import java.awt.*;

public class Size {
    public static void main(String[] args) {
	DrawingPanel p = new DrawingPanel(200, 200);
	Graphics g = p.getGraphics();
	// This is a forever loop
	// If you do this in your animations you won't be able
	// to save them as an image
	for(;;) {
	    // Animate squares getting bigger
	    for (int i = 0; i < 50; i++) {
		drawSquare(p, g, i * 4);
	    }
	    // Animate squares getting smaller
	    for (int i = 50; i > 0; i--) {
		drawSquare(p, g, i * 4);
	    }
	}
    }

    // Erases the canvas
    // Draws a square at 0, 0 that is size 'size'
    // Sleeps the panel for 1/20 of a second
    public static void drawSquare(DrawingPanel p, Graphics g, int size) {
	g.setColor(Color.WHITE);
	g.fillRect(0, 0, 200, 200);
	g.setColor(Color.RED);
	g.drawRect(0, 0, size, size);
	p.sleep(50);
    }
}