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 gnu.java.lang.CPStringBuilder;
042    
043    import java.awt.Frame;
044    import java.awt.Window;
045    
046    /**
047     * This event is generated when there is a change in a window. This includes
048     * creation, closing, iconification, activation, and focus changes. There
049     * are three listeners, for three types of events: WindowListeners deal with
050     * the lifecycle of a window, WindowStateListeners deal with window state
051     * like maximization, and WindowFocusListeners deal with focus switching to
052     * or from a window.
053     *
054     * @author Aaron M. Renn (arenn@urbanophile.com)
055     * @see WindowAdapter
056     * @see WindowListener
057     * @see WindowFocusListener
058     * @see WindowStateListener
059     * @since 1.1
060     * @status updated to 1.4
061     */
062    public class WindowEvent extends ComponentEvent
063    {
064      /**
065       * Compatible with JDK 1.1+.
066       */
067      private static final long serialVersionUID = -1567959133147912127L;
068    
069      /** This is the first id in the range of event ids used by this class. */
070      public static final int WINDOW_FIRST = 200;
071    
072      /** This is the id for a window that is opened. */
073      public static final int WINDOW_OPENED = 200;
074    
075      /** This is the id for a window that is about to close. */
076      public static final int WINDOW_CLOSING = 201;
077    
078      /** This is the id for a window that finished closing. */
079      public static final int WINDOW_CLOSED = 202;
080    
081      /** This is the id for a window that is iconified. */
082      public static final int WINDOW_ICONIFIED = 203;
083    
084      /** This is the id for a window that is de-iconified. */
085      public static final int WINDOW_DEICONIFIED = 204;
086    
087      /** This is the id for a window that is activated. */
088      public static final int WINDOW_ACTIVATED = 205;
089    
090      /** This is the id for a window that is de-activated. */
091      public static final int WINDOW_DEACTIVATED = 206;
092    
093      /**
094       * This is the id for a window becoming the focused window.
095       *
096       * @since 1.4
097       */
098      public static final int WINDOW_GAINED_FOCUS = 207;
099    
100      /**
101       * This is the id for a window losing all focus.
102       *
103       * @since 1.4
104       */
105      public static final int WINDOW_LOST_FOCUS = 208;
106    
107      /**
108       * This is the id for a window state change, such as maximization.
109       *
110       * @since 1.4
111       */
112      public static final int WINDOW_STATE_CHANGED = 209;
113    
114      /** This is the last id in the range of event ids used by this class. */
115      public static final int WINDOW_LAST = 209;
116    
117      /**
118       * The other Window involved in a focus or activation change. For
119       * WINDOW_ACTIVATED and WINDOW_GAINED_FOCUS events, this is the window that
120       * lost focus; for WINDOW_DEACTIVATED and WINDOW_LOST_FOCUS, this is the
121       * window that stole focus; and for other events (or when native
122       * implementation does not have the data available), this is null.
123       *
124       * @see #getOppositeWindow()
125       * @serial the opposite window, or null
126       * @since 1.4
127       */
128      private final Window opposite;
129    
130      /**
131       * The former state of the window.
132       *
133       * @serial bitmask of the old window state
134       * @since 1.4
135       */
136      private final int oldState;
137    
138      /**
139       * The present state of the window.
140       *
141       * @serial bitmask of the new window state
142       * @since 1.4
143       */
144      private final int newState;
145    
146      /**
147       * Initializes a new instance of <code>WindowEvent</code> with the specified
148       * parameters. Note that an invalid id leads to unspecified results.
149       *
150       * @param source the window that generated this event
151       * @param id the event id
152       * @param opposite the window that received the opposite event, or null
153       * @param oldState the previous state of this window
154       * @param newState the new state of this window
155       * @throws IllegalArgumentException if source is null
156       * @since 1.4
157       */
158      public WindowEvent(Window source, int id, Window opposite,
159                         int oldState, int newState)
160      {
161        super(source, id);
162        this.opposite = opposite;
163        this.oldState = oldState;
164        this.newState = newState;
165      }
166    
167      /**
168       * Initializes a new instance of <code>WindowEvent</code> with the specified
169       * parameters. Note that an invalid id leads to unspecified results.
170       *
171       * @param source the window that generated this event
172       * @param id the event id
173       * @param opposite the window that received the opposite event, or null
174       * @throws IllegalArgumentException if source is null
175       * @since 1.4
176       */
177      public WindowEvent(Window source, int id, Window opposite)
178      {
179        this(source, id, opposite, 0, 0);
180      }
181    
182      /**
183       * Initializes a new instance of <code>WindowEvent</code> with the specified
184       * parameters. Note that an invalid id leads to unspecified results.
185       *
186       * @param source the window that generated this event
187       * @param id the event id
188       * @param oldState the previous state of this window
189       * @param newState the new state of this window
190       * @throws IllegalArgumentException if source is null
191       * @since 1.4
192       */
193      public WindowEvent(Window source, int id, int oldState, int newState)
194      {
195        this(source, id, null, oldState, newState);
196      }
197    
198      /**
199       * Initializes a new instance of <code>WindowEvent</code> with the specified
200       * parameters. Note that an invalid id leads to unspecified results.
201       *
202       * @param source the window that generated this event
203       * @param id the event id
204       * @throws IllegalArgumentException if source is null
205       */
206      public WindowEvent(Window source, int id)
207      {
208        this(source, id, null, 0, 0);
209      }
210    
211      /**
212       * Returns the event source as a <code>Window</code>. If the source has
213       * subsequently been modified to a non-Window, this returns null.
214      *
215      * @return the event source as a <code>Window</code>
216      */
217      public Window getWindow()
218      {
219        return source instanceof Window ? (Window) source : null;
220      }
221    
222      /**
223       * Returns the opposite window if this window was involved in an activation
224       * or focus change. For WINDOW_ACTIVATED and WINDOW_GAINED_FOCUS events,
225       * this is the window that lost focus; for WINDOW_DEACTIVATED and
226       * WINDOW_LOST_FOCUS, this is the window that stole focus; and for other
227       * events (or when native implementation does not have the data available),
228       * this is null.
229       *
230       * @return the opposite window, or null
231       * @since 1.4
232       */
233      public Window getOppositeWindow()
234      {
235        return opposite;
236      }
237    
238      /**
239       * Returns the state of this window before the event. This is the bitwise
240       * or of fields in Frame: NORMAL, ICONIFIED, MAXIMIZED_HORIZ, MAXIMIZED_VERT,
241       * and MAXIMIZED_BOTH.
242       *
243       * @return the former state
244       * @see Frame#getExtendedState()
245       * @since 1.4
246       */
247      public int getOldState()
248      {
249        return oldState;
250      }
251    
252      /**
253       * Returns the state of this window after the event. This is the bitwise
254       * or of fields in Frame: NORMAL, ICONIFIED, MAXIMIZED_HORIZ, MAXIMIZED_VERT,
255       * and MAXIMIZED_BOTH.
256       *
257       * @return the updated state
258       * @see Frame#getExtendedState()
259       * @since 1.4
260       */
261      public int getNewState()
262      {
263        return newState;
264      }
265    
266      /**
267       * Returns a string that identifies this event. This is formatted as the
268       * field name of the id, followed by the opposite window, old state, and
269       * new state.
270       *
271       * @return a string that identifies this event
272       */
273      public String paramString()
274      {
275        CPStringBuilder s = new CPStringBuilder();
276        switch (id)
277          {
278          case WINDOW_OPENED:
279            s.append("WINDOW_OPENED,opposite=");
280            break;
281          case WINDOW_CLOSING:
282            s.append("WINDOW_CLOSING,opposite=");
283            break;
284          case WINDOW_CLOSED:
285            s.append("WINDOW_CLOSED,opposite=");
286            break;
287          case WINDOW_ICONIFIED:
288            s.append("WINDOW_ICONIFIED,opposite=");
289            break;
290          case WINDOW_DEICONIFIED:
291            s.append("WINDOW_DEICONIFIED,opposite=");
292            break;
293          case WINDOW_ACTIVATED:
294            s.append("WINDOW_ACTIVATED,opposite=");
295            break;
296          case WINDOW_DEACTIVATED:
297            s.append("WINDOW_DEACTIVATED,opposite=");
298            break;
299          case WINDOW_GAINED_FOCUS:
300            s.append("WINDOW_GAINED_FOCUS,opposite=");
301            break;
302          case WINDOW_LOST_FOCUS:
303            s.append("WINDOW_LOST_FOCUS,opposite=");
304            break;
305          case WINDOW_STATE_CHANGED:
306            s.append("WINDOW_STATE_CHANGED,opposite=");
307            break;
308          default:
309            s.append("unknown type,opposite=");
310          }
311        return s.append(opposite).append(",oldState=").append(oldState)
312          .append(",newState=").append(newState).toString();
313      }
314    } // class WindowEvent