/*
    * Copyright (c) 2005, The JUNG Authors 
    *
    * All rights reserved.
    *
    * This software is open-source under the BSD license; see either
    * "license.txt" or
    * https://github.com/jrtom/jung/blob/master/LICENSE for a description.
    * Created on Mar 8, 2005
   *
   */
  package edu.uci.ics.jung.visualization.control;
  
  import java.awt.event.MouseEvent;
  import java.awt.event.MouseWheelEvent;
  import java.awt.event.MouseWheelListener;
  
  import edu.uci.ics.jung.visualization.Layer;
  import edu.uci.ics.jung.visualization.VisualizationViewer;
  import edu.uci.ics.jung.visualization.transform.LensTransformer;
  import edu.uci.ics.jung.visualization.transform.MutableTransformer;
  
  /** 
   * HyperbolicMagnificationGraphMousePlugin changes the magnification
   * within the Hyperbolic projection of the HyperbolicTransformer.
   * 
   * @author Tom Nelson
   */
  public class LensMagnificationGraphMousePlugin extends AbstractGraphMousePlugin
      implements MouseWheelListener {
  
      protected final float floor;
      protected final float ceiling;
      protected final float delta;
      
  	/**
  	 * Creates an instance with modifier of CTRL_MASK, and default min/max/delta zoom values
  	 * of 1/4/0.2.
  	 */
  	public LensMagnificationGraphMousePlugin() {
  	    this(MouseEvent.CTRL_MASK);
  	}
      
  	/**
  	 * Creates an instance with modifier of CTRL_MASK, and the specified zoom parameters.
  	 * @param floor the minimum zoom value
  	 * @param ceiling the maximum zoom value
  	 * @param delta the change in zoom value caused by each mouse event
  	 */
      public LensMagnificationGraphMousePlugin(float floor, float ceiling, float delta) {
          this(MouseEvent.CTRL_MASK, floor, ceiling, delta);
      }
      
      /**
       * Creates an instance with the specified modifiers and the default min/max/delta zoom values
       * of 1/4/0.2.
       * @param modifiers the mouse event modifiers to specify
       */
      public LensMagnificationGraphMousePlugin(int modifiers) {
          this(modifiers, 1.0f, 4.0f, .2f);
      }
      
  	/**
  	 * Creates an instance with the specified mouse event modifiers and zoom parameters.
       * @param modifiers the mouse event modifiers to specify
  	 * @param floor the minimum zoom value
  	 * @param ceiling the maximum zoom value
  	 * @param delta the change in zoom value caused by each mouse event
  	 */
      public LensMagnificationGraphMousePlugin(int modifiers, float floor, float ceiling, float delta) {
          super(modifiers);
          this.floor = floor;
          this.ceiling = ceiling;
          this.delta = delta;
      }
  
      /**
       * override to check equality with a mask
       */
      public boolean checkModifiers(MouseEvent e) {
          return (e.getModifiers() & modifiers) != 0;
      }
  
      private void changeMagnification(MutableTransformer transformer, float delta) {
          if(transformer instanceof LensTransformer) {
              LensTransformer ht = (LensTransformer)transformer;
              float magnification = ht.getMagnification() + delta;
              magnification = Math.max(floor, magnification);
              magnification = Math.min(magnification, ceiling);
              ht.setMagnification(magnification);
          }
      }
  	/**
  	 * zoom the display in or out, depending on the direction of the
  	 * mouse wheel motion.
  	 */
      public void mouseWheelMoved(MouseWheelEvent e) {
          boolean accepted = checkModifiers(e);
          float delta = this.delta;
         if(accepted == true) {
             VisualizationViewer<?, ?> vv = (VisualizationViewer<?, ?>)e.getSource();
             MutableTransformer modelTransformer = vv.getRenderContext().getMultiLayerTransformer()
             	.getTransformer(Layer.LAYOUT);
             MutableTransformer viewTransformer = vv.getRenderContext().getMultiLayerTransformer()
             	.getTransformer(Layer.VIEW);
             int amount = e.getWheelRotation();
             if(amount < 0) {
                 delta = -delta;
             }
             changeMagnification(modelTransformer, delta);
             changeMagnification(viewTransformer, delta);
             vv.repaint();
             e.consume();
         }
     }
 }