Question

I am trying to create a traffic light for class. We are not allowed to use IDE’s so This is being done in text pad. How do I access each individual circle’s properties so that I can make one red, green, yellow?

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

public class Lab4Panel extends JPanel implements MouseListener {


public Lab4Panel(){
}

    JRadioButton red = new JRadioButton("Red", true);
    JRadioButton yellow = new JRadioButton("Yellow");
    JRadioButton green = new JRadioButton("Green");

int height, width;
int radius = 5;
int x = -1;
int y = -1;

protected void paintComponent(Graphics g){
    if (x<0 || y<0) {
        x = getWidth() / 2 - radius;
        y = getHeight() / 2 - radius;
    }
    super.paintComponent(g);
    g.drawRect(x - 5,y - 90, 40, 120);
    g.drawOval(x,y - 80, 4 * radius, 4 * radius);
    g.drawOval(x,y - 40, 4 * radius, 4 * radius);
    g.drawOval(x,y, 4 * radius, 4 * radius);

}




        public void mouseClicked(MouseEvent e)
            {
                if (e.getSource() == red){

                }

                else if (e.getSource() == yellow){

                }

                else if (e.getSource() == green){

                }



            }

    public void mouseExited(MouseEvent e){}
    public void mouseReleased(MouseEvent e){}
    public void mousePressed(MouseEvent e){}
    public void mouseMoved(MouseEvent e){}
    public void mouseEntered(MouseEvent e){}
}

Answer 1

You set the color in the drawing context: g.setColor( new Color( 255,0,0 ) ).