/*
    * Copyright (c) 2005, the JUNG Project and the Regents of the University of
    * California All rights reserved.
    *
    * This software is open-source under the BSD license; see either "license.txt"
    * or http://jung.sourceforge.net/license.txt for a description.
    *
    * Created on Apr 16, 2005
    */
  
  package edu.uci.ics.jung.visualization.transform;
  
  import java.awt.geom.AffineTransform;
  import java.awt.geom.Point2D;
  
  import javax.swing.event.ChangeListener;
  import javax.swing.event.EventListenerList;
  
  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;
  
  /**
   *
   * Provides methods to mutate the AffineTransform used by AffineTransformer
   * base class to map points from one coordinate system to
   * another.
   * 
   * 
   * @author Tom Nelson
   *
   * 
   */
  public class MutableAffineTransformer extends AffineTransformer 
  implements MutableTransformer, ShapeTransformer, ChangeEventSupport {
  
      protected ChangeEventSupport changeSupport =
          new DefaultChangeEventSupport(this);
      
      /**
       * create an instance that does not transform points
       *
       */
      public MutableAffineTransformer() {
          // nothing left to do
      }
      /**
       * Create an instance with the supplied transform
       */
      public MutableAffineTransformer(AffineTransform transform) {
          super(transform);
      }
  
      public String toString() {
          return "MutableAffineTransformer using "+transform;
      }
      /**
       * setter for the scale
       * fires a PropertyChangeEvent with the AffineTransforms representing
       * the previous and new values for scale and offset
       * @param scalex
       * @param scaley
       */
      public void scale(double scalex, double scaley, Point2D from) {
          AffineTransform xf = AffineTransform.getTranslateInstance(from.getX(),from.getY());
          xf.scale(scalex, scaley);
          xf.translate(-from.getX(), -from.getY());
          inverse = null;
          transform.preConcatenate(xf);
          fireStateChanged();
      }
      
      /**
       * setter for the scale
       * fires a PropertyChangeEvent with the AffineTransforms representing
       * the previous and new values for scale and offset
       * @param scalex
       * @param scaley
       */
      public void setScale(double scalex, double scaley, Point2D from) {
          transform.setToIdentity();
          scale(scalex, scaley, from);
      }
      
      /**
       * shears the transform by passed parameters
       * @param shx x value to shear
       * @param shy y value to shear
       */
      public void shear(double shx, double shy, Point2D from) {
          inverse = null;
          AffineTransform at = 
              AffineTransform.getTranslateInstance(from.getX(), from.getY());
          at.shear(shx, shy);
          at.translate(-from.getX(), -from.getY());
          transform.preConcatenate(at);
          fireStateChanged();
      }
      
     /**
      * replace the Transform's translate x and y values
      * with the passed values, leaving the scale values
      * unchanged
      * @param tx the x value 
      * @param ty the y value
      */
     public void setTranslate(double tx, double ty) {
         float scalex = (float) transform.getScaleX();
         float scaley = (float) transform.getScaleY();
         float shearx = (float) transform.getShearX();
         float sheary = (float) transform.getShearY();
         inverse = null;
         transform.setTransform(scalex, 
                 sheary, 
                 shearx, 
                 scaley,
                 tx, ty);
         fireStateChanged();
     }
     
     /**
      * Apply the passed values to the current Transform
      * @param offsetx the x-value
      * @param offsety the y-value
      */
     public void translate(double offsetx, double offsety) {
         inverse = null;
         transform.translate(offsetx, offsety);
         fireStateChanged();
     }
     
     /**
      * preconcatenates the rotation at the supplied point with the current transform
      */
     public void rotate(double theta, Point2D from) {
         AffineTransform rotate = 
             AffineTransform.getRotateInstance(theta, from.getX(), from.getY());
         inverse = null;
         transform.preConcatenate(rotate);
 
         fireStateChanged();
     }
     
     /**
      * rotates the current transform at the supplied points
      */
     public void rotate(double radians, double x, double y) {
         inverse = null;
         transform.rotate(radians, x, y);
         fireStateChanged();
     }
     
     public void concatenate(AffineTransform xform) {
         inverse = null;
         transform.concatenate(xform);
         fireStateChanged();
         
     }
     public void preConcatenate(AffineTransform xform) {
         inverse = null;
         transform.preConcatenate(xform);
         fireStateChanged();
     }   
 
     
     /**
      * Adds a <code>ChangeListener</code>.
      * @param l the listener to be added
      */
     public void addChangeListener(ChangeListener l) {
         changeSupport.addChangeListener(l);
     }
     
     /**
      * Removes a ChangeListener.
      * @param l the listener to be removed
      */
     public void removeChangeListener(ChangeListener l) {
         changeSupport.removeChangeListener(l);
     }
     
     /**
      * Returns an array of all the <code>ChangeListener</code>s added
      * with addChangeListener().
      *
      * @return all of the <code>ChangeListener</code>s added or an empty
      *         array if no listeners have been added
      */
     public ChangeListener[] getChangeListeners() {
         return changeSupport.getChangeListeners();
     }
 
     /**
      * Notifies all listeners that have registered interest for
      * notification on this event type.  The event instance 
      * is lazily created.
      * @see EventListenerList
      */
     public void fireStateChanged() {
         changeSupport.fireStateChanged();
     }
     
     public void setToIdentity() {
         inverse = null;
         transform.setToIdentity();
         fireStateChanged();
     }
 }