1 /*
2 * Copyright (c) 2007, 2013, 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.java2d.pipe.hw;
27
28 import java.util.Collections;
29 import java.util.HashMap;
30 import java.util.Iterator;
31 import java.util.Map;
32 import java.util.Set;
33 import java.lang.annotation.Native;
34
35
36 /**
37 * This class is used to notify listeners about accelerated device's
38 * events such as device reset or dispose that are about to occur.
39 */
40 public class AccelDeviceEventNotifier {
41
42 private static AccelDeviceEventNotifier theInstance;
43
44 /**
45 * A device is about to be reset. The listeners have to release all
46 * resources associated with the device which are required for the device
47 * to be reset.
48 */
49 @Native public static final int DEVICE_RESET = 0;
50
51 /**
52 * A device is about to be disposed. The listeners have to release all
53 * resources associated with the device.
54 */
55 @Native public static final int DEVICE_DISPOSED = 1;
56
57 private final Map<AccelDeviceEventListener, Integer> listeners;
58
59 private AccelDeviceEventNotifier() {
60 listeners = Collections.synchronizedMap(
61 new HashMap<AccelDeviceEventListener, Integer>(1));
62 }
63
64 /**
65 * Returns a singleton of AccelDeviceEventNotifier if it exists. If the
66 * passed boolean is false and singleton doesn't exist yet, null is
67 * returned. If the passed boolean is {@code true} and singleton doesn't
68 * exist it will be created and returned.
69 *
70 * @param create whether to create a singleton instance if doesn't yet
71 * exist
72 * @return a singleton instance or null
73 */
74 private static synchronized
75 AccelDeviceEventNotifier getInstance(boolean create)
76 {
77 if (theInstance == null && create) {
78 theInstance = new AccelDeviceEventNotifier();
79 }
80 return theInstance;
81 }
82
83 /**
84 * Called to indicate that a device event had occurred.
85 * If a singleton exists, the listeners (those associated with
86 * the device) will be notified.
87 *
88 * @param screen a screen number of the device which is a source of
89 * the event
90 * @param eventType a type of the event
91 * @see #DEVICE_DISPOSED
92 * @see #DEVICE_RESET
93 */
94 public static final void eventOccured(int screen, int eventType) {
95 AccelDeviceEventNotifier notifier = getInstance(false);
96 if (notifier != null) {
97 notifier.notifyListeners(eventType, screen);
98 }
99 }
100
101 /**
102 * Adds the listener associated with a device on particular screen.
103 *
104 * Note: the listener must be removed as otherwise it will forever
105 * be referenced by the notifier.
106 *
107 * @param l the listener
108 * @param screen the screen number indicating which device the listener is
109 * interested in.
110 */
111 public static final void addListener(AccelDeviceEventListener l,int screen){
112 getInstance(true).add(l, screen);
113 }
114
115 /**
116 * Removes the listener.
117 *
118 * @param l the listener
119 */
120 public static final void removeListener(AccelDeviceEventListener l) {
121 getInstance(true).remove(l);
122 }
123
124 private final void add(AccelDeviceEventListener theListener, int screen) {
125 listeners.put(theListener, screen);
126 }
127 private final void remove(AccelDeviceEventListener theListener) {
128 listeners.remove(theListener);
129 }
130
131 /**
132 * Notifies the listeners associated with the screen's device about the
133 * event.
134 *
135 * Implementation note: the current list of listeners is first duplicated
136 * which allows the listeners to remove themselves during the iteration.
137 *
138 * @param screen a screen number with which the device which is a source of
139 * the event is associated with
140 * @param eventType a type of the event
141 * @see #DEVICE_DISPOSED
142 * @see #DEVICE_RESET
143 */
144 private final void notifyListeners(int deviceEventType, int screen) {
145 HashMap<AccelDeviceEventListener, Integer> listClone;
146 Set<AccelDeviceEventListener> cloneSet;
147
148 synchronized(listeners) {
149 listClone =
150 new HashMap<AccelDeviceEventListener, Integer>(listeners);
151 }
152
153 cloneSet = listClone.keySet();
154 Iterator<AccelDeviceEventListener> itr = cloneSet.iterator();
155 while (itr.hasNext()) {
156 AccelDeviceEventListener current = itr.next();
157 Integer i = listClone.get(current);
158 // only notify listeners which are interested in this device
159 if (i != null && i.intValue() != screen) {
160 continue;
161 }
162 if (deviceEventType == DEVICE_RESET) {
163 current.onDeviceReset();
164 } else if (deviceEventType == DEVICE_DISPOSED) {
165 current.onDeviceDispose();
166 }
167 }
168 }
169 }