libjava/gnu/gcj/xlib/GC.java

/* Copyright (C) 2000  Free Software Foundation

   This file is part of libgcj.

This software is copyrighted work licensed under the terms of the
Libgcj License.  Please consult the file "LIBGCJ_LICENSE" for
details.  */

package gnu.gcj.xlib;

import gnu.gcj.RawData;
import java.awt.Rectangle;

/**
 * An X11 graphics context.  Unlike a traditional X11 graphics
 * context, the target drawable is part of the GC state.
 *
 * Implementation notes: There is no need to do coalescing of changes
 * since Xlib will do this for us.  The implementation relies on the
 * Xlib GC cache and will not try to be clever.
 *
 * @author Rolf W. Rasmussen <rolfwr@ii.uib.no>
 */
public class GC implements Cloneable
{
  
  public GC(Drawable target)
  {
    this.target = target;
    initStructure(null);
  }

  public Object clone()
  {
    GC gcClone = (GC) super.clone();
    gcClone.structure = null;
    gcClone.initStructure(this);
    gcClone.updateClip();
    return gcClone;
  }

  private native void initStructure(GC copyFrom);

  public GC create()
  {
    return (GC) clone();
  }

  public void finalize()
  {
    disposeImpl();
  }

  public void dispose()
  {
    disposeImpl();
  }

  public synchronized native void disposeImpl();

  public native void setForeground(long pixel);
  public native void setFont(gnu.gcj.xlib.Font font);

  /**
   * Set the clip region for the graphics operations performed by the
   * GC.
   *
   * This is one of the few costly operations of this class.  It is
   * suggested that the clip is only set or changed if really
   * necessary.  Higher level APIs can make such optimizations
   * transparent.
   *
   * @param rectangles the union of these rectangles describe the clip
   * region.
   */
  public void setClipRectangles(Rectangle[] rectangles)
  {
    clip = new Clip(rectangles);
    updateClip();
  }

  public native void drawString(String text, int x, int y);
  public native void drawLine(int x1, int y1, int x2, int y2);
  public native void drawRectangle(int x, int y, int w, int h);

  public native void fillRectangle(int x, int y, int w, int h);

  /** 
   * 
   * Clear area using the background pixel or pixmap of the drawable.
   * Note that this operation does not adhere to the current clip.
   */
  public native void clearArea(int x, int y, int w, int h,
			       boolean exposures);


  public native void putImage(XImage image,
			      int srcX, int srcY,
			      int destX, int destY,
			      int width, int height);

  public Drawable getDrawable()
  {
    return target;
  }

  private native void updateClip();

  private Drawable target;
  private RawData structure;
  private Clip clip;
}