//MyCanvasListen.java
//
//Class to listen to mouse on the listener canvas
//
//Naomi, Vicky, Christie


import java.awt.*;
import java.awt.event.*;
import java.io.*;


class MyCanvasListen extends Canvas implements MouseListener,
		                               MouseMotionListener
{

  CanvasObserver observer;

  int downx = 0, downy = 0, upx = 0, upy = 0;


  //*************************
  //
  //  init
  //
  //*************************
  public void init()
  {

  }// end init

  //*************************
  //
  //  constructor
  //
  //*************************
  public MyCanvasListen()
  {
    addMouseListener (this);
    addMouseMotionListener (this);

    setBackground(Color.white);
    setSize(200,200);
  
  }// end constructor  
   

  //*************************
  //
  //  mousePressed
  //
  //*************************
  public void mousePressed (MouseEvent e)     //MouseListener
  {
    downx = e.getX();  // Get x and y coordinates
    downy = e.getY();  //
    notifyObserver();

  }// end mousePressed


  //*************************
  //
  //  mouseClicked
  //
  //*************************     
  public void mouseClicked (MouseEvent e){}   //MouseListener
  

  //*************************
  //
  //  mouseReleased
  //
  //*************************
  public void mouseReleased (MouseEvent e)  //MouseListener
  {
    upx = e.getX();
    upy = e.getY();
    notifyObserver();
    repaint();

  }// end mouseReleased


  //*************************
  //
  //  mouseEntered
  //
  //*************************
  public void mouseEntered (MouseEvent e) {}  //MouseListener


  //*************************
  //
  //  mouseExited
  //
  //*************************
  public void mouseExited (MouseEvent e) {}   //MouseListener
  

  //*************************
  //
  //  mouseDragged
  //
  //*************************
  public void mouseDragged (MouseEvent e) {  //MouseMotionListener
    upx = e.getX();
    upy = e.getY();
    notifyObserver();
    repaint();

  }// end mouseDragged


  //*************************
  //
  //  mouseMoved
  //
  //*************************
  public void mouseMoved (MouseEvent e) {}    //MouseMotionListener


  //*************************
  //
  //  paint
  //
  //*************************
  public void paint( Graphics g )
  {
    int height, width, startX, startY;

    g.setColor(Color.black);
    
    if( downx >= upx ) //Determine the width and the coord. for the upper-left 
      {                  //edge of the rect, which will be the smaller of the 2
	width = (downx-upx); // numbers (either downx or upx)
	startX = upx;                         
      } 
    else
      {   
	width=(upx-downx);
	startX = downx;
      }
    if( downy >= upy )
      {
	height = (downy-upy);
	startY = upy;
      }  
    else
      {
	height=(upy-downy);
	startY = downy;
      }


    g.drawRect(startX, startY, width, height);
  

  }// end paint


  
  //*************************
  //
  //  notifyObserver
  //
  //*************************
  private void notifyObserver()
  {
    observer.canvasHasChanged(this);

  }// end notifyObserver
  

  //*************************
  //
  //  get_downx
  //
  //*************************
  public int get_downx()
  {
    return downx;
  }

  //*************************
  //
  //  get_downy
  //
  //*************************
  public int get_downy()
  {
    return downy;
  
  }// end get_downy


  //*************************
  //
  //  get_upx
  //
  //*************************
  public int get_upx()
  {
    return upx;
  
  }// end get_upx


  //*************************
  //
  //  get_upy
  //
  //*************************
  public int get_upy()
  {
    return upy;
  
  }// end get_upy


  //*************************
  //
  //  registerAsObserver
  //
  //*************************
  public void registerAsObserver(CanvasObserver observer)
  {
    this.observer = observer;
    notifyObserver();
  
  }// end registerAsObserver


}// end class MyCanvasListen