libjava/java/awt/event/InputEvent.java

   1 /* InputEvent.java -- common superclass of component input events
   2    Copyright (C) 1999, 2002 Free Software Foundation, Inc.
   3
   4 This file is part of GNU Classpath.
   5
   6 GNU Classpath is free software; you can redistribute it and/or modify
   7 it under the terms of the GNU General Public License as published by
   8 the Free Software Foundation; either version 2, or (at your option)
   9 any later version.
  10
  11 GNU Classpath is distributed in the hope that it will be useful, but
  12 WITHOUT ANY WARRANTY; without even the implied warranty of
  13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14 General Public License for more details.
  15
  16 You should have received a copy of the GNU General Public License
  17 along with GNU Classpath; see the file COPYING.  If not, write to the
  18 Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  19 02111-1307 USA.
  20
  21 Linking this library statically or dynamically with other modules is
  22 making a combined work based on this library.  Thus, the terms and
  23 conditions of the GNU General Public License cover the whole
  24 combination.
  25
  26 As a special exception, the copyright holders of this library give you
  27 permission to link this library with independent modules to produce an
  28 executable, regardless of the license terms of these independent
  29 modules, and to copy and distribute the resulting executable under
  30 terms of your choice, provided that you also meet, for each linked
  31 independent module, the terms and conditions of the license of that
  32 module.  An independent module is a module which is not derived from
  33 or based on this library.  If you modify this library, you may extend
  34 this exception to your version of the library, but you are not
  35 obligated to do so.  If you do not wish to do so, delete this
  36 exception statement from your version. */
  37
  38
  39 package java.awt.event;
  40
  41 import java.awt.Component;
  42 import gnu.java.awt.EventModifier;
  43
  44 /**
  45  * This is the common superclass for all component input classes. These are
  46  * passed to listeners before the component, so that listeners can consume
  47  * the event before it does its default behavior.
  48  *
  49  * @author Aaron M. Renn <arenn@urbanophile.com>
  50  * @see KeyEvent
  51  * @see KeyAdapter
  52  * @see MouseEvent
  53  * @see MouseAdapter
  54  * @see MouseMotionAdapter
  55  * @see MouseWheelEvent
  56  * @since 1.1
  57  * @status updated to 1.4
  58  */
  59 public abstract class InputEvent extends ComponentEvent
  60 {
  61   /**
  62    * Compatible with JDK 1.1+.
  63    */
  64   private static final long serialVersionUID = -2482525981698309786L;
  65
  66   /**
  67    * This is the bit mask which indicates the shift key is down. It is
  68    * recommended that SHIFT_DOWN_MASK be used instead.
  69    *
  70    * @see #SHIFT_DOWN_MASK
  71    */
  72   public static final int SHIFT_MASK = 1;
  73
  74   /**
  75    * This is the bit mask which indicates the control key is down. It is
  76    * recommended that CTRL_DOWN_MASK be used instead.
  77    *
  78    * @see #CTRL_DOWN_MASK
  79    */
  80   public static final int CTRL_MASK = 2;
  81
  82   /**
  83    * This is the bit mask which indicates the meta key is down. It is
  84    * recommended that META_DOWN_MASK be used instead.
  85    *
  86    * @see #META_DOWN_MASK
  87    */
  88   public static final int META_MASK = 4;
  89
  90   /**
  91    * This is the bit mask which indicates the alt key is down. It is
  92    * recommended that ALT_DOWN_MASK be used instead.
  93    *
  94    * @see #ALT_DOWN_MASK
  95    */
  96   public static final int ALT_MASK = 8;
  97
  98   /**
  99    * This is the bit mask which indicates the alt-graph modifier is in effect.
 100    * It is recommended that ALT_GRAPH_DOWN_MASK be used instead.
 101    *
 102    * @see #ALT_GRAPH_DOWN_MASK
 103    */
 104   public static final int ALT_GRAPH_MASK = 0x20;
 105
 106   /**
 107    * This bit mask indicates mouse button one is down. It is recommended that
 108    * BUTTON1_DOWN_MASK be used instead.
 109    *
 110    * @see #BUTTON1_DOWN_MASK
 111    */
 112   public static final int BUTTON1_MASK = 0x10;
 113
 114   /**
 115    * This bit mask indicates mouse button two is down. It is recommended that
 116    * BUTTON2_DOWN_MASK be used instead.
 117    *
 118    * @see #BUTTON2_DOWN_MASK
 119    */
 120   public static final int BUTTON2_MASK = 8;
 121
 122   /**
 123    * This bit mask indicates mouse button three is down. It is recommended
 124    * that BUTTON3_DOWN_MASK be used instead.
 125    *
 126    * @see #BUTTON3_DOWN_MASK
 127    */
 128   public static final int BUTTON3_MASK = 4;
 129
 130   /**
 131    * The SHIFT key extended modifier.
 132    *
 133    * @since 1.4
 134    */
 135   public static final int SHIFT_DOWN_MASK = 0x0040;
 136
 137   /**
 138    * The CTRL key extended modifier.
 139    *
 140    * @since 1.4
 141    */
 142   public static final int CTRL_DOWN_MASK = 0x0080;
 143
 144   /**
 145    * The META key extended modifier.
 146    *
 147    * @since 1.4
 148    */
 149   public static final int META_DOWN_MASK = 0x0100;
 150
 151   /**
 152    * The ALT key extended modifier.
 153    *
 154    * @since 1.4
 155    */
 156   public static final int ALT_DOWN_MASK = 0x0200;
 157
 158   /**
 159    * The mouse button1 key extended modifier.
 160    *
 161    * @since 1.4
 162    */
 163   public static final int BUTTON1_DOWN_MASK = 0x0400;
 164
 165   /**
 166    * The mouse button2 extended modifier.
 167    *
 168    * @since 1.4
 169    */
 170   public static final int BUTTON2_DOWN_MASK = 0x0800;
 171
 172   /**
 173    * The mouse button3 extended modifier.
 174    *
 175    * @since 1.4
 176    */
 177   public static final int BUTTON3_DOWN_MASK = 0x1000;
 178
 179   /**
 180    * The ALT_GRAPH key extended modifier.
 181    *
 182    * @since 1.4
 183    */
 184   public static final int ALT_GRAPH_DOWN_MASK = 0x2000;
 185
 186   /** The mask to convert new to old, package visible for use in subclasses. */
 187   static final int CONVERT_MASK
 188     = EventModifier.NEW_MASK & ~(BUTTON2_DOWN_MASK | BUTTON3_DOWN_MASK);
 189
 190   /**
 191    * The timestamp when this event occurred.
 192    *
 193    * @see #getWhen()
 194    * @serial the timestamp
 195    */
 196   private final long when;
 197
 198   /**
 199    * The modifiers in effect for this event. Package visible for use by
 200    * subclasses. The old style (bitmask 0x3f) should not be mixed with the
 201    * new style (bitmasks 0xffffffc0).
 202    *
 203    * @see #getModifiers()
 204    * @see MouseEvent
 205    * @serial the modifier state, stored in the new style
 206    */
 207   int modifiers;
 208
 209   /**
 210    * Initializes a new instance of <code>InputEvent</code> with the specified
 211    * source, id, timestamp, and modifiers. Note that an invalid id leads to
 212    * unspecified results.
 213    *
 214    * @param source the source of the event
 215    * @param id the event id
 216    * @param when the timestamp when the event occurred
 217    * @param modifiers the modifiers in effect for this event, old or new style
 218    * @throws IllegalArgumentException if source is null
 219    */
 220   InputEvent(Component source, int id, long when, int modifiers)
 221   {
 222     super(source, id);
 223     this.when = when;
 224     this.modifiers = EventModifier.extend(modifiers);
 225   }
 226
 227   /**
 228    * This method tests whether or not the shift key was down during the event.
 229    *
 230    * @return true if the shift key is down
 231    */
 232   public boolean isShiftDown()
 233   {
 234     return (modifiers & SHIFT_DOWN_MASK) != 0;
 235   }
 236
 237   /**
 238    * This method tests whether or not the control key was down during the
 239    * event.
 240    *
 241    * @return true if the control key is down
 242    */
 243   public boolean isControlDown()
 244   {
 245     return (modifiers & CTRL_DOWN_MASK) != 0;
 246   }
 247
 248   /**
 249    * This method tests whether or not the meta key was down during the event.
 250    *
 251    * @return true if the meta key is down
 252    */
 253   public boolean isMetaDown()
 254   {
 255     return (modifiers & META_DOWN_MASK) != 0;
 256   }
 257
 258   /**
 259    * This method tests whether or not the alt key was down during the event.
 260    *
 261    * @return true if the alt key is down
 262    */
 263   public boolean isAltDown()
 264   {
 265     return (modifiers & ALT_DOWN_MASK) != 0;
 266   }
 267
 268   /**
 269    * This method tests whether or not the alt-graph modifier was in effect
 270    * during the event.
 271    *
 272    * @return true if the alt-graph modifier is down
 273    */
 274   public boolean isAltGraphDown()
 275   {
 276     return (modifiers & ALT_GRAPH_DOWN_MASK) != 0;
 277   }
 278
 279   /**
 280    * This method returns the timestamp when this event occurred.
 281    *
 282    * @return the timestamp when this event occurred
 283    */
 284   public long getWhen()
 285   {
 286     return when;
 287   }
 288
 289   /**
 290    * This method returns the old-style modifiers in effect for this event.
 291    * Note that this is ambiguous between button2 and alt, and between
 292    * button3 and meta. Also, code which generated these modifiers tends to
 293    * only list the modifier that just changed, even if others were down at
 294    * the time. Consider using getModifiersEx instead. This will be a union
 295    * of the bit masks defined in this class that are applicable to the event.
 296    *
 297    * @return the modifiers in effect for this event
 298    * @see #getModifiersEx()
 299    */
 300   public int getModifiers()
 301   {
 302     return EventModifier.revert(modifiers);
 303   }
 304
 305   /**
 306    * Returns the extended modifiers (new-style) for this event. This represents
 307    * the state of all modal keys and mouse buttons at the time of the event,
 308    * and does not suffer from the problems mentioned in getModifiers.
 309    *
 310    * <p>For an example of checking multiple modifiers, this code will return
 311    * true only if SHIFT and BUTTON1 were pressed and CTRL was not:
 312    * <pre>
 313    * int onmask = InputEvent.SHIFT_DOWN_MASK | InputEvent.BUTTON1_DOWN_MASK;
 314    * int offmask = InputEvent.CTRL_DOWN_MASK;
 315    * return (event.getModifiersEx() & (onmask | offmask)) == onmask;
 316    * </pre>
 317    *
 318    * @return the bitwise or of all modifiers pressed during the event
 319    * @since 1.4
 320    */
 321   public int getModifiersEx()
 322   {
 323     return modifiers;
 324   }
 325
 326   /**
 327    * Consumes this event.  A consumed event is not processed further by the AWT
 328    * system.
 329    */
 330   public void consume()
 331   {
 332     consumed = true;
 333   }
 334
 335   /**
 336    * This method tests whether or not this event has been consumed.
 337    *
 338    * @return true if this event has been consumed
 339    */
 340   public boolean isConsumed()
 341   {
 342     return consumed;
 343   }
 344
 345   /**
 346    * Convert the extended modifier bitmask into a String, such as "Shift" or
 347    * "Ctrl+Button1".
 348    *
 349    * XXX Sun claims this can be localized via the awt.properties file - how
 350    * do we implement that?
 351    *
 352    * @return a string representation of the modifiers in this bitmask
 353    * @since 1.4
 354    */
 355   public static String getModifiersExText(int modifiers)
 356   {
 357     modifiers &= EventModifier.NEW_MASK;
 358     if (modifiers == 0)
 359       return "";
 360     StringBuffer s = new StringBuffer();
 361     if ((modifiers & META_DOWN_MASK) != 0)
 362       s.append("Meta+");
 363     if ((modifiers & CTRL_DOWN_MASK) != 0)
 364       s.append("Ctrl+");
 365     if ((modifiers & ALT_DOWN_MASK) != 0)
 366       s.append("Alt+");
 367     if ((modifiers & SHIFT_DOWN_MASK) != 0)
 368       s.append("Shift+");
 369     if ((modifiers & ALT_GRAPH_DOWN_MASK) != 0)
 370       s.append("Alt Graph+");
 371     if ((modifiers & BUTTON1_DOWN_MASK) != 0)
 372       s.append("Button1+");
 373     if ((modifiers & BUTTON2_DOWN_MASK) != 0)
 374       s.append("Button2+");
 375     if ((modifiers & BUTTON3_DOWN_MASK) != 0)
 376       s.append("Button3+");
 377     return s.substring(0, s.length() - 1);
 378   }
 379 } // class InputEvent