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

public class DrawPanel extends JFrame
{
 private DrawObjects panel = new DrawObjects();
 private JPanel BPanel = new JPanel();
 private JFrame window = new JFrame();

 //constructor
 DrawPanel(){
    buildGUI(); 
 }

 void buildGUI(){
     window.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
     window.setLayout(new GridLayout(2,2));
     window.add(panel);
     window.add(BPanel);
     BPanel.setBackground(Color.blue);

      //define buttons and add to panel
      JButton rect = new JButton("Rect");
      JButton oval = new JButton("Oval");
      BPanel.add(rect);
      BPanel.add(oval);

      rect.addActionListener(new ActionListener() {
          public void actionPerformed(ActionEvent e)
              {
                  panel.setType(1);
              }
      });

      oval.addActionListener(new ActionListener() {
          public void actionPerformed(ActionEvent e)
              {
              panel.setType(2);
              }
          }); 

      window.setVisible(true);
      window.setSize(1024, 800);     
}

 public static void main(String[] args)
  {
     //create this object
     new DrawPanel();
  }

  }//end class
  
  
class DrawObjects extends JPanel
{
public int x1,x2,y1,y2;
public int type = 1;//default draw type

public DrawObjects()
{
    init();
}

public void init(){
      setBackground(Color.WHITE);
      addMouseListener(new MouseAdapter()
       {
          public void mousePressed(MouseEvent m)
          {
               x1 = m.getX();
               y1 = m.getY();
               repaint();
          }
          public void mouseReleased(MouseEvent m)
          {
               x2 = m.getX();
               y2 = m.getY();
               repaint();
          }
        });

      addMouseMotionListener(new MouseMotionAdapter()
        {
           public void mouseDragged(MouseEvent m)
              {
                 x2 = m.getX();
                 y2 = m.getY();
                 repaint();
              }
          });
}

public void setType(int arg){
    if(arg == 1){
        type = 1;
    }else if(arg == 2){
        type = 2;
    }
}

  public void paintComponent(Graphics g)
  { 
      super.paintComponent(g);
      if(type == 1)
      {
          g.drawRect(x1,y1,x2,y2);
      }
      else if (type == 2)
      {
          g.drawOval(x1,y1,x2,y2);
      }
  }
    }