import java.awt.*;  import java.awt.image.BufferedImage;
    import java.awt.Color;
    import java.awt.Graphics;

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



    @SuppressWarnings("serial")
    public class SimpleComponent extends JFrame {

        public BufferedImage image = new BufferedImage(500, 500, BufferedImage.TYPE_INT_RGB);
        JPanel canvas = new JPanel();
        JPanel buttonPanel = new JPanel();
Point rect=null;
        Point lastPos = null;
        Point startPos = null;
        Point finishPos = null;
        Graphics graph;

        JButton drawButton = new JButton("Free");
        private Graphics gr;



        public SimpleComponent () {

            setLocation(0,0);
            setSize(300,600);
            setTitle("Photoshop");
            setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
            canvas.setBackground(Color.WHITE);

            //add buttons here
            buttonPanel.add(drawButton);

            //set the look
            getContentPane().add(canvas, BorderLayout.CENTER);
            getContentPane().add(buttonPanel, BorderLayout.NORTH);

            setVisible(true);

            graph = canvas.getGraphics();



        canvas.addMouseMotionListener(new MouseMotionListener () {
                public void mouseDragged (MouseEvent m) {
                    Point p = m.getPoint() ;

                     graph.drawLine(lastPos.x, lastPos.y, p.x, p.y);
                    lastPos = p ;

                }
                public void mouseMoved (MouseEvent m) {}
            });



    canvas.addMouseListener(new MouseListener () {
            public void mouseClicked(MouseEvent e) {startPos = e.getPoint();}
            public void mousePressed(MouseEvent e) {lastPos = e.getPoint();}
        public void mouseReleased(MouseEvent e) {
        lastPos = null;

                finishPos = e.getPoint();
                  if (finishPos.x<startPos.x&&finishPos.y<startPos.y) {
                        graph.drawLine(startPos.x, startPos.y, finishPos.x, startPos.y);
                    }
    startPos = null;}
            public void mouseEntered(MouseEvent e) {}
        public void mouseExited(MouseEvent e) {}
            });

        }


        public void captureCanvasImage (){
            Graphics g = image.createGraphics();
            canvas.paint(g);
        }





        public static void main (String [] args) {
            SimpleComponent p = new SimpleComponent();
            p.setVisible(true);
        }
    }