import java.awt.*;
import java.applet.*;
import java.awt.event.*;

// Applet that uses check boxes to determine what circle to draw.
public class ChoicesCheckBox extends Applet
{
    private CheckboxGroup colors;
    private Checkbox red, yellow, green;
    private Graphics g;

    public void init ()
    {
        colors = new CheckboxGroup ();
        red = new Checkbox ("Red", colors, true);
        this.add (red);
        red.addItemListener (new colorListener (Color.red, 50));
        yellow = new Checkbox ("Yellow", colors, false);
        this.add (yellow);
        yellow.addItemListener (new colorListener (Color.orange, 100));
        green = new Checkbox ("Green", colors, false);
        this.add (green);
        green.addItemListener (new colorListener (Color.green, 150));
        g = getGraphics ();
    } // method init

    // Inner class that listens for selection of a check box.
    class colorListener implements ItemListener
    {
        private Color c;
        private int y;

        colorListener (Color c, int y)
        {
            this.c = c;
            this.y = y;
        } // constructor

        public void itemStateChanged (ItemEvent event)
        {
            g.setColor (c);
            g.fillOval (80, y, 30, 30);
        } // method itemStateChanged
    } // class colorListener
} // class choices