import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import java.util.EventListener;


public class DrawingCanvasView extends JComponent
  implements ModelListener {

  protected MiniDrawModel model;
  protected DrawingCanvasController DCcontroller;
  protected Image imageBuffer;
  protected Graphics imageBufferGraphics;

  /* constructor */
  public DrawingCanvasView(MiniDrawModel m) {
    setBackground(Color.white);
    model = m;
    DCcontroller = createDrawingCanvasController();
    addDrawingCanvasListener(DCcontroller);
    model.addModelListener(this);
  }
  
  protected DrawingCanvasController
               createDrawingCanvasController() {
      return new DrawingCanvasController(this, model);
    }


  protected void addDrawingCanvasListener(EventListener listener) {
    addMouseListener((MouseListener) listener);
    addMouseMotionListener((MouseMotionListener) listener);
  }
  
  public void ModelUpdated() {
    // null so far
  }

  public void update(Graphics g){
     paint(g);
  }
  public void paint(Graphics g) {
     g.drawImage(imageBuffer,0, 0, this);
  }
  
  public void drawLineSegment(Point p1, Point p2) {
   imageBufferGraphics.drawLine(p1.x,p1.y,
                	       p2.x, p2.y);
   repaint();
  }

  public void setBounds(int x, int y, int width, int height) {
    Image newimageBuffer = createImage(width, height);
    imageBufferGraphics = newimageBuffer.getGraphics();
    if (imageBuffer != null) {
      imageBufferGraphics.drawImage(imageBuffer, 0, 0 ,this);
    }
    imageBuffer = newimageBuffer;
    super.setBounds(x, y, width, height);
    repaint();
  }
}