// Copyright 2007, FreeHEP.
package org.freehep.graphicsio.emf.gdi;
import org.freehep.graphicsio.emf.EMFTag;
import org.freehep.graphicsio.emf.EMFRenderer;
import org.freehep.graphicsio.emf.EMFConstants;
import com.google.code.appengine.awt.geom.GeneralPath;
import com.google.code.appengine.awt.geom.AffineTransform;
import com.google.code.appengine.awt.geom.Area;
import com.google.code.appengine.awt.Shape;
/**
* base class for all tags that change the
* clipping area of the {@link org.freehep.graphicsio.emf.EMFRenderer}
*
* @author Steffen Greiffenberg
* @version $Id$
*/
public abstract class AbstractClipPath extends EMFTag {
private int mode;
protected AbstractClipPath(int id, int version, int mode) {
super(id, version);
this.mode = mode;
}
public String toString() {
return super.toString() + "\n mode: " + mode;
}
public int getMode() {
return mode;
}
/**
* displays the tag using the renderer
*
* @param renderer EMFRenderer storing the drawing session data
* @param shape shape to use as clipping area
*/
public void render(EMFRenderer renderer, Shape shape) {
if (shape != null) {
// The new clipping region includes the intersection
// (overlapping areas) of the current clipping region and the current shape.
if (mode == EMFConstants.RGN_AND) {
renderer.clip(shape);
}
// The new clipping region is the current shape
else if (mode == EMFConstants.RGN_COPY) {
// rest the clip ...
AffineTransform at = renderer.getTransform();
// temporarly switch to the base transformation to
// aplly the base clipping area
renderer.resetTransformation();
// set the clip
renderer.setClip(renderer.getInitialClip());
renderer.setTransform(at);
renderer.clip(shape);
}
// The new clipping region includes the areas of the
// current clipping region with those of the current shape excluded.
else if (mode == EMFConstants.RGN_DIFF) {
Shape clip = renderer.getClip();
if (clip != null) {
Area a = new Area(shape);
a.subtract(new Area(clip));
renderer.setClip(a);
} else {
renderer.setClip(shape);
}
}
// The new clipping region includes the union (combined areas)
// of the current clipping region and the current shape.
else if(mode == EMFConstants.RGN_OR) {
GeneralPath path = new GeneralPath(shape);
Shape clip = renderer.getClip();
if (clip != null) {
path.append(clip, false);
}
renderer.setClip(path);
}
// The new clipping region includes the union of the current
// clipping region and the current shape but without the overlapping areas.
else if(mode == EMFConstants.RGN_XOR) {
Shape clip = renderer.getClip();
if (clip != null) {
Area a = new Area(shape);
a.exclusiveOr(new Area(clip));
renderer.setClip(a);
} else {
renderer.setClip(shape);
}
}
}
// delete the current shape
renderer.setPath(null);
}
}