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

public class DemoJPanel1 extends JPanel implements MouseListener,ItemListener,ActionListener,MouseMotionListener {
    JPanel mainPanel = new JPanel();
    int startX, startY,endX,endY;
    /*--------Default Constructor to Set Up JPanel--------*/
    DemoJPanel1(){
        mainPanel.setPreferredSize(new Dimension(300,300));
        mainPanel.setBackground(Color.blue);
        mainPanel.addMouseListener(this);
    }

    /*--------Shape Painter Function--------*/
    public void shapeDrawer() {
        Graphics2D g2 = (Graphics2D) getGraphics();
        g2.setColor(Color.white);
        int width = Math.abs(endX-startX);
        int height = Math.abs(endY-startY);
        minAndMax();
        g2.fillRect(startX, startY, width, height);
    }

    public void minAndMax() {

        if(startX > endX) {
            int temp = startX;
            startX = endX;
            endX = temp;
        }
        if(startY >endY) {
            int temp = startY;
            startY = endY;
            endY = temp;
        }
    }

    /*--------Mouse Motion Functions--------*/
        @Override
    public void mousePressed(MouseEvent e) {
            System.out.println("Test 1");
            this.startX = e.getX();
            this.startY = e.getY();
    }
    @Override
    public void mouseReleased(MouseEvent e) {
        this.endX = e.getX();
        this.endY = e.getY();
        shapeDrawer();
    }
    /*--------Not Used Mouse Motion Functions--------*/
    @Override
    public void mouseDragged(MouseEvent arg0) {
    }
    @Override
    public void mouseMoved(MouseEvent arg0) {
    }
    @Override
    public void actionPerformed(ActionEvent arg0) {
    }
    @Override
    public void itemStateChanged(ItemEvent arg0) {
    }
    @Override
    public void mouseClicked(MouseEvent e) {
    }
    @Override
    public void mouseEntered(MouseEvent e) {
    }
    @Override
    public void mouseExited(MouseEvent e) {
    }

}