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/* * Copyright (c) 2005, 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.awt; import java.awt.Component;import java.awt.Rectangle;import java.awt.event.PaintEvent; /** * PaintEventDispatcher is responsible for dispatching PaintEvents.  There * can be only one PaintEventDispatcher active at a particular time. * */public class PaintEventDispatcher {    /**     * Singleton dispatcher.     */    private static PaintEventDispatcher dispatcher;     /**     * Sets the current <code>PaintEventDispatcher</code>.     *     * @param dispatcher PaintEventDispatcher     */    public static void setPaintEventDispatcher(                          PaintEventDispatcher dispatcher) {        synchronized(PaintEventDispatcher.class) {            PaintEventDispatcher.dispatcher = dispatcher;        }    }     /**     * Returns the currently active <code>PaintEventDispatcher</code>.  This     * will never return null.     *     * @return PaintEventDispatcher     */    public static PaintEventDispatcher getPaintEventDispatcher() {        synchronized(PaintEventDispatcher.class) {            if (dispatcher == null) {                dispatcher = new PaintEventDispatcher();            }            return dispatcher;        }    }     /**     * Creates and returns the <code>PaintEvent</code> that should be     * dispatched for the specified component.  If this returns null     * no <code>PaintEvent</code> is dispatched.     * <p>     * <b>WARNING:</b> This is invoked from the native thread, be careful     * what methods you end up invoking here.     */    public PaintEvent createPaintEvent(Component target, int x, int y, int w,                                       int h) {         return new PaintEvent((Component)target, PaintEvent.PAINT,                              new Rectangle(x, y, w, h));    }     /**     * Returns true if a native background erase should be done for     * the specified Component.     */    public boolean shouldDoNativeBackgroundErase(Component c) {        return true;    }     /**     * This method is invoked from the toolkit thread when the surface     * data of the component needs to be replaced. The method run() of     * the Runnable argument performs surface data replacing, run()     * should be invoked on the EDT of this component's AppContext.     * Returns true if the Runnable has been enqueued to be invoked     * on the EDT.     * (Fix 6255371.)     */    public boolean queueSurfaceDataReplacing(Component c, Runnable r) {        return false;    }}