import java.awt.event.ComponentAdapter; import java.awt.event.ComponentEvent; import javax.swing.JFrame; public class GUI extends JFrame { private Timeline timeline; public GUI() { super("Gui"); this.setDefaultCloseOperation(EXIT_ON_CLOSE); this.setSize(600, 600); timeline = new Timeline(this); this.setContentPane(timeline.getTimeline()); this.getRootPane().addComponentListener(new ComponentAdapter() { public void componentResized(ComponentEvent e) { timeline.refresh(); } }); this.setVisible(true); } public static void main(String[] args) { new GUI(); } }