ballworldpanel.java

来自「一些JAVA的小程序」· Java 代码 · 共 27 行

import java.awt.*;
import javax.swing.*;

public class BallWorldPanel extends JPanel {

	public BallWorldPanel (Color ballColor) {
		aBall.setColor(ballColor);
		aBall.setMotion(3.0, 6.0);
	}

	private Ball aBall = new Ball(new Point(10, 15), 5);
	
	public void paint (Graphics g) {
		super.paint(g);
		aBall.paint(g);
	}

	public void moveBall(int width, int height) {
		aBall.move();
		int r = aBall.radius();
		if ((aBall.x() < r) || (aBall.x() > width - r))
			aBall.reflectHorz();
		if ((aBall.y() < r) || (aBall.y() > height - r))
			aBall.reflectVert();
	}
}