/*
 * 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
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package javax.swing;

import java.awt.Component;
import java.awt.Container;
import java.awt.Rectangle;
import java.awt.event.PaintEvent;
import java.security.AccessController;
import sun.awt.AppContext;
import sun.awt.SunToolkit;
import sun.awt.event.IgnorePaintEvent;
import sun.security.action.GetBooleanAction;
import sun.security.action.GetPropertyAction;

Swing's PaintEventDispatcher. If the component specified by the PaintEvent is a top level Swing component (JFrame, JWindow, JDialog, JApplet), this will forward the request to the RepaintManager for eventual painting.
/** * Swing's PaintEventDispatcher. If the component specified by the PaintEvent * is a top level Swing component (JFrame, JWindow, JDialog, JApplet), this * will forward the request to the RepaintManager for eventual painting. * */
class SwingPaintEventDispatcher extends sun.awt.PaintEventDispatcher { private static final boolean SHOW_FROM_DOUBLE_BUFFER; private static final boolean ERASE_BACKGROUND; static { SHOW_FROM_DOUBLE_BUFFER = "true".equals(AccessController.doPrivileged( new GetPropertyAction("swing.showFromDoubleBuffer", "true"))); ERASE_BACKGROUND = AccessController.doPrivileged( new GetBooleanAction("swing.nativeErase")); } public PaintEvent createPaintEvent(Component component, int x, int y, int w, int h) { if (component instanceof RootPaneContainer) { AppContext appContext = SunToolkit.targetToAppContext(component); RepaintManager rm = RepaintManager.currentManager(appContext); if (!SHOW_FROM_DOUBLE_BUFFER || !rm.show((Container)component, x, y, w, h)) { rm.nativeAddDirtyRegion(appContext, (Container)component, x, y, w, h); } // For backward compatibility generate an empty paint // event. Not doing this broke parts of Netbeans. return new IgnorePaintEvent(component, PaintEvent.PAINT, new Rectangle(x, y, w, h)); } else if (component instanceof SwingHeavyWeight) { AppContext appContext = SunToolkit.targetToAppContext(component); RepaintManager rm = RepaintManager.currentManager(appContext); rm.nativeAddDirtyRegion(appContext, (Container)component, x, y, w, h); return new IgnorePaintEvent(component, PaintEvent.PAINT, new Rectangle(x, y, w, h)); } return super.createPaintEvent(component, x, y, w, h); } public boolean shouldDoNativeBackgroundErase(Component c) { return ERASE_BACKGROUND || !(c instanceof RootPaneContainer); } public boolean queueSurfaceDataReplacing(Component c, Runnable r) { if (c instanceof RootPaneContainer) { AppContext appContext = SunToolkit.targetToAppContext(c); RepaintManager.currentManager(appContext). nativeQueueSurfaceDataRunnable(appContext, c, r); return true; } return super.queueSurfaceDataReplacing(c, r); } }