/*
*
* Copyright (c) 2009 Ikon srl, by Marco Venuti
* 
*/

(function($) {
    /*
    * A basic news vertical scroller.
    *
    * @param    delay      Delay (in milliseconds) between iterations. Default 4 seconds (5000ms)
    * @example  $(".news_scroller").newsScroller(5000);
    *
    * per poter calcolare correttamente l'altezza dell'elemto da scrollare
    * usare per gli items:  clear: both; float: left;
    *
    */
    $.fn.newsScroller = function(minItems, delay, speed, autoHide, dirVertical, OnScrollStart, OnScrollEnd) {
        minItems = minItems || 1 << 30;  // if less than minItems don't start the animation
        delay = delay || 5000;
        speed = speed || 250;
        autoHide = typeof autoHide === "boolean" ? autoHide : true;
        dirVertical = typeof dirVertical === "boolean" ? dirVertical : true;
        var initScroller = function(el) {
            stopScroller(el);
            el.items = $('>*', el);
            el.items.show();
            if (el.items.length <= minItems)
                return;
            else {
                if (autoHide)
                    el.items.slice(minItems).hide();
            }
            startScroller(el);
        };
        var startScroller = function(el) {
            el.scrollitemfn = setInterval(function() { doScrollItem(el) }, delay)
        };
        var stopScroller = function(el) {
            clearInterval(el.scrollitemfn);
        };
        var pauseScroller = function(el) {
            el.pause = true;
        };
        var resumeScroller = function(el) {
            el.pause = false;
        };
        var doScrollItem = function(el) {
            if (el.pause || el.pauseAnim || el.items.length <= minItems)
                return;
            // pause until animation has finished
            el.pauseAnim = true;
            el.items = $(el.items.selector, el.items.context);
            try {
                if (OnScrollStart && typeof (OnScrollStart) === "function")
                    OnScrollStart.call(this, el.items[0]);
            }
            catch (e) { }
            var itm1 = $(el.items[0]);
            var itm2 = itm1.clone(true);
            if (autoHide)
                $(el.items[minItems]).show();
            itm1.animate(dirVertical ? { marginTop: -itm1.height() + 'px'} : { marginLeft: -itm1.width() + 'px' }, speed, function() {
                itm1.remove();
                if (autoHide) {
                    itm1.hide();
                    itm2.hide();
                }
                $(el.items.context).append(itm2);
                el.pauseAnim = false;
                try {
                    if (OnScrollEnd && typeof (OnScrollEnd) === "function")
                        OnScrollEnd.call(this, el.items[0], itm2);
                }
                catch (e) { }
            });
        };
        //
        this.each(function() {
            initScroller(this);
            $(this).hover(function() { pauseScroller(this); }, function() { resumeScroller(this); });
        });
        return this;
    };

})(jQuery);