无意中发现的好玩代码——摇动的java对话框

信息资料来源：http://www.java2s.com/CN/Code/Java/Swing-Components/Shakeadialog.htm

import java.awt.Point;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JDialog;
import javax.swing.JOptionPane;
import javax.swing.Timer;

public class Main {
    JDialog dialog;
    Point naturalLocation;
    Timer shakeTimer;

    public Main(JDialog d) {
        dialog = d;
    }

    public void startShake() {
        final long startTime;
    
        naturalLocation = dialog.getLocation();
        startTime = System.currentTimeMillis();
        shakeTimer = new Timer(5, new ActionListener() {
            public void actionPerformed(ActionEvent e) {
                double TWO_PI = Math.PI * 2.0;
                double SHAKE_CYCLE = 50;

                long elapsed = System.currentTimeMillis() - startTime;
                double waveOffset = (elapsed % SHAKE_CYCLE) / SHAKE_CYCLE;
                double angle = waveOffset * TWO_PI;

                int SHAKE_DISTANCE = 10;

                int shakenX = (int) ((Math.sin(angle) * SHAKE_DISTANCE) + naturalLocation.x);
                dialog.setLocation(shakenX, naturalLocation.y);
                dialog.repaint();

                int SHAKE_DURATION = 1000;
                if (elapsed >= SHAKE_DURATION)
                    stopShake();
            }
        });
        shakeTimer.start();
    }

    public void stopShake() {
        shakeTimer.stop();
        dialog.setLocation(naturalLocation);
        dialog.repaint();
    }

    public static void main(String[] args) {
        JOptionPane pane = new JOptionPane("your message",JOptionPane.ERROR_MESSAGE, JOptionPane.OK_OPTION);
        JDialog d = pane.createDialog(null, "title");
        Main dec = new Main(d);
        d.pack();
        d.setModal(false);
        d.setVisible(true);
        dec.startShake();
    }
}