freedraw.java

一个实用的绘图软件

import java.applet.Applet;
import java.awt.*;
import java.awt.geom.*;
import java.awt.event.*;
public class freedraw  extends Applet implements MouseMotionListener,MouseListener
{
   int x,y;
   int x0,y0;
   public void init()
   {
	   setBackground(Color.cyan);
	   addMouseMotionListener(this);
	   addMouseListener(this);
   }
   public void paint(Graphics g)
   {
	Graphics2D g2d=(Graphics2D)g;
   	g2d.setColor(Color.red);
   	BasicStroke bs1=new BasicStroke(4);//BasicStroke是用来描写GraphicsD图形的外形
   	g2d.setStroke(bs1);
  	Ellipse2D obj=new Ellipse2D.Double(x0,y0,x-x0,y-y0);
   	g2d.clearRect(x0, y0, x-x0, y-y0);
   	g2d.draw(obj);
   }
   public void updata(Graphics g)
   {
		paint(g);
   }
   public void mouseDragged(MouseEvent e) 
   {
	x=(int)e.getX();
	y=(int)e.getY();
	repaint();
	}

	public void mouseMoved(MouseEvent e) 
	{
		// TODO Auto-generated method stub
		
	}

	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 mousePressed(MouseEvent e)
	{
           x0=(int)e.getX();
           y0=(int)e.getY();
	}

	public void mouseReleased(MouseEvent e) {
		// TODO Auto-generated method stub
		
	}
   
}