1 /*
   2  * Copyright (c) 2002, 2007, 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 package sun.java2d;
  27 
  28 import java.awt.Rectangle;
  29 import java.awt.image.Raster;
  30 import java.awt.image.ColorModel;
  31 import java.awt.GraphicsConfiguration;
  32 
  33 import sun.java2d.StateTrackable.State;
  34 import sun.java2d.loops.SurfaceType;
  35 import sun.java2d.pipe.NullPipe;
  36 
  37 /**
  38  * This class provides an empty implementation of the SurfaceData
  39  * abstract superclass.  All operations on it translate into NOP
  40  * or harmless operations.
  41  */
  42 public class NullSurfaceData extends SurfaceData {
  43     public static final SurfaceData theInstance = new NullSurfaceData();
  44 
  45     private NullSurfaceData() {
  46         super(State.IMMUTABLE, SurfaceType.Any, ColorModel.getRGBdefault());
  47     }
  48 
  49     /**
  50      * Sets this SurfaceData object to the invalid state.  All Graphics
  51      * objects must get a new SurfaceData object via the refresh method
  52      * and revalidate their pipelines before continuing.
  53      */
  54     public void invalidate() {
  55     }
  56 
  57     /**
  58      * Return a new SurfaceData object that represents the current state
  59      * of the destination that this SurfaceData object describes.
  60      * This method is typically called when the SurfaceData is invalidated.
  61      */
  62     public SurfaceData getReplacement() {
  63         return this;
  64     }
  65 
  66     private final static NullPipe nullpipe = new NullPipe();
  67 
  68     public void validatePipe(SunGraphics2D sg2d) {
  69         sg2d.drawpipe = nullpipe;
  70         sg2d.fillpipe = nullpipe;
  71         sg2d.shapepipe = nullpipe;
  72         sg2d.textpipe = nullpipe;
  73         sg2d.imagepipe = nullpipe;
  74     }
  75 
  76     public GraphicsConfiguration getDeviceConfiguration() {
  77         return null;
  78     }
  79 
  80     /**
  81      * Return a readable Raster which contains the pixels for the
  82      * specified rectangular region of the destination surface.
  83      * The coordinate origin of the returned Raster is the same as
  84      * the device space origin of the destination surface.
  85      * In some cases the returned Raster might also be writeable.
  86      * In most cases, the returned Raster might contain more pixels
  87      * than requested.
  88      *
  89      * @see #useTightBBoxes
  90      */
  91     public Raster getRaster(int x, int y, int w, int h) {
  92         throw new InvalidPipeException("should be NOP");
  93     }
  94 
  95     /**
  96      * Does the pixel accessibility of the destination surface
  97      * suggest that rendering algorithms might want to take
  98      * extra time to calculate a more accurate bounding box for
  99      * the operation being performed?
 100      * The typical case when this will be true is when a copy of
 101      * the pixels has to be made when doing a getRaster.  The
 102      * fewer pixels copied, the faster the operation will go.
 103      *
 104      * @see #getRaster
 105      */
 106     public boolean useTightBBoxes() {
 107         return false;
 108     }
 109 
 110     /**
 111      * Returns the pixel data for the specified Argb value packed
 112      * into an integer for easy storage and conveyance.
 113      */
 114     public int pixelFor(int rgb) {
 115         return rgb;
 116     }
 117 
 118     /**
 119      * Returns the Argb representation for the specified integer value
 120      * which is packed in the format of the associated ColorModel.
 121      */
 122     public int rgbFor(int pixel) {
 123         return pixel;
 124     }
 125 
 126     /**
 127      * Returns the bounds of the destination surface.
 128      */
 129     public Rectangle getBounds() {
 130         return new Rectangle();
 131     }
 132 
 133     /**
 134      * Performs Security Permissions checks to see if a Custom
 135      * Composite object should be allowed access to the pixels
 136      * of this surface.
 137      */
 138     protected void checkCustomComposite() {
 139         return;
 140     }
 141 
 142     /**
 143      * Performs a copyarea within this surface.  Returns
 144      * false if there is no algorithm to perform the copyarea
 145      * given the current settings of the SunGraphics2D.
 146      */
 147     public boolean copyArea(SunGraphics2D sg2d,
 148                             int x, int y, int w, int h, int dx, int dy)
 149     {
 150         return true;
 151     }
 152 
 153     /**
 154      * Returns destination Image associated with this SurfaceData (null)
 155      */
 156     public Object getDestination() {
 157         return null;
 158     }
 159 }