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 deviceEventType 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 }