Add multiple Polygon objects on the same JPanel frame

Question

So I have a DrawStar class that draws a star using Polygon like that:

public void paintComponent(Graphics g) {
    Graphics2D g2 = (Graphics2D) g;
    int[] cX =         


        

Answer 1

I reproduce your problem. It was Layout problem. By default JFrame has BorderLayout with CENTER alignment. You should change your layout and screen size.

JFrame starsframe = new JFrame();
starsframe.setTitle("Random stars...");
starsframe.setLayout(new GridLayout( 1,2));// Use gridLayout
DrawStar star1 = new DrawStar(300, 200, Color.red);
starsframe.add(star1);
DrawStar star2 = new DrawStar(400, 300, Color.blue);
starsframe.add(star2);

starsframe.setSize(1000,700);// Increase the screen size.
starsframe.setLocationRelativeTo(null);
starsframe.setVisible(true);
starsframe.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

To see the two stars I used GridLayout(1,2) and bigger setSize(1000, 700). But it is not optimum solution. You should get the x, y dynamically with corresponding to Screen Size using getWidth() and getHeight() method.