jdk/src/java.desktop/share/classes/sun/java2d/pipe/hw/AccelDeviceEventNotifier.java
changeset 25859 3317bb8137f4
parent 21278 ef8a3a2a72f2
child 30948 0a0972d3b58d
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/jdk/src/java.desktop/share/classes/sun/java2d/pipe/hw/AccelDeviceEventNotifier.java	Sun Aug 17 15:54:13 2014 +0100
@@ -0,0 +1,169 @@
+/*
+ * Copyright (c) 2007, 2013, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.  Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the LICENSE file that accompanied this code.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+package sun.java2d.pipe.hw;
+
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.Iterator;
+import java.util.Map;
+import java.util.Set;
+import java.lang.annotation.Native;
+
+
+/**
+ * This class is used to notify listeners about accelerated device's
+ * events such as device reset or dispose that are about to occur.
+ */
+public class AccelDeviceEventNotifier {
+
+    private static AccelDeviceEventNotifier theInstance;
+
+    /**
+     * A device is about to be reset. The listeners have to release all
+     * resources associated with the device which are required for the device
+     * to be reset.
+     */
+    @Native public static final int DEVICE_RESET = 0;
+
+    /**
+     * A device is about to be disposed. The listeners have to release all
+     * resources associated with the device.
+     */
+    @Native public static final int DEVICE_DISPOSED = 1;
+
+    private final Map<AccelDeviceEventListener, Integer> listeners;
+
+    private AccelDeviceEventNotifier() {
+        listeners = Collections.synchronizedMap(
+            new HashMap<AccelDeviceEventListener, Integer>(1));
+    }
+
+    /**
+     * Returns a singleton of AccelDeviceEventNotifier if it exists. If the
+     * passed boolean is false and singleton doesn't exist yet, null is
+     * returned. If the passed boolean is {@code true} and singleton doesn't
+     * exist it will be created and returned.
+     *
+     * @param create whether to create a singleton instance if doesn't yet
+     * exist
+     * @return a singleton instance or null
+     */
+    private static synchronized
+        AccelDeviceEventNotifier getInstance(boolean create)
+    {
+        if (theInstance == null && create) {
+            theInstance = new AccelDeviceEventNotifier();
+        }
+        return theInstance;
+    }
+
+    /**
+     * Called to indicate that a device event had occurred.
+     * If a singleton exists, the listeners (those associated with
+     * the device) will be notified.
+     *
+     * @param screen a screen number of the device which is a source of
+     * the event
+     * @param eventType a type of the event
+     * @see #DEVICE_DISPOSED
+     * @see #DEVICE_RESET
+     */
+    public static final void eventOccured(int screen, int eventType) {
+        AccelDeviceEventNotifier notifier = getInstance(false);
+        if (notifier != null) {
+            notifier.notifyListeners(eventType, screen);
+        }
+    }
+
+    /**
+     * Adds the listener associated with a device on particular screen.
+     *
+     * Note: the listener must be removed as otherwise it will forever
+     * be referenced by the notifier.
+     *
+     * @param l the listener
+     * @param screen the screen number indicating which device the listener is
+     * interested in.
+     */
+    public static final void addListener(AccelDeviceEventListener l,int screen){
+        getInstance(true).add(l, screen);
+    }
+
+    /**
+     * Removes the listener.
+     *
+     * @param l the listener
+     */
+    public static final void removeListener(AccelDeviceEventListener l) {
+        getInstance(true).remove(l);
+    }
+
+    private final void add(AccelDeviceEventListener theListener, int screen) {
+        listeners.put(theListener, screen);
+    }
+    private final void remove(AccelDeviceEventListener theListener) {
+        listeners.remove(theListener);
+    }
+
+    /**
+     * Notifies the listeners associated with the screen's device about the
+     * event.
+     *
+     * Implementation note: the current list of listeners is first duplicated
+     * which allows the listeners to remove themselves during the iteration.
+     *
+     * @param screen a screen number with which the device which is a source of
+     * the event is associated with
+     * @param eventType a type of the event
+     * @see #DEVICE_DISPOSED
+     * @see #DEVICE_RESET
+     */
+    private final void notifyListeners(int deviceEventType, int screen) {
+        HashMap<AccelDeviceEventListener, Integer> listClone;
+        Set<AccelDeviceEventListener> cloneSet;
+
+        synchronized(listeners) {
+            listClone =
+                new HashMap<AccelDeviceEventListener, Integer>(listeners);
+        }
+
+        cloneSet = listClone.keySet();
+        Iterator<AccelDeviceEventListener> itr = cloneSet.iterator();
+        while (itr.hasNext()) {
+            AccelDeviceEventListener current = itr.next();
+            Integer i = listClone.get(current);
+            // only notify listeners which are interested in this device
+            if (i != null && i.intValue() != screen) {
+                continue;
+            }
+            if (deviceEventType == DEVICE_RESET) {
+                current.onDeviceReset();
+            } else if (deviceEventType == DEVICE_DISPOSED) {
+                current.onDeviceDispose();
+            }
+        }
+    }
+}