/*!
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({
 *      type:1,                      //1代表图片2代表flash
 *		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( {
			type:1,
			src : null,
			closeSrc : null,
			href : "#",
			target:'_blank',
			autoHide : true,
			hideSecond : 10,
			top : 20,
			layout : "left",
			width : 100,
			height : 100,
			opacity : 0.5,
			setPosition : function(left, top) {
				return;
			}
		}, options || {});

		if (settings.src && settings.closeSrc) {
			if(settings.type==1){
			var imgEl = "<a href='" + settings.href
					+ "' target='"+settings.target+"'><img border=0 width='"
					+ settings.width + "px' height='" + settings.height
					+ "px' src='" + settings.src + "'/> <br></a>";
			}else{
				var imgEl = "<a href='" + settings.href
				+ "' target='"+settings.target+"'><embed src='"
								+ settings.src
								+ "' type='application/x-shockwave-flash'"
								+ " width='"
								+ settings.width
								+ "' height='"
								+ settings.height
								+ "' quality='high' "
								+ "pluginspage='http://www.macromedia.com/go/getflashplayer'></embed> <br></a>";
			}
			var closeImgEl = "<a href=\"#\"; onclick=\"this.parentElement.style.visibility='hidden'\"><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);