libjava/gnu/awt/xlib/XOffScreenImage.java

   1 /* Copyright (C) 2000, 2003  Free Software Foundation
   2
   3    This file is part of libgcj.
   4
   5 This software is copyrighted work licensed under the terms of the
   6 Libgcj License.  Please consult the file "LIBGCJ_LICENSE" for
   7 details.  */
   8
   9 package gnu.awt.xlib;
  10
  11 import java.awt.Image;
  12 import java.awt.Graphics;
  13 import java.awt.Graphics2D;
  14 import java.awt.GraphicsConfiguration;
  15 import java.awt.image.ColorModel;
  16 import java.awt.image.ImageObserver;
  17 import java.awt.image.ImageProducer;
  18 import java.util.Hashtable;
  19 import gnu.awt.j2d.DirectRasterGraphics;
  20 import gnu.awt.j2d.Graphics2DImpl;
  21 import gnu.awt.j2d.IntegerGraphicsState;
  22 import gnu.gcj.xlib.Drawable;
  23 import gnu.gcj.xlib.Pixmap;
  24 import gnu.gcj.xlib.Screen;
  25 import gnu.gcj.xlib.Visual;
  26
  27 /** Image class for xlib off-screen buffers.
  28  * The image is stored in a server-side pixmap for best performance.
  29  * This class supports getGraphics, so you can draw on the pixmap, and is
  30  * specially handled when doing drawImage, so that the image copy is done
  31  * entirely in the X server.
  32  * This class does not support rasterization, for which you'd need an XImage.
  33  *
  34  * @author  scott gilbertson <scottg@mantatest.com> <sgilbertson@cogeco.ca>
  35  */
  36 public class XOffScreenImage extends Image
  37                              implements IntegerGraphicsState.ScreenCoupledImage
  38 {
  39   private Pixmap pixmap;
  40   private XGraphicsConfiguration config;
  41   private int width;
  42   private int height;
  43
  44   /** Create a new XOffScreenImage
  45    * @param config Graphics configuration, to compare against on-screen
  46    *               components and to create the appropriate Graphics
  47    * @param drawable The drawable with which the image is compatible
  48    * @param width The width of the image
  49    * @param height The height of the image
  50    */
  51   XOffScreenImage (XGraphicsConfiguration config, Drawable drawable, int width, int height)
  52   {
  53     this.config = config;
  54     this.width = width;
  55     this.height = height;
  56     pixmap = new Pixmap (drawable, width, height, drawable.getDepth ());
  57   }
  58
  59   /** Get the pixmap which contains this image
  60    * @return The pixmap
  61    */
  62   public Pixmap getPixmap ()
  63   {
  64     return pixmap;
  65   }
  66
  67   /** Flushes (that is, destroys) any resources used for this image.  This
  68    * includes the actual image data.
  69    */
  70   public void flush ()
  71   {
  72     // FIXME: should dispose pixmap
  73     pixmap = null;
  74   }
  75
  76   /** Returns a graphics context object for drawing an off-screen object.
  77    * This method is only valid for off-screen objects.
  78    *
  79    * @return a graphics context object for an off-screen object
  80    * @see Graphics#createImage(int, int)
  81    */
  82   public Graphics getGraphics ()
  83   {
  84     DirectRasterGraphics gfxDevice = new XGraphics (pixmap, config);
  85     IntegerGraphicsState igState = new IntegerGraphicsState (gfxDevice);
  86     Graphics2DImpl gfx2d = new Graphics2DImpl (config);
  87     gfx2d.setState (igState);
  88     return gfx2d;
  89   }
  90
  91   /** Returns the height of the image, or -1 if it is unknown.  If the
  92    * image height is unknown, the observer object will be notified when
  93    * the value is known.
  94    *
  95    * @param observer the image observer for this object
  96    * @return the height in pixels
  97    * @see #getWidth(ImageObserver)
  98    */
  99   public int getHeight (ImageObserver observer)
 100   {
 101     return height;
 102   }
 103
 104   /** Returns the height of the image, or -1 if it is unknown.  If the
 105    * image height is unknown, the observer object will be notified when
 106    * the value is known.
 107    *
 108    * @return the height in pixels
 109    * @see #getWidth()
 110    */
 111   public int getHeight ()
 112   {
 113     return height;
 114   }
 115
 116   /** Returns the image producer object for this object. The producer is the
 117    * object which generates pixels for this image.
 118    *
 119    * @return the image producer for this object
 120    */
 121   public ImageProducer getSource ()
 122   {
 123     throw new UnsupportedOperationException ("getSource not supported");
 124   }
 125
 126   /** Returns the width of the image, or -1 if it is unknown.  If the
 127    * image width is unknown, the observer object will be notified when
 128    * the value is known.
 129    *
 130    * @param observer the image observer for this object
 131    * @return the width in pixels
 132    * @see #getHeight(ImageObserver)
 133    */
 134   public int getWidth (ImageObserver observer)
 135   {
 136     return width;
 137   }
 138
 139   /** Returns the width of the image, or -1 if it is unknown.  If the
 140    * image width is unknown, the observer object will be notified when
 141    * the value is known.
 142    *
 143    * @return the width in pixels
 144    * @see #getHeight()
 145    */
 146   public int getWidth ()
 147   {
 148     return width;
 149   }
 150
 151   /** This method requests a named property for an object.  The value of the
 152    * property is returned. The value <code>UndefinedProperty</code> is
 153    * returned if there is no property with the specified name.  The value
 154    * <code>null</code> is returned if the properties for the object are
 155    * not yet known.  In this case, the specified image observer is notified
 156    * when the properties are known.
 157    *
 158    * @param name the requested property name
 159    * @param observer the image observer for this object
 160    * @return the named property, if available
 161    * @see #UndefinedProperty
 162    */
 163   public Object getProperty (String name, ImageObserver observer)
 164   {
 165     return null;
 166   }
 167
 168   /** Get the GraphicsConfiguration to which this image is coupled
 169    * @return the GraphicsConfiguration
 170    */
 171   public GraphicsConfiguration getGraphicsConfiguration ()
 172   {
 173     return config;
 174   }
 175 }