libjava/java/awt/Menu.java

   1 /* Menu.java -- A Java AWT Menu
   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;
  40
  41 import java.awt.peer.MenuPeer;
  42 import java.io.Serializable;
  43 import java.util.Vector;
  44
  45 /**
  46   * This class represents a pull down or tear off menu in Java's AWT.
  47   *
  48   * @author Aaron M. Renn (arenn@urbanophile.com)
  49   */
  50 public class Menu extends MenuItem implements MenuContainer, Serializable
  51 {
  52
  53 /*
  54  * Static Variables
  55  */
  56
  57 // Serialization Constant
  58 private static final long serialVersionUID = -8809584163345499784L;
  59
  60 /*************************************************************************/
  61
  62 /*
  63  * Instance Variables
  64  */
  65
  66 /**
  67   * @serial The actual items in the menu
  68   */
  69 private Vector items = new Vector();
  70
  71 /**
  72   * @serial Flag indicating whether or not this menu is a tear off
  73   */
  74 private boolean isTearOff;
  75
  76 /**
  77   * @serial Indicates whether or not this is a help menu.
  78   */
  79 private boolean isHelpMenu;
  80
  81 // From the serialization spec.  FIXME: what should it be?
  82 private int menuSerializedDataVersion;
  83
  84 static final MenuItem separator = new MenuItem("-");
  85
  86 /*************************************************************************/
  87
  88 /*
  89  * Constructors
  90  */
  91
  92 /**
  93   * Initializes a new instance of <code>Menu</code> with no label and that
  94   * is not a tearoff;
  95   *
  96   * @exception HeadlessException If GraphicsEnvironment.isHeadless() is true.
  97   */
  98 public
  99 Menu()
 100 {
 101 }
 102
 103 /*************************************************************************/
 104
 105 /**
 106   * Initializes a new instance of <code>Menu</code> that is not a tearoff and
 107   * that has the specified label.
 108   *
 109   * @param label The menu label.
 110   *
 111   * @exception HeadlessException If GraphicsEnvironment.isHeadless() is true.
 112   */
 113 public
 114 Menu(String label)
 115 {
 116   this(label, false);
 117 }
 118
 119 /*************************************************************************/
 120
 121 /**
 122   * Initializes a new instance of <code>Menu</code> with the specified
 123   * label and tearoff status.
 124   *
 125   * @param label The label for this menu
 126   * @param isTearOff <code>true</code> if this menu is a tear off menu,
 127   * <code>false</code> otherwise.
 128   *
 129   * @exception HeadlessException If GraphicsEnvironment.isHeadless() is true.
 130   */
 131 public
 132 Menu(String label, boolean isTearOff)
 133 {
 134   super(label);
 135
 136   this.isTearOff = isTearOff;
 137
 138   if (label.equals("Help"))
 139     isHelpMenu = true;
 140
 141   if (GraphicsEnvironment.isHeadless())
 142     throw new HeadlessException ();
 143 }
 144
 145 /*************************************************************************/
 146
 147 /*
 148  * Instance Methods
 149  */
 150
 151 /**
 152   * Tests whether or not this menu is a tearoff.
 153   *
 154   * @return <code>true</code> if this menu is a tearoff, <code>false</code>
 155   * otherwise.
 156   */
 157 public boolean
 158 isTearOff()
 159 {
 160   return(isTearOff);
 161 }
 162
 163 /*************************************************************************/
 164
 165 /**
 166   * Returns the number of items in this menu.
 167   *
 168   * @return The number of items in this menu.
 169   */
 170 public int
 171 getItemCount()
 172 {
 173   return(items.size());
 174 }
 175
 176 /**
 177  * Returns the number of items in this menu.
 178  *
 179  * @return The number of items in this menu.
 180  *
 181  * @deprecated As of JDK 1.1, replaced by getItemCount().
 182  */
 183 public int countItems ()
 184 {
 185   return getItemCount ();
 186 }
 187
 188 /*************************************************************************/
 189
 190 /**
 191   * Returns the item at the specified index.
 192   *
 193   * @return The item at the specified index.
 194   *
 195   * @exception ArrayIndexOutOfBoundsException If the index value is not valid.
 196   */
 197 public MenuItem
 198 getItem(int index)
 199 {
 200   return((MenuItem)items.elementAt(index));
 201 }
 202
 203 /*************************************************************************/
 204
 205 /**
 206   * Adds the specified item to this menu.  If it was previously part of
 207   * another menu, it is first removed from that menu.
 208   *
 209   * @param item The new item to add.
 210   *
 211   * @return The item that was added.
 212   */
 213 public MenuItem
 214 add(MenuItem item)
 215 {
 216   items.addElement(item);
 217   if (item.parent != null)
 218     {
 219       item.parent.remove(item);
 220     }
 221   item.parent = this;
 222
 223   if (peer != null)
 224     {
 225       MenuPeer mp = (MenuPeer) peer;
 226       mp.addItem(item);
 227     }
 228
 229   return item;
 230 }
 231
 232 /*************************************************************************/
 233
 234 /**
 235   * Add an item with the specified label to this menu.
 236   *
 237   * @param label The label of the menu item to add.
 238   */
 239 public void
 240 add(String label)
 241 {
 242   add(new MenuItem(label));
 243 }
 244
 245 /*************************************************************************/
 246
 247 /**
 248   * Inserts the specified menu item into this menu at the specified index.
 249   *
 250   * @param item The menu item to add.
 251   * @param index The index of the menu item.
 252   *
 253   * XXX: FIXME
 254   *
 255   * @exception IllegalArgumentException If the index is less than zero.
 256   * @exception ArrayIndexOutOfBoundsException If the index is otherwise invalid.
 257   */
 258 public void
 259 insert(MenuItem item, int index)
 260 {
 261   if (index < 0)
 262     throw new IllegalArgumentException("Index is less than zero");
 263
 264   items.insertElementAt(item, index);
 265
 266   MenuPeer mp = (MenuPeer)getPeer();
 267   // FIXME: Need to add a peer method here.
 268 //    if (mp != null)
 269 //      mp.insertItem(item, index);
 270 }
 271
 272 /*************************************************************************/
 273
 274 /**
 275   * Inserts an item with the specified label into this menu at the specified index.
 276   *
 277   * @param label The label of the item to add.
 278   * @param index The index of the menu item.
 279   *
 280   * @exception IllegalArgumentException If the index is less than zero.
 281   * @exception ArrayIndexOutOfBoundsException If the index is otherwise invalid.
 282   */
 283 public void
 284 insert(String label, int index)
 285 {
 286   insert(new MenuItem(label), index);
 287 }
 288
 289 /*************************************************************************/
 290
 291 /**
 292   * Adds a separator bar at the current menu location.
 293   */
 294 public void
 295 addSeparator()
 296 {
 297   add(separator);
 298 }
 299
 300 /*************************************************************************/
 301
 302 /**
 303   * Inserts a separator bar at the specified index value.
 304   *
 305   * @param index The index at which to insert a separator bar.
 306   *
 307   * XXX: FIXME
 308   *
 309   * @exception IllegalArgumentException If the index is less than zero.
 310   * @exception ArrayIndexOutOfBoundsException If the index is otherwise invalid.
 311   */
 312 public void
 313 insertSeparator(int index)
 314 {
 315   insert(separator, index);
 316 }
 317
 318 /*************************************************************************/
 319
 320 /**
 321   * Deletes the item at the specified index from this menu.
 322   *
 323   * @param index The index of the item to remove.
 324   *
 325   * @exception ArrayIndexOutOfBoundsException If the index is otherwise invalid.
 326   */
 327 public synchronized void
 328 remove(int index)
 329 {
 330   items.removeElementAt(index);
 331
 332   MenuPeer mp = (MenuPeer)getPeer();
 333   if (mp != null)
 334     mp.delItem(index);
 335 }
 336
 337 /*************************************************************************/
 338
 339 /**
 340   * Removes the specifed item from the menu.  If the specified component
 341   * does not exist, this method does nothing. // FIXME: Right?
 342   *
 343   * @param item The component to remove.
 344   */
 345 public void
 346 remove(MenuComponent item)
 347 {
 348   int index = items.indexOf(item);
 349   if (index == -1)
 350     return;
 351
 352   remove(index);
 353 }
 354
 355 /*************************************************************************/
 356
 357 /**
 358   * Removes all the elements from this menu.
 359   */
 360 public synchronized void
 361 removeAll()
 362 {
 363   int count = getItemCount();
 364   for(int i = 0; i < count; i++)
 365     {
 366       // We must always remove item 0.
 367       remove(0);
 368     }
 369 }
 370
 371 /*************************************************************************/
 372
 373 /**
 374   * Creates the native peer for this object.
 375   */
 376 public void
 377 addNotify()
 378 {
 379   if (peer != null)
 380     peer = getToolkit().createMenu(this);
 381   super.addNotify ();
 382 }
 383
 384 /*************************************************************************/
 385
 386 /**
 387   * Destroys the native peer for this object.
 388   */
 389 public void
 390 removeNotify()
 391 {
 392   super.removeNotify();
 393 }
 394
 395 /*************************************************************************/
 396
 397 /**
 398   * Returns a debugging string for this menu.
 399   *
 400   * @return A debugging string for this menu.
 401   */
 402 public String
 403 paramString()
 404 {
 405   return (",isTearOff=" + isTearOff + ",isHelpMenu=" + isHelpMenu
 406           + super.paramString());
 407 }
 408
 409 // Accessibility API not yet implemented.
 410 // public AccessibleContext getAccessibleContext()
 411
 412 } // class Menu