1 /*
   2  * Copyright (c) 2011, 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 
  26 
  27 package sun.lwawt;
  28 
  29 import sun.awt.CGraphicsConfig;
  30 
  31 import java.awt.BufferCapabilities;
  32 import java.awt.BufferCapabilities.FlipContents;
  33 import java.awt.Canvas;
  34 import java.awt.Component;
  35 import java.awt.Graphics;
  36 import java.awt.Graphics2D;
  37 import java.awt.GraphicsConfiguration;
  38 import java.awt.Image;
  39 import java.awt.image.VolatileImage;
  40 import java.awt.peer.CanvasPeer;
  41 
  42 import javax.swing.JComponent;
  43 
  44 final class LWCanvasPeer extends LWComponentPeer<Component, JComponent>
  45         implements CanvasPeer {
  46 
  47     /**
  48      * The back buffer provide user with a BufferStrategy.
  49      */
  50     private VolatileImage backBuffer;
  51 
  52     LWCanvasPeer(final Canvas target,
  53                  final PlatformComponent platformComponent) {
  54         super(target, platformComponent);
  55     }
  56 
  57     @Override
  58     public void createBuffers(final int numBuffers,
  59                               final BufferCapabilities caps) {
  60         //TODO parameters should be used.
  61         final CGraphicsConfig gc = (CGraphicsConfig) getGraphicsConfiguration();
  62         final VolatileImage buffer = gc.createBackBufferImage(getTarget(), 0);
  63         synchronized (getStateLock()) {
  64             backBuffer = buffer;
  65         }
  66     }
  67 
  68     @Override
  69     public Image getBackBuffer() {
  70         synchronized (getStateLock()) {
  71             return backBuffer;
  72         }
  73     }
  74 
  75     @Override
  76     public void flip(final int x1, final int y1, final int x2, final int y2,
  77                      final FlipContents flipAction) {
  78         final VolatileImage buffer = (VolatileImage) getBackBuffer();
  79         if (buffer == null) {
  80             throw new IllegalStateException("Buffers have not been created");
  81         }
  82         final Graphics g = getGraphics();
  83         try {
  84             g.drawImage(buffer, x1, y1, x2, y2, x1, y1, x2, y2, null);
  85         } finally {
  86             g.dispose();
  87         }
  88         if (flipAction == FlipContents.BACKGROUND) {
  89             final Graphics2D bg = (Graphics2D) buffer.getGraphics();
  90             try {
  91                 bg.setBackground(getBackground());
  92                 bg.clearRect(0, 0, buffer.getWidth(), buffer.getHeight());
  93             } finally {
  94                 bg.dispose();
  95             }
  96         }
  97     }
  98 
  99     @Override
 100     public void destroyBuffers() {
 101         final Image buffer = getBackBuffer();
 102         if (buffer != null) {
 103             synchronized (getStateLock()) {
 104                 if (buffer == backBuffer) {
 105                     backBuffer = null;
 106                 }
 107             }
 108             buffer.flush();
 109         }
 110     }
 111 
 112     @Override
 113     public GraphicsConfiguration getAppropriateGraphicsConfiguration(
 114             GraphicsConfiguration gc)
 115     {
 116         // TODO
 117         return gc;
 118     }
 119 }