fadingpanel.java

java实现浏览器等本地桌面的功能

/*
 * $Id: FadingPanel.java,v 1.1 2005/05/25 23:13:25 rbair Exp $
 *
 * Copyright 2004 Sun Microsystems, Inc., 4150 Network Circle,
 * Santa Clara, California 95054, U.S.A. All rights reserved.
 */

package org.jdesktop.demo.login.romain;
import java.awt.Color;
import java.awt.Graphics;
import java.awt.Rectangle;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

import javax.swing.JComponent;
import javax.swing.Timer;

public class FadingPanel extends JComponent implements ActionListener {
    private Timer ticker = null;
    private int alpha = 0;
    private int step;
	private FadeListener fadeListener;

    public FadingPanel(FadeListener fadeListener) {
		this.fadeListener = fadeListener;
	}

	public void setVisible(boolean visible) {
        super.setVisible(visible);
        if (visible) {
            if (ticker != null) {
                ticker.stop();
            }
            alpha = 0;
            step = 25;
            ticker = new Timer(50, this);
            ticker.start();
        } else {
            if (ticker != null) {
                ticker.stop();
                ticker = null;
            }
        }
    }

    protected void paintComponent(Graphics g) {
        super.paintComponent(g);
        g.setColor(new Color(255, 255, 255, alpha));
        Rectangle clip = g.getClipBounds();
        g.fillRect(clip.x, clip.y, clip.width, clip.height);
    }
    
    public void switchDirection() {
    	step = -step;
    	ticker.start();
    }

    public void actionPerformed(ActionEvent e) {
        alpha += step;
        if (alpha >= 255) {
            alpha = 255;
            ticker.stop();
            fadeListener.fadeOutFinished();
        } else if (alpha < 0) {
        	alpha = 0;
        	ticker.stop();
        	fadeListener.fadeInFinished();
        }
        repaint();
    }
}