J. Duke | 319a3b9 | 2007-12-01 00:00:00 +0000 | [diff] [blame^] | 1 | /* |
| 2 | * Copyright 1995-2006 Sun Microsystems, Inc. All Rights Reserved. |
| 3 | * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| 4 | * |
| 5 | * This code is free software; you can redistribute it and/or modify it |
| 6 | * under the terms of the GNU General Public License version 2 only, as |
| 7 | * published by the Free Software Foundation. Sun designates this |
| 8 | * particular file as subject to the "Classpath" exception as provided |
| 9 | * by Sun in the LICENSE file that accompanied this code. |
| 10 | * |
| 11 | * This code is distributed in the hope that it will be useful, but WITHOUT |
| 12 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| 13 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| 14 | * version 2 for more details (a copy is included in the LICENSE file that |
| 15 | * accompanied this code). |
| 16 | * |
| 17 | * You should have received a copy of the GNU General Public License version |
| 18 | * 2 along with this work; if not, write to the Free Software Foundation, |
| 19 | * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| 20 | * |
| 21 | * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, |
| 22 | * CA 95054 USA or visit www.sun.com if you need additional information or |
| 23 | * have any questions. |
| 24 | */ |
| 25 | package java.awt; |
| 26 | |
| 27 | import java.io.IOException; |
| 28 | import java.io.ObjectInputStream; |
| 29 | import java.util.Vector; |
| 30 | import java.util.Enumeration; |
| 31 | import java.awt.peer.MenuBarPeer; |
| 32 | import java.awt.event.KeyEvent; |
| 33 | import javax.accessibility.*; |
| 34 | |
| 35 | /** |
| 36 | * The <code>MenuBar</code> class encapsulates the platform's |
| 37 | * concept of a menu bar bound to a frame. In order to associate |
| 38 | * the menu bar with a <code>Frame</code> object, call the |
| 39 | * frame's <code>setMenuBar</code> method. |
| 40 | * <p> |
| 41 | * <A NAME="mbexample"></A><!-- target for cross references --> |
| 42 | * This is what a menu bar might look like: |
| 43 | * <p> |
| 44 | * <img src="doc-files/MenuBar-1.gif" |
| 45 | * <alt="Diagram of MenuBar containing 2 menus: Examples and Options. |
| 46 | * Examples menu is expanded showing items: Basic, Simple, Check, and More Examples." |
| 47 | * ALIGN=center HSPACE=10 VSPACE=7> |
| 48 | * <p> |
| 49 | * A menu bar handles keyboard shortcuts for menu items, passing them |
| 50 | * along to its child menus. |
| 51 | * (Keyboard shortcuts, which are optional, provide the user with |
| 52 | * an alternative to the mouse for invoking a menu item and the |
| 53 | * action that is associated with it.) |
| 54 | * Each menu item can maintain an instance of <code>MenuShortcut</code>. |
| 55 | * The <code>MenuBar</code> class defines several methods, |
| 56 | * {@link MenuBar#shortcuts} and |
| 57 | * {@link MenuBar#getShortcutMenuItem} |
| 58 | * that retrieve information about the shortcuts a given |
| 59 | * menu bar is managing. |
| 60 | * |
| 61 | * @author Sami Shaio |
| 62 | * @see java.awt.Frame |
| 63 | * @see java.awt.Frame#setMenuBar(java.awt.MenuBar) |
| 64 | * @see java.awt.Menu |
| 65 | * @see java.awt.MenuItem |
| 66 | * @see java.awt.MenuShortcut |
| 67 | * @since JDK1.0 |
| 68 | */ |
| 69 | public class MenuBar extends MenuComponent implements MenuContainer, Accessible { |
| 70 | |
| 71 | static { |
| 72 | /* ensure that the necessary native libraries are loaded */ |
| 73 | Toolkit.loadLibraries(); |
| 74 | if (!GraphicsEnvironment.isHeadless()) { |
| 75 | initIDs(); |
| 76 | } |
| 77 | } |
| 78 | |
| 79 | /** |
| 80 | * This field represents a vector of the |
| 81 | * actual menus that will be part of the MenuBar. |
| 82 | * |
| 83 | * @serial |
| 84 | * @see #countMenus() |
| 85 | */ |
| 86 | Vector menus = new Vector(); |
| 87 | |
| 88 | /** |
| 89 | * This menu is a special menu dedicated to |
| 90 | * help. The one thing to note about this menu |
| 91 | * is that on some platforms it appears at the |
| 92 | * right edge of the menubar. |
| 93 | * |
| 94 | * @serial |
| 95 | * @see #getHelpMenu() |
| 96 | * @see #setHelpMenu(Menu) |
| 97 | */ |
| 98 | Menu helpMenu; |
| 99 | |
| 100 | private static final String base = "menubar"; |
| 101 | private static int nameCounter = 0; |
| 102 | |
| 103 | /* |
| 104 | * JDK 1.1 serialVersionUID |
| 105 | */ |
| 106 | private static final long serialVersionUID = -4930327919388951260L; |
| 107 | |
| 108 | /** |
| 109 | * Creates a new menu bar. |
| 110 | * @exception HeadlessException if GraphicsEnvironment.isHeadless() |
| 111 | * returns true. |
| 112 | * @see java.awt.GraphicsEnvironment#isHeadless |
| 113 | */ |
| 114 | public MenuBar() throws HeadlessException { |
| 115 | } |
| 116 | |
| 117 | /** |
| 118 | * Construct a name for this MenuComponent. Called by getName() when |
| 119 | * the name is null. |
| 120 | */ |
| 121 | String constructComponentName() { |
| 122 | synchronized (MenuBar.class) { |
| 123 | return base + nameCounter++; |
| 124 | } |
| 125 | } |
| 126 | |
| 127 | /** |
| 128 | * Creates the menu bar's peer. The peer allows us to change the |
| 129 | * appearance of the menu bar without changing any of the menu bar's |
| 130 | * functionality. |
| 131 | */ |
| 132 | public void addNotify() { |
| 133 | synchronized (getTreeLock()) { |
| 134 | if (peer == null) |
| 135 | peer = Toolkit.getDefaultToolkit().createMenuBar(this); |
| 136 | |
| 137 | int nmenus = getMenuCount(); |
| 138 | for (int i = 0 ; i < nmenus ; i++) { |
| 139 | getMenu(i).addNotify(); |
| 140 | } |
| 141 | } |
| 142 | } |
| 143 | |
| 144 | /** |
| 145 | * Removes the menu bar's peer. The peer allows us to change the |
| 146 | * appearance of the menu bar without changing any of the menu bar's |
| 147 | * functionality. |
| 148 | */ |
| 149 | public void removeNotify() { |
| 150 | synchronized (getTreeLock()) { |
| 151 | int nmenus = getMenuCount(); |
| 152 | for (int i = 0 ; i < nmenus ; i++) { |
| 153 | getMenu(i).removeNotify(); |
| 154 | } |
| 155 | super.removeNotify(); |
| 156 | } |
| 157 | } |
| 158 | |
| 159 | /** |
| 160 | * Gets the help menu on the menu bar. |
| 161 | * @return the help menu on this menu bar. |
| 162 | */ |
| 163 | public Menu getHelpMenu() { |
| 164 | return helpMenu; |
| 165 | } |
| 166 | |
| 167 | /** |
| 168 | * Sets the specified menu to be this menu bar's help menu. |
| 169 | * If this menu bar has an existing help menu, the old help menu is |
| 170 | * removed from the menu bar, and replaced with the specified menu. |
| 171 | * @param m the menu to be set as the help menu |
| 172 | */ |
| 173 | public void setHelpMenu(Menu m) { |
| 174 | synchronized (getTreeLock()) { |
| 175 | if (helpMenu == m) { |
| 176 | return; |
| 177 | } |
| 178 | if (helpMenu != null) { |
| 179 | remove(helpMenu); |
| 180 | } |
| 181 | if (m.parent != this) { |
| 182 | add(m); |
| 183 | } |
| 184 | helpMenu = m; |
| 185 | if (m != null) { |
| 186 | m.isHelpMenu = true; |
| 187 | m.parent = this; |
| 188 | MenuBarPeer peer = (MenuBarPeer)this.peer; |
| 189 | if (peer != null) { |
| 190 | if (m.peer == null) { |
| 191 | m.addNotify(); |
| 192 | } |
| 193 | peer.addHelpMenu(m); |
| 194 | } |
| 195 | } |
| 196 | } |
| 197 | } |
| 198 | |
| 199 | /** |
| 200 | * Adds the specified menu to the menu bar. |
| 201 | * If the menu has been part of another menu bar, |
| 202 | * removes it from that menu bar. |
| 203 | * |
| 204 | * @param m the menu to be added |
| 205 | * @return the menu added |
| 206 | * @see java.awt.MenuBar#remove(int) |
| 207 | * @see java.awt.MenuBar#remove(java.awt.MenuComponent) |
| 208 | */ |
| 209 | public Menu add(Menu m) { |
| 210 | synchronized (getTreeLock()) { |
| 211 | if (m.parent != null) { |
| 212 | m.parent.remove(m); |
| 213 | } |
| 214 | menus.addElement(m); |
| 215 | m.parent = this; |
| 216 | |
| 217 | MenuBarPeer peer = (MenuBarPeer)this.peer; |
| 218 | if (peer != null) { |
| 219 | if (m.peer == null) { |
| 220 | m.addNotify(); |
| 221 | } |
| 222 | peer.addMenu(m); |
| 223 | } |
| 224 | return m; |
| 225 | } |
| 226 | } |
| 227 | |
| 228 | /** |
| 229 | * Removes the menu located at the specified |
| 230 | * index from this menu bar. |
| 231 | * @param index the position of the menu to be removed. |
| 232 | * @see java.awt.MenuBar#add(java.awt.Menu) |
| 233 | */ |
| 234 | public void remove(int index) { |
| 235 | synchronized (getTreeLock()) { |
| 236 | Menu m = getMenu(index); |
| 237 | menus.removeElementAt(index); |
| 238 | MenuBarPeer peer = (MenuBarPeer)this.peer; |
| 239 | if (peer != null) { |
| 240 | m.removeNotify(); |
| 241 | m.parent = null; |
| 242 | peer.delMenu(index); |
| 243 | } |
| 244 | } |
| 245 | } |
| 246 | |
| 247 | /** |
| 248 | * Removes the specified menu component from this menu bar. |
| 249 | * @param m the menu component to be removed. |
| 250 | * @see java.awt.MenuBar#add(java.awt.Menu) |
| 251 | */ |
| 252 | public void remove(MenuComponent m) { |
| 253 | synchronized (getTreeLock()) { |
| 254 | int index = menus.indexOf(m); |
| 255 | if (index >= 0) { |
| 256 | remove(index); |
| 257 | } |
| 258 | } |
| 259 | } |
| 260 | |
| 261 | /** |
| 262 | * Gets the number of menus on the menu bar. |
| 263 | * @return the number of menus on the menu bar. |
| 264 | * @since JDK1.1 |
| 265 | */ |
| 266 | public int getMenuCount() { |
| 267 | return countMenus(); |
| 268 | } |
| 269 | |
| 270 | /** |
| 271 | * @deprecated As of JDK version 1.1, |
| 272 | * replaced by <code>getMenuCount()</code>. |
| 273 | */ |
| 274 | @Deprecated |
| 275 | public int countMenus() { |
| 276 | return getMenuCountImpl(); |
| 277 | } |
| 278 | |
| 279 | /* |
| 280 | * This is called by the native code, so client code can't |
| 281 | * be called on the toolkit thread. |
| 282 | */ |
| 283 | final int getMenuCountImpl() { |
| 284 | return menus.size(); |
| 285 | } |
| 286 | |
| 287 | /** |
| 288 | * Gets the specified menu. |
| 289 | * @param i the index position of the menu to be returned. |
| 290 | * @return the menu at the specified index of this menu bar. |
| 291 | */ |
| 292 | public Menu getMenu(int i) { |
| 293 | return getMenuImpl(i); |
| 294 | } |
| 295 | |
| 296 | /* |
| 297 | * This is called by the native code, so client code can't |
| 298 | * be called on the toolkit thread. |
| 299 | */ |
| 300 | final Menu getMenuImpl(int i) { |
| 301 | return (Menu)menus.elementAt(i); |
| 302 | } |
| 303 | |
| 304 | /** |
| 305 | * Gets an enumeration of all menu shortcuts this menu bar |
| 306 | * is managing. |
| 307 | * @return an enumeration of menu shortcuts that this |
| 308 | * menu bar is managing. |
| 309 | * @see java.awt.MenuShortcut |
| 310 | * @since JDK1.1 |
| 311 | */ |
| 312 | public synchronized Enumeration<MenuShortcut> shortcuts() { |
| 313 | Vector shortcuts = new Vector(); |
| 314 | int nmenus = getMenuCount(); |
| 315 | for (int i = 0 ; i < nmenus ; i++) { |
| 316 | Enumeration e = getMenu(i).shortcuts(); |
| 317 | while (e.hasMoreElements()) { |
| 318 | shortcuts.addElement(e.nextElement()); |
| 319 | } |
| 320 | } |
| 321 | return shortcuts.elements(); |
| 322 | } |
| 323 | |
| 324 | /** |
| 325 | * Gets the instance of <code>MenuItem</code> associated |
| 326 | * with the specified <code>MenuShortcut</code> object, |
| 327 | * or <code>null</code> if none of the menu items being managed |
| 328 | * by this menu bar is associated with the specified menu |
| 329 | * shortcut. |
| 330 | * @param s the specified menu shortcut. |
| 331 | * @see java.awt.MenuItem |
| 332 | * @see java.awt.MenuShortcut |
| 333 | * @since JDK1.1 |
| 334 | */ |
| 335 | public MenuItem getShortcutMenuItem(MenuShortcut s) { |
| 336 | int nmenus = getMenuCount(); |
| 337 | for (int i = 0 ; i < nmenus ; i++) { |
| 338 | MenuItem mi = getMenu(i).getShortcutMenuItem(s); |
| 339 | if (mi != null) { |
| 340 | return mi; |
| 341 | } |
| 342 | } |
| 343 | return null; // MenuShortcut wasn't found |
| 344 | } |
| 345 | |
| 346 | /* |
| 347 | * Post an ACTION_EVENT to the target of the MenuPeer |
| 348 | * associated with the specified keyboard event (on |
| 349 | * keydown). Returns true if there is an associated |
| 350 | * keyboard event. |
| 351 | */ |
| 352 | boolean handleShortcut(KeyEvent e) { |
| 353 | // Is it a key event? |
| 354 | int id = e.getID(); |
| 355 | if (id != KeyEvent.KEY_PRESSED && id != KeyEvent.KEY_RELEASED) { |
| 356 | return false; |
| 357 | } |
| 358 | |
| 359 | // Is the accelerator modifier key pressed? |
| 360 | int accelKey = Toolkit.getDefaultToolkit().getMenuShortcutKeyMask(); |
| 361 | if ((e.getModifiers() & accelKey) == 0) { |
| 362 | return false; |
| 363 | } |
| 364 | |
| 365 | // Pass MenuShortcut on to child menus. |
| 366 | int nmenus = getMenuCount(); |
| 367 | for (int i = 0 ; i < nmenus ; i++) { |
| 368 | Menu m = getMenu(i); |
| 369 | if (m.handleShortcut(e)) { |
| 370 | return true; |
| 371 | } |
| 372 | } |
| 373 | return false; |
| 374 | } |
| 375 | |
| 376 | /** |
| 377 | * Deletes the specified menu shortcut. |
| 378 | * @param s the menu shortcut to delete. |
| 379 | * @since JDK1.1 |
| 380 | */ |
| 381 | public void deleteShortcut(MenuShortcut s) { |
| 382 | int nmenus = getMenuCount(); |
| 383 | for (int i = 0 ; i < nmenus ; i++) { |
| 384 | getMenu(i).deleteShortcut(s); |
| 385 | } |
| 386 | } |
| 387 | |
| 388 | /* Serialization support. Restore the (transient) parent |
| 389 | * fields of Menubar menus here. |
| 390 | */ |
| 391 | |
| 392 | /** |
| 393 | * The MenuBar's serialized data version. |
| 394 | * |
| 395 | * @serial |
| 396 | */ |
| 397 | private int menuBarSerializedDataVersion = 1; |
| 398 | |
| 399 | /** |
| 400 | * Writes default serializable fields to stream. |
| 401 | * |
| 402 | * @param s the <code>ObjectOutputStream</code> to write |
| 403 | * @see AWTEventMulticaster#save(ObjectOutputStream, String, EventListener) |
| 404 | * @see #readObject(java.io.ObjectInputStream) |
| 405 | */ |
| 406 | private void writeObject(java.io.ObjectOutputStream s) |
| 407 | throws java.lang.ClassNotFoundException, |
| 408 | java.io.IOException |
| 409 | { |
| 410 | s.defaultWriteObject(); |
| 411 | } |
| 412 | |
| 413 | /** |
| 414 | * Reads the <code>ObjectInputStream</code>. |
| 415 | * Unrecognized keys or values will be ignored. |
| 416 | * |
| 417 | * @param s the <code>ObjectInputStream</code> to read |
| 418 | * @exception HeadlessException if |
| 419 | * <code>GraphicsEnvironment.isHeadless</code> returns |
| 420 | * <code>true</code> |
| 421 | * @see java.awt.GraphicsEnvironment#isHeadless |
| 422 | * @see #writeObject(java.io.ObjectOutputStream) |
| 423 | */ |
| 424 | private void readObject(ObjectInputStream s) |
| 425 | throws ClassNotFoundException, IOException, HeadlessException |
| 426 | { |
| 427 | // HeadlessException will be thrown from MenuComponent's readObject |
| 428 | s.defaultReadObject(); |
| 429 | for (int i = 0; i < menus.size(); i++) { |
| 430 | Menu m = (Menu)menus.elementAt(i); |
| 431 | m.parent = this; |
| 432 | } |
| 433 | } |
| 434 | |
| 435 | /** |
| 436 | * Initialize JNI field and method IDs |
| 437 | */ |
| 438 | private static native void initIDs(); |
| 439 | |
| 440 | |
| 441 | ///////////////// |
| 442 | // Accessibility support |
| 443 | //////////////// |
| 444 | |
| 445 | /** |
| 446 | * Gets the AccessibleContext associated with this MenuBar. |
| 447 | * For menu bars, the AccessibleContext takes the form of an |
| 448 | * AccessibleAWTMenuBar. |
| 449 | * A new AccessibleAWTMenuBar instance is created if necessary. |
| 450 | * |
| 451 | * @return an AccessibleAWTMenuBar that serves as the |
| 452 | * AccessibleContext of this MenuBar |
| 453 | * @since 1.3 |
| 454 | */ |
| 455 | public AccessibleContext getAccessibleContext() { |
| 456 | if (accessibleContext == null) { |
| 457 | accessibleContext = new AccessibleAWTMenuBar(); |
| 458 | } |
| 459 | return accessibleContext; |
| 460 | } |
| 461 | |
| 462 | /** |
| 463 | * Defined in MenuComponent. Overridden here. |
| 464 | */ |
| 465 | int getAccessibleChildIndex(MenuComponent child) { |
| 466 | return menus.indexOf(child); |
| 467 | } |
| 468 | |
| 469 | /** |
| 470 | * Inner class of MenuBar used to provide default support for |
| 471 | * accessibility. This class is not meant to be used directly by |
| 472 | * application developers, but is instead meant only to be |
| 473 | * subclassed by menu component developers. |
| 474 | * <p> |
| 475 | * This class implements accessibility support for the |
| 476 | * <code>MenuBar</code> class. It provides an implementation of the |
| 477 | * Java Accessibility API appropriate to menu bar user-interface elements. |
| 478 | * @since 1.3 |
| 479 | */ |
| 480 | protected class AccessibleAWTMenuBar extends AccessibleAWTMenuComponent |
| 481 | { |
| 482 | /* |
| 483 | * JDK 1.3 serialVersionUID |
| 484 | */ |
| 485 | private static final long serialVersionUID = -8577604491830083815L; |
| 486 | |
| 487 | /** |
| 488 | * Get the role of this object. |
| 489 | * |
| 490 | * @return an instance of AccessibleRole describing the role of the |
| 491 | * object |
| 492 | * @since 1.4 |
| 493 | */ |
| 494 | public AccessibleRole getAccessibleRole() { |
| 495 | return AccessibleRole.MENU_BAR; |
| 496 | } |
| 497 | |
| 498 | } // class AccessibleAWTMenuBar |
| 499 | |
| 500 | } |