仿QQ登陆提示窗口

package com.teamtop.kong.client;

import com.google.gwt.user.client.Timer;
import com.google.gwt.user.client.Window;
import com.google.gwt.user.client.ui.HTML;
import com.google.gwt.user.client.ui.PopupPanel;

/**
 * @author 	[e-mail] (Kong)
 * @version	CreatedTime:2010-3-1 上午11:58:17
 * @Description	仿QQ登陆右下角弹出窗口示例
 */

public class LoginPopupPanel extends PopupPanel {
	private String htmlText = "";
	
	/**
	 * 构造方法
	 * @param htmlText	显示在弹出窗口上的HTML内容
	 */
	public LoginPopupPanel(String htmlText) {
		this.htmlText = htmlText;
		this.setWidget(new HTML(this.htmlText));
		this.setWidth("200");
//		this.setAnimationEnabled(true);
	}
	
	/**
	 * 通过此方法调用窗口的渐入和渐隐
	 */
	public void popup() {
		this.show();
		final int left = Window.getClientWidth() - this.getOffsetWidth();
//		this.setHeight("0");
		int top = Window.getClientHeight();
		this.setPopupPosition(left, top);
		Timer upTimer = getTimer(left, Window.getClientHeight() - this.getOffsetHeight(), false);
		upTimer.schedule(500);
		Timer hideTimer = getTimer(left, Window.getClientHeight(), true);
		hideTimer.schedule(5000);
	}
	
	/**
	 * 通过Timer控制弹出窗口的渐入或渐隐
	 * @param left				窗体X轴坐标
	 * @param currentTop	窗体预定Y轴坐标
	 * @param isHide			是否为渐隐效果
	 * @return	
	 */
	private Timer getTimer(final int left, final int targetTop, final boolean isHide) {
		Timer timer = new Timer() {
			@Override
			public void run() {
				//当前Y轴位置
				int currentTop = getAbsoluteTop();
				if (isHide ? currentTop < targetTop : currentTop > targetTop) {
					//每过40毫秒，弹出窗口位置移动5
					currentTop = isHide ? currentTop + 5 : currentTop - 5;
					setPopupPosition(left, currentTop);
					this.schedule(50);
				} else {
					//移动超过预定位置时，重置到预定位置
					setPopupPosition(left, targetTop);
					if (isHide) {
						hide();
					}
				}				
			}			
		};
		return timer;
	}
}

调用：

    //添加自动弹出窗口
    LoginPopupPanel loginPopup = new LoginPopupPanel("欢迎访问！<br/>这里是测试信息窗口！");
    loginPopup.popup();