001    /* WindowEvent.java -- window change event
002       Copyright (C) 1999, 2002, 2005  Free Software Foundation, Inc.
003    
004    This file is part of GNU Classpath.
005    
006    GNU Classpath is free software; you can redistribute it and/or modify
007    it under the terms of the GNU General Public License as published by
008    the Free Software Foundation; either version 2, or (at your option)
009    any later version.
010    
011    GNU Classpath is distributed in the hope that it will be useful, but
012    WITHOUT ANY WARRANTY; without even the implied warranty of
013    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
014    General Public License for more details.
015    
016    You should have received a copy of the GNU General Public License
017    along with GNU Classpath; see the file COPYING.  If not, write to the
018    Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
019    02110-1301 USA.
020    
021    Linking this library statically or dynamically with other modules is
022    making a combined work based on this library.  Thus, the terms and
023    conditions of the GNU General Public License cover the whole
024    combination.
025    
026    As a special exception, the copyright holders of this library give you
027    permission to link this library with independent modules to produce an
028    executable, regardless of the license terms of these independent
029    modules, and to copy and distribute the resulting executable under
030    terms of your choice, provided that you also meet, for each linked
031    independent module, the terms and conditions of the license of that
032    module.  An independent module is a module which is not derived from
033    or based on this library.  If you modify this library, you may extend
034    this exception to your version of the library, but you are not
035    obligated to do so.  If you do not wish to do so, delete this
036    exception statement from your version. */
037    
038    
039    package java.awt.event;
040    
041    import java.awt.Frame;
042    import java.awt.Window;
043    
044    /**
045     * This event is generated when there is a change in a window. This includes
046     * creation, closing, iconification, activation, and focus changes. There
047     * are three listeners, for three types of events: WindowListeners deal with
048     * the lifecycle of a window, WindowStateListeners deal with window state
049     * like maximization, and WindowFocusListeners deal with focus switching to
050     * or from a window. 
051     *
052     * @author Aaron M. Renn (arenn@urbanophile.com)
053     * @see WindowAdapter
054     * @see WindowListener
055     * @see WindowFocusListener
056     * @see WindowStateListener
057     * @since 1.1
058     * @status updated to 1.4
059     */
060    public class WindowEvent extends ComponentEvent
061    {
062      /**
063       * Compatible with JDK 1.1+.
064       */
065      private static final long serialVersionUID = -1567959133147912127L;
066    
067      /** This is the first id in the range of event ids used by this class. */
068      public static final int WINDOW_FIRST = 200;
069    
070      /** This is the id for a window that is opened. */
071      public static final int WINDOW_OPENED = 200;
072    
073      /** This is the id for a window that is about to close. */
074      public static final int WINDOW_CLOSING = 201;
075    
076      /** This is the id for a window that finished closing. */
077      public static final int WINDOW_CLOSED = 202;
078    
079      /** This is the id for a window that is iconified. */
080      public static final int WINDOW_ICONIFIED = 203;
081    
082      /** This is the id for a window that is de-iconified. */
083      public static final int WINDOW_DEICONIFIED = 204;
084    
085      /** This is the id for a window that is activated. */
086      public static final int WINDOW_ACTIVATED = 205;
087    
088      /** This is the id for a window that is de-activated. */
089      public static final int WINDOW_DEACTIVATED = 206;
090    
091      /**
092       * This is the id for a window becoming the focused window.
093       *
094       * @since 1.4
095       */
096      public static final int WINDOW_GAINED_FOCUS = 207;
097    
098      /**
099       * This is the id for a window losing all focus.
100       *
101       * @since 1.4
102       */
103      public static final int WINDOW_LOST_FOCUS = 208;
104    
105      /**
106       * This is the id for a window state change, such as maximization.
107       *
108       * @since 1.4
109       */
110      public static final int WINDOW_STATE_CHANGED = 209;
111    
112      /** This is the last id in the range of event ids used by this class. */
113      public static final int WINDOW_LAST = 209;
114    
115      /**
116       * The other Window involved in a focus or activation change. For
117       * WINDOW_ACTIVATED and WINDOW_GAINED_FOCUS events, this is the window that
118       * lost focus; for WINDOW_DEACTIVATED and WINDOW_LOST_FOCUS, this is the
119       * window that stole focus; and for other events (or when native
120       * implementation does not have the data available), this is null.
121       *
122       * @see #getOppositeWindow()
123       * @serial the opposite window, or null
124       * @since 1.4
125       */
126      private final Window opposite;
127    
128      /**
129       * The former state of the window.
130       *
131       * @serial bitmask of the old window state
132       * @since 1.4
133       */
134      private final int oldState;
135    
136      /**
137       * The present state of the window.
138       *
139       * @serial bitmask of the new window state
140       * @since 1.4
141       */
142      private final int newState;
143    
144      /**
145       * Initializes a new instance of <code>WindowEvent</code> with the specified
146       * parameters. Note that an invalid id leads to unspecified results.
147       *
148       * @param source the window that generated this event
149       * @param id the event id
150       * @param opposite the window that received the opposite event, or null
151       * @param oldState the previous state of this window
152       * @param newState the new state of this window
153       * @throws IllegalArgumentException if source is null
154       * @since 1.4
155       */
156      public WindowEvent(Window source, int id, Window opposite,
157                         int oldState, int newState)
158      {
159        super(source, id);
160        this.opposite = opposite;
161        this.oldState = oldState;
162        this.newState = newState;
163      }
164    
165      /**
166       * Initializes a new instance of <code>WindowEvent</code> with the specified
167       * parameters. Note that an invalid id leads to unspecified results.
168       *
169       * @param source the window that generated this event
170       * @param id the event id
171       * @param opposite the window that received the opposite event, or null
172       * @throws IllegalArgumentException if source is null
173       * @since 1.4
174       */
175      public WindowEvent(Window source, int id, Window opposite)
176      {
177        this(source, id, opposite, 0, 0);
178      }
179    
180      /**
181       * Initializes a new instance of <code>WindowEvent</code> with the specified
182       * parameters. Note that an invalid id leads to unspecified results.
183       *
184       * @param source the window that generated this event
185       * @param id the event id
186       * @param oldState the previous state of this window
187       * @param newState the new state of this window
188       * @throws IllegalArgumentException if source is null
189       * @since 1.4
190       */
191      public WindowEvent(Window source, int id, int oldState, int newState)
192      {
193        this(source, id, null, oldState, newState);
194      }
195    
196      /**
197       * Initializes a new instance of <code>WindowEvent</code> with the specified
198       * parameters. Note that an invalid id leads to unspecified results.
199       *
200       * @param source the window that generated this event
201       * @param id the event id
202       * @throws IllegalArgumentException if source is null
203       */
204      public WindowEvent(Window source, int id)
205      {
206        this(source, id, null, 0, 0);
207      }
208    
209      /**
210       * Returns the event source as a <code>Window</code>. If the source has
211       * subsequently been modified to a non-Window, this returns null.
212      *
213      * @return the event source as a <code>Window</code>
214      */
215      public Window getWindow()
216      {
217        return source instanceof Window ? (Window) source : null;
218      }
219    
220      /**
221       * Returns the opposite window if this window was involved in an activation
222       * or focus change. For WINDOW_ACTIVATED and WINDOW_GAINED_FOCUS events,
223       * this is the window that lost focus; for WINDOW_DEACTIVATED and
224       * WINDOW_LOST_FOCUS, this is the window that stole focus; and for other
225       * events (or when native implementation does not have the data available),
226       * this is null.
227       *
228       * @return the opposite window, or null
229       * @since 1.4
230       */
231      public Window getOppositeWindow()
232      {
233        return opposite;
234      }
235    
236      /**
237       * Returns the state of this window before the event. This is the bitwise
238       * or of fields in Frame: NORMAL, ICONIFIED, MAXIMIZED_HORIZ, MAXIMIZED_VERT,
239       * and MAXIMIZED_BOTH.
240       *
241       * @return the former state
242       * @see Frame#getExtendedState()
243       * @since 1.4
244       */
245      public int getOldState()
246      {
247        return oldState;
248      }
249    
250      /**
251       * Returns the state of this window after the event. This is the bitwise
252       * or of fields in Frame: NORMAL, ICONIFIED, MAXIMIZED_HORIZ, MAXIMIZED_VERT,
253       * and MAXIMIZED_BOTH.
254       *
255       * @return the updated state
256       * @see Frame#getExtendedState()
257       * @since 1.4
258       */
259      public int getNewState()
260      {
261        return newState;
262      }
263    
264      /**
265       * Returns a string that identifies this event. This is formatted as the
266       * field name of the id, followed by the opposite window, old state, and
267       * new state.
268       *
269       * @return a string that identifies this event
270       */
271      public String paramString()
272      {
273        StringBuffer s = new StringBuffer();
274        switch (id)
275          {
276          case WINDOW_OPENED:
277            s.append("WINDOW_OPENED,opposite=");
278            break;
279          case WINDOW_CLOSING:
280            s.append("WINDOW_CLOSING,opposite=");
281            break;
282          case WINDOW_CLOSED:
283            s.append("WINDOW_CLOSED,opposite=");
284            break;
285          case WINDOW_ICONIFIED:
286            s.append("WINDOW_ICONIFIED,opposite=");
287            break;
288          case WINDOW_DEICONIFIED:
289            s.append("WINDOW_DEICONIFIED,opposite=");
290            break;
291          case WINDOW_ACTIVATED:
292            s.append("WINDOW_ACTIVATED,opposite=");
293            break;
294          case WINDOW_DEACTIVATED:
295            s.append("WINDOW_DEACTIVATED,opposite=");
296            break;
297          case WINDOW_GAINED_FOCUS:
298            s.append("WINDOW_GAINED_FOCUS,opposite=");
299            break;
300          case WINDOW_LOST_FOCUS:
301            s.append("WINDOW_LOST_FOCUS,opposite=");
302            break;
303          case WINDOW_STATE_CHANGED:
304            s.append("WINDOW_STATE_CHANGED,opposite=");
305            break;
306          default:
307            s.append("unknown type,opposite=");
308          }
309        return s.append(opposite).append(",oldState=").append(oldState)
310          .append(",newState=").append(newState).toString();
311      }
312    } // class WindowEvent