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

public class FreehandTool implements Tool {
   
  protected DrawingCanvas canvas;
  protected Point startingMousePosition;

  public FreehandTool(DrawingCanvas c) {
   canvas = c;
  }
  
  protected void drawLineSegment(Point p1, Point p2) {
    canvas.getimageBufferGraphics().drawLine(p1.x,p1.y,
				           p2.x, p2.y);
    /* redraw only the small rectangle  */
    /* containing the new line segment  */
    int x0 = Math.min(p1.x, p2.x);
    int y0 = Math.min(p1.y, p2.y);
    int dx = Math.abs(p2.x - p1.x)+ 1;
    int dy = Math.abs(p2.y - p1.y) + 1;
    canvas.repaint(x0, y0, dx, dy);
  }

 public void mousePressed(MouseEvent e)  {
   /* Establish starting point for next drawing */
   startingMousePosition = e.getPoint();
 }

 public void mouseDragged(MouseEvent e)  {
   Point newMousePosition = e.getPoint();
   drawLineSegment(startingMousePosition,
				newMousePosition);
   /* update current mouse coordinates */
   startingMousePosition = newMousePosition;
 }

   /*null methods*/

   public void mouseReleased(MouseEvent e) { }
}