libjava/java/awt/MenuComponent.java

   1 /* MenuComponent.java -- Superclass of all AWT menu components
   2    Copyright (C) 1999, 2000, 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;
  40
  41 import java.awt.peer.MenuComponentPeer;
  42
  43 // FIXME: Java 1.0 event model unimplemented
  44
  45 /**
  46   * This is the superclass of all non-menu AWT widgets.
  47   *
  48   * @author Aaron M. Renn (arenn@urbanophile.com)
  49   */
  50 public abstract class MenuComponent implements java.io.Serializable
  51 {
  52
  53 /*
  54  * Static Variables
  55  */
  56
  57 // Serialization Constant
  58 private static final long serialVersionUID = -4536902356223894379L;
  59
  60 /*************************************************************************/
  61
  62 /*
  63  * Instance Variables
  64  */
  65
  66   // FIXME: missing serialized fields `nameExplicitlySet',
  67   // `newEventsOnly', and `accessibleContext'.
  68
  69 // The font for this component
  70 private Font font;
  71
  72 // The name of the component
  73 private String name;
  74
  75 // The parent of this component
  76 transient MenuContainer parent;
  77
  78 // The native peer for this componet
  79 transient MenuComponentPeer peer;
  80
  81 // The synchronization locking object for this component
  82 private transient Object tree_lock = this;
  83
  84 // The toolkit for this object
  85 private static transient Toolkit toolkit = Toolkit.getDefaultToolkit();
  86
  87 /*************************************************************************/
  88
  89 /*
  90  * Constructors
  91  */
  92
  93 /**
  94   * Default constructor for subclasses.
  95   *
  96   * @exception HeadlessException If GraphicsEnvironment.isHeadless() is true.
  97   */
  98 public
  99 MenuComponent()
 100 {
 101   if (GraphicsEnvironment.isHeadless())
 102     throw new HeadlessException ();
 103 }
 104
 105 /*************************************************************************/
 106
 107 /*
 108  * Instance Methods
 109  */
 110
 111 /**
 112   * Returns the font in use for this component.
 113   *
 114   * @return The font for this component.
 115   */
 116 public Font
 117 getFont()
 118 {
 119   return(font);
 120 }
 121
 122 /*************************************************************************/
 123
 124 /**
 125   * Sets the font for this component to the specified font.
 126   *
 127   * @param font The new font for this component.
 128   */
 129 public void
 130 setFont(Font font)
 131 {
 132   this.font = font;
 133 }
 134
 135 /*************************************************************************/
 136
 137 /**
 138   * Returns the name of this component.
 139   *
 140   * @return The name of this component.
 141   */
 142 public String
 143 getName()
 144 {
 145   return(name);
 146 }
 147
 148 /*************************************************************************/
 149
 150 /**
 151   * Sets the name of this component to the specified name.
 152   *
 153   * @param name The new name of this component.
 154   */
 155 public void
 156 setName(String name)
 157 {
 158   this.name = name;
 159 }
 160
 161 /*************************************************************************/
 162
 163 /**
 164   * Returns the parent of this component.
 165   *
 166   * @return The parent of this component.
 167   */
 168 public MenuContainer
 169 getParent()
 170 {
 171   return(parent);
 172 }
 173
 174 /*************************************************************************/
 175
 176 // Sets the parent of this component.
 177 final void
 178 setParent(MenuContainer parent)
 179 {
 180   this.parent = parent;
 181 }
 182
 183 /*************************************************************************/
 184
 185 /**
 186   * Returns the native windowing system peer for this component.
 187   *
 188   * @return The peer for this component.
 189   */
 190 public MenuComponentPeer
 191 getPeer()
 192 {
 193   return(peer);
 194 }
 195
 196 /*************************************************************************/
 197
 198 // Sets the peer for this component.
 199 final void
 200 setPeer(MenuComponentPeer peer)
 201 {
 202   this.peer = peer;
 203 }
 204
 205 /*************************************************************************/
 206
 207 /**
 208   * Destroys this component's native peer
 209   */
 210 public void
 211 removeNotify()
 212 {
 213   if (peer != null)
 214     peer.dispose();
 215   peer = null;
 216 }
 217
 218 /*************************************************************************/
 219
 220 /**
 221   * Returns the toolkit in use for this component.
 222   *
 223   * @return The toolkit for this component.
 224   */
 225 final Toolkit
 226 getToolkit()
 227 {
 228   return(toolkit);
 229 }
 230
 231 /*************************************************************************/
 232
 233 /**
 234   * Returns the object used for synchronization locks on this component
 235   * when performing tree and layout functions.
 236   *
 237   * @return The synchronization lock for this component.
 238   */
 239 protected final Object
 240 getTreeLock()
 241 {
 242   return(tree_lock);
 243 }
 244
 245 /*************************************************************************/
 246
 247 // The sync lock object for this component.
 248 final void
 249 setTreeLock(Object tree_lock)
 250 {
 251   this.tree_lock = tree_lock;
 252 }
 253
 254 /*************************************************************************/
 255
 256 /**
 257   * AWT 1.0 event dispatcher.
 258   *
 259   * @deprecated Deprecated in favor of <code>dispatchEvent()</code>.
 260   */
 261 public boolean
 262 postEvent(Event event)
 263 {
 264   return(false);
 265 }
 266
 267 /*************************************************************************/
 268
 269 /**
 270   * Sends this event to this component or a subcomponent for processing.
 271   *
 272   * @param event The event to dispatch
 273   */
 274 public final void
 275 dispatchEvent(AWTEvent event)
 276 {
 277   // See comment in Component.dispatchEvent().
 278   dispatchEventImpl(event);
 279 }
 280
 281 void
 282 dispatchEventImpl(AWTEvent e)
 283 {
 284   // This is overridden by subclasses that support events.
 285 }
 286
 287 /*************************************************************************/
 288
 289 /**
 290   * Processes the specified event.  In this class, this method simply
 291   * calls one of the more specific event handlers.
 292   *
 293   * @param event The event to process.
 294   */
 295 protected void
 296 processEvent(AWTEvent event)
 297 {
 298 }
 299
 300 /*************************************************************************/
 301
 302 /**
 303   * Returns a string representation of this component.
 304   *
 305   * @return A string representation of this component
 306   */
 307 public String
 308 toString()
 309 {
 310   return this.getClass().getName() + "[" + paramString() + "]";
 311 }
 312
 313 /*************************************************************************/
 314
 315 /**
 316   * Returns a debugging string for this component
 317   */
 318 protected String
 319 paramString()
 320 {
 321   return "name=" + getName();
 322 }
 323
 324 // Accessibility API not yet implemented.
 325 // public AccessibleContext getAccessibleContext()
 326
 327 } // class Component