painter.java

一个用JAVA编写的用鼠标随便画图程序

package chapter13;

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

public class Painter extends JFrame {
    private int pointCount = 0;
    private Point points[] = new Point[ 1000 ];
    
    public Painter() {
    	super( "A simple paint program" );
    	
    	getContentPane().add( new JLabel( "Drag the mouse to draw" ), BorderLayout.SOUTH );
    	addMouseMotionListener(
    			new MouseMotionAdapter() {
    				public void mouseDragged( MouseEvent event ) {
    					if( pointCount < points.length ) {
    						points[ pointCount ] = event.getPoint();
    					    ++pointCount;
    					    repaint();
    					}
    				}
    			}
         );
    	
    	setSize( 300, 150 );
    	setVisible( true );
    }    

    public void paint( Graphics g ) {
	    super.paint( g );
	    for( int i = 1; i < points.length; i++ )
		    g.fillOval( points[ i ] .x,points[i].y,4,4);
    }
    
    public static void main( String args[] ) {
    	Painter application = new Painter();
    	application.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    }
    
}