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| 1 | /* | ||
| 2 | * Copyright (c) 1999, 2007, Oracle and/or its affiliates. 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. Oracle designates this | ||
| 8 | * particular file as subject to the "Classpath" exception as provided | ||
| 9 | * by Oracle 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA | ||
| 22 | * or visit www.oracle.com if you need additional information or have any | ||
| 23 | * questions. | ||
| 24 | */ | ||
| 25 | |||
| 26 | package sun.awt; | ||
| 27 | |||
| 28 | import java.awt.*; | ||
| 29 | import java.awt.event.InputEvent; | ||
| 30 | import java.awt.event.InvocationEvent; | ||
| 31 | |||
| 32 | /** | ||
| 33 | * A stateless class which responds to native mouse moves, Component resizes, | ||
| 34 | * Component moves, showing and hiding of Components, minimizing and | ||
| 35 | * maximizing of top level Windows, addition and removal of Components, | ||
| 36 | * and calls to setCursor(). | ||
| 37 | */ | ||
| 38 | public abstract class GlobalCursorManager { | ||
| 39 | |||
| 40 | class NativeUpdater implements Runnable { | ||
| 41 | boolean pending = false; | ||
| 42 | |||
| 43 | public void run() { | ||
| 44 | boolean shouldUpdate = false; | ||
| 45 | synchronized (this) { | ||
| 46 | if (pending) { | ||
| 47 | pending = false; | ||
| 48 | shouldUpdate = true; | ||
| 49 | } | ||
| 50 | } | ||
| 51 | if (shouldUpdate) { | ||
| 52 | _updateCursor(false); | ||
| 53 | } | ||
| 54 | } | ||
| 55 | |||
| 56 | public void postIfNotPending(Component heavy, InvocationEvent in) { | ||
| 57 | boolean shouldPost = false; | ||
| 58 | synchronized (this) { | ||
| 59 | if (!pending) { | ||
| 60 | pending = shouldPost = true; | ||
| 61 | } | ||
| 62 | } | ||
| 63 | if (shouldPost) { | ||
| 64 | SunToolkit.postEvent(SunToolkit.targetToAppContext(heavy), in); | ||
| 65 | } | ||
| 66 | } | ||
| 67 | } | ||
| 68 | |||
| 69 | /** | ||
| 70 | * Use a singleton NativeUpdater for better performance. We cannot use | ||
| 71 | * a singleton InvocationEvent because we want each event to have a fresh | ||
| 72 | * timestamp. | ||
| 73 | */ | ||
| 74 | private final NativeUpdater nativeUpdater = new NativeUpdater(); | ||
| 75 | |||
| 76 | /** | ||
| 77 | * The last time the cursor was updated, in milliseconds. | ||
| 78 | */ | ||
| 79 | private long lastUpdateMillis; | ||
| 80 | |||
| 81 | /** | ||
| 82 | * Locking object for synchronizing access to lastUpdateMillis. The VM | ||
| 83 | * does not guarantee atomicity of longs. | ||
| 84 | */ | ||
| 85 | private final Object lastUpdateLock = new Object(); | ||
| 86 | |||
| 87 | /** | ||
| 88 | * Should be called for any activity at the Java level which may affect | ||
| 89 | * the global cursor, except for Java MOUSE_MOVED events. | ||
| 90 | */ | ||
| 91 | public void updateCursorImmediately() { | ||
| 92 | synchronized (nativeUpdater) { | ||
| 93 | nativeUpdater.pending = false; | ||
| 94 | } | ||
| 95 | _updateCursor(false); | ||
| 96 | } | ||
| 97 | |||
| 98 | /** | ||
| 99 | * Should be called in response to Java MOUSE_MOVED events. The update | ||
| 100 | * will be discarded if the InputEvent is outdated. | ||
| 101 | * | ||
| 102 | * @param e the InputEvent which triggered the cursor update. | ||
| 103 | */ | ||
| 104 | public void updateCursorImmediately(InputEvent e) { | ||
| 105 | boolean shouldUpdate; | ||
| 106 | synchronized (lastUpdateLock) { | ||
| 107 | shouldUpdate = (e.getWhen() >= lastUpdateMillis); | ||
| 108 | } | ||
| 109 | if (shouldUpdate) { | ||
| 110 | _updateCursor(true); | ||
| 111 | } | ||
| 112 | } | ||
| 113 | |||
| 114 | /** | ||
| 115 | * Should be called in response to a native mouse enter or native mouse | ||
| 116 | * button released message. Should not be called during a mouse drag. | ||
| 117 | */ | ||
| 118 | public void updateCursorLater(Component heavy) { | ||
| 119 | nativeUpdater.postIfNotPending(heavy, new InvocationEvent | ||
| 120 | (Toolkit.getDefaultToolkit(), nativeUpdater)); | ||
| 121 | } | ||
| 122 | |||
| 123 | protected GlobalCursorManager() { } | ||
| 124 | |||
| 125 | /** | ||
| 126 | * Set the global cursor to the specified cursor. The component over | ||
| 127 | * which the Cursor current resides is provided as a convenience. Not | ||
| 128 | * all platforms may require the Component. | ||
| 129 | */ | ||
| 130 | protected abstract void setCursor(Component comp, Cursor cursor, | ||
| 131 | boolean useCache); | ||
| 132 | /** | ||
| 133 | * Returns the global cursor position, in screen coordinates. | ||
| 134 | */ | ||
| 135 | protected abstract void getCursorPos(Point p); | ||
| 136 | |||
| 137 | protected abstract Component findComponentAt(Container con, int x, int y); | ||
| 138 | protected abstract Point getLocationOnScreen(Component com); | ||
| 139 | |||
| 140 | /** | ||
| 141 | * Returns the most specific, visible, heavyweight Component | ||
| 142 | * under the cursor. This method should return null iff the cursor is | ||
| 143 | * not over any Java Window. | ||
| 144 | * | ||
| 145 | * @param useCache If true, the implementation is free to use caching | ||
| 146 | * mechanisms because the Z-order, visibility, and enabled state of the | ||
| 147 | * Components has not changed. If false, the implementation should not | ||
| 148 | * make these assumptions. | ||
| 149 | */ | ||
| 150 | protected abstract Component findHeavyweightUnderCursor(boolean useCache); | ||
| 151 | |||
| 152 | /** | ||
| 153 | * Updates the global cursor. We apply a three-step scheme to cursor | ||
| 154 | * updates:<p> | ||
| 155 | * | ||
| 156 | * (1) InputEvent updates which are outdated are discarded by | ||
| 157 | * <code>updateCursorImmediately(InputEvent)</code>.<p> | ||
| 158 | * | ||
| 159 | * (2) If 'useCache' is true, the native code is free to use a cached | ||
| 160 | * value to determine the most specific, visible, enabled heavyweight | ||
| 161 | * because this update is occuring in response to a mouse move. If | ||
| 162 | * 'useCache' is false, the native code must perform a new search given | ||
| 163 | * the current mouse coordinates. | ||
| 164 | * | ||
| 165 | * (3) Once we have determined the most specific, visible, enabled | ||
| 166 | * heavyweight, we use findComponentAt to find the most specific, visible, | ||
| 167 | * enabled Component. | ||
| 168 | */ | ||
| 169 | private void _updateCursor(boolean useCache) { | ||
| 170 | |||
| 171 | synchronized (lastUpdateLock) { | ||
| 172 | lastUpdateMillis = System.currentTimeMillis(); | ||
| 173 | } | ||
| 174 | |||
| 175 | Point queryPos = null, p = null; | ||
| 176 | Component comp; | ||
| 177 | |||
| 178 | try { | ||
| 179 | comp = findHeavyweightUnderCursor(useCache); | ||
| 180 | if (comp == null) { | ||
| 181 | updateCursorOutOfJava(); | ||
| 182 | return; | ||
| 183 | } | ||
| 184 | |||
| 185 | if (comp instanceof Window) { | ||
| 186 | p = AWTAccessor.getComponentAccessor().getLocation(comp); | ||
| 187 | } else if (comp instanceof Container) { | ||
| 188 | p = getLocationOnScreen(comp); | ||
| 189 | } | ||
| 190 | if (p != null) { | ||
| 191 | queryPos = new Point(); | ||
| 192 | getCursorPos(queryPos); | ||
| 193 | Component c = findComponentAt((Container)comp, | ||
| 194 | queryPos.x - p.x, | ||
| 195 | queryPos.y - p.y); | ||
| 196 | // If findComponentAt returns null, then something bad has | ||
| 197 | // happened. For example, the heavyweight Component may | ||
| 198 | // have been hidden or disabled by another thread. In that | ||
| 199 | // case, we'll just use the originial heavyweight. | ||
| 200 | if (c != null) { | ||
| 201 | comp = c; | ||
| 202 | } | ||
| 203 | } | ||
| 204 | |||
| 205 | setCursor(comp, AWTAccessor.getComponentAccessor().getCursor(comp), useCache); | ||
| 206 | |||
| 207 | } catch (IllegalComponentStateException e) { | ||
| 208 | // Shouldn't happen, but if it does, abort. | ||
| 209 | } | ||
| 210 | } | ||
| 211 | |||
| 212 | protected void updateCursorOutOfJava() { | ||
| 213 | // Cursor is not over a Java Window. Do nothing...usually | ||
| 214 | // But we need to update it in case of grab on X. | ||
| 215 | } | ||
| 216 | } | ||