/* * Copyright (c) 2003, 2008, 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; import sun.awt.image.SunVolatileImage;import sun.awt.image.VolatileSurfaceManager; /** * This factory creates platform specific VolatileSurfaceManager * implementations. * * There are two platform specific SurfaceManagerFactories in OpenJDK, * UnixSurfaceManagerFactory and WindowsSurfaceManagerFactory. * The actually used SurfaceManagerFactory is set by the respective platform * GraphicsEnvironment implementations in the static initializer. */public abstract class SurfaceManagerFactory {     /**     * The single shared instance.     */    private static SurfaceManagerFactory instance;     /**     * Returns the surface manager factory instance. This returns a factory     * that has been set by {@link #setInstance(SurfaceManagerFactory)}.     *     * @return the surface manager factory     */    public synchronized static SurfaceManagerFactory getInstance() {         if (instance == null) {            throw new IllegalStateException("No SurfaceManagerFactory set.");        }        return instance;    }     /**     * Sets the surface manager factory. This may only be called once, and it     * may not be set back to {@code null} when the factory is already     * instantiated.     *     * @param factory the factory to set     */    public synchronized static void setInstance(SurfaceManagerFactory factory) {         if (factory == null) {            // We don't want to allow setting this to null at any time.            throw new IllegalArgumentException("factory must be non-null");        }         if (instance != null) {            // We don't want to re-set the instance at any time.            throw new IllegalStateException("The surface manager factory is already initialized");        }         instance = factory;    }     /**     * Creates a new instance of a VolatileSurfaceManager given any     * arbitrary SunVolatileImage.  An optional context Object can be supplied     * as a way for the caller to pass pipeline-specific context data to     * the VolatileSurfaceManager (such as a backbuffer handle, for example).     */     public abstract VolatileSurfaceManager         createVolatileManager(SunVolatileImage image, Object context);}