How to “do something” on Swing component resizing?

Question

I\'ve a class which extends JPanel. I overwrote protected void paintComponent(Graphics g).

There is a variable which has to be recalculate

Answer 1

Here's what I use (where CoordinatePlane is a JPanel):

I'm not an expert

public CoordinatePlane() {
    setBackground(Color.WHITE);
    this.addComponentListener(new ComponentAdapter(){
        public void componentResized(ComponentEvent e) {
            //YOUR CODE HERE         
        }
    });
}