Luz

java

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

public class Luz extends JPanel{
    
    Color on;
    int radius = 20;
    int border = 3;
    boolean active;
    
    Luz(Color color){
	on = color;
	active = false;	
    }
    
    public void turnOn(boolean a) {
	active = a;
	repaint();
    }
    
    public Dimension getPreferredSize(){
	int size = (radius+border)*2;
	return new Dimension( size, size );
    }
    
    public void paintComponent(Graphics g){
	g.setColor( Color.black );
	g.fillRect(0,0,getWidth(),getHeight());
	
	if (active){
	    g.setColor( on );
	} else {
	    g.setColor( on.darker().darker().darker() );
	}
	g.fillOval( border,border,2*radius,2*radius );
    }
}