public/javascript/libs/select2.js
function() {
            var $dropdown = this.dropdown,
                offset = this.container.offset(),
                height = this.container.outerHeight(false),
                width = this.container.outerWidth(false),
                dropHeight = $dropdown.outerHeight(false),
                viewPortRight = $(window).scrollLeft() + $(window).width(),
                viewportBottom = $(window).scrollTop() + $(window).height(),
                dropTop = offset.top + height,
                dropLeft = offset.left,
                enoughRoomBelow = dropTop + dropHeight <= viewportBottom,
                enoughRoomAbove = (offset.top - dropHeight) >= this.body().scrollTop(),
                dropWidth = $dropdown.outerWidth(false),
                enoughRoomOnRight = dropLeft + dropWidth <= viewPortRight,
                aboveNow = $dropdown.hasClass("select2-drop-above"),
                bodyOffset,
                above,
                css,
                resultsListNode;

            if (this.opts.dropdownAutoWidth) {
                resultsListNode = $('.select2-results', $dropdown)[0];
                $dropdown.addClass('select2-drop-auto-width');
                $dropdown.css('width', '');
                // Add scrollbar width to dropdown if vertical scrollbar is present
                dropWidth = $dropdown.outerWidth(false) + (resultsListNode.scrollHeight === resultsListNode.clientHeight ? 0 : scrollBarDimensions.width);
                dropWidth > width ? width = dropWidth : dropWidth = width;
                enoughRoomOnRight = dropLeft + dropWidth <= viewPortRight;
            }
            else {
                this.container.removeClass('select2-drop-auto-width');
            }

            //console.log("below/ droptop:", dropTop, "dropHeight", dropHeight, "sum", (dropTop+dropHeight)+" viewport bottom", viewportBottom, "enough?", enoughRoomBelow);
            //console.log("above/ offset.top", offset.top, "dropHeight", dropHeight, "top", (offset.top-dropHeight), "scrollTop", this.body().scrollTop(), "enough?", enoughRoomAbove);

            // fix positioning when body has an offset and is not position: static
            if (this.body().css('position') !== 'static') {
                bodyOffset = this.body().offset();
                dropTop -= bodyOffset.top;
                dropLeft -= bodyOffset.left;
            }

            // always prefer the current above/below alignment, unless there is not enough room
            if (aboveNow) {
                above = true;
                if (!enoughRoomAbove && enoughRoomBelow) above = false;
            } else {
                above = false;
                if (!enoughRoomBelow && enoughRoomAbove) above = true;
            }

            if (!enoughRoomOnRight) {
               dropLeft = offset.left + width - dropWidth;
            }

            if (above) {
                dropTop = offset.top - dropHeight;
                this.container.addClass("select2-drop-above");
                $dropdown.addClass("select2-drop-above");
            }
            else {
                this.container.removeClass("select2-drop-above");
                $dropdown.removeClass("select2-drop-above");
            }

            css = $.extend({
                top: dropTop,
                left: dropLeft,
                width: width
            }, evaluate(this.opts.dropdownCss));

            $dropdown.css(css);
        }
function() {
            var $dropdown = this.dropdown,
                offset = this.container.offset(),
                height = this.container.outerHeight(false),
                width = this.container.outerWidth(false),
                dropHeight = $dropdown.outerHeight(false),
                viewPortRight = $(window).scrollLeft() + $(window).width(),
                viewportBottom = $(window).scrollTop() + $(window).height(),
                dropTop = offset.top + height,
                dropLeft = offset.left,
                enoughRoomBelow = dropTop + dropHeight <= viewportBottom,
                enoughRoomAbove = (offset.top - dropHeight) >= this.body().scrollTop(),
                dropWidth = $dropdown.outerWidth(false),
                enoughRoomOnRight = dropLeft + dropWidth <= viewPortRight,
                aboveNow = $dropdown.hasClass("select2-drop-above"),
                bodyOffset,
                above,
                css,
                resultsListNode;

            if (this.opts.dropdownAutoWidth) {
                resultsListNode = $('.select2-results', $dropdown)[0];
                $dropdown.addClass('select2-drop-auto-width');
                $dropdown.css('width', '');
                // Add scrollbar width to dropdown if vertical scrollbar is present
                dropWidth = $dropdown.outerWidth(false) + (resultsListNode.scrollHeight === resultsListNode.clientHeight ? 0 : scrollBarDimensions.width);
                dropWidth > width ? width = dropWidth : dropWidth = width;
                enoughRoomOnRight = dropLeft + dropWidth <= viewPortRight;
            }
            else {
                this.container.removeClass('select2-drop-auto-width');
            }

            //console.log("below/ droptop:", dropTop, "dropHeight", dropHeight, "sum", (dropTop+dropHeight)+" viewport bottom", viewportBottom, "enough?", enoughRoomBelow);
            //console.log("above/ offset.top", offset.top, "dropHeight", dropHeight, "top", (offset.top-dropHeight), "scrollTop", this.body().scrollTop(), "enough?", enoughRoomAbove);

            // fix positioning when body has an offset and is not position: static
            if (this.body().css('position') !== 'static') {
                bodyOffset = this.body().offset();
                dropTop -= bodyOffset.top;
                dropLeft -= bodyOffset.left;
            }

            // always prefer the current above/below alignment, unless there is not enough room
            if (aboveNow) {
                above = true;
                if (!enoughRoomAbove && enoughRoomBelow) above = false;
            } else {
                above = false;
                if (!enoughRoomBelow && enoughRoomAbove) above = true;
            }

            if (!enoughRoomOnRight) {
               dropLeft = offset.left + width - dropWidth;
            }

            if (above) {
                dropTop = offset.top - dropHeight;
                this.container.addClass("select2-drop-above");
                $dropdown.addClass("select2-drop-above");
            }
            else {
                this.container.removeClass("select2-drop-above");
                $dropdown.removeClass("select2-drop-above");
            }

            css = $.extend({
                top: dropTop,
                left: dropLeft,
                width: width
            }, evaluate(this.opts.dropdownCss));

            $dropdown.css(css);
        }
abstract