001/* InputEvent.java -- common superclass of component input events
002   Copyright (C) 1999, 2002, 2004, 2005  Free Software Foundation, Inc.
003
004This file is part of GNU Classpath.
005
006GNU Classpath is free software; you can redistribute it and/or modify
007it under the terms of the GNU General Public License as published by
008the Free Software Foundation; either version 2, or (at your option)
009any later version.
010
011GNU Classpath is distributed in the hope that it will be useful, but
012WITHOUT ANY WARRANTY; without even the implied warranty of
013MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
014General Public License for more details.
015
016You should have received a copy of the GNU General Public License
017along with GNU Classpath; see the file COPYING.  If not, write to the
018Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
01902110-1301 USA.
020
021Linking this library statically or dynamically with other modules is
022making a combined work based on this library.  Thus, the terms and
023conditions of the GNU General Public License cover the whole
024combination.
025
026As a special exception, the copyright holders of this library give you
027permission to link this library with independent modules to produce an
028executable, regardless of the license terms of these independent
029modules, and to copy and distribute the resulting executable under
030terms of your choice, provided that you also meet, for each linked
031independent module, the terms and conditions of the license of that
032module.  An independent module is a module which is not derived from
033or based on this library.  If you modify this library, you may extend
034this exception to your version of the library, but you are not
035obligated to do so.  If you do not wish to do so, delete this
036exception statement from your version. */
037
038
039package java.awt.event;
040
041import gnu.java.awt.EventModifier;
042import gnu.java.lang.CPStringBuilder;
043
044import java.awt.Component;
045
046/**
047 * This is the common superclass for all component input classes. These are
048 * passed to listeners before the component, so that listeners can consume
049 * the event before it does its default behavior.
050 *
051 * @author Aaron M. Renn (arenn@urbanophile.com)
052 * @see KeyEvent
053 * @see KeyAdapter
054 * @see MouseEvent
055 * @see MouseAdapter
056 * @see MouseMotionAdapter
057 * @see MouseWheelEvent
058 * @since 1.1
059 * @status updated to 1.4
060 */
061public abstract class InputEvent extends ComponentEvent
062{
063  /**
064   * Compatible with JDK 1.1+.
065   */
066  private static final long serialVersionUID = -2482525981698309786L;
067
068  /**
069   * This is the bit mask which indicates the shift key is down. It is
070   * recommended that SHIFT_DOWN_MASK be used instead.
071   *
072   * @see #SHIFT_DOWN_MASK
073   */
074  public static final int SHIFT_MASK = 1;
075
076  /**
077   * This is the bit mask which indicates the control key is down. It is
078   * recommended that CTRL_DOWN_MASK be used instead.
079   *
080   * @see #CTRL_DOWN_MASK
081   */
082  public static final int CTRL_MASK = 2;
083
084  /**
085   * This is the bit mask which indicates the meta key is down. It is
086   * recommended that META_DOWN_MASK be used instead.
087   *
088   * @see #META_DOWN_MASK
089   */
090  public static final int META_MASK = 4;
091
092  /**
093   * This is the bit mask which indicates the alt key is down. It is
094   * recommended that ALT_DOWN_MASK be used instead.
095   *
096   * @see #ALT_DOWN_MASK
097   */
098  public static final int ALT_MASK = 8;
099
100  /**
101   * This is the bit mask which indicates the alt-graph modifier is in effect.
102   * It is recommended that ALT_GRAPH_DOWN_MASK be used instead.
103   *
104   * @see #ALT_GRAPH_DOWN_MASK
105   */
106  public static final int ALT_GRAPH_MASK = 0x20;
107
108  /**
109   * This bit mask indicates mouse button one is down. It is recommended that
110   * BUTTON1_DOWN_MASK be used instead.
111   *
112   * @see #BUTTON1_DOWN_MASK
113   */
114  public static final int BUTTON1_MASK = 0x10;
115
116  /**
117   * This bit mask indicates mouse button two is down. It is recommended that
118   * BUTTON2_DOWN_MASK be used instead.
119   *
120   * @see #BUTTON2_DOWN_MASK
121   */
122  public static final int BUTTON2_MASK = 8;
123
124  /**
125   * This bit mask indicates mouse button three is down. It is recommended
126   * that BUTTON3_DOWN_MASK be used instead.
127   *
128   * @see #BUTTON3_DOWN_MASK
129   */
130  public static final int BUTTON3_MASK = 4;
131
132  /**
133   * The SHIFT key extended modifier.
134   *
135   * @since 1.4
136   */
137  public static final int SHIFT_DOWN_MASK = 0x0040;
138
139  /**
140   * The CTRL key extended modifier.
141   *
142   * @since 1.4
143   */
144  public static final int CTRL_DOWN_MASK = 0x0080;
145
146  /**
147   * The META key extended modifier.
148   *
149   * @since 1.4
150   */
151  public static final int META_DOWN_MASK = 0x0100;
152
153  /**
154   * The ALT key extended modifier.
155   *
156   * @since 1.4
157   */
158  public static final int ALT_DOWN_MASK = 0x0200;
159
160  /**
161   * The mouse button1 key extended modifier.
162   *
163   * @since 1.4
164   */
165  public static final int BUTTON1_DOWN_MASK = 0x0400;
166
167  /**
168   * The mouse button2 extended modifier.
169   *
170   * @since 1.4
171   */
172  public static final int BUTTON2_DOWN_MASK = 0x0800;
173
174  /**
175   * The mouse button3 extended modifier.
176   *
177   * @since 1.4
178   */
179  public static final int BUTTON3_DOWN_MASK = 0x1000;
180
181  /**
182   * The ALT_GRAPH key extended modifier.
183   *
184   * @since 1.4
185   */
186  public static final int ALT_GRAPH_DOWN_MASK = 0x2000;
187
188  /** The mask to convert new to old, package visible for use in subclasses. */
189  static final int CONVERT_MASK
190    = EventModifier.NEW_MASK & ~(BUTTON2_DOWN_MASK | BUTTON3_DOWN_MASK);
191
192  /**
193   * The timestamp when this event occurred.
194   *
195   * @see #getWhen()
196   * @serial the timestamp
197   */
198  private final long when;
199
200  /**
201   * The old-style modifiers in effect for this event. Package visible
202   * for use by subclasses. The old style (bitmask 0x3f) should not be
203   * mixed with the new style (bitmasks 0xffffffc0).
204   *
205   * @see #getModifiers()
206   * @see MouseEvent
207   * @serial the modifier state, stored in the old style
208   */
209  int modifiers;
210
211  /**
212   * The new-style modifiers in effect for this event. Package visible
213   * for use by subclasses. The old style (bitmask 0x3f) should not be
214   * mixed with the new style (bitmasks 0xffffffc0).
215   *
216   * @see #getModifiersEx()
217   * @see MouseEvent
218   * @serial the modifier state, stored in the new style
219   */
220  int modifiersEx;
221
222  /**
223   * Initializes a new instance of <code>InputEvent</code> with the specified
224   * source, id, timestamp, and modifiers. Note that an invalid id leads to
225   * unspecified results.
226   *
227   * @param source the source of the event
228   * @param id the event id
229   * @param when the timestamp when the event occurred
230   * @param modifiers the modifiers in effect for this event, old or new style
231   * @throws IllegalArgumentException if source is null
232   */
233  InputEvent(Component source, int id, long when, int modifiers)
234  {
235    super(source, id);
236    this.when = when;
237    this.modifiers = modifiers & EventModifier.OLD_MASK;
238    this.modifiersEx = modifiers & EventModifier.NEW_MASK;
239  }
240
241  /**
242   * This method tests whether or not the shift key was down during the event.
243   *
244   * @return true if the shift key is down
245   */
246  public boolean isShiftDown()
247  {
248    return ((modifiers & SHIFT_MASK) != 0)
249      || ((modifiersEx & SHIFT_DOWN_MASK) != 0);
250  }
251
252  /**
253   * This method tests whether or not the control key was down during the
254   * event.
255   *
256   * @return true if the control key is down
257   */
258  public boolean isControlDown()
259  {
260    return ((modifiers & CTRL_MASK) != 0)
261      || ((modifiersEx & CTRL_DOWN_MASK) != 0);
262  }
263
264  /**
265   * This method tests whether or not the meta key was down during the event.
266   *
267   * @return true if the meta key is down
268   */
269  public boolean isMetaDown()
270  {
271    return ((modifiers & META_MASK) != 0)
272      || ((modifiersEx & META_DOWN_MASK) != 0);
273  }
274
275  /**
276   * This method tests whether or not the alt key was down during the event.
277   *
278   * @return true if the alt key is down
279   */
280  public boolean isAltDown()
281  {
282    return ((modifiers & ALT_MASK) != 0)
283      || ((modifiersEx & ALT_DOWN_MASK) != 0);
284  }
285
286  /**
287   * This method tests whether or not the alt-graph modifier was in effect
288   * during the event.
289   *
290   * @return true if the alt-graph modifier is down
291   */
292  public boolean isAltGraphDown()
293  {
294    return ((modifiers & ALT_GRAPH_MASK) != 0)
295      || ((modifiersEx & ALT_GRAPH_DOWN_MASK) != 0);
296  }
297
298  /**
299   * This method returns the timestamp when this event occurred.
300   *
301   * @return the timestamp when this event occurred
302   */
303  public long getWhen()
304  {
305    return when;
306  }
307
308  /**
309   * This method returns the old-style modifiers in effect for this event. 
310   * Note that this is ambiguous between button2 and alt, and between
311   * button3 and meta. Also, code which generated these modifiers tends to
312   * only list the modifier that just changed, even if others were down at
313   * the time. Consider using getModifiersEx instead. This will be a union
314   * of the bit masks defined in this class that are applicable to the event.
315   *
316   * @return the modifiers in effect for this event
317   * @see #getModifiersEx()
318   */
319  public int getModifiers()
320  {
321    return modifiers;
322  }
323
324  /**
325   * Returns the extended modifiers (new-style) for this event. This represents
326   * the state of all modal keys and mouse buttons at the time of the event,
327   * and does not suffer from the problems mentioned in getModifiers.
328   *
329   * <p>For an example of checking multiple modifiers, this code will return
330   * true only if SHIFT and BUTTON1 were pressed and CTRL was not:
331   * <pre>
332   * int onmask = InputEvent.SHIFT_DOWN_MASK | InputEvent.BUTTON1_DOWN_MASK;
333   * int offmask = InputEvent.CTRL_DOWN_MASK;
334   * return (event.getModifiersEx() & (onmask | offmask)) == onmask;
335   * </pre>
336   *
337   * @return the bitwise or of all modifiers pressed during the event
338   * @since 1.4
339   */
340  public int getModifiersEx()
341  {
342    return modifiersEx;
343  }
344
345  /**
346   * Consumes this event.  A consumed event is not processed further by the AWT
347   * system.
348   */
349  public void consume()
350  {
351    consumed = true;
352  }
353
354  /**
355   * This method tests whether or not this event has been consumed.
356   *
357   * @return true if this event has been consumed
358   */
359  public boolean isConsumed()
360  {
361    return consumed;
362  }
363
364  /**
365   * Convert the extended modifier bitmask into a String, such as "Shift" or
366   * "Ctrl+Button1".
367   *
368   * XXX Sun claims this can be localized via the awt.properties file - how
369   * do we implement that?
370   *
371   * @param modifiers the modifiers
372   * @return a string representation of the modifiers in this bitmask
373   * @since 1.4
374   */
375  public static String getModifiersExText(int modifiers)
376  {
377    modifiers &= EventModifier.NEW_MASK;
378    if (modifiers == 0)
379      return "";
380    CPStringBuilder s = new CPStringBuilder();
381    if ((modifiers & META_DOWN_MASK) != 0)
382      s.append("Meta+");
383    if ((modifiers & CTRL_DOWN_MASK) != 0)
384      s.append("Ctrl+");
385    if ((modifiers & ALT_DOWN_MASK) != 0)
386      s.append("Alt+");
387    if ((modifiers & SHIFT_DOWN_MASK) != 0)
388      s.append("Shift+");
389    if ((modifiers & ALT_GRAPH_DOWN_MASK) != 0)
390      s.append("Alt Graph+");
391    if ((modifiers & BUTTON1_DOWN_MASK) != 0)
392      s.append("Button1+");
393    if ((modifiers & BUTTON2_DOWN_MASK) != 0)
394      s.append("Button2+");
395    if ((modifiers & BUTTON3_DOWN_MASK) != 0)
396      s.append("Button3+");
397    return s.substring(0, s.length() - 1);
398  }
399} // class InputEvent