BufferedImage

package rrr;
 
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import java.awt.Color;
 
public class Rrr extends JFrame implements ActionListener,
        MouseListener, MouseMotionListener{
 
     final int PEN_OP = 1;
 
     int mousex = 0;
     int mousey = 0;
 
     int prevx = 0;
     int prevy = 0;
 
     boolean initialPen = true;
 
     int opStatus = PEN_OP;
 
     JButton penButton = new JButton("Pen");
 
     JPanel controlPanel = new JPanel(new GridLayout(11,2,0,0));
     JPanel drawPanel = new JPanel();
 
    public Rrr() {
        super("Graph Editor");
        setPreferredSize(new Dimension(800, 600));
        pack();
        setVisible(true);
        this.addWindowListener(new WindowAdapter() {
            public void windowClosing(WindowEvent e) {
                System.exit(0);
            }
        });
        init();
    }
    public void init() {
        setLayout(new BorderLayout());
 
        controlPanel.add(penButton);
 
        controlPanel.setBounds(0, 0, 100, 300);
  
        controlPanel.setBackground(Color.orange);
        drawPanel.setBackground(Color.white);
        drawPanel.setLayout(new BoxLayout(drawPanel, BoxLayout.Y_AXIS));
 
        add(controlPanel, "West");
        add(drawPanel, "Center");
 
        penButton.addActionListener(this);
 
        drawPanel.addMouseMotionListener(this);
        drawPanel.addMouseListener(this);
 
    }  
    @Override
    public void actionPerformed(ActionEvent e) {
        if (e.getActionCommand() == "Pen")
            opStatus = PEN_OP;
    }
    public void penOperation(MouseEvent e) {
        Graphics2D g = (Graphics2D) drawPanel.getGraphics();
     
        g.setColor(Color.black);
        if (initialPen) {
            setGraphicalDefaults(e);
            initialPen = false;
            g.drawLine(prevx, prevy, mousex, mousey);
        }
            if (mouseHasMoved(e)) {
                mousex = e.getX();
                mousey = e.getY();
                g.drawLine(prevx, prevy, mousex, mousey);
                prevx = mousex;
                prevy = mousey;
               }
        }
    public boolean mouseHasMoved(MouseEvent e) {
        return (mousex != e.getX() || mousey != e.getY());
    }
    
    public void setGraphicalDefaults(MouseEvent e) {
        mousex = e.getX();
        mousey = e.getY();
        prevx = e.getX();
        prevy = e.getY();
    }
    public void releasedPen() {
        initialPen = true;
    }
    @Override
    public void mouseClicked(MouseEvent e) {}
    @Override
    public void mousePressed(MouseEvent e) {}
    @Override
    public void mouseReleased(MouseEvent e) { 
        switch (opStatus) {
            case PEN_OP : releasedPen();
                break;            
        }
    }
    @Override
    public void mouseEntered(MouseEvent e) {}
    @Override
    public void mouseExited(MouseEvent e) {}
    @Override
    public void mouseDragged(MouseEvent e) {    
        switch (opStatus) {
            case PEN_OP : penOperation(e);
                break;            
        }
    }
    @Override
    public void mouseMoved(MouseEvent e) {}
     public static void main(String[] args) {
         try {
            for (javax.swing.UIManager.LookAndFeelInfo info : javax.swing.UIManager.getInstalledLookAndFeels()) {
                if ("Nimbus".equals(info.getName())) {
                    javax.swing.UIManager.setLookAndFeel(info.getClassName());
                    break;
                }
            }
        } catch (ClassNotFoundException ex) {
            java.util.logging.Logger.getLogger(Rrr.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        } catch (InstantiationException ex) {
            java.util.logging.Logger.getLogger(Rrr.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        } catch (IllegalAccessException ex) {
            java.util.logging.Logger.getLogger(Rrr.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        } catch (javax.swing.UnsupportedLookAndFeelException ex) {
            java.util.logging.Logger.getLogger(Rrr.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        }
       SwingUtilities.invokeLater(new Runnable() {
 
            @Override
            public void run() {
                new Rrr();
            }
           
       });
    }
}