J. Duke | 319a3b9 | 2007-12-01 00:00:00 +0000 | [diff] [blame^] | 1 | /* |
| 2 | * Copyright 2000-2007 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 | |
| 26 | package sun.awt; |
| 27 | |
| 28 | import java.awt.IllegalComponentStateException; |
| 29 | import java.util.Collections; |
| 30 | import java.util.Iterator; |
| 31 | import java.util.Map; |
| 32 | import java.util.Set; |
| 33 | import java.util.HashMap; |
| 34 | import java.util.WeakHashMap; |
| 35 | |
| 36 | import java.util.logging.*; |
| 37 | |
| 38 | /** |
| 39 | * This class is used to aid in keeping track of DisplayChangedListeners and |
| 40 | * notifying them when a display change has taken place. DisplayChangedListeners |
| 41 | * are notified when the display's bit depth is changed, or when a top-level |
| 42 | * window has been dragged onto another screen. |
| 43 | * |
| 44 | * It is safe for a DisplayChangedListener to be added while the list is being |
| 45 | * iterated. |
| 46 | * |
| 47 | * The displayChanged() call is propagated after some occurrence (either |
| 48 | * due to user action or some other application) causes the display mode |
| 49 | * (e.g., depth or resolution) to change. All heavyweight components need |
| 50 | * to know when this happens because they need to create new surfaceData |
| 51 | * objects based on the new depth. |
| 52 | * |
| 53 | * displayChanged() is also called on Windows when they are moved from one |
| 54 | * screen to another on a system equipped with multiple displays. |
| 55 | */ |
| 56 | public class SunDisplayChanger { |
| 57 | private static final Logger log = Logger.getLogger("sun.awt.multiscreen.SunDisplayChanger"); |
| 58 | |
| 59 | // Create a new synchronizedMap with initial capacity of one listener. |
| 60 | // It is asserted that the most common case is to have one GraphicsDevice |
| 61 | // and one top-level Window. |
| 62 | private Map listeners = Collections.synchronizedMap(new WeakHashMap(1)); |
| 63 | |
| 64 | public SunDisplayChanger() {} |
| 65 | |
| 66 | /* |
| 67 | * Add a DisplayChangeListener to this SunDisplayChanger so that it is |
| 68 | * notified when the display is changed. |
| 69 | */ |
| 70 | public void add(DisplayChangedListener theListener) { |
| 71 | if (log.isLoggable(Level.FINE)) { |
| 72 | if (theListener == null) { |
| 73 | log.log(Level.FINE, "Assertion (theListener != null) failed"); |
| 74 | } |
| 75 | } |
| 76 | if (log.isLoggable(Level.FINER)) { |
| 77 | log.log(Level.FINER, "Adding listener: " + theListener); |
| 78 | } |
| 79 | listeners.put(theListener, null); |
| 80 | } |
| 81 | |
| 82 | /* |
| 83 | * Remove the given DisplayChangeListener from this SunDisplayChanger. |
| 84 | */ |
| 85 | public void remove(DisplayChangedListener theListener) { |
| 86 | if (log.isLoggable(Level.FINE)) { |
| 87 | if (theListener == null) { |
| 88 | log.log(Level.FINE, "Assertion (theListener != null) failed"); |
| 89 | } |
| 90 | } |
| 91 | if (log.isLoggable(Level.FINER)) { |
| 92 | log.log(Level.FINER, "Removing listener: " + theListener); |
| 93 | } |
| 94 | listeners.remove(theListener); |
| 95 | } |
| 96 | |
| 97 | /* |
| 98 | * Notify our list of DisplayChangedListeners that a display change has |
| 99 | * taken place by calling their displayChanged() methods. |
| 100 | */ |
| 101 | public void notifyListeners() { |
| 102 | if (log.isLoggable(Level.FINEST)) { |
| 103 | log.log(Level.FINEST, "notifyListeners"); |
| 104 | } |
| 105 | // This method is implemented by making a clone of the set of listeners, |
| 106 | // and then iterating over the clone. This is because during the course |
| 107 | // of responding to a display change, it may be appropriate for a |
| 108 | // DisplayChangedListener to add or remove itself from a SunDisplayChanger. |
| 109 | // If the set itself were iterated over, rather than a clone, it is |
| 110 | // trivial to get a ConcurrentModificationException by having a |
| 111 | // DisplayChangedListener remove itself from its list. |
| 112 | // Because all display change handling is done on the event thread, |
| 113 | // synchronization provides no protection against modifying the listener |
| 114 | // list while in the middle of iterating over it. -bchristi 7/10/2001 |
| 115 | |
| 116 | HashMap listClone; |
| 117 | Set cloneSet; |
| 118 | |
| 119 | synchronized(listeners) { |
| 120 | listClone = new HashMap(listeners); |
| 121 | } |
| 122 | |
| 123 | cloneSet = listClone.keySet(); |
| 124 | Iterator itr = cloneSet.iterator(); |
| 125 | while (itr.hasNext()) { |
| 126 | DisplayChangedListener current = |
| 127 | (DisplayChangedListener) itr.next(); |
| 128 | try { |
| 129 | if (log.isLoggable(Level.FINEST)) { |
| 130 | log.log(Level.FINEST, "displayChanged for listener: " + current); |
| 131 | } |
| 132 | current.displayChanged(); |
| 133 | } catch (IllegalComponentStateException e) { |
| 134 | // This DisplayChangeListener is no longer valid. Most |
| 135 | // likely, a top-level window was dispose()d, but its |
| 136 | // Java objects have not yet been garbage collected. In any |
| 137 | // case, we no longer need to track this listener, though we |
| 138 | // do need to remove it from the original list, not the clone. |
| 139 | listeners.remove(current); |
| 140 | } |
| 141 | } |
| 142 | } |
| 143 | |
| 144 | /* |
| 145 | * Notify our list of DisplayChangedListeners that a palette change has |
| 146 | * taken place by calling their paletteChanged() methods. |
| 147 | */ |
| 148 | public void notifyPaletteChanged() { |
| 149 | if (log.isLoggable(Level.FINEST)) { |
| 150 | log.finest("notifyPaletteChanged"); |
| 151 | } |
| 152 | // This method is implemented by making a clone of the set of listeners, |
| 153 | // and then iterating over the clone. This is because during the course |
| 154 | // of responding to a display change, it may be appropriate for a |
| 155 | // DisplayChangedListener to add or remove itself from a SunDisplayChanger. |
| 156 | // If the set itself were iterated over, rather than a clone, it is |
| 157 | // trivial to get a ConcurrentModificationException by having a |
| 158 | // DisplayChangedListener remove itself from its list. |
| 159 | // Because all display change handling is done on the event thread, |
| 160 | // synchronization provides no protection against modifying the listener |
| 161 | // list while in the middle of iterating over it. -bchristi 7/10/2001 |
| 162 | |
| 163 | HashMap listClone; |
| 164 | Set cloneSet; |
| 165 | |
| 166 | synchronized (listeners) { |
| 167 | listClone = new HashMap(listeners); |
| 168 | } |
| 169 | cloneSet = listClone.keySet(); |
| 170 | Iterator itr = cloneSet.iterator(); |
| 171 | while (itr.hasNext()) { |
| 172 | DisplayChangedListener current = |
| 173 | (DisplayChangedListener) itr.next(); |
| 174 | try { |
| 175 | if (log.isLoggable(Level.FINEST)) { |
| 176 | log.log(Level.FINEST, "paletteChanged for listener: " + current); |
| 177 | } |
| 178 | current.paletteChanged(); |
| 179 | } catch (IllegalComponentStateException e) { |
| 180 | // This DisplayChangeListener is no longer valid. Most |
| 181 | // likely, a top-level window was dispose()d, but its |
| 182 | // Java objects have not yet been garbage collected. In any |
| 183 | // case, we no longer need to track this listener, though we |
| 184 | // do need to remove it from the original list, not the clone. |
| 185 | listeners.remove(current); |
| 186 | } |
| 187 | } |
| 188 | } |
| 189 | } |