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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: 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: for (int i = 0; i < selectedPath.size(); i++) 220: { 221: subElements = ((MenuElement) selectedPath.get(i)).getSubElements(); 222: for (int j = 0; j < subElements.length; j++) 223: { 224: MenuElement me = subElements[j]; 225: if (me != null && (me.getComponent()).equals(c)) 226: return true; 227: } 228: } 229: 230: return false; 231: } 232: 233: /** 234: * DOCUMENT ME! 235: * 236: * @param e DOCUMENT ME! 237: */ 238: public void processKeyEvent(KeyEvent e) 239: { 240: throw new UnsupportedOperationException("not implemented"); 241: } 242: 243: /** 244: * Forwards given mouse event to all of the source subcomponents. 245: * 246: * @param event Mouse event 247: */ 248: public void processMouseEvent(MouseEvent event) 249: { 250: Component source = ((Component) event.getSource()); 251: 252: // In the case of drag event, event.getSource() returns component 253: // where drag event originated. However menu element processing this 254: // event should be the one over which mouse is currently located, 255: // which is not necessary the source of the drag event. 256: Component mouseOverMenuComp; 257: 258: // find over which menu element the mouse is currently located 259: if (event.getID() == MouseEvent.MOUSE_DRAGGED 260: || event.getID() == MouseEvent.MOUSE_RELEASED) 261: mouseOverMenuComp = componentForPoint(source, event.getPoint()); 262: else 263: mouseOverMenuComp = source; 264: 265: // Process this event only if mouse is located over some menu element 266: if (mouseOverMenuComp != null && (mouseOverMenuComp instanceof MenuElement)) 267: { 268: MenuElement[] path = getPath(mouseOverMenuComp); 269: ((MenuElement) mouseOverMenuComp).processMouseEvent(event, path, 270: manager); 271: 272: // FIXME: Java specification says that mouse events should be 273: // forwarded to subcomponents. The code below does it, but 274: // menu's work fine without it. This code is commented for now. 275: 276: /* 277: MenuElement[] subComponents = ((MenuElement) mouseOverMenuComp) 278: .getSubElements(); 279: 280: for (int i = 0; i < subComponents.length; i++) 281: { 282: subComponents[i].processMouseEvent(event, path, manager); 283: } 284: */ 285: } 286: else 287: { 288: if (event.getID() == MouseEvent.MOUSE_RELEASED) 289: clearSelectedPath(); 290: } 291: } 292: 293: /** 294: * Sets menu selection to the specified path 295: * 296: * @param path new selection path 297: */ 298: public void setSelectedPath(MenuElement[] path) 299: { 300: if (path == null) 301: { 302: clearSelectedPath(); 303: return; 304: } 305: 306: int i; 307: int minSize = path.length; // size of the smaller path. 308: 309: if (path.length > selectedPath.size()) 310: { 311: minSize = selectedPath.size(); 312: 313: // if new selected path contains more elements then current 314: // selection then first add all elements at 315: // the indexes > selectedPath.size 316: for (i = selectedPath.size(); i < path.length; i++) 317: { 318: selectedPath.add(path[i]); 319: path[i].menuSelectionChanged(true); 320: } 321: } 322: 323: else if (path.length < selectedPath.size()) 324: { 325: // if new selected path contains less elements then current 326: // selection then first remove all elements from the selection 327: // at the indexes > path.length 328: for (i = selectedPath.size() - 1; i >= path.length; i--) 329: { 330: ((MenuElement) selectedPath.get(i)).menuSelectionChanged(false); 331: selectedPath.remove(i); 332: } 333: 334: minSize = path.length; 335: } 336: 337: // Now compare elements in new and current selection path at the 338: // same location and adjust selection until 339: // same menu elements will be encountered at the 340: // same index in both current and new selection path. 341: MenuElement oldSelectedItem; 342: 343: for (i = minSize - 1; i >= 0; i--) 344: { 345: oldSelectedItem = (MenuElement) selectedPath.get(i); 346: 347: if (path[i].equals(oldSelectedItem)) 348: break; 349: 350: oldSelectedItem.menuSelectionChanged(false); 351: path[i].menuSelectionChanged(true); 352: selectedPath.setElementAt(path[i], i); 353: } 354: 355: fireStateChanged(); 356: } 357: 358: /** 359: * Returns path to the specified component 360: * 361: * @param c component for which to find path for 362: * 363: * @return path to the specified component 364: */ 365: private MenuElement[] getPath(Component c) 366: { 367: // FIXME: There is the same method in BasicMenuItemUI. However I 368: // cannot use it here instead of this method, since I cannot assume that 369: // all the menu elements on the selected path are JMenuItem or JMenu. 370: // For now I've just duplicated it here. Please 371: // fix me or delete me if another better approach will be found, and 372: // this method will not be necessary. 373: ArrayList path = new ArrayList(); 374: 375: // if given component is JMenu, we also need to include 376: // it's popup menu in the path 377: if (c instanceof JMenu) 378: path.add(((JMenu) c).getPopupMenu()); 379: while (c instanceof MenuElement) 380: { 381: path.add(0, (MenuElement) c); 382: 383: if (c instanceof JPopupMenu) 384: c = ((JPopupMenu) c).getInvoker(); 385: else 386: c = c.getParent(); 387: } 388: 389: MenuElement[] pathArray = new MenuElement[path.size()]; 390: path.toArray(pathArray); 391: return pathArray; 392: } 393: }
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