1/*
2 * Copyright (c) 2003, 2008, 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
26package sun.java2d;
27
28import sun.awt.image.SunVolatileImage;
29import sun.awt.image.VolatileSurfaceManager;
30
31/**
32 * This factory creates platform specific VolatileSurfaceManager
33 * implementations.
34 *
35 * There are two platform specific SurfaceManagerFactories in OpenJDK,
36 * UnixSurfaceManagerFactory and WindowsSurfaceManagerFactory.
37 * The actually used SurfaceManagerFactory is set by the respective platform
38 * GraphicsEnvironment implementations in the static initializer.
39 */
40public abstract class SurfaceManagerFactory {
41
42    /**
43     * The single shared instance.
44     */
45    private static SurfaceManagerFactory instance;
46
47    /**
48     * Returns the surface manager factory instance. This returns a factory
49     * that has been set by {@link #setInstance(SurfaceManagerFactory)}.
50     *
51     * @return the surface manager factory
52     */
53    public static synchronized SurfaceManagerFactory getInstance() {
54
55        if (instance == null) {
56            throw new IllegalStateException("No SurfaceManagerFactory set.");
57        }
58        return instance;
59    }
60
61    /**
62     * Sets the surface manager factory. This may only be called once, and it
63     * may not be set back to {@code null} when the factory is already
64     * instantiated.
65     *
66     * @param factory the factory to set
67     */
68    public static synchronized void setInstance(SurfaceManagerFactory factory) {
69
70        if (factory == null) {
71            // We don't want to allow setting this to null at any time.
72            throw new IllegalArgumentException("factory must be non-null");
73        }
74
75        if (instance != null) {
76            // We don't want to re-set the instance at any time.
77            throw new IllegalStateException("The surface manager factory is already initialized");
78        }
79
80        instance = factory;
81    }
82
83    /**
84     * Creates a new instance of a VolatileSurfaceManager given any
85     * arbitrary SunVolatileImage.  An optional context Object can be supplied
86     * as a way for the caller to pass pipeline-specific context data to
87     * the VolatileSurfaceManager (such as a backbuffer handle, for example).
88     */
89     public abstract VolatileSurfaceManager
90         createVolatileManager(SunVolatileImage image, Object context);
91}
92