沙鸥的问题,记在账上

Question

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
//import com.zxh.swing.*;public class MyPainter1 extends JFrame{
   private JButton line=new JButton("line");
   private JButton oval=new JButton("oval");
   private JButton rectangle=new JButton("rectangle");
   private JPanel buttonPanel=new JPanel();
   private Container c;
   private int flag;
   private int x,y,x1,y1;
   LineFigure lineFigure = null;
   public MyPainter1() {
               super("MyTextArea");
               flag=0;
               c=getContentPane();
        c.setLayout(new BorderLayout());
        c.add(buttonPanel,BorderLayout.WEST);
        buttonPanel.setLayout(new FlowLayout());
        buttonPanel.add(line);
        buttonPanel.add(oval);
        buttonPanel.add(rectangle);
        line.addActionListener(new lineListener());
        //oval.addActionListener(new ovalListener());
        // rectangle.addActionListener(new rectangleListener());
        addMouseListener(new DrawListener());
        lineFigure=new LineFigure();
        setSize(640,480);
        setVisible(true);
        }        public void paint(Graphics g){
            super.paint(g);
            if(lineFigure != null){
                lineFigure.paint(g);
            }
        }class lineListener implements ActionListener {
    public void actionPerformed(ActionEvent e){
    flag=1;
    }
}/*class ovalListener implements ActionListener{
    public void actionPerformed(ActionEvent e){
        flag=1;
    }
}class rectangleListener implements ActionListener{
    public void actionPerformed(ActionEvent e){
        flag=1;
        }
}*/
class DrawListener extends MouseAdapter {
    public void mousePressed(MouseEvent e){
        x = e.getX();
        y = e.getY();
    }
    public void mouseReleased(MouseEvent e){
        x1=e.getX();
        y1=e.getY();
        repaint();
    }//    public void mouseClicked(MouseEvent e) {
//        if (flag==1) {
//            x=e.getX();
//            y=e.getY();
//            flag=2;
//        }
//        else if (flag==2) {
//            x1=e.getX();
//            y1=e.getY();
//            repaint();
//        }
//    }
} public abstract class Figure{        public abstract void paint(Graphics g);
     }     class LineFigure extends Figure {
            public void paint(Graphics g){
//             if(flag==2)
                 g.drawLine(x,y,x1,y1);//»æÖÆÖ±Ïß
//             flag=0;
         }
     }     /*class OvalFigure extends Figure {
         public void paint(Graphics g){
             int X,Y;
             if(x>x1)
             X=x1;
             else
             X=x;
             if(y>y1)
             Y=y1;
             else
             Y=y1;
             if(flag==2)g.drawOval(X,Y,Math.abs(x1-x),Math.abs(y1-y));//»æÖÆÍÖÔ²
             flag=0;
         }
     }
     class RectFigure extends Figure {
         public void paint(Graphics g){
             int X,Y;
             if(x>x1)
             X=x1;
             else
             X=x;
             if(y>y1)
             Y=y1;
             else
             Y=y;
             if(flag==2)g.drawRect(X,Y,Math.abs(x1-x),Math.abs(y1-y)); //»æÖƾØÐÎ
             flag=0;
         }
     }
*/public static void main(String args[]){
    MyPainter1 app=new MyPainter1();
//    app.addWindowListener(new MyWindowListener());
    }
}