WindowEvent


1   /*
2    * @(#)WindowEvent.java 1.34 03/12/19
3    *
4    * Copyright 2004 Sun Microsystems, Inc. All rights reserved.
5    * SUN PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
6    */
7   
8   package java.awt.event;
9   
10  import java.awt.Component  ;
11  import java.awt.Event  ;
12  import java.awt.Window  ;
13  
14  import sun.awt.AppContext;
15  import sun.awt.SunToolkit;
16  
17  /**
18   * A low-level event that indicates that a window has changed its status. This
19   * low-level event is generated by a Window object when it is opened, closed,
20   * activated, deactivated, iconified, or deiconified, or when focus is
21   * transfered into or out of the Window.
22   * <P>
23   * The event is passed to every <code>WindowListener</code>
24   * or <code>WindowAdapter</code> object which registered to receive such
25   * events using the window's <code>addWindowListener</code> method.
26   * (<code>WindowAdapter</code> objects implement the
27   * <code>WindowListener</code> interface.) Each such listener object
28   * gets this <code>WindowEvent</code> when the event occurs.
29   *
30   * @author Carl Quinn
31   * @author Amy Fowler
32   * @version 1.34, 12/19/03
33   *
34   * @see WindowAdapter
35   * @see WindowListener
36   * @see <a HREF="http://java.sun.com/docs/books/tutorial/post1.0/ui/windowlistener.html">Tutorial: Writing a Window Listener</a>
37   * @see <a HREF="http://www.awl.com/cp/javaseries/jcl1_2.html">Reference: The Java Class Libraries (update file)</a>
38   *
39   * @since JDK1.1
40   */
41  public class WindowEvent extends ComponentEvent   {
42  
43      /**
44       * The first number in the range of ids used for window events.
45       */
46      public static final int WINDOW_FIRST        = 200;
47  
48      /**
49       * The window opened event.  This event is delivered only
50       * the first time a window is made visible.
51       */
52      public static final int WINDOW_OPENED   = WINDOW_FIRST; // 200
53  
54      /**
55       * The "window is closing" event. This event is delivered when
56       * the user attempts to close the window from the window's system menu.  
57       * If the program does not explicitly hide or dispose the window
58       * while processing this event, the window close operation will be
59       * cancelled.
60       */
61      public static final int WINDOW_CLOSING  = 1 + WINDOW_FIRST; //Event.WINDOW_DESTROY
62  
63      /**
64       * The window closed event. This event is delivered after
65       * the window has been closed as the result of a call to dispose.
66       */
67      public static final int WINDOW_CLOSED   = 2 + WINDOW_FIRST;
68  
69      /**
70       * The window iconified event. This event is delivered when
71       * the window has been changed from a normal to a minimized state.
72       * For many platforms, a minimized window is displayed as
73       * the icon specified in the window's iconImage property.
74       * @see java.awt.Frame#setIconImage
75       */
76      public static final int WINDOW_ICONIFIED    = 3 + WINDOW_FIRST; //Event.WINDOW_ICONIFY
77  
78      /**
79       * The window deiconified event type. This event is delivered when
80       * the window has been changed from a minimized to a normal state.
81       */
82      public static final int WINDOW_DEICONIFIED  = 4 + WINDOW_FIRST; //Event.WINDOW_DEICONIFY
83  
84      /**
85       * The window-activated event type. This event is delivered when the Window
86       * becomes the active Window. Only a Frame or a Dialog can be the active
87       * Window. The native windowing system may denote the active Window or its
88       * children with special decorations, such as a highlighted title bar. The
89       * active Window is always either the focused Window, or the first Frame or
90       * Dialog that is an owner of the focused Window.
91       */
92      public static final int WINDOW_ACTIVATED    = 5 + WINDOW_FIRST;
93  
94      /**
95       * The window-deactivated event type. This event is delivered when the
96       * Window is no longer the active Window. Only a Frame or a Dialog can be
97       * the active Window. The native windowing system may denote the active
98       * Window or its children with special decorations, such as a highlighted
99       * title bar. The active Window is always either the focused Window, or the
100      * first Frame or Dialog that is an owner of the focused Window.
101      */
102     public static final int WINDOW_DEACTIVATED  = 6 + WINDOW_FIRST;
103 
104     /**
105      * The window-gained-focus event type. This event is delivered when the
106      * Window becomes the focused Window, which means that the Window, or one
107      * of its subcomponents, will receive keyboard events.
108      */
109     public static final int WINDOW_GAINED_FOCUS = 7 + WINDOW_FIRST;
110 
111     /**
112      * The window-lost-focus event type. This event is delivered when a Window
113      * is no longer the focused Window, which means keyboard events will no
114      * longer be delivered to the Window or any of its subcomponents.
115      */
116     public static final int WINDOW_LOST_FOCUS   = 8 + WINDOW_FIRST;
117 
118     /**
119      * The window-state-changed event type.  This event is delivered
120      * when a Window's state is changed by virtue of it being
121      * iconified, maximized etc.
122      * @since 1.4
123      */
124     public static final int WINDOW_STATE_CHANGED = 9 + WINDOW_FIRST;
125 
126     /**
127      * The last number in the range of ids used for window events.
128      */
129     public static final int WINDOW_LAST         = WINDOW_STATE_CHANGED;
130 
131     /**
132      * The other Window involved in this focus or activation change. For a
133      * WINDOW_ACTIVATED or WINDOW_GAINED_FOCUS event, this is the Window that
134      * lost activation or focus. For a WINDOW_DEACTIVATED or WINDOW_LOST_FOCUS
135      * event, this is the Window that gained activation or focus. For any other
136      * type of WindowEvent, or if the focus or activation change occurs with a
137      * native application, a Java application in a different VM, or with no
138      * other Window, null is returned.
139      *
140      * @see #getOppositeWindow
141      * @since 1.4
142      */
143     transient Window   opposite;
144 
145     /**
146      * TBS
147      */ 
148     int oldState;
149     int newState;
150 
151 
152     /*
153      * JDK 1.1 serialVersionUID
154      */
155     private static final long serialVersionUID = -1567959133147912127L;
156 
157 
158     /**
159      * Constructs a <code>WindowEvent</code> object.
160      * <p>Note that passing in an invalid <code>id</code> results in
161      * unspecified behavior. This method throws an
162      * <code>IllegalArgumentException</code> if <code>source</code>
163      * is <code>null</code>.
164      *
165      * @param source    the <code>Window</code> object
166      *                    that originated the event
167      * @param id        an integer indicating the type of event.
168      * @param opposite  the other window involved in the focus or activation
169      *                      change, or <code>null</code>
170      * @param oldState  previous state of the window for window state
171      *                      change event
172      * @param newState  new state of the window for window state change event
173      * @throws IllegalArgumentException if <code>source</code> is null
174      * @since 1.4
175      */
176     public WindowEvent(Window   source, int id, Window   opposite,
177                int oldState, int newState)
178     {
179         super(source, id);
180     this.opposite = opposite;
181     this.oldState = oldState;
182     this.newState = newState;
183     }
184 
185     /**
186      * Constructs a <code>WindowEvent</code> object with the
187      * specified opposite <code>Window</code>. The opposite
188      * <code>Window</code> is the other <code>Window</code>
189      * involved in this focus or activation change.
190      * For a <code>WINDOW_ACTIVATED</code> or
191      * <code>WINDOW_GAINED_FOCUS</code> event, this is the
192      * <code>Window</code> that lost activation or focus.
193      * For a <code>WINDOW_DEACTIVATED</code> or
194      * <code>WINDOW_LOST_FOCUS</code> event, this is the
195      * <code>Window</code> that gained activation or focus.
196      * If this focus change occurs with a native application, with a
197      * Java application in a different VM, or with no other
198      * <code>Window</code>, then the opposite Window is <code>null</code>.
199      * <p>Note that passing in an invalid <code>id</code> results in
200      * unspecified behavior. This method throws an
201      * <code>IllegalArgumentException</code> if <code>source</code>
202      * is <code>null</code>.
203      *
204      * @param source     the <code>Window</code> object that
205      *                   originated the event
206      * @param id         <code>WINDOW_ACTIVATED</code>,
207      *                   <code>WINDOW_DEACTIVATED</code>,
208      *                   <code>WINDOW_GAINED_FOCUS</code>,
209      *                   or <code>WINDOW_LOST_FOCUS</code>. It is
210      *                   expected that this constructor will not be used for
211      *                   other <code>WindowEvent</code> types because the
212      *                   opposite <code>Window</code> of such events
213      *                   will always be <code>null</code>
214      * @param opposite   the other <code>Window</code> involved in the
215      *                   focus or activation change, or <code>null</code>
216      * @throws IllegalArgumentException if <code>source</code> is null
217      */
218     public WindowEvent(Window   source, int id, Window   opposite) {
219         this(source, id, opposite, 0, 0);
220     }
221 
222     /**
223      * Constructs a <code>WindowEvent</code> object with the specified
224      * previous and new window states.
225      * <p>Note that passing in an invalid <code>id</code> results in
226      * unspecified behavior. This method throws an
227      * <code>IllegalArgumentException</code> if <code>source</code>
228      * is <code>null</code>.
229      * 
230      * @param source    the <code>Window</code> object
231      *                  that originated the event
232      * @param id    <code>WINDOW_STATE_CHANGED</code> event type.
233      *                  It is expected that this constructor will not
234      *                  be used for other <code>WindowEvent</code>
235      *                  types, because the previous and new window
236      *                  states are meaningless for other event types.
237      * @param oldState  an integer representing the previous window state
238      * @param newState  an integer representing the new window state
239      * @throws IllegalArgumentException if <code>source</code> is null
240      * @since 1.4
241      */
242     public WindowEvent(Window   source, int id, int oldState, int newState) {
243     this(source, id, null, oldState, newState);
244     }
245 
246     /**
247      * Constructs a <code>WindowEvent</code> object.
248      * <p>Note that passing in an invalid <code>id</code> results in
249      * unspecified behavior. This method throws an
250      * <code>IllegalArgumentException</code> if <code>source</code>
251      * is <code>null</code>.
252      *
253      * @param source the <code>Window</code> object that originated the event
254      * @param id     an integer indicating the type of event
255      * @throws IllegalArgumentException if <code>source</code> is null
256      */
257     public WindowEvent(Window   source, int id) {
258         this(source, id, null, 0, 0);
259     }
260 
261     /**
262      * Returns the originator of the event.
263      *
264      * @return the Window object that originated the event
265      */
266     public Window   getWindow() {
267         return (source instanceof Window  ) ? (Window  )source : null;
268     }
269 
270     /**
271      * Returns the other Window involved in this focus or activation change.
272      * For a WINDOW_ACTIVATED or WINDOW_GAINED_FOCUS event, this is the Window
273      * that lost activation or focus. For a WINDOW_DEACTIVATED or
274      * WINDOW_LOST_FOCUS event, this is the Window that gained activation or
275      * focus. For any other type of WindowEvent, or if the focus or activation
276      * change occurs with a native application, with a Java application in a
277      * different VM or context, or with no other Window, null is returned.
278      *
279      * @return the other Window involved in the focus or activation change, or
280      *         null
281      * @since 1.4
282      */
283     public Window   getOppositeWindow() {
284         if (opposite == null) {
285         return null;
286     }
287 
288         return (SunToolkit.targetToAppContext(opposite) ==
289         AppContext.getAppContext())
290         ? opposite
291         : null;
292     }
293 
294     /**
295      * For <code>WINDOW_STATE_CHANGED</code> events returns the
296      * previous state of the window. The state is
297      * represented as a bitwise mask.
298      * <ul>
299      * <li><code>NORMAL</code>
300      * <br>Indicates that no state bits are set.
301      * <li><code>ICONIFIED</code>
302      * <li><code>MAXIMIZED_HORIZ</code>
303      * <li><code>MAXIMIZED_VERT</code>
304      * <li><code>MAXIMIZED_BOTH</code>
305      * <br>Concatenates <code>MAXIMIZED_HORIZ</code>
306      * and <code>MAXIMIZED_VERT</code>.
307      * </ul>
308      *
309      * @return a bitwise mask of the previous window state
310      * @see java.awt.Frame#getExtendedState()
311      * @since 1.4
312      */
313     public int getOldState() {
314     return oldState;
315     }
316 
317     /**
318      * For <code>WINDOW_STATE_CHANGED</code> events returns the
319      * new state of the window. The state is
320      * represented as a bitwise mask.
321      * <ul>
322      * <li><code>NORMAL</code>
323      * <br>Indicates that no state bits are set.
324      * <li><code>ICONIFIED</code>
325      * <li><code>MAXIMIZED_HORIZ</code>
326      * <li><code>MAXIMIZED_VERT</code>
327      * <li><code>MAXIMIZED_BOTH</code>
328      * <br>Concatenates <code>MAXIMIZED_HORIZ</code>
329      * and <code>MAXIMIZED_VERT</code>.
330      * </ul>
331      *
332      * @return a bitwise mask of the new window state
333      * @see java.awt.Frame#getExtendedState()
334      * @since 1.4
335      */
336     public int getNewState() {
337     return newState;
338     }
339 
340     /**
341      * Returns a parameter string identifying this event.
342      * This method is useful for event-logging and for debugging.
343      *
344      * @return a string identifying the event and its attributes
345      */
346     public String   paramString() {
347         String   typeStr;
348         switch(id) {
349           case WINDOW_OPENED:
350               typeStr = "WINDOW_OPENED";
351               break;
352           case WINDOW_CLOSING:
353               typeStr = "WINDOW_CLOSING";
354               break;
355           case WINDOW_CLOSED:
356               typeStr = "WINDOW_CLOSED";
357               break;
358           case WINDOW_ICONIFIED:
359               typeStr = "WINDOW_ICONIFIED";
360               break;
361           case WINDOW_DEICONIFIED:
362               typeStr = "WINDOW_DEICONIFIED";
363               break;
364           case WINDOW_ACTIVATED:
365               typeStr = "WINDOW_ACTIVATED";
366               break;
367           case WINDOW_DEACTIVATED:
368               typeStr = "WINDOW_DEACTIVATED";
369               break;
370       case WINDOW_GAINED_FOCUS:
371           typeStr = "WINDOW_GAINED_FOCUS";
372           break;
373       case WINDOW_LOST_FOCUS:
374           typeStr = "WINDOW_LOST_FOCUS";
375           break;
376       case WINDOW_STATE_CHANGED:
377           typeStr = "WINDOW_STATE_CHANGED";
378           break;
379           default:
380               typeStr = "unknown type";
381         }
382     typeStr += ",opposite=" + getOppositeWindow()
383         + ",oldState=" + oldState + ",newState=" + newState;
384 
385         return typeStr;
386     }
387 }
388
A to Z: JavaDoc & Examples Daily Java News & Articles Open Source Projects Open Source Codes Free Computer Books Remove Frame
Popular Tags