINDOW_FIRST; //Event.WINDOW_DESTROY
80 
81     /**
82      * The window closed event. This event is delivered after the displayable
83      * window has been closed as the result of a call to dispose.
84      * @see java.awt.Component#isDisplayable
85      * @see Window#dispose
86      */
87     @Native public static final int WINDOW_CLOSED       = 2 + WINDOW_FIRST;
88 
89     /**
90      * The window iconified event. This event is delivered when
91      * the window has been changed from a normal to a minimized state.
92      * For many platforms, a minimized window is displayed as
93      * the icon specified in the window's iconImage property.
94      * @see java.awt.Frame#setIconImage
95      */
96     @Native public static final int WINDOW_ICONIFIED    = 3 + WINDOW_FIRST; //Event.WINDOW_ICONIFY
97 
98     /**
99      * The window deiconified event type. This event is delivered when
100      * the window has been changed from a minimized to a normal state.
101      */
102     @Native public static final int WINDOW_DEICONIFIED  = 4 + WINDOW_FIRST; //Event.WINDOW_DEICONIFY
103 
104     /**
105      * The window-activated event type. This event is delivered when the Window
106      * becomes the active Window. Only a Frame or a Dialog can be the active
107      * Window. The native windowing system may denote the active Window or its
108      * children with special decorations, such as a highlighted title bar. The
109      * active Window is always either the focused Window, or the first Frame or
110      * Dialog that is an owner of the focused Window.
111      */
112     @Native public static final int WINDOW_ACTIVATED    = 5 + WINDOW_FIRST;
113 
114     /**
115      * The window-deactivated event type. This event is delivered when the
116      * Window is no longer the active Window. Only a Frame or a Dialog can be
117      * the active Window. The native windowing system may denote the active
118      * Window or its children with special decorations, such as a highlighted
119      * title bar. The active Window is always either the focused Window, or the
120      * first Frame or Dialog that is an owner of the focused Window.
121      */
122     @Native public static final int WINDOW_DEACTIVATED  = 6 + WINDOW_FIRST;
123 
124     /**
125      * The window-gained-focus event type. This event is delivered when the
126      * Window becomes the focused Window, which means that the Window, or one
127      * of its subcomponents, will receive keyboard events.
128      */
129     @Native public static final int WINDOW_GAINED_FOCUS = 7 + WINDOW_FIRST;
130 
131     /**
132      * The window-lost-focus event type. This event is delivered when a Window
133      * is no longer the focused Window, which means keyboard events will no
134      * longer be delivered to the Window or any of its subcomponents.
135      */
136     @Native public static final int WINDOW_LOST_FOCUS   = 8 + WINDOW_FIRST;
137 
138     /**
139      * The window-state-changed event type.  This event is delivered
140      * when a Window's state is changed by virtue of it being
141      * iconified, maximized etc.
142      * @since 1.4
143      */
144     @Native public static final int WINDOW_STATE_CHANGED = 9 + WINDOW_FIRST;
145 
146     /**
147      * The last number in the range of ids used for window events.
148      */
149     public static final int WINDOW_LAST         = WINDOW_STATE_CHANGED;
150 
151     /**
152      * The other Window involved in this focus or activation change. For a
153      * WINDOW_ACTIVATED or WINDOW_GAINED_FOCUS event, this is the Window that
154      * lost activation or focus. For a WINDOW_DEACTIVATED or WINDOW_LOST_FOCUS
155      * event, this is the Window that gained activation or focus. For any other
156      * type of WindowEvent, or if the focus or activation change occurs with a
157      * native application, a Java application in a different VM, or with no
158      * other Window, null is returned.
159      *
160      * @see #getOppositeWindow
161      * @since 1.4
162      */
163     transient Window opposite;
164 
165     /**
166      * TBS
167      */
168     int oldState;
169     int newState;
170 
171 
172     /*
173      * JDK 1.1 serialVersionUID
174      */
175     private static final long serialVersionUID = -1567959133147912127L;
176 
177 
178     /**
179      * Constructs a {@code WindowEvent} object.
180      * <p>This method throws an
181      * {@code IllegalArgumentException} if {@code source}
182      * is {@code null}.
183      *
184      * @param source    The {@code Window} object
185      *                    that originated the event
186      * @param id        An integer indicating the type of event.
187      *                     For information on allowable values, see
188      *                     the class description for {@link WindowEvent}
189      * @param opposite  The other window involved in the focus or activation
190      *                      change, or {@code null}
191      * @param oldState  Previous state of the window for window state change event.
192      *                  See {@code #getOldState()} for allowable values
193      * @param newState  New state of the window for window state change event.
194      *                  See {@code #getNewState()} for allowable values
195      * @throws IllegalArgumentException if {@code source} is null
196      * @see #getWindow()
197      * @see #getID()
198      * @see #getOppositeWindow()
199      * @see #getOldState()
200      * @see #getNewState()
201      * @since 1.4
202      */
WindowEvent(Window source, int id, Window opposite, int oldState, int newState)203     public WindowEvent(Window source, int id, Window opposite,
204                        int oldState, int newState)
205     {
206         super(source, id);
207         this.opposite = opposite;
208         this.oldState = oldState;
209         this.newState = newState;
210     }
211 
212     /**
213      * Constructs a {@code WindowEvent} object with the
214      * specified opposite {@code Window}. The opposite
215      * {@code Window} is the other {@code Window}
216      * involved in this focus or activation change.
217      * For a {@code WINDOW_ACTIVATED} or
218      * {@code WINDOW_GAINED_FOCUS} event, this is the
219      * {@code Window} that lost activation or focus.
220      * For a {@code WINDOW_DEACTIVATED} or
221      * {@code WINDOW_LOST_FOCUS} event, this is the
222      * {@code Window} that gained activation or focus.
223      * If this focus change occurs with a native application, with a
224      * Java application in a different VM, or with no other
225      * {@code Window}, then the opposite Window is {@code null}.
226      * <p>This method throws an
227      * {@code IllegalArgumentException} if {@code source}
228      * is {@code null}.
229      *
230      * @param source     The {@code Window} object that
231      *                   originated the event
232      * @param id        An integer indicating the type of event.
233      *                     For information on allowable values, see
234      *                     the class description for {@link WindowEvent}.
235      *                  It is expected that this constructor will not
236      *                  be used for other then
237      *                  {@code WINDOW_ACTIVATED},{@code WINDOW_DEACTIVATED},
238      *                  {@code WINDOW_GAINED_FOCUS}, or {@code WINDOW_LOST_FOCUS}.
239      *                  {@code WindowEvent} types,
240      *                  because the opposite {@code Window} of other event types
241      *                  will always be {@code null}.
242      * @param opposite   The other {@code Window} involved in the
243      *                   focus or activation change, or {@code null}
244      * @throws IllegalArgumentException if {@code source} is null
245      * @see #getWindow()
246      * @see #getID()
247      * @see #getOppositeWindow()
248      * @since 1.4
249      */
WindowEvent(Window source, int id, Window opposite)250     public WindowEvent(Window source, int id, Window opposite) {
251         this(source, id, opposite, 0, 0);
252     }
253 
254     /**
255      * Constructs a {@code WindowEvent} object with the specified
256      * previous and new window states.
257      * <p>This method throws an
258      * {@code IllegalArgumentException} if {@code source}
259      * is {@code null}.
260      *
261      * @param source    The {@code Window} object
262      *                  that originated the event
263      * @param id        An integer indicating the type of event.
264      *                     For information on allowable values, see
265      *                     the class description for {@link WindowEvent}.
266      *                  It is expected that this constructor will not
267      *                  be used for other then
268      *                  {@code WINDOW_STATE_CHANGED}
269      *                  {@code WindowEvent}
270      *                  types, because the previous and new window
271      *                  states are meaningless for other event types.
272      * @param oldState  An integer representing the previous window state.
273      *                  See {@code #getOldState()} for allowable values
274      * @param newState  An integer representing the new window state.
275      *                  See {@code #getNewState()} for allowable values
276      * @throws IllegalArgumentException if {@code source} is null
277      * @see #getWindow()
278      * @see #getID()
279      * @see #getOldState()
280      * @see #getNewState()
281      * @since 1.4
282      */
WindowEvent(Window source, int id, int oldState, int newState)283     public WindowEvent(Window source, int id, int oldState, int newState) {
284         this(source, id, null, oldState, newState);
285     }
286 
287     /**
288      * Constructs a {@code WindowEvent} object.
289      * <p>This method throws an
290      * {@code IllegalArgumentException} if {@code source}
291      * is {@code null}.
292      *
293      * @param source The {@code Window} object that originated the event
294      * @param id     An integer indicating the type of event.
295      *                     For information on allowable values, see
296      *                     the class description for {@link WindowEvent}.
297      * @throws IllegalArgumentException if {@code source} is null
298      * @see #getWindow()
299      * @see #getID()
300      */
WindowEvent(Window source, int id)301     public WindowEvent(Window source, int id) {
302         this(source, id, null, 0, 0);
303     }
304 
305     /**
306      * Returns the originator of the event.
307      *
308      * @return the Window object that originated the event
309      */
getWindow()310     public Window getWindow() {
311         return (source instanceof Window) ? (Window)source : null;
312     }
313 
314     /**
315      * Returns the other Window involved in this focus or activation change.
316      * For a WINDOW_ACTIVATED or WINDOW_GAINED_FOCUS event, this is the Window
317      * that lost activation or focus. For a WINDOW_DEACTIVATED or
318      * WINDOW_LOST_FOCUS event, this is the Window that gained activation or
319      * focus. For any other type of WindowEvent, or if the focus or activation
320      * change occurs with a native application, with a Java application in a
321      * different VM or context, or with no other Window, null is returned.
322      *
323      * @return the other Window involved in the focus or activation change, or
324      *         null
325      * @since 1.4
326      */
getOppositeWindow()327     public Window getOppositeWindow() {
328         if (opposite == null) {
329             return null;
330         }
331 
332         return (SunToolkit.targetToAppContext(opposite) ==
333                 AppContext.getAppContext())
334             ? opposite
335             : null;
336     }
337 
338     /**
339      * For {@code WINDOW_STATE_CHANGED} events returns the
340      * previous state of the window. The state is
341      * represented as a bitwise mask.
342      * <ul>
343      * <li>{@code NORMAL}
344      * <br>Indicates that no state bits are set.
345      * <li>{@code ICONIFIED}
346      * <li>{@code MAXIMIZED_HORIZ}
347      * <li>{@code MAXIMIZED_VERT}
348      * <li>{@code MAXIMIZED_BOTH}
349      * <br>Concatenates {@code MAXIMIZED_HORIZ}
350      * and {@code MAXIMIZED_VERT}.
351      * </ul>
352      *
353      * @return a bitwise mask of the previous window state
354      * @see java.awt.Frame#getExtendedState()
355      * @since 1.4
356      */
getOldState()357     public int getOldState() {
358         return oldState;
359     }
360 
361     /**
362      * For {@code WINDOW_STATE_CHANGED} events returns the
363      * new state of the window. The state is
364      * represented as a bitwise mask.
365      * <ul>
366      * <li>{@code NORMAL}
367      * <br>Indicates that no state bits are set.
368      * <li>{@code ICONIFIED}
369      * <li>{@code MAXIMIZED_HORIZ}
370      * <li>{@code MAXIMIZED_VERT}
371      * <li>{@code MAXIMIZED_BOTH}
372      * <br>Concatenates {@code MAXIMIZED_HORIZ}
373      * and {@code MAXIMIZED_VERT}.
374      * </ul>
375      *
376      * @return a bitwise mask of the new window state
377      * @see java.awt.Frame#getExtendedState()
378      * @since 1.4
379      */
getNewState()380     public int getNewState() {
381         return newState;
382     }
383 
384     /**
385      * Returns a parameter string identifying this event.
386      * This method is useful for event-logging and for debugging.
387      *
388      * @return a string identifying the event and its attributes
389      */
paramString()390     public String paramString() {
391         String typeStr;
392         switch(id) {
393           case WINDOW_OPENED:
394               typeStr = "WINDOW_OPENED";
395               break;
396           case WINDOW_CLOSING:
397               typeStr = "WINDOW_CLOSING";
398               break;
399           case WINDOW_CLOSED:
400               typeStr = "WINDOW_CLOSED";
401               break;
402           case WINDOW_ICONIFIED:
403               typeStr = "WINDOW_ICONIFIED";
404               break;
405           case WINDOW_DEICONIFIED:
406               typeStr = "WINDOW_DEICONIFIED";
407               break;
408           case WINDOW_ACTIVATED:
409               typeStr = "WINDOW_ACTIVATED";
410               break;
411           case WINDOW_DEACTIVATED:
412               typeStr = "WINDOW_DEACTIVATED";
413               break;
414           case WINDOW_GAINED_FOCUS:
415               typeStr = "WINDOW_GAINED_FOCUS";
416               break;
417           case WINDOW_LOST_FOCUS:
418               typeStr = "WINDOW_LOST_FOCUS";
419               break;
420           case WINDOW_STATE_CHANGED:
421               typeStr = "WINDOW_STATE_CHANGED";
422               break;
423           default:
424               typeStr = "unknown type";
425         }
426         typeStr += ",opposite=" + getOppositeWindow()
427             + ",oldState=" + oldState + ",newState=" + newState;
428 
429         return typeStr;
430     }
431 }
432