package edu.uci.ics.jung.visualization;
   
   import java.awt.Shape;
   import java.awt.geom.AffineTransform;
   import java.awt.geom.Point2D;
   
   import javax.swing.event.ChangeEvent;
   import javax.swing.event.ChangeListener;
   
  import edu.uci.ics.jung.visualization.transform.MutableAffineTransformer;
  import edu.uci.ics.jung.visualization.transform.MutableTransformer;
  import edu.uci.ics.jung.visualization.transform.shape.ShapeTransformer;
  import edu.uci.ics.jung.visualization.util.ChangeEventSupport;
  import edu.uci.ics.jung.visualization.util.DefaultChangeEventSupport;
  
  /**
   * A basic implementation of the MultiLayerTransformer interface that 
   * provides two Layers: VIEW and LAYOUT. It also provides ChangeEventSupport
   * @author Tom Nelson - tomnelson@dev.java.net
   *
   */
  public class BasicTransformer implements MultiLayerTransformer, 
  	ShapeTransformer, ChangeListener, ChangeEventSupport  {
  
      protected ChangeEventSupport changeSupport =
          new DefaultChangeEventSupport(this);
  
      protected MutableTransformer viewTransformer = 
          new MutableAffineTransformer(new AffineTransform());
      
      protected MutableTransformer layoutTransformer =
          new MutableAffineTransformer(new AffineTransform());
  
      /**
       * Creates an instance and notifies the view and layout Functions to listen to
       * changes published by this instance.
       */
      public BasicTransformer() {
  		super();
  		viewTransformer.addChangeListener(this);
  		layoutTransformer.addChangeListener(this);
  	}
  
      protected void setViewTransformer(MutableTransformer Function) {
          this.viewTransformer.removeChangeListener(this);
          this.viewTransformer = Function;
          this.viewTransformer.addChangeListener(this);
      }
  
      protected void setLayoutTransformer(MutableTransformer Function) {
          this.layoutTransformer.removeChangeListener(this);
          this.layoutTransformer = Function;
          this.layoutTransformer.addChangeListener(this);
      }
  
  
  	protected MutableTransformer getLayoutTransformer() {
  		return layoutTransformer;
  	}
  
  	protected MutableTransformer getViewTransformer() {
  		return viewTransformer;
  	}
  
  	public Point2D inverseTransform(Point2D p) {
  	    return inverseLayoutTransform(inverseViewTransform(p));
  	}
  	
  	protected Point2D inverseViewTransform(Point2D p) {
  	    return viewTransformer.inverseTransform(p);
  	}
  
      protected Point2D inverseLayoutTransform(Point2D p) {
          return layoutTransformer.inverseTransform(p);
      }
  
  	public Point2D transform(Point2D p) {
  	    return viewTransform(layoutTransform(p));
  	}
      
      protected Point2D viewTransform(Point2D p) {
          return viewTransformer.transform(p);
      }
      
      protected Point2D layoutTransform(Point2D p) {
          return layoutTransformer.transform(p);
      }
      
  	public Shape inverseTransform(Shape shape) {
  	    return inverseLayoutTransform(inverseViewTransform(shape));
  	}
  	
  	protected Shape inverseViewTransform(Shape shape) {
  	    return viewTransformer.inverseTransform(shape);
  	}
  
      protected Shape inverseLayoutTransform(Shape shape) {
          return layoutTransformer.inverseTransform(shape);
      }
 
 	public Shape transform(Shape shape) {
 	    return viewTransform(layoutTransform(shape));
 	}
     
     protected Shape viewTransform(Shape shape) {
         return viewTransformer.transform(shape);
     }
     
     protected Shape layoutTransform(Shape shape) {
         return layoutTransformer.transform(shape);
     }
     
     public void setToIdentity() {
     	layoutTransformer.setToIdentity();
     	viewTransformer.setToIdentity();
     }
     
     public void addChangeListener(ChangeListener l) {
         changeSupport.addChangeListener(l);
     }
     
     public void removeChangeListener(ChangeListener l) {
         changeSupport.removeChangeListener(l);
     }
     
     public ChangeListener[] getChangeListeners() {
         return changeSupport.getChangeListeners();
     }
 
     public void fireStateChanged() {
         changeSupport.fireStateChanged();
     }   
     
 	public void stateChanged(ChangeEvent e) {
 	    fireStateChanged();
 	}
 
 	public MutableTransformer getTransformer(Layer layer) {
 		if(layer == Layer.LAYOUT) return layoutTransformer;
 		if(layer == Layer.VIEW) return viewTransformer;
 		return null;
 	}
 
 	public Point2D inverseTransform(Layer layer, Point2D p) {
 		if(layer == Layer.LAYOUT) return inverseLayoutTransform(p);
 		if(layer == Layer.VIEW) return inverseViewTransform(p);
 		return null;
 	}
 
 	public void setTransformer(Layer layer, MutableTransformer Function) {
 		if(layer == Layer.LAYOUT) setLayoutTransformer(Function);
 		if(layer == Layer.VIEW) setViewTransformer(Function);
 		
 	}
 
 	public Point2D transform(Layer layer, Point2D p) {
 		if(layer == Layer.LAYOUT) return layoutTransform(p);
 		if(layer == Layer.VIEW) return viewTransform(p);
 		return null;
 	}
 
 	public Shape transform(Layer layer, Shape shape) {
 		if(layer == Layer.LAYOUT) return layoutTransform(shape);
 		if(layer == Layer.VIEW) return viewTransform(shape);
 		return null;
 	}
 	
 	public Shape inverseTransform(Layer layer, Shape shape) {
 		if(layer == Layer.LAYOUT) return inverseLayoutTransform(shape);
 		if(layer == Layer.VIEW) return inverseViewTransform(shape);
 		return null;
 	}
 }