// JavaScript Document
function scrollingAD(_id, _width, _height, _bgColor, _direction, _delay, _pauseTime, _size, _isHover) {
        this.id              = _id;
        this.width           = _width;
        this.height          = _height;
        this.bgColor         = _bgColor;
        this.direction       = _direction;
        this.delay           = _delay;
        this.pauseTime       = _pauseTime;
        this.size            = _size;
        this.object          = null;
        this.isMove          = true;
        
        if((this.id == "") || (this.id == null)) {
                alert("A必须输入对象的 ID 才能创建滚动区域！");
                this.isMove = false;
                return false;
        }
        
        if(document.getElementById(this.id)) {
                this.object = document.getElementById(this.id);
        } else {
                window.alert("B滚动区域创建失败！\n请确认 " + this.id + " 是否拼写错误。");
                this.isMove = false;
                return false;
        }
}

scrollingAD.prototype.checkNumber = function(_attribute, defaultValue) {        
        if(isNaN(_attribute)) {
                return defaultValue;
        } else {
                return ((typeof(parseInt(_attribute)) == "number") ? parseInt(_attribute) : defaultValue);
        }
}

scrollingAD.prototype.move = function() {
        if(this.isMove == false) return false;
        
        var defaultWidth           = 200;
        var defaultHeight          = 50;
        var defaultDelay           = 20;
        var defaultPauseTime       = 2000;
        var defaultIsHover         = true;
        var defaultBgColor         = "transparent";
        var defaultDirection       = "up";
        
        this.width          = this.checkNumber(this.width, defaultWidth);
        this.height         = this.checkNumber(this.height, defaultHeight);
        this.delay          = this.checkNumber(this.delay, defaultDelay);
        this.pauseTime      = this.checkNumber(this.pauseTime, defaultPauseTime);
        this.isHover        = (typeof(this.isHover) == "boolean") ? this.isHover : defaultIsHover;
        
        if(this.direction == "left") {
                this.size       = this.checkNumber(this.size, this.width);
        } else {
                this.size       = this.checkNumber(this.size, this.height);
        }
        
        if((this.bgColor == null) || (typeof(this.bgColor) == undefined)) {
                this.bgColor = defaultBgColor;
        } else {
                this.bgColor = this.bgColor;
        }
        
        if((this.direction == null) || (typeof(this.direction) == undefined)) {
                this.direction = defaultDirection;        
        } else {
                this.direction = (this.direction.search(/(^up$)|(^left$)/gi) != -1) ? this.direction.toLowerCase() : defaultDirection;
        }
        
        // 创建滚动区域；
        with(this.object) {
                style.display         = "block";
                style.width           = this.width + "px";
                style.height          = this.height + "px";
                style.overflow        = "hidden";
                style.backgroundColor = this.bgColor;
        }
        
        if(this.direction == "up") {
                this.object.innerHTML = "<div id=\"" + this.id + "_mirror\">" + this.object.innerHTML + "</div>" + "<div>" + this.object.innerHTML + "</div><input type=\"hidden\" value=\"1\" id=\"" + this.id + "_isHover\" />";
        } else {
                this.object.innerHTML = "<span id=\"" + this.id + "_mirror\">" + this.object.innerHTML + "</span>" + "<span>" + this.object.innerHTML + "</span><input type=\"hidden\" value=\"1\" id=\"" + this.id + "_isHover\" />";
        }
                
        if(document.getElementById(this.id)) {
                var evalString;
                if(this.direction == "up") {
                        evalString = "scrollToUp(\"" + this.id + "\", " + this.isHover + ", " + this.delay + ", " + this.size + ", " + this.pauseTime + ", 0) ";
                } else {
                        evalString = "scrollToLeft(\"" + this.id + "\", " + this.isHover + ", " + this.delay + ", " + this.size + ", " + this.pauseTime + ", 0) ";
                }
                eval(evalString);
                
        } else {
                return false;
        }
        
        function pixelToNum(_string)        {
        //该函数用于去掉数值后面的px，并将之转化为数字。
                if(_string.slice(_string.length - 2) == "px") {
                        return parseInt(_string.slice(0, (_string.length - 2)));
                } else  {
                        return _string;
                }
        }
        
        function scrollToLeft(_id, _isHover, _delay, _size, _pauseTime, _s) {
                var obj = document.getElementById(_id);
                var mirror = document.getElementById(_id + "_mirror");        
                
                if(_size*(1 + parseInt(_s)) + pixelToNum(mirror.style.marginLeft) >= 0) {
                        var evalString =_id + "_timer = window.setTimeout(function() {scrollToLeft(\"" + _id + "\", " + _isHover + ", " + _delay + ", " + _size + ", " + _pauseTime + ", " + _s + ");}, " + _delay + ")";
                
                        if(_isHover) {
                                mirror.onmouseover = function() {document.getElementById(_id + "_isHover").value = 0;}
                                mirror.onmouseout  = function() {document.getElementById(_id + "_isHover").value = 1;}
                                var step = parseInt(document.getElementById(_id + "_isHover").value);
                                mirror.style.marginLeft = (pixelToNum(mirror.style.marginLeft) - step) + "px";        
                                eval("var " + evalString);
                        } else {                                
                                mirror.style.marginLeft = (pixelToNum(mirror.style.marginLeft) - 1) + "px";        
                                eval("var " + evalString);
                        }
                } else {
                        if(mirror.offsetWidth + pixelToNum(mirror.style.marginLeft) >= 0) {
                                _s += 1;
                                window.setTimeout(function() {scrollToLeft(_id, _isHover, _delay, _size, _pauseTime, _s)}, _pauseTime);
                        } else {
                                mirror.style.marginLeft = mirror.offsetWidth + pixelToNum(mirror.style.marginLeft) + "px";;
                                window.setTimeout(function() {scrollToLeft(_id, _isHover, _delay, _size, _pauseTime, 0)}, _pauseTime);
                        }
                }
                
        }

        function scrollToUp(_id, _isHover, _delay, _size, _pauseTime, _s) {
                var obj = document.getElementById(_id);
                var mirror = document.getElementById(_id + "_mirror");        
                
                if(_size*(1 + parseInt(_s)) + pixelToNum(mirror.style.marginTop) >= 0) {
                        var evalString =_id + "_timer = window.setTimeout(function() {scrollToUp(\"" + _id + "\", " + _isHover + ", " + _delay + ", " + _size + ", " + _pauseTime + ", " + _s + ");}, " + _delay + ")";
                
                        if(_isHover) {
                                mirror.onmouseover = function() {document.getElementById(_id + "_isHover").value = 0;}
                                mirror.onmouseout  = function() {document.getElementById(_id + "_isHover").value = 1;}
                                var step = parseInt(document.getElementById(_id + "_isHover").value);
                                mirror.style.marginTop = (pixelToNum(mirror.style.marginTop) - step) + "px";        
                                eval("var " + evalString);
                        } else {                                
                                mirror.style.marginTop = (pixelToNum(mirror.style.marginTop) - 1) + "px";        
                                eval("var " + evalString);
                        }
                } else {
                        if(mirror.offsetHeight + pixelToNum(mirror.style.marginTop) >= 0) {
                                _s += 1;
                                window.setTimeout(function() {scrollToUp(_id, _isHover, _delay, _size, _pauseTime, _s)}, _pauseTime);
                        } else {
                                mirror.style.marginTop = mirror.offsetHeight + pixelToNum(mirror.style.marginTop) + "px";;
                                window.setTimeout(function() {scrollToUp(_id, _isHover, _delay, _size, _pauseTime, 0)}, _pauseTime);
                        }
                }
        }
}

//var sampleDiv = new scrollingAD("divId", 200, 100, "yellow", "up", 10, 2000, 20, true);
//sampleDiv.move();