/*
    * 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.BasicStroke;
  import java.awt.Color;
  import java.awt.Cursor;
  import java.awt.Dimension;
  import java.awt.Graphics;
  import java.awt.Graphics2D;
  import java.awt.Point;
  import java.awt.RenderingHints;
  import java.awt.Toolkit;
  import java.awt.event.MouseEvent;
  import java.awt.event.MouseListener;
  import java.awt.event.MouseMotionListener;
  import java.awt.geom.Point2D;
  import java.awt.image.BufferedImage;
  import java.util.Collections;
  
  import edu.uci.ics.jung.visualization.Layer;
  import edu.uci.ics.jung.visualization.VisualizationViewer;
  import edu.uci.ics.jung.visualization.transform.MutableTransformer;
  
  /** 
   * ShearingGraphMousePlugin allows the user to drag with the mouse
   * to shear the transform either in the horizontal or vertical direction.
   * By default, the control or meta key must be depressed to activate
   * shearing. 
   * 
   * 
   * @author Tom Nelson
   */
  public class ShearingGraphMousePlugin extends AbstractGraphMousePlugin
      implements MouseListener, MouseMotionListener {
  
      private static int mask = MouseEvent.CTRL_MASK;
      
      static {
          if(System.getProperty("os.name").startsWith("Mac")) {
              mask = MouseEvent.META_MASK;
          }
      }
  	/**
  	 * create an instance with default modifier values
  	 */
  	public ShearingGraphMousePlugin() {
  	    this(MouseEvent.BUTTON1_MASK | mask);
  	}
  
  	/**
  	 * create an instance with passed modifier values
  	 * @param modifiers the mouse modifiers to use
  	 */
  	public ShearingGraphMousePlugin(int modifiers) {
  	    super(modifiers);
  	    Dimension cd = Toolkit.getDefaultToolkit().getBestCursorSize(16,16);
          BufferedImage cursorImage = 
          		new BufferedImage(cd.width,cd.height,BufferedImage.TYPE_INT_ARGB);
          Graphics g = cursorImage.createGraphics();
          Graphics2D g2 = (Graphics2D)g;
          g2.addRenderingHints(Collections.singletonMap(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON));
          g.setColor(new Color(0,0,0,0));
          g.fillRect(0,0,16,16);
          
          int left = 0;
          int top = 0;
          int right = 15;
          int bottom = 15;
          
          g.setColor(Color.white);
          g2.setStroke(new BasicStroke(3));
          g.drawLine(left+2,top+5,right-2,top+5);
          g.drawLine(left+2,bottom-5,right-2,bottom-5);
          g.drawLine(left+2,top+5,left+4,top+3);
          g.drawLine(left+2,top+5,left+4,top+7);
          g.drawLine(right-2,bottom-5,right-4,bottom-3);
          g.drawLine(right-2,bottom-5,right-4,bottom-7);
  
          g.setColor(Color.black);
          g2.setStroke(new BasicStroke(1));
          g.drawLine(left+2,top+5,right-2,top+5);
          g.drawLine(left+2,bottom-5,right-2,bottom-5);
          g.drawLine(left+2,top+5,left+4,top+3);
          g.drawLine(left+2,top+5,left+4,top+7);
          g.drawLine(right-2,bottom-5,right-4,bottom-3);
          g.drawLine(right-2,bottom-5,right-4,bottom-7);
          g.dispose();
          cursor = Toolkit.getDefaultToolkit().createCustomCursor(cursorImage, new Point(), "RotateCursor");
  	}
 
 	public void mousePressed(MouseEvent e) {
 	    VisualizationViewer<?, ?> vv = (VisualizationViewer<?, ?>)e.getSource();
 	    boolean accepted = checkModifiers(e);
 	    down = e.getPoint();
 	    if(accepted) {
 	        vv.setCursor(cursor);
 	    }
 	}
     
     public void mouseReleased(MouseEvent e) {
         VisualizationViewer<?, ?> vv = (VisualizationViewer<?, ?>)e.getSource();
         down = null;
         vv.setCursor(Cursor.getPredefinedCursor(Cursor.DEFAULT_CURSOR));
     }
     
     public void mouseDragged(MouseEvent e) {
         if(down == null) return;
         VisualizationViewer<?, ?> vv = (VisualizationViewer<?, ?>)e.getSource();
         boolean accepted = checkModifiers(e);
         if(accepted) {
             MutableTransformer modelTransformer = 
             	vv.getRenderContext().getMultiLayerTransformer().getTransformer(Layer.LAYOUT);
             vv.setCursor(cursor);
             Point2D q = down;
             Point2D p = e.getPoint();
             float dx = (float) (p.getX()-q.getX());
             float dy = (float) (p.getY()-q.getY());
 
             Dimension d = vv.getSize();
             float shx = 2.f*dx/d.height;
             float shy = 2.f*dy/d.width;
             Point2D center = vv.getCenter();
             if(p.getX() < center.getX()) {
                 shy = -shy;
             }
             if(p.getY() < center.getY()) {
                 shx = -shx;
             }
             modelTransformer.shear(shx, shy, center);
             down.x = e.getX();
             down.y = e.getY();
         
             e.consume();
         }
     }
 
     public void mouseClicked(MouseEvent e) {
         // TODO Auto-generated method stub
         
     }
 
     public void mouseEntered(MouseEvent e) {
         // TODO Auto-generated method stub
         
     }
 
     public void mouseExited(MouseEvent e) {
         // TODO Auto-generated method stub
         
     }
 
     public void mouseMoved(MouseEvent e) {
         // TODO Auto-generated method stub
         
     }
 }