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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: SwingUtilities.convertPointToScreen(sourcePointOnScreen, source); 150: 151: Point compPointOnScreen; 152: Component resultComp = null; 153: 154: // For each menu element on the selected path, express its location 155: // in terms of screen coordinates and check if there is any 156: // menu element on the selected path that contains given source point. 157: for (int i = 0; i < selectedPath.size(); i++) 158: { 159: Component comp = ((Component) selectedPath.get(i)); 160: Dimension size = comp.getSize(); 161: 162: // convert location of this menu item to screen coordinates 163: compPointOnScreen = comp.getLocationOnScreen(); 164: 165: if (compPointOnScreen.x <= sourcePointOnScreen.x 166: && sourcePointOnScreen.x < compPointOnScreen.x + size.width 167: && compPointOnScreen.y <= sourcePointOnScreen.y 168: && sourcePointOnScreen.y < compPointOnScreen.y + size.height) 169: { 170: Point p = sourcePointOnScreen; 171: SwingUtilities.convertPointFromScreen(p, comp); 172: resultComp = SwingUtilities.getDeepestComponentAt(comp, p.x, p.y); 173: break; 174: } 175: } 176: return resultComp; 177: } 178: 179: /** 180: * Returns shared instance of MenuSelection Manager 181: * 182: * @return default Manager 183: */ 184: public static MenuSelectionManager defaultManager() 185: { 186: return manager; 187: } 188: 189: /** 190: * Returns path representing current menu selection 191: * 192: * @return Current selection path 193: */ 194: public MenuElement[] getSelectedPath() 195: { 196: MenuElement[] path = new MenuElement[selectedPath.size()]; 197: 198: for (int i = 0; i < path.length; i++) 199: path[i] = (MenuElement) selectedPath.get(i); 200: 201: return path; 202: } 203: 204: /** 205: * Returns true if specified component is part of current menu 206: * heirarchy and false otherwise 207: * 208: * @param c Component for which to check 209: * @return True if specified component is part of current menu 210: */ 211: public boolean isComponentPartOfCurrentMenu(Component c) 212: { 213: MenuElement[] subElements; 214: for (int i = 0; i < selectedPath.size(); i++) 215: { 216: subElements = ((MenuElement) selectedPath.get(i)).getSubElements(); 217: for (int j = 0; j < subElements.length; j++) 218: { 219: MenuElement me = subElements[j]; 220: if (me != null && (me.getComponent()).equals(c)) 221: return true; 222: } 223: } 224: 225: return false; 226: } 227: 228: /** 229: * DOCUMENT ME! 230: * 231: * @param e DOCUMENT ME! 232: */ 233: public void processKeyEvent(KeyEvent e) 234: { 235: throw new UnsupportedOperationException("not implemented"); 236: } 237: 238: /** 239: * Forwards given mouse event to all of the source subcomponents. 240: * 241: * @param event Mouse event 242: */ 243: public void processMouseEvent(MouseEvent event) 244: { 245: Component source = ((Component) event.getSource()); 246: 247: // In the case of drag event, event.getSource() returns component 248: // where drag event originated. However menu element processing this 249: // event should be the one over which mouse is currently located, 250: // which is not necessary the source of the drag event. 251: Component mouseOverMenuComp; 252: 253: // find over which menu element the mouse is currently located 254: if (event.getID() == MouseEvent.MOUSE_DRAGGED 255: || event.getID() == MouseEvent.MOUSE_RELEASED) 256: mouseOverMenuComp = componentForPoint(source, event.getPoint()); 257: else 258: mouseOverMenuComp = source; 259: 260: // Process this event only if mouse is located over some menu element 261: if (mouseOverMenuComp != null && (mouseOverMenuComp instanceof MenuElement)) 262: { 263: MenuElement[] path = getPath(mouseOverMenuComp); 264: ((MenuElement) mouseOverMenuComp).processMouseEvent(event, path, 265: manager); 266: 267: // FIXME: Java specification says that mouse events should be 268: // forwarded to subcomponents. The code below does it, but 269: // menu's work fine without it. This code is commented for now. 270: 271: /* 272: MenuElement[] subComponents = ((MenuElement) mouseOverMenuComp) 273: .getSubElements(); 274: 275: for (int i = 0; i < subComponents.length; i++) 276: { 277: subComponents[i].processMouseEvent(event, path, manager); 278: } 279: */ 280: } 281: else 282: { 283: if (event.getID() == MouseEvent.MOUSE_RELEASED) 284: clearSelectedPath(); 285: } 286: } 287: 288: /** 289: * Sets menu selection to the specified path 290: * 291: * @param path new selection path 292: */ 293: public void setSelectedPath(MenuElement[] path) 294: { 295: if (path == null) 296: { 297: clearSelectedPath(); 298: return; 299: } 300: 301: int i; 302: int minSize = path.length; // size of the smaller path. 303: 304: if (path.length > selectedPath.size()) 305: { 306: minSize = selectedPath.size(); 307: 308: // if new selected path contains more elements then current 309: // selection then first add all elements at 310: // the indexes > selectedPath.size 311: for (i = selectedPath.size(); i < path.length; i++) 312: { 313: selectedPath.add(path[i]); 314: path[i].menuSelectionChanged(true); 315: } 316: } 317: 318: else if (path.length < selectedPath.size()) 319: { 320: // if new selected path contains less elements then current 321: // selection then first remove all elements from the selection 322: // at the indexes > path.length 323: for (i = selectedPath.size() - 1; i >= path.length; i--) 324: { 325: ((MenuElement) selectedPath.get(i)).menuSelectionChanged(false); 326: selectedPath.remove(i); 327: } 328: 329: minSize = path.length; 330: } 331: 332: // Now compare elements in new and current selection path at the 333: // same location and adjust selection until 334: // same menu elements will be encountered at the 335: // same index in both current and new selection path. 336: MenuElement oldSelectedItem; 337: 338: for (i = minSize - 1; i >= 0; i--) 339: { 340: oldSelectedItem = (MenuElement) selectedPath.get(i); 341: 342: if (path[i].equals(oldSelectedItem)) 343: break; 344: 345: oldSelectedItem.menuSelectionChanged(false); 346: path[i].menuSelectionChanged(true); 347: selectedPath.setElementAt(path[i], i); 348: } 349: 350: fireStateChanged(); 351: } 352: 353: /** 354: * Returns path to the specified component 355: * 356: * @param c component for which to find path for 357: * 358: * @return path to the specified component 359: */ 360: private MenuElement[] getPath(Component c) 361: { 362: // FIXME: There is the same method in BasicMenuItemUI. However I 363: // cannot use it here instead of this method, since I cannot assume that 364: // all the menu elements on the selected path are JMenuItem or JMenu. 365: // For now I've just duplicated it here. Please 366: // fix me or delete me if another better approach will be found, and 367: // this method will not be necessary. 368: ArrayList path = new ArrayList(); 369: 370: // if given component is JMenu, we also need to include 371: // it's popup menu in the path 372: if (c instanceof JMenu) 373: path.add(((JMenu) c).getPopupMenu()); 374: while (c instanceof MenuElement) 375: { 376: path.add(0, (MenuElement) c); 377: 378: if (c instanceof JPopupMenu) 379: c = ((JPopupMenu) c).getInvoker(); 380: else 381: c = c.getParent(); 382: } 383: 384: MenuElement[] pathArray = new MenuElement[path.size()]; 385: path.toArray(pathArray); 386: return pathArray; 387: } 388: }
GNU Classpath (0.18) |