/* 
 * ContentSwitcher: 页面内容切换器
 * 公司：易企达（北京）科技有限公司
 * 开始：2008-05-04
 * 目的：实现页面上指定模块内容可以自动切换
 * 历史：
 */

function $(id)
{
	return document.getElementById(id);
}

function _CallHelper(aObject, aType)
{   
    if (aType == 0)
        return function(){aObject.Fade();};
    else if (aType == 1)
        return function(){aObject.Change();};
    else if (aType == 2)
        return function(){if (aObject.Switcher != null) aObject.Switcher.Pause();};
    else if (aType == 3)
        return function(){if (aObject.Switcher != null) aObject.Switcher.Resume();};
    else if (aType == 4)
        return function(){aObject.panelCanvas.Go(aObject.panelIndex);};
    else    
        return function(){alert(aType);};
}

function SetOpacity(aObj, aDegree)
{
    var canvas=aObj;
    var degree=aDegree;
    if (canvas.filters&&canvas.filters[0])
    {
	    if (typeof canvas.filters[0].opacity=="number") //if IE6+
		    canvas.filters(0).opacity=degree;
	    else //else if IE5.5-
		    canvas.style.filter="alpha(opacity="+degree+")"
    }
    else if (canvas.style.opacity)
    {
        canvas.style.opacity=degree/100
    }
    else if (canvas.style.MozOpacity)
    {
        canvas.style.MozOpacity=degree/101
    }
    else if (canvas.style.KhtmlOpacity)
    {
	    canvas.style.KhtmlOpacity=degree/100
    }    
}

function Content(picURL, hrefURL)
{
    this.PicURL=picURL;    
    this.HrefURL=hrefURL;    
    
    this.Canvas=null;
}

Content.prototype.GetContentHTML=function()
{
    if (this.HrefURL != null && this.HrefURL != "")
        return  "<a href='" + this.HrefURL + "' target='_blank'><img border='0' src='" + this.PicURL + "' width='" + this.Canvas.Width + "px' height='" + this.Canvas.Height + "px' ></a>";
    else
        return  "<img border='0' src='" + this.PicURL + "' width='" + this.Canvas.Width + "px' height='" + this.Canvas.Height + "px' >";
}

function HTMLContent(sHTML)
{
    this.HTML = sHTML;
}

HTMLContent.prototype.GetContentHTML=function()
{
    return this.HTML;
}

function ContentCanvas(canvasContainerID, canvasWidth, canvasHeight)
{
    this.ContainerID=canvasContainerID;
    this.Width=canvasWidth;
    this.Height=canvasHeight;
    this.ContentIndex = -1;
    this.Degree=10;
    this.Interval=60;
    this.ControlPanelWidth=16;
    this.ControlPanelHeight=16;
    
    this.ContentArray=new Array();
    this.ContentPanelArray = new Array();
    this.Switcher=null;
    
    var container = $(canvasContainerID);
    if (container != null)
    {
        container.style.position='relative';
        container.style.overflow='hidden';
        container.onmouseover=_CallHelper(this, 2);
        container.onmouseout=_CallHelper(this, 3);
        var sHTML = "<div id='" + this.ContainerID + "_div1' style='border:0px solid red;z-index:2;position:absolute;width:" + this.Width + "px;height:" + this.Height+ "px;top:0;left:0;filter:progid:DXImageTransform.Microsoft.alpha(opacity=100);-moz-opacity:100;-khtml-opacity:100;opacity:1;background-color:white'></div>" + 
		    "<div id='" + this.ContainerID + "_div2' style='border:0px solid red;z-index:1;position:absolute;width:" + this.Width + "px;height:" + this.Height+ "px;top:0;left:0;filter:progid:DXImageTransform.Microsoft.alpha(opacity=10);-moz-opacity:10;-khtml-opacity:10;opacity:0.1;background-color:white'></div>";
	    container.innerHTML=sHTML;
    }
    
    this.DIV = $(this.ContainerID + "_div1");
    this.DIVBase = $(this.ContainerID + "_div2");
}

ContentCanvas.prototype.AddContent=function(aContent)
{
    aContent.Canvas = this;
    this.ContentArray.push(aContent);
    
    var panel=document.createElement("div");
    panel.style.zIndex=3;
    panel.style.position="absolute";
    panel.style.left="0px";
    panel.style.top="0px";
    panel.style.width=this.ControlPanelWidth + "px";
    panel.style.height=this.ControlPanelHeight + "px";
    panel.style.border="1px solid white";
    panel.style.backgroundColor = "black";
    panel.style.color="white";
    panel.style.cursor="pointer";
    panel.style.fontSize="12px";
    panel.style.textAlign="center";
    panel.innerHTML = this.ContentArray.length;
    panel.panelIndex=this.ContentPanelArray.length;
    panel.panelCanvas=this;
    panel.onclick=_CallHelper(panel, 4);
    $(this.ContainerID).appendChild(panel);
    this.ContentPanelArray.push(panel);
    this.SortPanel();
    SetOpacity(panel, 70);
}

ContentCanvas.prototype.SortPanel = function()
{
    var MaxColumn = Math.floor(this.Width / this.ControlPanelWidth);
    var RowCount = Math.floor(this.ContentPanelArray.length / MaxColumn) + 1;
    
    for(var row = 0; row < RowCount; row++)
    {
        for (var col = 0; col < MaxColumn; col++)
        {
            var index=row * MaxColumn + col;
            if (index >= this.ContentPanelArray.length) return;
            
            var Panel = this.ContentPanelArray[index];
            Panel.style.top = (this.Height - (RowCount - row) * this.ControlPanelHeight - 3) + "px";
            Panel.style.left = (col * this.ControlPanelWidth + 5) + "px";
        }
    }
}

ContentCanvas.prototype.AddPicContent=function(aPicUrl, aPicHref)
{
    var content = new Content(aPicUrl, aPicHref);
    return this.AddContent(content);
}

ContentCanvas.prototype.GetCount=function()
{
    return this.ContentArray.length;
}

ContentCanvas.prototype.Fade=function()
{
    this.Degree+=10;    
    SetOpacity(this.DIVBase, this.Degree);    
    if (this.Degree < 100)
    {            
        if (this.Degree == 10)
        {
    	    var temp = this.DIVBase.style.zIndex;
	        this.DIVBase.style.zIndex = this.DIV.style.zIndex;
	        this.DIV.style.zIndex=temp;        	        
        }
        setTimeout(_CallHelper(this, 0), this.Interval);
    }
    else
    {
        var temp = this.DIVBase;
        this.DIVBase = this.DIV;
        this.DIV = temp;
        this.Switcher.GoNext();    
    }
}

ContentCanvas.prototype.Go=function(n)
{
    if (this.Switcher.LastTimeID != 0)
    {
        clearTimeout(this.Switcher.LastTimeID);
        this.Switcher.LastTimeID = 0;
    }
    
    if (this.ContentIndex == -1)
    {
        this.ContentIndex = 0;
        this.DIV.innerHTML=this.ContentArray[this.ContentIndex].GetContentHTML();
        
        this.Switcher.GoNext();
    }
    else
    {
        this.ContentIndex = n;
        if (this.ContentIndex >= this.GetCount())
        {
            this.ContentIndex = 0;
        }

        this.DIVBase.innerHTML=this.ContentArray[this.ContentIndex].GetContentHTML();
        this.Degree=0;
        this.Fade();
    }
    
    for(var i=0; i < this.ContentPanelArray.length; i++)
    {    
        if (i != this.ContentIndex)
            this.ContentPanelArray[i].style.background="black";
        else
            this.ContentPanelArray[i].style.background="red";        
    }
}

ContentCanvas.prototype.GoNext=function()
{
    if (this.ContentArray.length == 0)
    {
         this.Switcher.GoNext();
         return;
    }
    
    this.Go(this.ContentIndex + 1);
}

// 创建一个ContentSwitcher对象
function ContentSwitcher()
{
    // 属性
    this.Index=-1;
    this.Interval=3000;
    this.IsActive=false;
    this.LastTimeID = 0;
    
    this.CanvasArray=new Array();
}

ContentSwitcher.prototype.AddCanvas=function(canvasContainerID, canvasWidth, canvasHeight)
{
    var canvas = new ContentCanvas(canvasContainerID, canvasWidth, canvasHeight);
    canvas.Switcher=this;    
    this.CanvasArray.push(canvas);
    return canvas;
}

ContentSwitcher.prototype.Start=function()
{
    if (this.IsActive) return;
    if (this.GetCount() == 0) return;
    
    this.IsActive = true;
    this.GoNext();
}

ContentSwitcher.prototype.GoNext=function()
{
    if (!this.IsActive) return;
    
    if (this.Index == -1)
    {
        this.Index = 0;
        this.CanvasArray[0].GoNext();
    }
    else
    {
        this.Index ++;
        if(this.Index >= this.GetCount())
        {
            this.Index = 0;
        }        
        this.LastTimeID=setTimeout(_CallHelper(this, 1), this.Interval);
    }
}

ContentSwitcher.prototype.Change=function()
{
    if (!this.IsActive) return;
    
    this.CanvasArray[this.Index].GoNext();
}

ContentSwitcher.prototype.GetCount=function()
{
    return this.CanvasArray.length;
}

ContentSwitcher.prototype.Pause=function()
{
    this.IsActive = false;
    if (this.LastTimeID != 0)
    {
        clearTimeout(this.LastTimeID);
        this.LastTimeID = 0;
    }
}

ContentSwitcher.prototype.Resume=function()
{
    if (this.IsActive) return;
    
    this.IsActive = true;
    this.GoNext();
}

ContentSwitcher.prototype.Stop=function()
{
    this.Index = -1;
    this.IsActive = false;
    for(var i=0; i < this.CanvasArray.length; i++)
    {
        this.CanvasArray[i].Index = -1;
    }
}