AWTHomework3

package awtHomework3;
import java.awt.*;
import java.awt.event.*;

public class AWTHomework3 extends Frame {
    private Panel westPanel = new Panel( new GridLayout(0,1));
    private Button bRed = new Button("Red");
    private Button bGreen = new Button("Green");
    private Button bBlue = new Button("Blue");
    private Button bClear = new Button("Clear");
    private Button bExit = new Button("Exit");
    private Label coords = new Label("Coordinates:");
    private TextField coordsX = new TextField();
    private TextField coordsY = new TextField();
    private Panel centerPanel = new Panel();

    public AWTHomework3() {
        setTitle("EventDemoExample");
        setSize( 400,250 );
        setVisible( true );
        bRed.addMouseListener(new BEvent());
        bGreen.addMouseListener(new BEvent());
        bBlue.addMouseListener(new BEvent());
        bClear.addMouseListener(new BEvent());
        bExit.addMouseListener(new BEvent());
        centerPanel.addMouseListener( new DrawCircle());
        westPanel.add(bRed);
        westPanel.add(bGreen);
        westPanel.add(bBlue);
        westPanel.add(bClear);
        westPanel.add(bExit);
        westPanel.add(coords);
        coordsX.setEditable(false);
        coordsY.setEditable(false);
        westPanel.add(coordsX);
        westPanel.add(coordsY);
        add(westPanel, BorderLayout.WEST);
        centerPanel.setBackground(Color.WHITE);
        centerPanel.setVisible(true);
        add(centerPanel, BorderLayout.CENTER);
        addWindowListener( new ExitProgram());
    }

    class ExitProgram extends WindowAdapter {
        public void windowClosing( WindowEvent e ) {
            System.exit(0);
        }
    }

    class BEvent extends MouseAdapter {
        public void mousePressed( MouseEvent e ) {
            Button x = (Button)e.getSource();
            switch(x.getLabel()) {
            case "Red": centerPanel.setBackground( Color.RED);
            break;
            case "Blue": centerPanel.setBackground( Color.BLUE);
            break;
            case "Green": centerPanel.setBackground( Color.GREEN);
            break;
            case "Clear": centerPanel.repaint();
            coordsX.setText(""); coordsY.setText("");
            break;
            case "Exit": System.exit(0);
            break;
            }
        }
    }

    class DrawCircle extends MouseAdapter {
        public void mousePressed( MouseEvent e ) {
            int x = e.getX(); int y = e.getY();
            centerPanel.setForeground( Color.BLACK);
            Graphics dot = centerPanel.getGraphics();
            dot.fillOval( x, y, 10, 10);
            String xx = ""+x, yy = ""+y;
            coordsX.setText( xx );
            coordsY.setText( yy );
        }
    }

    public static void main(String[] args) {
        new AWTHomework3();
    }
}