libjava/java/awt/Menu.java

   1 /* Menu.java -- A Java AWT Menu
   2    Copyright (C) 1999, 2002, 2004 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 import java.util.Enumeration;
  45
  46 /**
  47   * This class represents a pull down or tear off menu in Java's AWT.
  48   *
  49   * @author Aaron M. Renn (arenn@urbanophile.com)
  50   */
  51 public class Menu extends MenuItem implements MenuContainer, Serializable
  52 {
  53
  54 /*
  55  * Static Variables
  56  */
  57
  58 // Serialization Constant
  59 private static final long serialVersionUID = -8809584163345499784L;
  60
  61 /*************************************************************************/
  62
  63 /*
  64  * Instance Variables
  65  */
  66
  67 /**
  68   * @serial The actual items in the menu
  69   */
  70 private Vector items = new Vector();
  71
  72 /**
  73   * @serial Flag indicating whether or not this menu is a tear off
  74   */
  75 private boolean isTearOff;
  76
  77 /**
  78   * @serial Indicates whether or not this is a help menu.
  79   */
  80 private boolean isHelpMenu;
  81
  82 // From the serialization spec.  FIXME: what should it be?
  83 private int menuSerializedDataVersion;
  84
  85 static final MenuItem separator = new MenuItem("-");
  86
  87 /*************************************************************************/
  88
  89 /*
  90  * Constructors
  91  */
  92
  93 /**
  94   * Initializes a new instance of <code>Menu</code> with no label and that
  95   * is not a tearoff;
  96   *
  97   * @exception HeadlessException If GraphicsEnvironment.isHeadless() is true.
  98   */
  99 public
 100 Menu()
 101 {
 102 }
 103
 104 /*************************************************************************/
 105
 106 /**
 107   * Initializes a new instance of <code>Menu</code> that is not a tearoff and
 108   * that has the specified label.
 109   *
 110   * @param label The menu label.
 111   *
 112   * @exception HeadlessException If GraphicsEnvironment.isHeadless() is true.
 113   */
 114 public
 115 Menu(String label)
 116 {
 117   this(label, false);
 118 }
 119
 120 /*************************************************************************/
 121
 122 /**
 123   * Initializes a new instance of <code>Menu</code> with the specified
 124   * label and tearoff status.
 125   *
 126   * @param label The label for this menu
 127   * @param isTearOff <code>true</code> if this menu is a tear off menu,
 128   * <code>false</code> otherwise.
 129   *
 130   * @exception HeadlessException If GraphicsEnvironment.isHeadless() is true.
 131   */
 132 public
 133 Menu(String label, boolean isTearOff)
 134 {
 135   super(label);
 136
 137   this.isTearOff = isTearOff;
 138
 139   if (label.equals("Help"))
 140     isHelpMenu = true;
 141
 142   if (GraphicsEnvironment.isHeadless())
 143     throw new HeadlessException ();
 144 }
 145
 146 /*************************************************************************/
 147
 148 /*
 149  * Instance Methods
 150  */
 151
 152 /**
 153   * Tests whether or not this menu is a tearoff.
 154   *
 155   * @return <code>true</code> if this menu is a tearoff, <code>false</code>
 156   * otherwise.
 157   */
 158 public boolean
 159 isTearOff()
 160 {
 161   return(isTearOff);
 162 }
 163
 164 /*************************************************************************/
 165
 166 /**
 167   * Returns the number of items in this menu.
 168   *
 169   * @return The number of items in this menu.
 170   */
 171 public int
 172 getItemCount()
 173 {
 174   return(items.size());
 175 }
 176
 177 /**
 178  * Returns the number of items in this menu.
 179  *
 180  * @return The number of items in this menu.
 181  *
 182  * @deprecated As of JDK 1.1, replaced by getItemCount().
 183  */
 184 public int countItems ()
 185 {
 186   return getItemCount ();
 187 }
 188
 189 /*************************************************************************/
 190
 191 /**
 192   * Returns the item at the specified index.
 193   *
 194   * @return The item at the specified index.
 195   *
 196   * @exception ArrayIndexOutOfBoundsException If the index value is not valid.
 197   */
 198 public MenuItem
 199 getItem(int index)
 200 {
 201   return((MenuItem)items.elementAt(index));
 202 }
 203
 204 /*************************************************************************/
 205
 206 /**
 207   * Adds the specified item to this menu.  If it was previously part of
 208   * another menu, it is first removed from that menu.
 209   *
 210   * @param item The new item to add.
 211   *
 212   * @return The item that was added.
 213   */
 214 public MenuItem
 215 add(MenuItem item)
 216 {
 217   items.addElement(item);
 218   if (item.parent != null)
 219     {
 220       item.parent.remove(item);
 221     }
 222   item.parent = this;
 223
 224   if (peer != null)
 225     {
 226       MenuPeer mp = (MenuPeer) peer;
 227       mp.addItem(item);
 228     }
 229
 230   return item;
 231 }
 232
 233 /*************************************************************************/
 234
 235 /**
 236   * Add an item with the specified label to this menu.
 237   *
 238   * @param label The label of the menu item to add.
 239   */
 240 public void
 241 add(String label)
 242 {
 243   add(new MenuItem(label));
 244 }
 245
 246 /*************************************************************************/
 247
 248 /**
 249   * Inserts the specified menu item into this menu at the specified index.
 250   *
 251   * @param item The menu item to add.
 252   * @param index The index of the menu item.
 253   *
 254   * XXX: FIXME
 255   *
 256   * @exception IllegalArgumentException If the index is less than zero.
 257   * @exception ArrayIndexOutOfBoundsException If the index is otherwise invalid.
 258   */
 259 public void
 260 insert(MenuItem item, int index)
 261 {
 262   if (index < 0)
 263     throw new IllegalArgumentException("Index is less than zero");
 264
 265   items.insertElementAt(item, index);
 266
 267   MenuPeer mp = (MenuPeer)getPeer();
 268   // FIXME: Need to add a peer method here.
 269 //    if (mp != null)
 270 //      mp.insertItem(item, index);
 271 }
 272
 273 /*************************************************************************/
 274
 275 /**
 276   * Inserts an item with the specified label into this menu at the specified index.
 277   *
 278   * @param label The label of the item to add.
 279   * @param index The index of the menu item.
 280   *
 281   * @exception IllegalArgumentException If the index is less than zero.
 282   * @exception ArrayIndexOutOfBoundsException If the index is otherwise invalid.
 283   */
 284 public void
 285 insert(String label, int index)
 286 {
 287   insert(new MenuItem(label), index);
 288 }
 289
 290 /*************************************************************************/
 291
 292 /**
 293   * Adds a separator bar at the current menu location.
 294   */
 295 public void
 296 addSeparator()
 297 {
 298   if (peer != null)
 299     ((MenuPeer) peer).addSeparator();
 300 }
 301
 302 /*************************************************************************/
 303
 304 /**
 305   * Inserts a separator bar at the specified index value.
 306   *
 307   * @param index The index at which to insert a separator bar.
 308   *
 309   * XXX: FIXME
 310   *
 311   * @exception IllegalArgumentException If the index is less than zero.
 312   * @exception ArrayIndexOutOfBoundsException If the index is otherwise invalid.
 313   */
 314 public void
 315 insertSeparator(int index)
 316 {
 317   insert(separator, index);
 318 }
 319
 320 /*************************************************************************/
 321
 322 /**
 323   * Deletes the item at the specified index from this menu.
 324   *
 325   * @param index The index of the item to remove.
 326   *
 327   * @exception ArrayIndexOutOfBoundsException If the index is otherwise invalid.
 328   */
 329 public synchronized void
 330 remove(int index)
 331 {
 332   items.removeElementAt(index);
 333
 334   MenuPeer mp = (MenuPeer)getPeer();
 335   if (mp != null)
 336     mp.delItem(index);
 337 }
 338
 339 /*************************************************************************/
 340
 341 /**
 342   * Removes the specifed item from the menu.  If the specified component
 343   * does not exist, this method does nothing. // FIXME: Right?
 344   *
 345   * @param item The component to remove.
 346   */
 347 public void
 348 remove(MenuComponent item)
 349 {
 350   int index = items.indexOf(item);
 351   if (index == -1)
 352     return;
 353
 354   remove(index);
 355 }
 356
 357 /*************************************************************************/
 358
 359 /**
 360   * Removes all the elements from this menu.
 361   */
 362 public synchronized void
 363 removeAll()
 364 {
 365   int count = getItemCount();
 366   for(int i = 0; i < count; i++)
 367     {
 368       // We must always remove item 0.
 369       remove(0);
 370     }
 371 }
 372
 373 /*************************************************************************/
 374
 375 /**
 376   * Creates the native peer for this object.
 377   */
 378 public void
 379 addNotify()
 380 {
 381   if (peer == null)
 382     peer = getToolkit().createMenu(this);
 383   Enumeration e = items.elements();
 384   while (e.hasMoreElements())
 385   {
 386     MenuItem mi = (MenuItem)e.nextElement();
 387     mi.addNotify();
 388   }
 389   super.addNotify ();
 390 }
 391
 392 /*************************************************************************/
 393
 394 /**
 395   * Destroys the native peer for this object.
 396   */
 397 public void
 398 removeNotify()
 399 {
 400   Enumeration e = items.elements();
 401   while (e.hasMoreElements())
 402   {
 403     MenuItem mi = (MenuItem) e.nextElement();
 404     mi.removeNotify();
 405   }
 406   super.removeNotify();
 407 }
 408
 409 /*************************************************************************/
 410
 411 /**
 412   * Returns a debugging string for this menu.
 413   *
 414   * @return A debugging string for this menu.
 415   */
 416 public String
 417 paramString()
 418 {
 419   return (",isTearOff=" + isTearOff + ",isHelpMenu=" + isHelpMenu
 420           + super.paramString());
 421 }
 422
 423 // Accessibility API not yet implemented.
 424 // public AccessibleContext getAccessibleContext()
 425
 426 } // class Menu