/*!
jquery.higo_plugins_ad.js(v0.1)
http://www.higosoft.cn
mailto:wdong0472@gmail.com

Copyright (c) 2011 wdong
Dual licensed under the MIT and GPL licenses.
*/

/*
 * 创建浮动图片广告（Generate a dock AD image）
 *
 * USAGE: 
 *	$(selector).higo_plugins_ad({
 *		src:null,                    // 广告图片路径
 *		closeSrc:null,               // 关闭图片路径
 *		href:"#",                    // 广告图片链接地址
 *		autoHide:true,               // 是否自动隐藏
 *		hideSecond:10,               // 延迟隐藏秒数
 *		top:20,                      // 距离顶部偏移高度
 *		layout:"left",               // 图片位置：left 居左 ,right 居右, center 居中, 
 *		width:100,                   // 宽度
 *		height:100,                  // 高度
 *		opacity:0.5					 // 透明度opacity:0.5(firefox), filter:alpha(opacity=50)(IE)
 *		setPosition:function(left, top){ // 预留自定义显示位置的方法（尚未实现）
 *			return;
 *		}	
 *	})
 */
 
(function ($) {
    $.fn.lastScrollY = 0;
    $.fn.higo_plugins_ad = function (options) {
        $(this).addClass("higo_plugins_ad");
        var settings = $.extend({
            //src: null,
            closeSrc: null,
            href: "#",
            autoHide: true,
            hideSecond: 10,
            top: 20,
            layout: "left",
            width: 100,
            height: 100,
            opacity: 0.5,
            setPosition: function (left, top) {
                return;
            }
        }, options || {});

        if (1 == 1) {
//                        var imgEl = "<a href='" + settings.href + "' target='_blank'>";
                        //imgEl += "<img border=0 width='" + settings.width + "px' height='" + settings.height + "px' src='" + settings.src + "'/> ";


            var imgEl = "<br>";
            var closeImgEl = "<a href=\"#\"; onclick=\"$(this).parent().hide()\"><img border=0 src='" + settings.closeSrc + "'/></a>";

            $(this).append(imgEl + closeImgEl);

            $(this).css("position", "absolute");
            $(this).css("top", settings.top + "px");
            $(this).css("opacity", settings.opacity);
            $(this).css("filter", "alpha(opacity=" + parseInt(settings.opacity * 100) + ")");

            switch (settings.layout) {
                case "left":
                    $(this).css("left", "22px");
                    break;
                case "right":
                    $(this).css("right", "22px");
                    break;
                //                case "center":  
                //                    var left = (parseInt(window.screen.availWidth) - parseInt(settings.width)) / 2 + "px";  
                //                    $(this).css("left", left);  
                //                    break;  
                default:
                    $(this).css("left", "22px");
                    break;
            }
        } else {
            return;
        }

        if (settings.autoHide) {
            setTimeout("(function(){$('" + $(this).selector + "').hide();})();", parseInt(settings.hideSecond) * 1000);
        }

        window.onscroll = function () {
            var diffY;
            if (document.documentElement && document.documentElement.scrollTop)
                diffY = document.documentElement.scrollTop;
            else if (document.body)
                diffY = document.body.scrollTop
            else {
                /*Netscape stuff*/
            }

            percent = 1 * (diffY - $.fn.lastScrollY);
            if (percent > 0)
                percent = Math.ceil(percent);
            else
                percent = Math.floor(percent);

            var top = $('.higo_plugins_ad').css("top");

            $('.higo_plugins_ad').css("top", parseInt(top) + percent + "px");
            $.fn.lastScrollY += percent;
        }
    }
})(jQuery);