Frames | No Frames |
1: /* MenuSelectionManager.java -- 2: Copyright (C) 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., 51 Franklin Street, Fifth Floor, Boston, MA 19: 02110-1301 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 javax.swing; 40: 41: import java.awt.Component; 42: import java.awt.Dimension; 43: import java.awt.Point; 44: import java.awt.event.KeyEvent; 45: import java.awt.event.MouseEvent; 46: import java.util.ArrayList; 47: import java.util.Vector; 48: 49: import javax.swing.event.ChangeEvent; 50: import javax.swing.event.ChangeListener; 51: import javax.swing.event.EventListenerList; 52: 53: /** 54: * This class manages current menu selectection. It provides 55: * methods to clear and set current selected menu path. 56: * It also fires StateChange event to its registered 57: * listeners whenever selected path of the current menu hierarchy 58: * changes. 59: * 60: */ 61: public class MenuSelectionManager 62: { 63: /** ChangeEvent fired when selected path changes*/ 64: protected ChangeEvent changeEvent = new ChangeEvent(this); 65: 66: /** List of listeners for this MenuSelectionManager */ 67: protected EventListenerList listenerList = new EventListenerList(); 68: 69: /** Default manager for the current menu hierarchy*/ 70: private static final MenuSelectionManager manager = new MenuSelectionManager(); 71: 72: /** Path to the currently selected menu */ 73: private Vector selectedPath = new Vector(); 74: 75: /** 76: * Fires StateChange event to registered listeners 77: */ 78: protected void fireStateChanged() 79: { 80: ChangeListener[] listeners = getChangeListeners(); 81: 82: for (int i = 0; i < listeners.length; i++) 83: listeners[i].stateChanged(changeEvent); 84: } 85: 86: /** 87: * Adds ChangeListener to this MenuSelectionManager 88: * 89: * @param listener ChangeListener to add 90: */ 91: public void addChangeListener(ChangeListener listener) 92: { 93: listenerList.add(ChangeListener.class, listener); 94: } 95: 96: /** 97: * Removes ChangeListener from the list of registered listeners 98: * for this MenuSelectionManager. 99: * 100: * @param listener ChangeListner to remove 101: */ 102: public void removeChangeListener(ChangeListener listener) 103: { 104: listenerList.remove(ChangeListener.class, listener); 105: } 106: 107: /** 108: * Returns list of registered listeners with MenuSelectionManager 109: * 110: * @since 1.4 111: */ 112: public ChangeListener[] getChangeListeners() 113: { 114: return (ChangeListener[]) listenerList.getListeners(ChangeListener.class); 115: } 116: 117: /** 118: * Unselects all the menu elements on the selection path 119: */ 120: public void clearSelectedPath() 121: { 122: // Send events from the bottom most item in the menu - hierarchy to the 123: // top most 124: for (int i = selectedPath.size() - 1; i >= 0; i--) 125: ((MenuElement) selectedPath.get(i)).menuSelectionChanged(false); 126: 127: // clear selected path 128: selectedPath.clear(); 129: 130: // notify all listeners that the selected path was changed 131: fireStateChanged(); 132: } 133: 134: /** 135: * This method returns menu element on the selected path that contains 136: * given source point. If no menu element on the selected path contains this 137: * point, then null is returned. 138: * 139: * @param source Component relative to which sourcePoint is given 140: * @param sourcePoint point for which we want to find menu element that contains it 141: * 142: * @return Returns menu element that contains given source point and belongs 143: * to the currently selected path. Null is return if no such menu element found. 144: */ 145: public Component componentForPoint(Component source, Point sourcePoint) 146: { 147: // Convert sourcePoint to screen coordinates. 148: Point sourcePointOnScreen = sourcePoint; 149: 150: if (source.isShowing()) 151: SwingUtilities.convertPointToScreen(sourcePointOnScreen, source); 152: 153: Point compPointOnScreen; 154: Component resultComp = null; 155: 156: // For each menu element on the selected path, express its location 157: // in terms of screen coordinates and check if there is any 158: // menu element on the selected path that contains given source point. 159: for (int i = 0; i < selectedPath.size(); i++) 160: { 161: Component comp = ((Component) selectedPath.get(i)); 162: Dimension size = comp.getSize(); 163: 164: // convert location of this menu item to screen coordinates 165: compPointOnScreen = comp.getLocationOnScreen(); 166: 167: if (compPointOnScreen.x <= sourcePointOnScreen.x 168: && sourcePointOnScreen.x < compPointOnScreen.x + size.width 169: && compPointOnScreen.y <= sourcePointOnScreen.y 170: && sourcePointOnScreen.y < compPointOnScreen.y + size.height) 171: { 172: Point p = sourcePointOnScreen; 173: 174: if (comp.isShowing()) 175: SwingUtilities.convertPointFromScreen(p, comp); 176: 177: resultComp = SwingUtilities.getDeepestComponentAt(comp, p.x, p.y); 178: break; 179: } 180: } 181: return resultComp; 182: } 183: 184: /** 185: * Returns shared instance of MenuSelection Manager 186: * 187: * @return default Manager 188: */ 189: public static MenuSelectionManager defaultManager() 190: { 191: return manager; 192: } 193: 194: /** 195: * Returns path representing current menu selection 196: * 197: * @return Current selection path 198: */ 199: public MenuElement[] getSelectedPath() 200: { 201: MenuElement[] path = new MenuElement[selectedPath.size()]; 202: 203: for (int i = 0; i < path.length; i++) 204: path[i] = (MenuElement) selectedPath.get(i); 205: 206: return path; 207: } 208: 209: /** 210: * Returns true if specified component is part of current menu 211: * heirarchy and false otherwise 212: * 213: * @param c Component for which to check 214: * @return True if specified component is part of current menu 215: */ 216: public boolean isComponentPartOfCurrentMenu(Component c) 217: { 218: MenuElement[] subElements; 219: boolean ret = false; 220: for (int i = 0; i < selectedPath.size(); i++) 221: { 222: // Check first element. 223: MenuElement first = (MenuElement) selectedPath.get(i); 224: if (SwingUtilities.isDescendingFrom(c, first.getComponent())) 225: { 226: ret = true; 227: break; 228: } 229: else 230: { 231: // Check sub elements. 232: subElements = first.getSubElements(); 233: for (int j = 0; j < subElements.length; j++) 234: { 235: MenuElement me = subElements[j]; 236: if (me != null 237: && (SwingUtilities.isDescendingFrom(c, me.getComponent()))) 238: { 239: ret = true; 240: break; 241: } 242: } 243: } 244: } 245: 246: return ret; 247: } 248: 249: /** 250: * Processes key events on behalf of the MenuElements. MenuElement 251: * instances should always forward their key events to this method and 252: * get their {@link MenuElement#processKeyEvent(KeyEvent, MenuElement[], 253: * MenuSelectionManager)} eventually called back. 254: * 255: * @param e the key event 256: */ 257: public void processKeyEvent(KeyEvent e) 258: { 259: MenuElement[] selection = (MenuElement[]) 260: selectedPath.toArray(new MenuElement[selectedPath.size()]); 261: if (selection.length == 0) 262: return; 263: 264: MenuElement[] path; 265: for (int index = selection.length - 1; index >= 0; index--) 266: { 267: MenuElement el = selection[index]; 268: // This method's main purpose is to forward key events to the 269: // relevant menu items, so that they can act in response to their 270: // mnemonics beeing typed. So we also need to forward the key event 271: // to all the subelements of the currently selected menu elements 272: // in the path. 273: MenuElement[] subEls = el.getSubElements(); 274: path = null; 275: for (int subIndex = 0; subIndex < subEls.length; subIndex++) 276: { 277: MenuElement sub = subEls[subIndex]; 278: // Skip elements that are not showing or not enabled. 279: if (sub == null || ! sub.getComponent().isShowing() 280: || ! sub.getComponent().isEnabled()) 281: { 282: continue; 283: } 284: 285: if (path == null) 286: { 287: path = new MenuElement[index + 2]; 288: System.arraycopy(selection, 0, path, 0, index + 1); 289: } 290: path[index + 1] = sub; 291: sub.processKeyEvent(e, path, this); 292: if (e.isConsumed()) 293: break; 294: } 295: if (e.isConsumed()) 296: break; 297: } 298: 299: // Dispatch to first element in selection if it hasn't been consumed. 300: if (! e.isConsumed()) 301: { 302: path = new MenuElement[1]; 303: path[0] = selection[0]; 304: path[0].processKeyEvent(e, path, this); 305: } 306: } 307: 308: /** 309: * Forwards given mouse event to all of the source subcomponents. 310: * 311: * @param event Mouse event 312: */ 313: public void processMouseEvent(MouseEvent event) 314: { 315: Component source = ((Component) event.getSource()); 316: 317: // In the case of drag event, event.getSource() returns component 318: // where drag event originated. However menu element processing this 319: // event should be the one over which mouse is currently located, 320: // which is not necessary the source of the drag event. 321: Component mouseOverMenuComp; 322: 323: // find over which menu element the mouse is currently located 324: if (event.getID() == MouseEvent.MOUSE_DRAGGED 325: || event.getID() == MouseEvent.MOUSE_RELEASED) 326: mouseOverMenuComp = componentForPoint(source, event.getPoint()); 327: else 328: mouseOverMenuComp = source; 329: 330: // Process this event only if mouse is located over some menu element 331: if (mouseOverMenuComp != null && (mouseOverMenuComp instanceof MenuElement)) 332: { 333: MenuElement[] path = getPath(mouseOverMenuComp); 334: ((MenuElement) mouseOverMenuComp).processMouseEvent(event, path, 335: manager); 336: 337: // FIXME: Java specification says that mouse events should be 338: // forwarded to subcomponents. The code below does it, but 339: // menu's work fine without it. This code is commented for now. 340: 341: /* 342: MenuElement[] subComponents = ((MenuElement) mouseOverMenuComp) 343: .getSubElements(); 344: 345: for (int i = 0; i < subComponents.length; i++) 346: { 347: subComponents[i].processMouseEvent(event, path, manager); 348: } 349: */ 350: } 351: else 352: { 353: if (event.getID() == MouseEvent.MOUSE_RELEASED) 354: clearSelectedPath(); 355: } 356: } 357: 358: /** 359: * Sets menu selection to the specified path 360: * 361: * @param path new selection path 362: */ 363: public void setSelectedPath(MenuElement[] path) 364: { 365: if (path == null) 366: { 367: clearSelectedPath(); 368: return; 369: } 370: 371: int minSize = path.length; // size of the smaller path. 372: int currentSize = selectedPath.size(); 373: int firstDiff = 0; 374: 375: // Search first item that is different in the current and new path. 376: for (int i = 0; i < minSize; i++) 377: { 378: if (i < currentSize && (MenuElement) selectedPath.get(i) == path[i]) 379: firstDiff++; 380: else 381: break; 382: } 383: 384: // Remove items from selection and send notification. 385: for (int i = currentSize - 1; i >= firstDiff; i--) 386: { 387: MenuElement el = (MenuElement) selectedPath.get(i); 388: selectedPath.remove(i); 389: el.menuSelectionChanged(false); 390: } 391: 392: // Add new items to selection and send notification. 393: for (int i = firstDiff; i < minSize; i++) 394: { 395: if (path[i] != null) 396: { 397: selectedPath.add(path[i]); 398: path[i].menuSelectionChanged(true); 399: } 400: } 401: 402: fireStateChanged(); 403: } 404: 405: /** 406: * Returns path to the specified component 407: * 408: * @param c component for which to find path for 409: * 410: * @return path to the specified component 411: */ 412: private MenuElement[] getPath(Component c) 413: { 414: // FIXME: There is the same method in BasicMenuItemUI. However I 415: // cannot use it here instead of this method, since I cannot assume that 416: // all the menu elements on the selected path are JMenuItem or JMenu. 417: // For now I've just duplicated it here. Please 418: // fix me or delete me if another better approach will be found, and 419: // this method will not be necessary. 420: ArrayList path = new ArrayList(); 421: 422: // if given component is JMenu, we also need to include 423: // it's popup menu in the path 424: if (c instanceof JMenu) 425: path.add(((JMenu) c).getPopupMenu()); 426: while (c instanceof MenuElement) 427: { 428: path.add(0, (MenuElement) c); 429: 430: if (c instanceof JPopupMenu) 431: c = ((JPopupMenu) c).getInvoker(); 432: else 433: c = c.getParent(); 434: } 435: 436: MenuElement[] pathArray = new MenuElement[path.size()]; 437: path.toArray(pathArray); 438: return pathArray; 439: } 440: }