_11.trafficlight.java

//Traffic light
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
class TrafficLight extends JPanel implements ActionListener{
private JRadioButton r1;
private JRadioButton r2;
private JRadioButton r3;
private Color red_c;
private Color green_c;
private Color orange_c;
public TrafficLight(){
setBounds(0,0,600,480);
r1 = new JRadioButton("Red");
r2 = new JRadioButton("Green");
r3 = new JRadioButton("Orange");
ButtonGroup group = new ButtonGroup();
r1.setSelected(true);
group.add(r1);
group.add(r2);
group.add(r3);
add(r1);
add(r2);
add(r3);
red_c = Color.red;
green_c = getBackground ();
orange_c = getBackground();
r1.addActionListener(this);
r2.addActionListener(this);
r3.addActionListener(this);
}
public void actionPerformed(ActionEvent e){
if(r1.isSelected() == true){
red_c = Color.red;
green_c = getBackground ();
orange_c = getBackground();
}
else if(r2.isSelected() == true){
red_c = getBackground ();
green_c = Color.green;
orange_c = getBackground();
}
else if(r3.isSelected() == true){
red_c = getBackground ();
green_c = getBackground();
orange_c = Color.orange;
}
repaint();
}
public void paintComponent(Graphics g){
super.paintComponent(g);
g.drawOval(50,50,50,50);
g.drawOval(50,110,50,50);
g.drawOval(50,170,50,50);
g.setColor(red_c);
g.fillOval(50,50,50,50);
g.setColor(orange_c);
g.fillOval(50,110,50,50);
g.setColor(green_c);
g.fillOval(50,170,50,50);
}
}
class Test2{
public static void main(String args[]){
JFrame f1 = new JFrame();
f1.setVisible(true);
f1.setSize(600,480);
f1.setLayout(null);
TrafficLight t = new TrafficLight();
f1.add(t);
}}