libjava/java/awt/ColorPaintContext.java

   1 /* ColorPaintContext.java -- context for painting solid colors
   2    Copyright (C) 2002, 2004, 2005  Free Software Foundation, Inc.
   3
   4 This file is part of GNU Classpath.
   5
   6 GNU Classpath is free software; you can redistribute it and/or modify
   7 it under the terms of the GNU General Public License as published by
   8 the Free Software Foundation; either version 2, or (at your option)
   9 any later version.
  10
  11 GNU Classpath is distributed in the hope that it will be useful, but
  12 WITHOUT ANY WARRANTY; without even the implied warranty of
  13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14 General Public License for more details.
  15
  16 You should have received a copy of the GNU General Public License
  17 along with GNU Classpath; see the file COPYING.  If not, write to the
  18 Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  19 02111-1307 USA.
  20
  21 Linking this library statically or dynamically with other modules is
  22 making a combined work based on this library.  Thus, the terms and
  23 conditions of the GNU General Public License cover the whole
  24 combination.
  25
  26 As a special exception, the copyright holders of this library give you
  27 permission to link this library with independent modules to produce an
  28 executable, regardless of the license terms of these independent
  29 modules, and to copy and distribute the resulting executable under
  30 terms of your choice, provided that you also meet, for each linked
  31 independent module, the terms and conditions of the license of that
  32 module.  An independent module is a module which is not derived from
  33 or based on this library.  If you modify this library, you may extend
  34 this exception to your version of the library, but you are not
  35 obligated to do so.  If you do not wish to do so, delete this
  36 exception statement from your version. */
  37
  38
  39 package java.awt;
  40
  41 import java.awt.image.ColorModel;
  42 import java.awt.image.Raster;
  43
  44 /**
  45  * This class provides a paint context which will fill a rectanglar region of
  46  * a raster scan with the given color. However, it is not yet completely
  47  * implemented.
  48  *
  49  * @author Eric Blake (ebb9@email.byu.edu)
  50  */
  51 class ColorPaintContext implements PaintContext
  52 {
  53   /**
  54    * The color to fill any raster with. Package visible for use in
  55    * SystemColor.
  56    */
  57   final int color;
  58   final ColorModel colorModel;
  59
  60   private ColorRaster cachedRaster;
  61
  62
  63   /**
  64    * Create the context for a given color.
  65    *
  66    * @param c The solid color to use.
  67    */
  68   ColorPaintContext(int colorRGB)
  69   {
  70     this(ColorModel.getRGBdefault(), colorRGB);
  71   }
  72
  73   /**
  74    * Create the context for a given color.
  75    *
  76    * @param cm The color model of this context.
  77    * @param c The solid color to use.
  78    */
  79   ColorPaintContext(ColorModel cm,int colorRGB)
  80   {
  81     color = colorRGB;
  82     colorModel = cm;
  83   }
  84
  85   /**
  86    * Release the resources allocated for the paint. As the color is constant,
  87    * there aren't any resources.
  88    */
  89   public void dispose()
  90   {
  91   }
  92
  93   /**
  94    * Return the color model of this context.
  95    *
  96    * @return the context color model
  97    */
  98   public ColorModel getColorModel()
  99   {
 100     return colorModel;
 101   }
 102
 103   /**
 104    * Return a raster containing the colors for the graphics operation.
 105    *
 106    * @param x the x-coordinate, in device space
 107    * @param y the y-coordinate, in device space
 108    * @param w the width, in device space
 109    * @param h the height, in device space
 110    * @return a raster for the given area and color
 111    */
 112   public Raster getRaster(int x, int y, int width, int height)
 113   {
 114    if(  cachedRaster == null
 115        || cachedRaster.getWidth() < width
 116        || cachedRaster.getHeight() < height)
 117    {
 118      cachedRaster = new ColorRaster(colorModel, 0, 0, width, height, color);
 119    }
 120    return cachedRaster.createChild(0 ,0 ,width ,height ,x ,y , null);
 121   }
 122
 123   /**
 124    * A ColorRaster is a raster that is completely filled with one color. The
 125    * data layout is taken from the color model given to the constructor.
 126    */
 127   private class ColorRaster extends Raster
 128   {
 129
 130     /**
 131      * Create a raster that is compaltible with the given color model and
 132      * filled with the given color.
 133      * @param cm The color model for this raster.
 134      * @param x The smallest horizontal corrdinate in the raster.
 135      * @param y The smallest vertical coordinate in the raster.
 136      * @param width The width of the raster.
 137      * @param height The height of the raster.
 138      * @param rgbPixel The RGB value of the color for this raster.
 139      */
 140     ColorRaster(ColorModel cm,int x, int y, int width, int height, int rgbPixel)
 141     {
 142       super(cm.createCompatibleSampleModel(width,height),new Point(x,y));
 143       Object pixel = cm.getDataElements(rgbPixel,null);
 144       getSampleModel().setDataElements(0, 0,
 145                                        width, height,
 146                                        multiplyData(pixel,null,width*height),
 147                                        dataBuffer);
 148     }
 149
 150
 151
 152     private Object multiplyData(Object src, Object dest, int factor)
 153     {
 154       Object from;
 155       int srcLength = 0;
 156       if (src instanceof byte[])
 157       {
 158         srcLength = ((byte[])src).length;
 159
 160         if (dest == null) dest = new byte[factor * srcLength];
 161       }
 162       else if (src instanceof short[])
 163       {
 164         srcLength = ((short[])src).length;
 165         if (dest == null) dest = new short[factor * srcLength];
 166       }
 167       else if (src instanceof int[])
 168       {
 169         srcLength = ((int[]) src).length;
 170         if (dest == null) dest = new int[factor * srcLength];
 171       }
 172       else
 173       {
 174         throw new ClassCastException("Unknown data buffer type");
 175       }
 176
 177       System.arraycopy(src,0,dest,0,srcLength);
 178
 179       int count = 1;
 180       while(count*2 < factor)
 181       {
 182         System.arraycopy(dest, 0, dest, count * srcLength, count*srcLength);
 183         count *= 2;
 184       }
 185
 186       if(factor > count)
 187         System.arraycopy(dest,0, dest, count * srcLength,
 188                          (factor - count) * srcLength );
 189
 190       return dest;
 191     }
 192
 193   }
 194
 195 } // class ColorPaintContext