Java example source code file (LWRepaintArea.java)

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Java - Java tags/keywords

awt, component, graphics, lwcomponentpeer, lwrepaintarea, object, override

The LWRepaintArea.java Java example source code

/*
 * Copyright (c) 2011, 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.lwawt;

import java.awt.Component;
import java.awt.Graphics;

import sun.awt.AWTAccessor;
import sun.awt.RepaintArea;

/**
 * Emulates appearance of heavyweight components before call of the user code.
 *
 * @author Sergey Bylokhov
 */
final class LWRepaintArea extends RepaintArea {

    @Override
    protected void updateComponent(final Component comp, final Graphics g) {
        // We shouldn't paint native component as a result of UPDATE events,
        // just flush onscreen back-buffer.
        if (comp != null) {
            super.updateComponent(comp, g);
            LWComponentPeer.flushOnscreenGraphics();
        }
    }

    @Override
    protected void paintComponent(final Component comp, final Graphics g) {
        if (comp != null) {
            Object peer = AWTAccessor.getComponentAccessor().getPeer(comp);
            if (peer != null) {
                ((LWComponentPeer<?, ?>) peer).paintPeer(g);
            }
            super.paintComponent(comp, g);
            LWComponentPeer.flushOnscreenGraphics();
        }
    }
}