import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Rectangle;
import java.awt.RenderingHints;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.Timer;
public class SwingTimerBasedAnimationScaleRotate extends JPanel implements ActionListener {
Timer timer;
private double angle = 0;
private double scale = 1;
private double delta = 0.01;
Rectangle.Float r = new Rectangle.Float(20, 20, 200, 200);
public SwingTimerBasedAnimationScaleRotate() {
timer = new Timer(10, this);
timer.start();
}
public void paint(Graphics g) {
int h = getHeight();
int w = getWidth();
Graphics2D g2d = (Graphics2D) g;
g2d.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
g2d.setRenderingHint(RenderingHints.KEY_RENDERING, RenderingHints.VALUE_RENDER_QUALITY);
g2d.translate(w / 2, h / 2);
g2d.rotate(angle);
g2d.scale(scale, scale);
g2d.fill(r);
}
public static void main(String[] args) {
JFrame frame = new JFrame("Moving star");
frame.add(new SwingTimerBasedAnimationScaleRotate());
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setSize(420, 250);
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
public void actionPerformed(ActionEvent e) {
if (scale < 0.01) {
delta = -delta;
} else if (scale > 0.99) {
delta = -delta;
}
scale += delta;
angle += 0.01;
repaint();
}
}
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