Orbit/app/assets/javascripts/jquery.gridster.js

/*
 * jquery.coords
 * https://github.com/ducksboard/gridster.js
 * https://github.com/evaldsurtans/gridster.js/
 *
 * Copyright (c) 2012 ducksboard
 * Licensed under the MIT licenses.
 */

;(function($, window, document, undefined){
    /**
    * Creates objects with coordinates (x1, y1, x2, y2, cx, cy, width, height)
    * to simulate DOM elements on the screen.
    * Coords is used by Gridster to create a faux grid with any DOM element can
    * collide.
    *
    * @class Coords
    * @param {HTMLElement|Object} obj The jQuery HTMLElement or a object with: left,
    * top, width and height properties.
    * @return {Object} Coords instance.
    * @constructor
    */
    function Coords(obj) {
        if (obj[0] && $.isPlainObject(obj[0])) {
            this.data = obj[0];
        }else {
            this.el = obj;
        }

        this.isCoords = true;
        this.coords = {};
        this.init();
        return this;
    }


    var fn = Coords.prototype;


    fn.init = function(){
        this.set();
        this.original_coords = this.get();
    };


    fn.set = function(update, not_update_offsets) {
        var el = this.el;

        if (el && !update) {
            this.data = el.offset();
            this.data.width = el.width();
            this.data.height = el.height();
        }

        if (el && update && !not_update_offsets) {
            var offset = el.offset();
            this.data.top = offset.top;
            this.data.left = offset.left;
        }

        var d = this.data;

        this.coords.x1 = d.left;
        this.coords.y1 = d.top;
        this.coords.x2 = d.left + d.width;
        this.coords.y2 = d.top + d.height;
        this.coords.cx = d.left + (d.width / 2);
        this.coords.cy = d.top + (d.height / 2);
        this.coords.width  = d.width;
        this.coords.height = d.height;
        this.coords.el  = el || false ;

        return this;
    };


    fn.update = function(data){
        if (!data && !this.el) {
            return this;
        }

        if (data) {
            var new_data = $.extend({}, this.data, data);
            this.data = new_data;
            return this.set(true, true);
        }

        this.set(true);
        return this;
    };


    fn.get = function(){
        return this.coords;
    };


    //jQuery adapter
    $.fn.coords = function() {
        if (this.data('coords') ) {
            return this.data('coords');
        }

        var ins = new Coords(this, arguments[0]);
        this.data('coords', ins);
        return ins;
    };

}(jQuery, window, document));
;/*
 * jquery.collision
 * https://github.com/ducksboard/gridster.js
 *
 * Copyright (c) 2012 ducksboard
 * Licensed under the MIT licenses.
 */

;(function($, window, document, undefined){

    var defaults = {
        colliders_context: document.body
        // ,on_overlap: function(collider_data){},
        // on_overlap_start : function(collider_data){},
        // on_overlap_stop : function(collider_data){}
    };


    /**
    * Detects collisions between a DOM element against other DOM elements or
    * Coords objects.
    *
    * @class Collision
    * @uses Coords
    * @param {HTMLElement} el The jQuery wrapped HTMLElement.
    * @param {HTMLElement|Array} colliders Can be a jQuery collection
    *  of HTMLElements or an Array of Coords instances.
    * @param {Object} [options] An Object with all options you want to
    *        overwrite:
    *   @param {Function} [options.on_overlap_start] Executes a function the first
    *    time each `collider ` is overlapped.
    *   @param {Function} [options.on_overlap_stop] Executes a function when a
    *    `collider` is no longer collided.
    *   @param {Function} [options.on_overlap] Executes a function when the
    * mouse is moved during the collision.
    * @return {Object} Collision instance.
    * @constructor
    */
    function Collision(el, colliders, options) {
        this.options = $.extend(defaults, options);
        this.$element = el;
        this.last_colliders = [];
        this.last_colliders_coords = [];
        if (typeof colliders === 'string' || colliders instanceof jQuery) {
            this.$colliders = $(colliders,
                 this.options.colliders_context).not(this.$element);
        }else{
            this.colliders = $(colliders);
        }

        this.init();
    }


    var fn = Collision.prototype;


    fn.init = function() {
        this.find_collisions();
    };


    fn.overlaps = function(a, b) {
        var x = false;
        var y = false;

        if ((b.x1 >= a.x1 && b.x1 <= a.x2) ||
            (b.x2 >= a.x1 && b.x2 <= a.x2) ||
            (a.x1 >= b.x1 && a.x2 <= b.x2)
        ) { x = true; }

        if ((b.y1 >= a.y1 && b.y1 <= a.y2) ||
            (b.y2 >= a.y1 && b.y2 <= a.y2) ||
            (a.y1 >= b.y1 && a.y2 <= b.y2)
        ) { y = true; }

        return (x && y);
    };


    fn.detect_overlapping_region = function(a, b){
        var regionX = '';
        var regionY = '';

        if (a.y1 > b.cy && a.y1 < b.y2) { regionX = 'N'; }
        if (a.y2 > b.y1 && a.y2 < b.cy) { regionX = 'S'; }
        if (a.x1 > b.cx && a.x1 < b.x2) { regionY = 'W'; }
        if (a.x2 > b.x1 && a.x2 < b.cx) { regionY = 'E'; }

        return (regionX + regionY) || 'C';
    };


    fn.calculate_overlapped_area_coords = function(a, b){
        var x1 = Math.max(a.x1, b.x1);
        var y1 = Math.max(a.y1, b.y1);
        var x2 = Math.min(a.x2, b.x2);
        var y2 = Math.min(a.y2, b.y2);

        return $({
            left: x1,
            top: y1,
             width : (x2 - x1),
            height: (y2 - y1)
          }).coords().get();
    };


    fn.calculate_overlapped_area = function(coords){
        return (coords.width * coords.height);
    };


    fn.manage_colliders_start_stop = function(new_colliders_coords, start_callback, stop_callback){
        var last = this.last_colliders_coords;

        for (var i = 0, il = last.length; i < il; i++) {
            if ($.inArray(last[i], new_colliders_coords) === -1) {
                start_callback.call(this, last[i]);
            }
        }

        for (var j = 0, jl = new_colliders_coords.length; j < jl; j++) {
            if ($.inArray(new_colliders_coords[j], last) === -1) {
                stop_callback.call(this, new_colliders_coords[j]);
            }

        }
    };


    fn.find_collisions = function(player_data_coords){
        var self = this;
        var colliders_coords = [];
        var colliders_data = [];
        var $colliders = (this.colliders || this.$colliders);
        var count = $colliders.length;
        var player_coords = self.$element.coords()
                             .update(player_data_coords || false).get();

        while(count--){
          var $collider = self.$colliders ?
                           $($colliders[count]) : $colliders[count];
          var $collider_coords_ins = ($collider.isCoords) ?
                  $collider : $collider.coords();
          var collider_coords = $collider_coords_ins.get();
          var overlaps = self.overlaps(player_coords, collider_coords);

          if (!overlaps) {
            continue;
          }

          var region = self.detect_overlapping_region(
              player_coords, collider_coords);

            //todo: make this an option
            if (region === 'C'){
                var area_coords = self.calculate_overlapped_area_coords(
                    player_coords, collider_coords);
                var area = self.calculate_overlapped_area(area_coords);
                var collider_data = {
                    area: area,
                    area_coords : area_coords,
                    region: region,
                    coords: collider_coords,
                    player_coords: player_coords,
                    el: $collider
                };

                if (self.options.on_overlap) {
                    self.options.on_overlap.call(this, collider_data);
                }
                colliders_coords.push($collider_coords_ins);
                colliders_data.push(collider_data);
            }
        }

        if (self.options.on_overlap_stop || self.options.on_overlap_start) {
            this.manage_colliders_start_stop(colliders_coords,
                self.options.on_overlap_stop, self.options.on_overlap_start);
        }

        this.last_colliders_coords = colliders_coords;

        return colliders_data;
    };


    fn.get_closest_colliders = function(player_data_coords){
        var colliders = this.find_collisions(player_data_coords);

        colliders.sort(function(a, b) {
            /* if colliders are being overlapped by the "C" (center) region,
             * we have to set a lower index in the array to which they are placed
             * above in the grid. */
            if (a.region === 'C' && b.region === 'C') {
                if (a.coords.y1 < b.coords.y1 || a.coords.x1 < b.coords.x1) {
                    return - 1;
                }else{
                    return 1;
                }
            }

            if (a.area < b.area) {
                return 1;
            }

            return 1;
        });
        return colliders;
    };


    //jQuery adapter
    $.fn.collision = function(collider, options) {
          return new Collision( this, collider, options );
    };


}(jQuery, window, document));
;;(function(window, undefined) {
    /* Debounce and throttle functions taken from underscore.js */
    window.debounce = function(func, wait, immediate) {
        var timeout;
        return function() {
          var context = this, args = arguments;
          var later = function() {
            timeout = null;
            if (!immediate) func.apply(context, args);
          };
          if (immediate && !timeout) func.apply(context, args);
          clearTimeout(timeout);
          timeout = setTimeout(later, wait);
        };
    };


    window.throttle = function(func, wait) {
        var context, args, timeout, throttling, more, result;
        var whenDone = debounce(
            function(){ more = throttling = false; }, wait);
        return function() {
          context = this; args = arguments;
          var later = function() {
            timeout = null;
            if (more) func.apply(context, args);
            whenDone();
          };
          if (!timeout) timeout = setTimeout(later, wait);
          if (throttling) {
            more = true;
          } else {
            result = func.apply(context, args);
          }
          whenDone();
          throttling = true;
          return result;
        };
    };

})(window);
;/*
 * jquery.draggable
 * https://github.com/ducksboard/gridster.js
 *
 * Copyright (c) 2012 ducksboard
 * Licensed under the MIT licenses.
 */

;(function($, window, document, undefined){

    var defaults = {
        items: '.gs_w',
        distance: 1,
        limit: true,
        offset_left: 0,
        autoscroll: true,
        ignore_dragging: ['INPUT', 'TEXTAREA', 'SELECT', 'BUTTON'],
        handle: null
        // ,drag: function(e){},
        // start : function(e, ui){},
        // stop : function(e){}
    };

    var $window = $(window);
    var isTouch = !!('ontouchstart' in window);
    var pointer_events = {
        start: isTouch ? 'touchstart' : 'mousedown.draggable',
        move: isTouch ? 'touchmove' : 'mousemove.draggable',
        end: isTouch ? 'touchend' : 'mouseup.draggable'
    };

    /**
    * Basic drag implementation for DOM elements inside a container.
    * Provide start/stop/drag callbacks.
    *
    * @class Draggable
    * @param {HTMLElement} el The HTMLelement that contains all the widgets
    *  to be dragged.
    * @param {Object} [options] An Object with all options you want to
    *        overwrite:
    *    @param {HTMLElement|String} [options.items] Define who will
    *     be the draggable items. Can be a CSS Selector String or a
    *     collection of HTMLElements.
    *    @param {Number} [options.distance] Distance in pixels after mousedown
    *     the mouse must move before dragging should start.
    *    @param {Boolean} [options.limit] Constrains dragging to the width of
    *     the container
    *    @param {offset_left} [options.offset_left] Offset added to the item
    *     that is being dragged.
    *    @param {Number} [options.drag] Executes a callback when the mouse is
    *     moved during the dragging.
    *    @param {Number} [options.start] Executes a callback when the drag
    *     starts.
    *    @param {Number} [options.stop] Executes a callback when the drag stops.
    * @return {Object} Returns `el`.
    * @constructor
    */
    function Draggable(el, options) {
      this.options = $.extend({}, defaults, options);
      this.$body = $(document.body);
      this.$container = $(el);
      this.$dragitems = $(this.options.items, this.$container);
      this.is_dragging = false;
      this.player_min_left = 0 + this.options.offset_left;
      this.init();
    }

    var fn = Draggable.prototype;

    fn.init = function() {
        this.calculate_positions();
        this.$container.css('position', 'relative');
        this.disabled = false;
        this.events();

        $(window).bind('resize',
            throttle($.proxy(this.calculate_positions, this), 200));
    };

    fn.events = function() {
        this.$container.on('selectstart', $.proxy(this.on_select_start, this));

        this.$container.on(pointer_events.start, this.options.items, $.proxy(
            this.drag_handler, this));

        this.$body.on(pointer_events.end, $.proxy(function(e) {
            this.is_dragging = false;
            if (this.disabled) { return; }
            this.$body.off(pointer_events.move);
            if (this.drag_start) {
                this.on_dragstop(e);
            }
        }, this));
    };

    fn.get_actual_pos = function($el) {
        var pos = $el.position();
        return pos;
    };


    fn.get_mouse_pos = function(e) {
        if (isTouch) {
            var oe = e.originalEvent;
            e = oe.touches.length ? oe.touches[0] : oe.changedTouches[0];
        }

        return {
            left: e.clientX,
            top: e.clientY
        };
    };


    fn.get_offset = function(e) {
        e.preventDefault();
        var mouse_actual_pos = this.get_mouse_pos(e);
        var diff_x = Math.round(
            mouse_actual_pos.left - this.mouse_init_pos.left);
        var diff_y = Math.round(mouse_actual_pos.top - this.mouse_init_pos.top);

        var left = Math.round(this.el_init_offset.left + diff_x - this.baseX);
        var top = Math.round(
            this.el_init_offset.top + diff_y - this.baseY + this.scrollOffset);

        if (this.options.limit) {
            if (left > this.player_max_left) {
                left = this.player_max_left;
            }else if(left < this.player_min_left) {
                left = this.player_min_left;
            }
        }

        return {
            left: left,
            top: top,
            mouse_left: mouse_actual_pos.left,
            mouse_top: mouse_actual_pos.top
        };
    };


    fn.manage_scroll = function(offset) {
        /* scroll document */
        var nextScrollTop;
        var scrollTop = $window.scrollTop();
        var min_window_y = scrollTop;
        var max_window_y = min_window_y + this.window_height;

        var mouse_down_zone = max_window_y - 50;
        var mouse_up_zone = min_window_y + 50;

        var abs_mouse_left = offset.mouse_left;
        var abs_mouse_top = min_window_y + offset.mouse_top;

        var max_player_y = (this.doc_height - this.window_height +
            this.player_height);

        if (abs_mouse_top >= mouse_down_zone) {
            nextScrollTop = scrollTop + 30;
            if (nextScrollTop < max_player_y) {
                $window.scrollTop(nextScrollTop);
                this.scrollOffset = this.scrollOffset + 30;
            }
        }

        if (abs_mouse_top <= mouse_up_zone) {
            nextScrollTop = scrollTop - 30;
            if (nextScrollTop > 0) {
                $window.scrollTop(nextScrollTop);
                this.scrollOffset = this.scrollOffset - 30;
            }
        }
    };


    fn.calculate_positions = function(e) {
        this.window_height = $window.height();
    };


    fn.drag_handler = function(e) {
        var node = e.target.nodeName;
        if (this.disabled || e.which !== 1 && !isTouch) {
            return;
        }

        if (this.ignore_drag(e)) {
            return;
        }

        var self = this;
        var first = true;
        this.$player = $(e.currentTarget);

        this.el_init_pos = this.get_actual_pos(this.$player);
        this.mouse_init_pos = this.get_mouse_pos(e);
        this.offsetY = this.mouse_init_pos.top - this.el_init_pos.top;

        this.$body.on(pointer_events.move, function(mme){
            var mouse_actual_pos = self.get_mouse_pos(mme);
            var diff_x = Math.abs(
                mouse_actual_pos.left - self.mouse_init_pos.left);
            var diff_y = Math.abs(
                mouse_actual_pos.top - self.mouse_init_pos.top);
            if (!(diff_x > self.options.distance ||
                diff_y > self.options.distance)
            ) {
                return false;
            }

            if (first) {
                first = false;
                self.on_dragstart.call(self, mme);
                return false;
            }

            if (self.is_dragging === true) {
                self.on_dragmove.call(self, mme);
            }

            return false;
        });

        return false;
    };


    fn.on_dragstart = function(e) {
        e.preventDefault();
        this.drag_start = true;
        this.is_dragging = true;
        var offset = this.$container.offset();
        this.baseX = Math.round(offset.left);
        this.baseY = Math.round(offset.top);
        this.doc_height = $(document).height();

        if (this.options.helper === 'clone') {
            this.$helper = this.$player.clone()
                .appendTo(this.$container).addClass('helper');
            this.helper = true;
        }else{
            this.helper = false;
        }
        this.scrollOffset = 0;
        this.el_init_offset = this.$player.offset();
        this.player_width = this.$player.width();
        this.player_height = this.$player.height();
        this.player_max_left = (this.$container.width() - this.player_width +
            this.options.offset_left);

        if (this.options.start) {
            this.options.start.call(this.$player, e, {
                helper: this.helper ? this.$helper : this.$player
            });
        }
        return false;
    };


    fn.on_dragmove = function(e) {
        var offset = this.get_offset(e);

        this.options.autoscroll && this.manage_scroll(offset);

        (this.helper ? this.$helper : this.$player).css({
            'position': 'absolute',
            'left' : offset.left,
            'top' : offset.top
        });

        var ui = {
            'position': {
                'left': offset.left,
                'top': offset.top
            }
        };

        if (this.options.drag) {
            this.options.drag.call(this.$player, e, ui);
        }
        return false;
    };


    fn.on_dragstop = function(e) {
        var offset = this.get_offset(e);
        this.drag_start = false;

        var ui = {
            'position': {
                'left': offset.left,
                'top': offset.top
            }
        };

        if (this.options.stop) {
            this.options.stop.call(this.$player, e, ui);
        }

        if (this.helper) {
            this.$helper.remove();
        }

        return false;
    };

    fn.on_select_start = function(e) {
        if (this.disabled) { return; }

        if (this.ignore_drag(e)) {
            return;
        }

        return false;
    };

    fn.enable = function() {
        this.disabled = false;
    };

    fn.disable = function() {
        this.disabled = true;
    };


    fn.destroy = function(){
        this.disable();
        $.removeData(this.$container, 'drag');
    };

    fn.ignore_drag = function(event) {
        if (this.options.handle) {
            return !$(event.target).is(this.options.handle);
        }

        return $.inArray(event.target.nodeName, this.options.ignore_dragging) >= 0;
    };

    //jQuery adapter
    $.fn.dragg = function ( options ) {
        return this.each(function () {
            if (!$.data(this, 'drag')) {
                $.data(this, 'drag', new Draggable( this, options ));
            }
        });
    };


}(jQuery, window, document));
;/*
 * jquery.gridster
 * https://github.com/ducksboard/gridster.js
 *
 * Copyright (c) 2012 ducksboard
 * Licensed under the MIT licenses.
 */
;( function($, window, document, undefined) {

        //ToDo Max_cols and Max_size_x conflict.. need to unify
        var defaults = {
            namespace : '',
            widget_selector : 'li',
            static_class : 'static',
            widget_margins : [10, 10],
            widget_base_dimensions : [400, 225],
            extra_rows : 1,
            extra_cols : 10,
            min_cols : 1,
            max_cols : 60,
            min_rows : 15,
            max_rows : 15,
            max_size_x : 6,
            enabled : true,
            resize_handle : null,
            resize_variations : [],
            autogenerate_stylesheet : true,
            avoid_overlapped_widgets : true,
            shift_larger_widgets_down : true,
            serialize_params : function($w, wgd) {
                return {
                    col : wgd.col,
                    row : wgd.row,
                    size_x : wgd.size_x,
                    size_y : wgd.size_y
                };
            },
            collision : {},
            draggable : {
                distance : 4,
                items : ".gs_w:not(.static)"
            }
        };

        /**
         * @class Gridster
         * @uses Draggable
         * @uses Collision
         * @param {HTMLElement} el The HTMLelement that contains all the widgets.
         * @param {Object} [options] An Object with all options you want to
         *        overwrite:
         *    @param {HTMLElement|String} [options.widget_selector] Define who will
         *     be the draggable widgets. Can be a CSS Selector String or a
         *     collection of HTMLElements
         *    @param {Array} [options.widget_margins] Margin between widgets.
         *     The first index for the horizontal margin (left, right) and
         *     the second for the vertical margin (top, bottom).
         *    @param {Array} [options.widget_base_dimensions] Base widget dimensions
         *     in pixels. The first index for the width and the second for the
         *     height.
         *    @param {Number} [options.extra_cols] Add more columns in addition to
         *     those that have been calculated.
         *    @param {Number} [options.extra_rows] Add more rows in addition to
         *     those that have been calculated.
         *    @param {Number} [options.min_cols] The minimum required columns.
         *    @param {Number} [options.min_rows] The minimum required rows.
         *    @param {Number} [options.max_size_x] The maximum number of columns
         *     that a widget can span.
         *    @param {Boolean} [options.autogenerate_stylesheet] If true, all the
         *     CSS required to position all widgets in their respective columns
         *     and rows will be generated automatically and injected to the
         *     `<head>` of the document. You can set this to false, and write
         *     your own CSS targeting rows and cols via data-attributes like so:
         *     `[data-col="1"] { left: 10px; }`
         *    @param {Boolean} [options.avoid_overlapped_widgets] Avoid that widgets loaded
         *     from the DOM can be overlapped. It is helpful if the positions were
         *     bad stored in the database or if there was any conflict.
         *    @param {Function} [options.serialize_params] Return the data you want
         *     for each widget in the serialization. Two arguments are passed:
         *     `$w`: the jQuery wrapped HTMLElement, and `wgd`: the grid
         *     coords object (`col`, `row`, `size_x`, `size_y`).
         *    @param {Object} [options.collision] An Object with all options for
         *     Collision class you want to overwrite. See Collision docs for
         *     more info.
         *    @param {Object} [options.draggable] An Object with all options for
         *     Draggable class you want to overwrite. See Draggable docs for more
         *     info.
         *
         * @constructor
         */
        function Gridster(el, options) {
            this.options = $.extend(true, defaults, options);
            this.$el = $(el);
            this.$wrapper = this.$el.parent();
            this.$widgets = this.$el.children(this.options.widget_selector).addClass('gs_w');
            this.widgets = [];
            this.$changed = $([]);
            this.w_queue = {};
            this.wrapper_width = this.$wrapper.width();
            this.min_widget_width = (this.options.widget_margins[0] * 2) + this.options.widget_base_dimensions[0];
            this.min_widget_height = (this.options.widget_margins[1] * 2) + this.options.widget_base_dimensions[1];
            this.init();
        }


        Gridster.generated_stylesheets = [];

        var fn = Gridster.prototype;

        fn.init = function() {
            this.generate_grid_and_stylesheet();
            this.get_widgets_from_DOM();
            this.set_dom_grid_height();
            this.$wrapper.addClass('ready');
            this.draggable();

            if (!this.options.enabled) {
                this.disable();
            }

            this.refresh_resize_handlers();

            $(window).bind('resize', throttle($.proxy(this.recalculate_faux_grid, this), 200));
        };

        fn.update_sizes = function(width, height, marginX, marginY) {
            this.options.widget_base_dimensions = [width, height];
            this.options.widget_margins = [marginX, marginY];
            this.wrapper_width = this.$wrapper.width();
            this.min_widget_width = (this.options.widget_margins[0] * 2) + this.options.widget_base_dimensions[0];
            this.min_widget_height = (this.options.widget_margins[1] * 2) + this.options.widget_base_dimensions[1];
            this.generate_stylesheet();
            var self = this;

            self.set_dom_grid_height();
            setTimeout(function() {
                self.set_dom_grid_height();
            }, 650);
        };

        /**
         * Bind resize handlers
         *
         * @method refresh_resize_handlers
         */
        fn.refresh_resize_handlers = function() {
            if (this.options.resize_handle) {
                this.$resizeHandle = $(this.options.resize_handle).filter(':not(.gridster-applied)').addClass('gridster-applied');
                this.$resizeHandle.bind('click', $.proxy(this.click_resize_handle, this));
            }
        };

        /**
         * Release bindings
         *
         * @method destroy
         */
        fn.destroy = function() {
            $(window).unbind('resize');

            if (this.$resizeHandle) {
                this.$resizeHandle.unbind('click');
            }
        };

        /**
         * Resize box
         *
         * @method click_resize_handle
         * @return {Class} Returns the instance of the Gridster Class.
         */
        fn.click_resize_handle = function(event) {

            event.preventDefault();

            if (!this.isEnabled()) {
                return this;
            }

            var $li = $(event.target).parents('li:first');

            for (var i = 0; i < this.options.resize_variations.length; i++) {
                var variation = this.options.resize_variations[i];

                if (parseInt($li.attr('data-sizex')) === variation.sizex && parseInt($li.attr('data-sizey')) === variation.sizey) {
                    i++;

                    if (i >= this.options.resize_variations.length) {
                        i = 0;
                    }

                    variation = this.options.resize_variations[i];

                    this.resize_widget($li, variation.sizex, variation.sizey);
                    this.$el.trigger('gridster:resize_handle');

                    break;
                }
            }
                        
            this.set_dom_grid_height();

            return this;
        };

        /**
         * Disables dragging.
         *
         * @method disable
         * @return {Class} Returns the instance of the Gridster Class.
         */
        fn.disable = function() {
            this.$wrapper.find('.player-revert').removeClass('player-revert');
            this.drag_api.disable();

            this.$wrapper.removeClass('enabled');
            this.$wrapper.addClass('disabled');

            return this;
        };

        /**
         * Enables dragging.
         *
         * @method enable
         * @return {Class} Returns the instance of the Gridster Class.
         */
        fn.enable = function() {
            this.drag_api.enable();

            this.$wrapper.removeClass('disabled');
            this.$wrapper.addClass('enabled');

            return this;
        };

        /**
         * Is in enabled-mode
         *
         * @method isEnabled
         * @return {bool}
         */
        fn.isEnabled = function() {
            return !this.$wrapper.hasClass('disabled');
        };

        /**
         * Add a new widget to the grid.
         *
         * @method add_widget
         * @param {String|HTMLElement} html The string representing the HTML of the widget
         *  or the HTMLElement.
         * @param {Number} [size_x] The nº of rows the widget occupies horizontally.
         * @param {Number} [size_y] The nº of columns the widget occupies vertically.
         * @param {Number} [col] The column the widget should start in.
         * @param {Number} [row] The row the widget should start in.
         * @return {HTMLElement} Returns the jQuery wrapped HTMLElement representing.
         *  the widget that was just created.
         */
        fn.add_widget = function(html, size_x, size_y, col, row) {
            
            var pos;
            size_x || ( size_x = 1);
            size_y || ( size_y = 1);

            if (!col & !row) {
                pos = this.next_position(size_x, size_y);
            } else {
                pos = {
                    col : col,
                    row : row
                };

                this.empty_cells(col, row, size_x, size_y);
            }

            var $w = $(html).attr({
                'data-col' : pos.col,
                'data-row' : pos.row,
                'data-sizex' : size_x,
                'data-sizey' : size_y
            }).addClass('gs_w').css('opacity', 0).show().appendTo(this.$el);

            this.$widgets = this.$widgets.add($w);
            this.$changed = this.$changed.add($w);

            this.register_widget($w);

            this.add_faux_rows(pos.size_y);
            //this.add_faux_cols(pos.size_x);

            this.set_dom_grid_height();

            this.refresh_resize_handlers();

            var self = this;
            //for Each
            setTimeout(function() {
                $w.css('opacity', 1);
            }, 200);

            clearTimeout(self.timeotThrottleAddWidget2);
            self.timeotThrottleAddWidget2 = setTimeout(function() {
                self.timeotThrottleAddWidget2 = 0;
                self.set_dom_grid_height();
            }, 600);

            return $w;
        };

        /**
         * Change the size of a widget.
         *
         * @method resize_widget
         * @param {HTMLElement} $widget The jQuery wrapped HTMLElement
         *  representing the widget.
         * @param {Number} size_x The number of columns that will occupy the widget.
         * @param {Number} size_y The number of rows that will occupy the widget.
         * @return {HTMLElement} Returns $widget.
         */
        fn.resize_widget = function($widget, size_x, size_y) {
            
            var wgd = $widget.coords().grid;            
            size_x || ( size_x = wgd.size_x);
            size_y || ( size_y = wgd.size_y);
                
            if (size_x > this.cols) {
                size_x = this.cols;
            }

            var old_cells_occupied = this.get_cells_occupied(wgd);
            var old_size_x = wgd.size_x;
            var old_size_y = wgd.size_y;
            var old_col = wgd.col;
            var new_col = old_col;
            var wider = size_x > old_size_x;
            var taller = size_y > old_size_y;

            if (old_col + size_x - 1 > this.cols) {
                var diff = old_col + (size_x - 1) - this.cols;
                var c = old_col - diff;
                new_col = Math.max(1, c);
            }

            var new_grid_data = {
                col : new_col,
                row : wgd.row,
                size_x : size_x,
                size_y : size_y
            };

            var new_cells_occupied = this.get_cells_occupied(new_grid_data);

            var empty_cols = [];
            $.each(old_cells_occupied.cols, function(i, col) {
                if ($.inArray(col, new_cells_occupied.cols) === -1) {
                    empty_cols.push(col);
                }
            });

            var occupied_cols = [];
            $.each(new_cells_occupied.cols, function(i, col) {
                if ($.inArray(col, old_cells_occupied.cols) === -1) {
                    occupied_cols.push(col);
                }
            });

            var empty_rows = [];
            $.each(old_cells_occupied.rows, function(i, row) {
                if ($.inArray(row, new_cells_occupied.rows) === -1) {
                    empty_rows.push(row);
                }
            });

            var occupied_rows = [];
            $.each(new_cells_occupied.rows, function(i, row) {
                if ($.inArray(row, old_cells_occupied.rows) === -1) {
                    occupied_rows.push(row);
                }
            });

            this.remove_from_gridmap(wgd);                                   

            if (occupied_cols.length) {
                var cols_to_empty = [new_col, wgd.row, size_x, Math.min(old_size_y, size_y), $widget];
                this.empty_cells.apply(this, cols_to_empty);
            }

            if (occupied_rows.length) {
                var rows_to_empty = [new_col, wgd.row, size_x, size_y, $widget];
                this.empty_cells.apply(this, rows_to_empty);
            }

            wgd.col = new_col;
            wgd.size_x = size_x;
            wgd.size_y = size_y;
            this.add_to_gridmap(new_grid_data, $widget);

            //update coords instance attributes
            $widget.data('coords').update({
                width : (size_x * this.options.widget_base_dimensions[0] + ((size_x - 1) * this.options.widget_margins[0]) * 2),
                height : (size_y * this.options.widget_base_dimensions[1] + ((size_y - 1) * this.options.widget_margins[1]) * 2)
            });

            if (size_y > old_size_y) {
                this.add_faux_rows(size_y - old_size_y);
            }

            if (size_x > old_size_x) {
                this.add_faux_cols(size_x - old_size_x);
            }

            $widget.attr({
                'data-col' : new_col,
                'data-sizex' : size_x,
                'data-sizey' : size_y
            });

            if (empty_cols.length) {
                var cols_to_remove_holes = [empty_cols[0], wgd.row, empty_cols.length, Math.min(old_size_y, size_y), $widget];

                this.remove_empty_cells.apply(this, cols_to_remove_holes);
            }

            if (empty_rows.length) {
                var rows_to_remove_holes = [new_col, wgd.row, size_x, size_y, $widget];
                this.remove_empty_cells.apply(this, rows_to_remove_holes);
            }

            return $widget;
        };

        /**
         * Move down widgets in cells represented by the arguments col, row, size_x,
         * size_y
         *
         * @method empty_cells
         * @param {Number} col The column where the group of cells begin.
         * @param {Number} row The row where the group of cells begin.
         * @param {Number} size_x The number of columns that the group of cells
         * occupy.
         * @param {Number} size_y The number of rows that the group of cells
         * occupy.
         * @param {HTMLElement} $exclude Exclude widgets from being moved.
         * @return {Class} Returns the instance of the Gridster Class.
         */
        fn.empty_cells = function(col, row, size_x, size_y, $exclude) {
            var $nexts = this.widgets_below({
                col : col,
                row : row - size_y,
                size_x : size_x,
                size_y : size_y
            });

            $nexts.not($exclude).each($.proxy(function(i, w) {
                var wgd = $(w).coords().grid;
                if (!wgd || !(wgd.row <= (row + size_y - 1))) {
                    return;
                }
                var diff = (row + size_y) - wgd.row;
                this.move_widget_down($(w), diff);
            }, this));

            this.set_dom_grid_height();

            return this;
        };

        /**
         * Move up widgets below cells represented by the arguments col, row, size_x,
         * size_y.
         *
         * @method remove_empty_cells
         * @param {Number} col The column where the group of cells begin.
         * @param {Number} row The row where the group of cells begin.
         * @param {Number} size_x The number of columns that the group of cells
         * occupy.
         * @param {Number} size_y The number of rows that the group of cells
         * occupy.
         * @param {HTMLElement} $exclude Exclude widgets from being moved.
         * @return {Class} Returns the instance of the Gridster Class.
         */
        fn.remove_empty_cells = function(col, row, size_x, size_y, exclude) {
            var $nexts = this.widgets_below({
                col : col,
                row : row,
                size_x : size_x,
                size_y : size_y
            });

            $nexts.not(exclude).each($.proxy(function(i, widget) {
                this.move_widget_up($(widget), size_y);
            }, this));

            this.set_dom_grid_height();

            return this;
        };

        /**
         * Get the most left column below to add a new widget.
         *
         * @method next_position
         * @param {Number} size_x The nº of rows the widget occupies horizontally.
         * @param {Number} size_y The nº of columns the widget occupies vertically.
         * @return {Object} Returns a grid coords object representing the future
         *  widget coords.
         */
        fn.next_position = function(size_x, size_y) {
            size_x || ( size_x = 1);
            size_y || ( size_y = 1);
            var ga = this.gridmap;
            var cols_l = ga.length;
            var valid_pos = [];
            var rows_l;

            for (var c = 1; c < cols_l; c++) {
                rows_l = ga[c].length;
                for (var r = 1; r <= rows_l; r++) {
                    var can_move_to = this.can_move_to({
                        size_x : size_x,
                        size_y : size_y
                    }, c, r);

                    if (can_move_to) {
                        valid_pos.push({
                            col : c,
                            row : r,
                            size_y : size_y,
                            size_x : size_x
                        });
                    }
                }
            }

            if (valid_pos.length) {
                return this.sort_by_row_and_col_asc(valid_pos)[0];
            }
            return false;
        };

        fn.remove_by_grid = function(col, row) {
            var $w = this.is_widget(col, row);
            if ($w) {
                this.remove_widget($w);
            }
        }
        /**
         * Remove a widget from the grid.
         *
         * @method remove_widget
         * @param {HTMLElement} el The jQuery wrapped HTMLElement you want to remove.
         * @param {Boolean|Function} silent If true, widgets below the removed one
         * will not move up. If a Function is passed it will be used as callback.
         * @param {Function} callback Function executed when the widget is removed.
         * @param {Boolean} execute at once
         * @return {Class} Returns the instance of the Gridster Class.
         */
        fn.remove_widget = function(el, silent, callback, noTimeout) {
            var $el = el instanceof jQuery ? el : $(el);
            var wgd = $el.coords().grid;

            // if silent is a function assume it's a callback
            if ($.isFunction(silent)) {
                callback = silent;
                silent = false;
            }

            this.cells_occupied_by_placeholder = {};
            this.$widgets = this.$widgets.not($el);

            var $nexts = this.widgets_below($el);

            this.remove_from_gridmap(wgd);

            $el.removeClass('portfolio-top-box').css('opacity', 0);

            if (noTimeout) {
                this.remove_widget_callback($nexts, $el, silent, wgd, callback);
            } else {
                setTimeout($.proxy(this.remove_widget_callback, this), 100, $nexts, $el, silent, wgd, callback);
            }
        };

        /*
         * Callback to remove_widget
         */
        fn.remove_widget_callback = function($nexts, $el, silent, wgd, callback) {
            $el.remove();

            if (!silent) {
                $nexts.each($.proxy(function(i, widget) {
                    this.move_widget_up($(widget), wgd.size_y);
                }, this));

                this.set_dom_grid_height();
            }

            var self = this;
            clearTimeout(this.timeoutThrottleRemoveCallback);
            this.timeoutThrottleRemoveCallback = setTimeout(function() {
                self.timeoutThrottleRemoveCallback = 0;
                self.set_dom_grid_height();
            }, 600);

            if (callback) {
                callback.call(this, el);
            }
        };

        /**
         * Remove all widgets from the grid.
         *
         * @method remove_all_widgets
         * @param {Function} callback Function executed for each widget removed.
         * @return {Class} Returns the instance of the Gridster Class.
         */
        fn.remove_all_widgets = function(callback) {
            this.$widgets.each($.proxy(function(i, el) {
                this.remove_widget(el, true, callback);
            }, this));

            return this;
        };

        /**
         * Returns a serialized array of the widgets in the grid.
         *
         * @method serialize
         * @param {HTMLElement} [$widgets] The collection of jQuery wrapped
         *  HTMLElements you want to serialize. If no argument is passed all widgets
         *  will be serialized.
         * @return {Array} Returns an Array of Objects with the data specified in
         *  the serialize_params option.
         */
        fn.serialize = function($widgets) {
            $widgets || ( $widgets = this.$widgets);
            var result = [];
            $widgets.each($.proxy(function(i, widget) {
                if ( typeof ($(widget).coords().grid) != "undefined") {
                    result.push(this.options.serialize_params($(widget), $(widget).coords().grid));
                }
            }, this));

            return result;
        };

        /**
         * Returns a serialized array of the widgets that have changed their
         *  position.
         *
         * @method serialize_changed
         * @return {Array} Returns an Array of Objects with the data specified in
         *  the serialize_params option.
         */
        fn.serialize_changed = function() {
            return this.serialize(this.$changed);
        };

        /**
         * Creates the grid coords object representing the widget a add it to the
         * mapped array of positions.
         *
         * @method register_widget
         * @return {Array} Returns the instance of the Gridster class.
         */
        fn.register_widget = function($el) {

            var wgd = {
                'col' : parseFloat($el.attr('data-col')),
                'row' : parseFloat($el.attr('data-row')),
                'size_x' : parseFloat($el.attr('data-sizex')),
                'size_y' : parseFloat($el.attr('data-sizey')),
                'el' : $el
            };

            if (this.options.avoid_overlapped_widgets && !this.can_move_to({
                size_x : wgd.size_x,
                size_y : wgd.size_y
            }, wgd.col, wgd.row)) {
                if (!$el.hasClass('.disp_ad')) {
                    $el.remove();
                    return false;
                }
                wgd = this.next_position(wgd.size_x, wgd.size_y);
                wgd.el = $el;
                $el.attr({
                    'data-col' : wgd.col,
                    'data-row' : wgd.row,
                    'data-sizex' : wgd.size_x,
                    'data-sizey' : wgd.size_y
                });
            }

            // attach Coord object to player data-coord attribute
            $el.data('coords', $el.coords());

            // Extend Coord object with grid position info
            $el.data('coords').grid = wgd;

            this.add_to_gridmap(wgd, $el);

            return this;
        };

        /**
         * Update in the mapped array of positions the value of cells represented by
         * the grid coords object passed in the `grid_data` param.
         *
         * @param {Object} grid_data The grid coords object representing the cells
         *  to update in the mapped array.
         * @param {HTMLElement|Boolean} value Pass `false` or the jQuery wrapped
         *  HTMLElement, depends if you want to delete an existing position or add
         *  a new one.
         * @method update_widget_position
         * @return {Class} Returns the instance of the Gridster Class.
         */
        fn.update_widget_position = function(grid_data, value) {
            this.for_each_cell_occupied(grid_data, function(col, row) {
                if (!this.gridmap[col]) {
                    return this;
                }
                this.gridmap[col][row] = value;
            });
            return this;
        };

        /**
         * Remove a widget from the mapped array of positions.
         *
         * @method remove_from_gridmap
         * @param {Object} grid_data The grid coords object representing the cells
         *  to update in the mapped array.
         * @return {Class} Returns the instance of the Gridster Class.
         */
        fn.remove_from_gridmap = function(grid_data) {
            return this.update_widget_position(grid_data, false);
        };

        /**
         * Add a widget to the mapped array of positions.
         *
         * @method add_to_gridmap
         * @param {Object} grid_data The grid coords object representing the cells
         *  to update in the mapped array.
         * @param {HTMLElement|Boolean} value The value to set in the specified
         *  position .
         * @return {Class} Returns the instance of the Gridster Class.
         */
        fn.add_to_gridmap = function(grid_data, value) {
            this.update_widget_position(grid_data, value || grid_data.el);
            /*if (grid_data.el) {
             var $widgets = this.widgets_below(grid_data.el);
             $widgets.each($.proxy(function(i, widget) {
             console.log("from_add_to_gridmap");
             this.move_widget_up( $(widget));
             }, this));
             } */
        };

        /**
         * Make widgets draggable.
         *
         * @uses Draggable
         * @method draggable
         * @return {Class} Returns the instance of the Gridster Class.
         */
        fn.draggable = function() {
            var self = this;
            var draggable_options = $.extend(true, {}, this.options.draggable, {
                offset_left : this.options.widget_margins[0],
                start : function(event, ui) {
                    self.$widgets.filter('.player-revert').removeClass('player-revert');

                    self.$player = $(this);
                    self.$helper = self.options.draggable.helper === 'clone' ? $(ui.helper) : self.$player;
                    self.helper = !self.$helper.is(self.$player);

                    self.on_start_drag.call(self, event, ui);
                    self.$el.trigger('gridster:dragstart');
                },
                stop : function(event, ui) {
                    self.on_stop_drag.call(self, event, ui);
                    self.$el.trigger('gridster:dragstop');
                },
                drag : throttle(function(event, ui) {
                    self.on_drag.call(self, event, ui);
                    self.$el.trigger('gridster:drag');
                }, 60)
            });

            this.drag_api = this.$el.dragg(draggable_options).data('drag');
            return this;
        };

        /**
         * This function is executed when the player begins to be dragged.
         *
         * @method on_start_drag
         * @param {Event} The original browser event
         * @param {Object} A prepared ui object.
         */
        fn.on_start_drag = function(event, ui) {

            this.$helper.add(this.$player).add(this.$wrapper).addClass('dragging');

            this.$player.addClass('player');
            this.player_grid_data = this.$player.coords().grid;
            this.placeholder_grid_data = $.extend({}, this.player_grid_data);

            //set new grid height along the dragging period
            this.$el.css('height', this.$el.height() + (this.player_grid_data.size_y * this.min_widget_height));

            var colliders = this.faux_grid;
            var coords = this.$player.data('coords').coords;

            this.cells_occupied_by_player = this.get_cells_occupied(this.player_grid_data);
            this.cells_occupied_by_placeholder = this.get_cells_occupied(this.placeholder_grid_data);

            this.last_cols = [];
            this.last_rows = [];

            // see jquery.collision.js
            this.collision_api = this.$helper.collision(colliders, this.options.collision);

            this.$preview_holder = $('<li />', {
                'class' : 'preview-holder',
                'data-row' : this.$player.attr('data-row'),
                'data-col' : this.$player.attr('data-col'),
                css : {
                    width : coords.width,
                    height : coords.height
                }
            }).appendTo(this.$el);

            if (this.options.draggable.start) {
                this.options.draggable.start.call(this, event, ui);
            }
        };

        /**
         * This function is executed when the player is being dragged.
         *
         * @method on_drag
         * @param {Event} The original browser event
         * @param {Object} A prepared ui object.
         */
        fn.on_drag = function(event, ui) {
            //break if dragstop has been fired
            if (this.$player === null) {
                return false;
            }

            var abs_offset = {
                left : ui.position.left + this.baseX,
                top : ui.position.top + this.baseY
            };

            this.colliders_data = this.collision_api.get_closest_colliders(abs_offset);

            this.on_overlapped_column_change(this.on_start_overlapping_column, this.on_stop_overlapping_column);

            this.on_overlapped_row_change(this.on_start_overlapping_row, this.on_stop_overlapping_row);

            if (this.helper && this.$player) {
                this.$player.css({
                    'left' : ui.position.left,
                    'top' : ui.position.top
                });
            }

            if (this.options.draggable.drag) {
                this.options.draggable.drag.call(this, event, ui);
            }
        };

        /**
         * This function is executed when the player stops being dragged.
         *
         * @method on_stop_drag
         * @param {Event} The original browser event
         * @param {Object} A prepared ui object.
         */
        fn.on_stop_drag = function(event, ui) {
            this.$helper.add(this.$player).add(this.$wrapper).removeClass('dragging');

            ui.position.left = ui.position.left + this.baseX;
            ui.position.top = ui.position.top + this.baseY;
            this.colliders_data = this.collision_api.get_closest_colliders(ui.position);

            this.on_overlapped_column_change(this.on_start_overlapping_column, this.on_stop_overlapping_column);

            this.on_overlapped_row_change(this.on_start_overlapping_row, this.on_stop_overlapping_row);

            this.$player.addClass('player-revert').removeClass('player').attr({
                'data-col' : this.placeholder_grid_data.col,
                'data-row' : this.placeholder_grid_data.row
            }).css({
                'left' : '',
                'top' : ''
            });

            this.$changed = this.$changed.add(this.$player);

            this.cells_occupied_by_player = this.get_cells_occupied(this.placeholder_grid_data);
            this.set_cells_player_occupies(this.placeholder_grid_data.col, this.placeholder_grid_data.row);

            this.$player.coords().grid.row = this.placeholder_grid_data.row;
            this.$player.coords().grid.col = this.placeholder_grid_data.col;

            if (this.options.draggable.stop) {
                this.options.draggable.stop.call(this, event, ui);
            }

            this.$preview_holder.remove();

            this.$player = null;
            this.$helper = null;
            this.placeholder_grid_data = {};
            this.player_grid_data = {};
            this.cells_occupied_by_placeholder = {};
            this.cells_occupied_by_player = {};
            this.w_queue = {};

            this.set_dom_grid_height();
        };

        /**
         * Executes the callbacks passed as arguments when a column begins to be
         * overlapped or stops being overlapped.
         *
         * @param {Function} start_callback Function executed when a new column
         *  begins to be overlapped. The column is passed as first argument.
         * @param {Function} stop_callback Function executed when a column stops
         *  being overlapped. The column is passed as first argument.
         * @method on_overlapped_column_change
         * @return {Class} Returns the instance of the Gridster Class.
         */
        fn.on_overlapped_column_change = function(start_callback, stop_callback) {
            if (!this.colliders_data.length) {
                return;
            }
            var cols = this.get_targeted_columns(this.colliders_data[0].el.data.col);

            var last_n_cols = this.last_cols.length;
            var n_cols = cols.length;
            var i;

            for ( i = 0; i < n_cols; i++) {
                if ($.inArray(cols[i], this.last_cols) === -1) {
                    (start_callback || $.noop).call(this, cols[i]);
                }
            }

            for ( i = 0; i < last_n_cols; i++) {
                if ($.inArray(this.last_cols[i], cols) === -1) {
                    (stop_callback || $.noop).call(this, this.last_cols[i]);
                }
            }

            this.last_cols = cols;

            return this;
        };

        /**
         * Executes the callbacks passed as arguments when a row starts to be
         * overlapped or stops being overlapped.
         *
         * @param {Function} start_callback Function executed when a new row begins
         *  to be overlapped. The row is passed as first argument.
         * @param {Function} stop_callback Function executed when a row stops being
         *  overlapped. The row is passed as first argument.
         * @method on_overlapped_row_change
         * @return {Class} Returns the instance of the Gridster Class.
         */
        fn.on_overlapped_row_change = function(start_callback, end_callback) {
            if (!this.colliders_data.length) {
                return;
            }
            var rows = this.get_targeted_rows(this.colliders_data[0].el.data.row);
            var last_n_rows = this.last_rows.length;
            var n_rows = rows.length;
            var i;

            for ( i = 0; i < n_rows; i++) {
                if ($.inArray(rows[i], this.last_rows) === -1) {
                    (start_callback || $.noop).call(this, rows[i]);
                }
            }

            for ( i = 0; i < last_n_rows; i++) {
                if ($.inArray(this.last_rows[i], rows) === -1) {
                    (end_callback || $.noop).call(this, this.last_rows[i]);
                }
            }

            this.last_rows = rows;
        };

        /**
         * Sets the current position of the player
         *
         * @param {Function} start_callback Function executed when a new row begins
         *  to be overlapped. The row is passed as first argument.
         * @param {Function} stop_callback Function executed when a row stops being
         *  overlapped. The row is passed as first argument.
         * @method set_player
         * @return {Class} Returns the instance of the Gridster Class.
         */
        fn.set_player = function(col, row, no_player) {
            var self = this;
            var swap = false;
            if (!no_player) {
                this.empty_cells_player_occupies();
            }
            var cell = !no_player ? self.colliders_data[0].el.data : {
                col : col
            };
            var to_col = cell.col;
            var to_row = cell.row || row;

            this.player_grid_data = {
                col : to_col,
                row : to_row,
                size_y : this.player_grid_data.size_y,
                size_x : this.player_grid_data.size_x
            };

            this.cells_occupied_by_player = this.get_cells_occupied(this.player_grid_data);

            //Added placeholder for more advanced movement.
            this.cells_occupied_by_placeholder = this.get_cells_occupied(this.placeholder_grid_data);

            var $overlapped_widgets = this.get_widgets_overlapped(this.player_grid_data);

            var player_size_y = this.player_grid_data.size_y;
            var player_size_x = this.player_grid_data.size_x;
            var placeholder_cells = this.cells_occupied_by_placeholder;
            var $gr = this;

            //Queue Swaps
            $overlapped_widgets.each($.proxy(function(i, w) {
                var $w = $(w);
                var wgd = $w.coords().grid;
                var outside_col = placeholder_cells.cols[0] + player_size_x - 1;
                var outside_row = placeholder_cells.rows[0] + player_size_y - 1;
                if ($w.hasClass($gr.options.static_class)) {
                    //next iteration
                    return true;
                }
                if (wgd.size_x <= player_size_x && wgd.size_y <= player_size_y) {
                    if (!$gr.is_swap_occupied(placeholder_cells.cols[0], wgd.row, wgd.size_x, wgd.size_y) && !$gr.is_player_in(placeholder_cells.cols[0], wgd.row) && !$gr.is_in_queue(placeholder_cells.cols[0], wgd.row, $w)) {
                        swap = $gr.queue_widget(placeholder_cells.cols[0], wgd.row, $w);
                    } else if (!$gr.is_swap_occupied(outside_col, wgd.row, wgd.size_x, wgd.size_y) && !$gr.is_player_in(outside_col, wgd.row) && !$gr.is_in_queue(outside_col, wgd.row, $w)) {
                        swap = $gr.queue_widget(outside_col, wgd.row, $w);
                    } else if (!$gr.is_swap_occupied(wgd.col, placeholder_cells.rows[0], wgd.size_x, wgd.size_y) && !$gr.is_player_in(wgd.col, placeholder_cells.rows[0]) && !$gr.is_in_queue(wgd.col, placeholder_cells.rows[0], $w)) {
                        swap = $gr.queue_widget(wgd.col, placeholder_cells.rows[0], $w);
                    } else if (!$gr.is_swap_occupied(wgd.col, outside_row, wgd.size_x, wgd.size_y) && !$gr.is_player_in(wgd.col, outside_row) && !$gr.is_in_queue(wgd.col, outside_row, $w)) {
                        swap = $gr.queue_widget(wgd.col, outside_row, $w);
                    } else if (!$gr.is_swap_occupied(placeholder_cells.cols[0], placeholder_cells.rows[0], wgd.size_x, wgd.size_y) && !$gr.is_player_in(placeholder_cells.cols[0], placeholder_cells.rows[0]) && !$gr.is_in_queue(placeholder_cells.cols[0], placeholder_cells.rows[0], $w)) {
                        swap = $gr.queue_widget(placeholder_cells.cols[0], placeholder_cells.rows[0], $w);
                    } else {
                        //in one last attempt we check for any other empty spaces
                        for (var c = 0; c < player_size_x; c++) {
                            for (var r = 0; r < player_size_y; r++) {
                                var colc = placeholder_cells.cols[0] + c;
                                var rowc = placeholder_cells.rows[0] + r;
                                if (!$gr.is_swap_occupied(colc, rowc, wgd.size_x, wgd.size_y) && !$gr.is_player_in(colc, rowc) && !$gr.is_in_queue(colc, rowc, $w)) {
                                    swap = $gr.queue_widget(colc, rowc, $w);
                                    c = player_size_x;
                                    break;
                                }
                            }
                        }

                    }
                } else if ($gr.options.shift_larger_widgets_down && !swap) {
                    $overlapped_widgets.each($.proxy(function(i, w) {
                        var $w = $(w);
                        var wgd = $w.coords().grid;

                        if ($gr.can_go_down($w)) {
                            $gr.move_widget_down($w, $gr.player_grid_data.size_y);
                            $gr.set_placeholder(to_col, to_row);
                        }
                    }));
                }

                $gr.clean_up_changed();
            }));

            /* To show queued items in console
            for(var key in this.w_queue){
            console.log("key " +key);
            console.log(this.w_queue[key]);
            }
            */

            //Move queued widgets
            if (swap && this.can_placeholder_be_set(to_col, to_row, player_size_x, player_size_y)) {
                for (var key in this.w_queue) {
                    var col = parseInt(key.split("_")[0]);
                    var row = parseInt(key.split("_")[1]);
                    if (this.w_queue[key] != "full") {
                        this.new_move_widget_to_legacy(this.w_queue[key], col, row);
                    }
                }
                this.set_placeholder(to_col, to_row);
            }

            /* if there is not widgets overlapping in the new player position,
             * update the new placeholder position. */
            if (!$overlapped_widgets.length) {
                var pp = this.can_go_player_up(this.player_grid_data);
                if (pp !== false) {
                    to_row = pp;
                }
                if (this.can_placeholder_be_set(to_col, to_row, player_size_x, player_size_y)) {
                    this.set_placeholder(to_col, to_row);
                }
            }

            this.w_queue = {};

            return {
                col : to_col,
                row : to_row
            };
        };

        fn.is_swap_occupied = function(col, row, w_size_x, w_size_y) {
            var occupied = false;
            for (var c = 0; c < w_size_x; c++) {
                for (var r = 0; r < w_size_y; r++) {
                    var colc = col + c;
                    var rowc = row + r;
                    var key = colc + "_" + rowc;
                    if (this.is_occupied(colc, rowc)) {
                        occupied = true;
                    } else if ( key in this.w_queue) {
                        if (this.w_queue[key] == "full") {
                            occupied = true;
                            continue;
                        }
                        $tw = this.w_queue[key];
                        tgd = $tw.coords().grid;
                        //remove queued items if no longer under player.
                        if (!this.is_widget_under_player(tgd.col, tgd.row)) {
                            delete this.w_queue[key];
                        }
                    }
                    if (rowc > parseInt(this.options.max_rows)) {
                        occupied = true;
                    }
                    if (colc > parseInt(this.options.max_cols)) {
                        occupied = true;
                    }
                    if (this.is_player_in(colc, rowc)) {
                        occupied = true;
                    }
                }
            }

            return occupied;
        }

        fn.can_placeholder_be_set = function(col, row, player_size_x, player_size_y) {
            var can_set = true;
            for (var c = 0; c < player_size_x; c++) {
                for (var r = 0; r < player_size_y; r++) {
                    var colc = col + c;
                    var rowc = row + r;
                    var key = colc + "_" + rowc;
                    var $tw = this.is_widget(colc, rowc);
                    //if this space is occupied and not queued for move.
                    if (rowc > parseInt(this.options.max_rows)) {
                        can_set = false;
                    }
                    if (colc > parseInt(this.options.max_cols)) {
                        can_set = false;
                    }
                    if (this.is_occupied(colc, rowc) && !this.is_widget_queued_and_can_move($tw)) {
                        can_set = false;
                    }
                }
            }
            return can_set;
        }

        fn.queue_widget = function(col, row, $widget) {
            var $w = $widget
            var wgd = $w.coords().grid;
            var primary_key = col + "_" + row;
            if ( primary_key in this.w_queue) {
                return false;
            }

            this.w_queue[primary_key] = $w;

            for (var c = 0; c < wgd.size_x; c++) {
                for (var r = 0; r < wgd.size_y; r++) {
                    var colc = col + c;
                    var rowc = row + r;
                    var key = colc + "_" + rowc;
                    if (key == primary_key) {
                        continue;
                    }
                    this.w_queue[key] = "full";
                }
            }

            return true;
        }

        fn.is_widget_queued_and_can_move = function($widget) {
            var queued = false;
            if ($widget === false) {
                return false;
            }

            for (var key in this.w_queue) {
                if (this.w_queue[key] == "full") {
                    continue;
                }
                if (this.w_queue[key].attr("data-col") == $widget.attr("data-col") && this.w_queue[key].attr("data-row") == $widget.attr("data-row")) {
                    queued = true;
                    //test whole space
                    var $w = this.w_queue[key];
                    var dcol = parseInt(key.split("_")[0]);
                    var drow = parseInt(key.split("_")[1]);
                    var wgd = $w.coords().grid;

                    for (var c = 0; c < wgd.size_x; c++) {
                        for (var r = 0; r < wgd.size_y; r++) {
                            var colc = dcol + c;
                            var rowc = drow + r;
                            if (this.is_player_in(colc, rowc)) {
                                queued = false;
                            }

                        }
                    }

                }
            }

            return queued
        }

        fn.is_in_queue = function(col, row, $widget) {
            var queued = false;
            var key = col + "_" + row;

            if (( key in this.w_queue)) {
                if (this.w_queue[key] == "full") {
                    queued = true;
                } else {
                    $tw = this.w_queue[key];
                    tgd = $tw.coords().grid;
                    if (!this.is_widget_under_player(tgd.col, tgd.row)) {
                        delete this.w_queue[key]
                        queued = false;
                    } else if (this.w_queue[key].attr("data-col") == $widget.attr("data-col") && this.w_queue[key].attr("data-row") == $widget.attr("data-row")) {
                        delete this.w_queue[key]
                        queued = false;
                    } else {
                        queued = true;
                    }
                }
            }

            return queued;
        }
        /**
         * See which of the widgets in the $widgets param collection can go to
         * a upper row and which not.
         *
         * @method widgets_contraints
         * @param {HTMLElements} $widgets A jQuery wrapped collection of
         * HTMLElements.
         * @return {Array} Returns a literal Object with two keys: `can_go_up` &
         * `can_not_go_up`. Each contains a set of HTMLElements.
         */
        fn.widgets_constraints = function($widgets) {
            var $widgets_can_go_up = $([]);
            var $widgets_can_not_go_up;
            var wgd_can_go_up = [];
            var wgd_can_not_go_up = [];

            $widgets.each($.proxy(function(i, w) {
                var $w = $(w);
                var wgd = $w.coords().grid;
                if (this.can_go_widget_up(wgd)) {
                    $widgets_can_go_up = $widgets_can_go_up.add($w);
                    wgd_can_go_up.push(wgd);
                } else {
                    wgd_can_not_go_up.push(wgd);
                }
            }, this));

            $widgets_can_not_go_up = $widgets.not($widgets_can_go_up);

            return {
                can_go_up : this.sort_by_row_asc(wgd_can_go_up),
                can_not_go_up : this.sort_by_row_desc(wgd_can_not_go_up)
            };
        };

        /**
         * Sorts an Array of grid coords objects (representing the grid coords of
         * each widget) in ascending way.
         *
         * @method sort_by_row_asc
         * @param {Array} widgets Array of grid coords objects
         * @return {Array} Returns the array sorted.
         */
        fn.sort_by_row_asc = function(widgets) {
            widgets = widgets.sort(function(a, b) {
                if (!a.row) {
                    a = $(a).coords().grid;
                    b = $(b).coords().grid;
                }

                if (a.row > b.row) {
                    return 1;
                }
                return -1;
            });

            return widgets;
        };

        /**
         * Sorts an Array of grid coords objects (representing the grid coords of
         * each widget) placing first the empty cells upper left.
         *
         * @method sort_by_row_and_col_asc
         * @param {Array} widgets Array of grid coords objects
         * @return {Array} Returns the array sorted.
         */
        fn.sort_by_row_and_col_asc = function(widgets) {
            widgets = widgets.sort(function(a, b) {
                if (a.row > b.row || a.row === b.row && a.col > b.col) {
                    return 1;
                }
                return -1;
            });

            return widgets;
        };

        /**
         * Sorts an Array of grid coords objects by column (representing the grid
         * coords of each widget) in ascending way.
         *
         * @method sort_by_col_asc
         * @param {Array} widgets Array of grid coords objects
         * @return {Array} Returns the array sorted.
         */
        fn.sort_by_col_asc = function(widgets) {
            widgets = widgets.sort(function(a, b) {
                if (a.col > b.col) {
                    return 1;
                }
                return -1;
            });

            return widgets;
        };

        /**
         * Sorts an Array of grid coords objects (representing the grid coords of
         * each widget) in descending way.
         *
         * @method sort_by_row_desc
         * @param {Array} widgets Array of grid coords objects
         * @return {Array} Returns the array sorted.
         */
        fn.sort_by_row_desc = function(widgets) {
            widgets = widgets.sort(function(a, b) {
                if (a.row + a.size_y < b.row + b.size_y) {
                    return 1;
                }
                return -1;
            });
            return widgets;
        };

        /**
         * Sorts an Array of grid coords objects (representing the grid coords of
         * each widget) in descending way.

         * Depreciated.
         *
         * @method manage_movements
         * @param {HTMLElements} $widgets A jQuery collection of HTMLElements
         *  representing the widgets you want to move.
         * @param {Number} to_col The column to which we want to move the widgets.
         * @param {Number} to_row The row to which we want to move the widgets.
         * @return {Class} Returns the instance of the Gridster Class.
         */
        fn.manage_movements = function($widgets, to_col, to_row) {
            $.each($widgets, $.proxy(function(i, w) {
                var wgd = w;
                var $w = wgd.el;

                var can_go_widget_up = this.can_go_widget_up(wgd);

                if (can_go_widget_up) {
                    //target CAN go up
                    //so move widget up
                    this.move_widget_to($w, can_go_widget_up);
                    this.set_placeholder(to_col, can_go_widget_up + wgd.size_y);

                } else {
                    //target can't go up
                    var can_go_player_up = this.can_go_player_up(this.player_grid_data);

                    if (!can_go_player_up) {
                        // target can't go up
                        // player cant't go up
                        // so we need to move widget down to a position that dont
                        // overlaps player
                        var y = (to_row + this.player_grid_data.size_y) - wgd.row;
                        if (this.can_go_down($w)) {
                            console.log("In Move Down!")
                            this.move_widget_down($w, y);
                            this.set_placeholder(to_col, to_row);
                        }
                    }
                }
            }, this));

            return this;
        };

        /**
         * Determines if there is a widget in the row and col given. Or if the
         * HTMLElement passed as first argument is the player.
         *
         * @method is_player
         * @param {Number|HTMLElement} col_or_el A jQuery wrapped collection of
         * HTMLElements.
         * @param {Number} [row] The column to which we want to move the widgets.
         * @return {Boolean} Returns true or false.
         */
        fn.is_player = function(col_or_el, row) {
            if (row && !this.gridmap[col_or_el]) {
                return false;
            }
            var $w = row ? this.gridmap[col_or_el][row] : col_or_el;
            return $w && ($w.is(this.$player) || $w.is(this.$helper));
        };

        /**
         * Determines if the widget that is being dragged is currently over the row
         * and col given.
         *
         * @method is_player_in
         * @param {Number} col The column to check.
         * @param {Number} row The row to check.
         * @return {Boolean} Returns true or false.
         */
        fn.is_player_in = function(col, row) {
            var c = this.cells_occupied_by_player || {};
            return $.inArray(col, c.cols) >= 0 && $.inArray(row, c.rows) >= 0;
        };

        /**
         * Determines if the placeholder is currently over the row and col given.
         *
         * @method is_placeholder_in
         * @param {Number} col The column to check.
         * @param {Number} row The row to check.
         * @return {Boolean} Returns true or false.
         */
        fn.is_placeholder_in = function(col, row) {
            var c = this.cells_occupied_by_placeholder || {};
            return this.is_placeholder_in_col(col) && $.inArray(row, c.rows) >= 0;
        };

        /**
         * Determines if the placeholder is currently over the column given.
         *
         * @method is_placeholder_in_col
         * @param {Number} col The column to check.
         * @return {Boolean} Returns true or false.
         */
        fn.is_placeholder_in_col = function(col) {
            var c = this.cells_occupied_by_placeholder || [];
            return $.inArray(col, c.cols) >= 0;
        };

        /**
         * Determines if the cell represented by col and row params is empty.
         *
         * @method is_empty
         * @param {Number} col The column to check.
         * @param {Number} row The row to check.
         * @return {Boolean} Returns true or false.
         */
        fn.is_empty = function(col, row) {
            if (typeof this.gridmap[col] !== 'undefined') {
                if(typeof this.gridmap[col][row] !== 'undefined' &&
                     this.gridmap[col][row] === false
                ) {
                    return true;
                }
                return false;
            }
            return true;
        };

        /**
         * Determines if the cell represented by col and row params is occupied.
         *
         * @method is_occupied
         * @param {Number} col The column to check.
         * @param {Number} row The row to check.
         * @return {Boolean} Returns true or false.
         */
        fn.is_occupied = function(col, row) {
            if (!this.gridmap[col]) {
                return false;
            }

            if (this.gridmap[col][row]) {
                return true;
            }
            return false;
        };

        /**
         * Determines if there is a widget in the cell represented by col/row params.
         *
         * @method is_widget
         * @param {Number} col The column to check.
         * @param {Number} row The row to check.
         * @return {Boolean|HTMLElement} Returns false if there is no widget,
         * else returns the jQuery HTMLElement
         */
        fn.is_widget = function(col, row) {
            var cell = this.gridmap[col];
            if (!cell) {
                return false;
            }

            cell = cell[row];

            if (cell) {
                return cell;
            }

            return false;
        };

        /**
         * Determines if widget is supposed to be static.
         * @method is_static
         * @param {Number} col The column to check.
         * @param {Number} row The row to check.
         * @return {Boolean} Returns true if widget exists and has static class,
         * else returns false
         */

        fn.is_static = function(col, row) {
            var cell = this.gridmap[col];
            if (!cell) {
                return false;
            }

            cell = cell[row];

            if (cell) {
                if (cell.hasClass(this.options.static_class)) {
                    return true;
                }
            }

            return false;
        };

        /**
         * Determines if there is a widget in the cell represented by col/row
         * params and if this is under the widget that is being dragged.
         *
         * @method is_widget_under_player
         * @param {Number} col The column to check.
         * @param {Number} row The row to check.
         * @return {Boolean} Returns true or false.
         */
        fn.is_widget_under_player = function(col, row) {
            if (this.is_widget(col, row)) {
                return this.is_player_in(col, row);
            }
            return false;
        };

        /**
         * Get widgets overlapping with the player or with the object passed
         * representing the grid cells.
         *
         * @method get_widgets_under_player
         * @return {HTMLElement} Returns a jQuery collection of HTMLElements
         */
        fn.get_widgets_under_player = function(cells) {
            cells || ( cells = this.cells_occupied_by_player || {
                cols : [],
                rows : []
            });
            var $widgets = $([]);

            $.each(cells.cols, $.proxy(function(i, col) {
                $.each(cells.rows, $.proxy(function(i, row) {
                    if (this.is_widget(col, row)) {
                        $widgets = $widgets.add(this.gridmap[col][row]);
                    }
                }, this));
            }, this));

            return $widgets;
        };

        /**
         * Put placeholder at the row and column specified.
         *
         * @method set_placeholder
         * @param {Number} col The column to which we want to move the
         *  placeholder.
         * @param {Number} row The row to which we want to move the
         *  placeholder.
         * @return {Class} Returns the instance of the Gridster Class.
         */
        fn.set_placeholder = function(col, row) {
            var phgd = $.extend({}, this.placeholder_grid_data);
            var $nexts = this.widgets_below({
                col : phgd.col,
                row : phgd.row,
                size_y : phgd.size_y,
                size_x : phgd.size_x
            });

            // Prevents widgets go out of the grid
            var right_col = (col + phgd.size_x - 1);
            if (right_col > this.cols) {
                col = col - (right_col - col);
            }

            var moved_down = this.placeholder_grid_data.row < row;
            var changed_column = this.placeholder_grid_data.col !== col;

            this.placeholder_grid_data.col = col;
            this.placeholder_grid_data.row = row;

            this.cells_occupied_by_placeholder = this.get_cells_occupied(this.placeholder_grid_data);

            this.$preview_holder.attr({
                'data-row' : row,
                'data-col' : col
            });

            if (moved_down || changed_column) {
                $nexts.each($.proxy(function(i, widget) {
                    //Make sure widget is at it's topmost position
                    $w = $(widget);
                    wgd = $w.coords().grid;

                    var can_go_widget_up = this.can_go_widget_up(wgd);

                    if (can_go_widget_up) {
                        this.move_widget_to($w, can_go_widget_up);
                    }

                }, this));
            }

            var $widgets_under_ph = this.get_widgets_under_player(this.cells_occupied_by_placeholder);
            if ($widgets_under_ph.length) {
                $widgets_under_ph.each($.proxy(function(i, widget) {
                    var $w = $(widget);
                    this.move_widget_down($w, row + phgd.size_y - $w.data('coords').grid.row);
                }, this));
            }

        };

        /**
         * Determines whether the player can move to a position above.
         *
         * @method can_go_player_up
         * @param {Object} widget_grid_data The actual grid coords object of the
         *  player.
         * @return {Number|Boolean} If the player can be moved to an upper row
         *  returns the row number, else returns false.
         */
        fn.can_go_player_up = function(widget_grid_data) {
            var p_bottom_row = widget_grid_data.row + widget_grid_data.size_y - 1;
            var result = true;
            var upper_rows = [];
            var min_row = 10000;
            var $widgets_under_player = this.get_widgets_under_player();

            /* generate an array with columns as index and array with upper rows
             * empty as value */
            this.for_each_column_occupied(widget_grid_data, function(tcol) {
                var grid_col = this.gridmap[tcol];
                var r = p_bottom_row + 1;
                upper_rows[tcol] = [];

                while (--r > 0) {
                    if (this.is_empty(tcol, r) || this.is_player(tcol, r) || this.is_widget(tcol, r) && grid_col[r].is($widgets_under_player)) {
                        upper_rows[tcol].push(r);
                        min_row = r < min_row ? r : min_row;
                    } else {
                        break;
                    }
                }

                if (upper_rows[tcol].length === 0) {
                    result = false;
                    return true;
                    //break
                }

                upper_rows[tcol].sort();
            });

            if (!result) {
                return false;
            }

            return this.get_valid_rows(widget_grid_data, upper_rows, min_row);
        };

        /**
         * Determines whether a widget can move to a position above.
         *
         * @method can_go_widget_up
         * @param {Object} widget_grid_data The actual grid coords object of the
         *  widget we want to check.
         * @return {Number|Boolean} If the widget can be moved to an upper row
         *  returns the row number, else returns false.
         */
        fn.can_go_widget_up = function(widget_grid_data) {
            var p_bottom_row = widget_grid_data.row + widget_grid_data.size_y - 1;
            var result = true;
            var upper_rows = [];
            var min_row = 10000;

            /* generate an array with columns as index and array with topmost rows
             * empty as value */
            this.for_each_column_occupied(widget_grid_data, function(tcol) {
                var grid_col = this.gridmap[tcol];
                upper_rows[tcol] = [];

                var r = p_bottom_row + 1;
                // iterate over each row
                while (--r > 0) {
                    if (this.is_widget(tcol, r) && !this.is_player_in(tcol, r)) {
                        if (!grid_col[r].is(widget_grid_data.el)) {
                            break;
                        }
                    }

                    if (!this.is_player(tcol, r) && !this.is_placeholder_in(tcol, r) && !this.is_player_in(tcol, r)) {
                        upper_rows[tcol].push(r);
                    }

                    if (r < min_row) {
                        min_row = r;
                    }
                }

                if (upper_rows[tcol].length === 0) {
                    result = false;
                    return true;
                    //break
                }

                upper_rows[tcol].sort();
            });

            if (!result) {
                return false;
            }

            return this.get_valid_rows(widget_grid_data, upper_rows, min_row);
        };

        /**
         * Search a valid row for the widget represented by `widget_grid_data' in
         * the `upper_rows` array. Iteration starts from row specified in `min_row`.
         *
         * @method get_valid_rows
         * @param {Object} widget_grid_data The actual grid coords object of the
         *  player.
         * @param {Array} upper_rows An array with columns as index and arrays
         *  of valid rows as values.
         * @param {Number} min_row The upper row from which the iteration will start.
         * @return {Number|Boolean} Returns the upper row valid from the `upper_rows`
         *  for the widget in question.
         */
        fn.get_valid_rows = function(widget_grid_data, upper_rows, min_row) {
            var p_top_row = widget_grid_data.row;
            var p_bottom_row = widget_grid_data.row + widget_grid_data.size_y - 1;
            var size_y = widget_grid_data.size_y;
            var r = min_row - 1;
            var valid_rows = [];

            while (++r <= p_bottom_row) {
                var common = true;
                $.each(upper_rows, function(col, rows) {
                    if ($.isArray(rows) && $.inArray(r, rows) === -1) {
                        common = false;
                    }
                });

                if (common === true) {
                    valid_rows.push(r);
                    if (valid_rows.length === size_y) {
                        break;
                    }
                }
            }

            var new_row = false;
            if (size_y === 1) {
                if (valid_rows[0] !== p_top_row) {
                    new_row = valid_rows[0] || false;
                }
            } else {
                if (valid_rows[0] !== p_top_row) {
                    new_row = this.get_consecutive_numbers_index(valid_rows, size_y);
                }
            }

            return new_row;
        };

        fn.get_consecutive_numbers_index = function(arr, size_y) {
            var max = arr.length;
            var result = [];
            var first = true;
            var prev = -1;
            // or null?

            for (var i = 0; i < max; i++) {
                if (first || arr[i] === prev + 1) {
                    result.push(i);
                    if (result.length === size_y) {
                        break;
                    }
                    first = false;
                } else {
                    result = [];
                    first = true;
                }

                prev = arr[i];
            }

            return result.length >= size_y ? arr[result[0]] : false;
        };

        /**
         * Get widgets overlapping with the player.
         *
         * @method get_widgets_overlapped
         * @return {HTMLElements} Returns a jQuery collection of HTMLElements.
         */
        fn.get_widgets_overlapped = function() {
            var $w;
            var $widgets = $([]);
            var used = [];
            var rows_from_bottom = this.cells_occupied_by_player.rows.slice(0);
            rows_from_bottom.reverse();

            $.each(this.cells_occupied_by_player.cols, $.proxy(function(i, col) {
                $.each(rows_from_bottom, $.proxy(function(i, row) {
                    // if there is a widget in the player position
                    if (!this.gridmap[col]) {
                        return true;
                    }//next iteration
                    var $w = this.gridmap[col][row];
                    if (this.is_occupied(col, row) && !this.is_player($w) && $.inArray($w, used) === -1) {
                        $widgets = $widgets.add($w);
                        used.push($w);
                    }

                }, this));
            }, this));

            return $widgets;
        };

        /**
         * This callback is executed when the player begins to collide with a column.
         *
         * @method on_start_overlapping_column
         * @param {Number} col The collided column.
         * @return {HTMLElements} Returns a jQuery collection of HTMLElements.
         */
        fn.on_start_overlapping_column = function(col) {
            this.set_player(col, false);
        };

        /**
         * A callback executed when the player begins to collide with a row.
         *
         * @method on_start_overlapping_row
         * @param {Number} col The collided row.
         * @return {HTMLElements} Returns a jQuery collection of HTMLElements.
         */
        fn.on_start_overlapping_row = function(row) {
            this.set_player(false, row);
        };

        /**
         * A callback executed when the the player ends to collide with a column.
         *
         * @method on_stop_overlapping_column
         * @param {Number} col The collided row.
         * @return {HTMLElements} Returns a jQuery collection of HTMLElements.
         */
        fn.on_stop_overlapping_column = function(col) {
            //this.set_player(col, false);
            var self = this;
            if (this.options.shift_larger_widgets_down) {
                this.for_each_widget_below(col, this.cells_occupied_by_player.rows[0], function(tcol, trow) {
                    self.move_widget_up(this, self.player_grid_data.size_y);
                });
            }
        };

        /**
         * This callback is executed when the player ends to collide with a row.
         *
         * @method on_stop_overlapping_row
         * @param {Number} row The collided row.
         * @return {HTMLElements} Returns a jQuery collection of HTMLElements.
         */
        fn.on_stop_overlapping_row = function(row) {
            //this.set_player(false, row);
            var self = this;
            var cols = this.cells_occupied_by_player.cols;
            if (this.options.shift_larger_widgets_down) {
                for (var c = 0, cl = cols.length; c < cl; c++) {
                    this.for_each_widget_below(cols[c], row, function(tcol, trow) {
                        console.log("from_on_stop_overlapping_row");
                        self.move_widget_up(this, self.player_grid_data.size_y);
                    });
                }
            }
        };

        //Must call this before changing positions
        //Clears out all previous positions
        fn.clear_grid_data = function() {
            var self = this;
            this.$widgets.each(function() {
                var widget_grid_data = $(this).coords().grid;
                if (widget_grid_data) {
                    self.remove_from_gridmap(widget_grid_data);
                }
            });

            for (var i = 0; i < page.base.gridster.gridmap.length; i++) {
                if (page.base.gridster.gridmap[i]) {
                    for (var j = 0; j < page.base.gridster.gridmap[i].length; j++) {
                        page.base.gridster.gridmap[i][j] = false;
                    }
                }
            }
        };
        
        fn.new_move_widget_to_legacy = function($widget, col, row) {
           var self = this;
            var widget_grid_data = $widget.coords().grid;

            this.remove_from_gridmap(widget_grid_data);

            widget_grid_data.row = row;
            widget_grid_data.col = col;

            this.gridmap[col][row] = $widget;

            this.add_to_gridmap(widget_grid_data);
            $widget.attr('data-row', row);
            $widget.attr('data-col', col);
            this.update_widget_position(widget_grid_data, $widget);
            this.$changed = this.$changed.add($widget);

            this.set_dom_grid_height();

            return this;
        }

        fn.new_move_widget_to = function($widget, col, row, clearData) {
            var self = this;
            var widget_grid_data = $widget.coords().grid;

            if (clearData) {
                self.remove_from_gridmap(widget_grid_data);
            }

            widget_grid_data.row = row;
            widget_grid_data.col = col;

            this.add_to_gridmap(widget_grid_data);

            this.update_widget_position(widget_grid_data, $widget);
            $widget.attr('data-row', row);
            $widget.attr('data-col', col);

            this.set_dom_grid_height();

            return this;
        }
        /**
         * Move a widget to a specific row. The cell or cells must be empty.
         * If the widget has widgets below, all of these widgets will be moved also
         * if they can.
         *
         * @method move_widget_to
         * @param {HTMLElement} $widget The jQuery wrapped HTMLElement of the
         * widget is going to be moved.
         * @return {Class} Returns the instance of the Gridster Class.
         */
        fn.move_widget_to = function($widget, row) {
            var self = this;
            var widget_grid_data = $widget.coords().grid;
            var diff = row - widget_grid_data.row;
            var $next_widgets = this.widgets_below($widget);

            var can_move_to_new_cell = this.can_move_to(widget_grid_data, widget_grid_data.col, row, $widget);

            if (can_move_to_new_cell === false) {
                return false;
            }

            this.remove_from_gridmap(widget_grid_data);
            widget_grid_data.row = row;
            this.add_to_gridmap(widget_grid_data);
            $widget.attr('data-row', row);
            this.$changed = this.$changed.add($widget);

            $next_widgets.each(function(i, widget) {
                var $w = $(widget);
                var wgd = $w.coords().grid;
                var can_go_up = self.can_go_widget_up(wgd);
                if (can_go_up && can_go_up !== wgd.row) {
                    self.move_widget_to($w, can_go_up);
                }
            });

            return this;
        };

        /**
         * Move up the specified widget and all below it.
         *
         * @method move_widget_up
         * @param {HTMLElement} $widget The widget you want to move.
         * @param {Number} [y_units] The number of cells that the widget has to move.
         * @return {Class} Returns the instance of the Gridster Class.
         */
        fn.move_widget_up = function($widget, y_units) {
            var el_grid_data = $widget.coords().grid;
            var actual_row = Math.floor(el_grid_data.row);
            var moved = [];
            var can_go_up = true;
            y_units || ( y_units = 1);

            if (!this.can_go_up($widget)) {
                return false;
            }//break;

            this.for_each_column_occupied(el_grid_data, function(col) {
                // can_go_up
                if ($.inArray($widget, moved) === -1) {
                    var widget_grid_data = $widget.coords().grid;
                    var next_row = actual_row - y_units;
                    next_row = this.can_go_up_to_row(widget_grid_data, col, next_row);
                    if (!next_row) {
                        return true;
                    }

                    var $next_widgets = this.widgets_below($widget);

                    this.remove_from_gridmap(widget_grid_data);
                    widget_grid_data.row = next_row;
                    this.add_to_gridmap(widget_grid_data);
                    $widget.attr('data-row', widget_grid_data.row);
                    this.$changed = this.$changed.add($widget);

                    moved.push($widget);

                    /* $next_widgets.each($.proxy(function(i, widget) {
                     console.log("from_within_move_widget_up");
                     this.move_widget_up($(widget), y_units);
                     }, this)); */
                }
            });

        };

        /**
         * Move down the specified widget and all below it.
         *
         * @method move_widget_down
         * @param {HTMLElement} $widget The jQuery object representing the widget
         *  you want to move.
         * @param {Number} The number of cells that the widget has to move.
         * @return {Class} Returns the instance of the Gridster Class.
         */
        fn.move_widget_down = function($widget, y_units) {

            if (y_units <= 0) {
                return false;
            }
            var el_grid_data = $widget.coords().grid;
            var actual_row = el_grid_data.row;
            var moved = [];
            var y_diff = y_units;

            if (!$widget) {
                return false;
            }

            if ($.inArray($widget, moved) === -1) {

                var widget_grid_data = $widget.coords().grid;
                var next_row = actual_row + y_units;
                var $next_widgets = this.widgets_below($widget);

                this.remove_from_gridmap(widget_grid_data);

                $next_widgets.each($.proxy(function(i, widget) {
                    var $w = $(widget);
                    var wd = $w.coords().grid;
                    var tmp_y = this.displacement_diff(wd, widget_grid_data, y_diff);

                    if (tmp_y > 0) {
                        this.move_widget_down($w, tmp_y);
                    }
                }, this));

                widget_grid_data.row = next_row;
                this.update_widget_position(widget_grid_data, $widget);
                $widget.attr('data-row', widget_grid_data.row);
                this.$changed = this.$changed.add($widget);

                moved.push($widget);
            }
        };

        /**
         * Check if the widget can move to the specified row, else returns the
         * upper row possible.
         *
         * @method can_go_up_to_row
         * @param {Number} widget_grid_data The current grid coords object of the
         *  widget.
         * @param {Number} col The target column.
         * @param {Number} row The target row.
         * @return {Boolean|Number} Returns the row number if the widget can move
         *  to the target position, else returns false.
         */
        fn.can_go_up_to_row = function(widget_grid_data, col, row) {
            var ga = this.gridmap;
            var result = true;
            var urc = [];
            // upper_rows_in_columns
            var actual_row = widget_grid_data.row;
            var r;
            row = Math.floor(row);

            /* generate an array with columns as index and array with
             * upper rows empty in the column */
            this.for_each_column_occupied(widget_grid_data, function(tcol) {
                var grid_col = ga[tcol];
                urc[tcol] = [];

                r = Math.floor(actual_row);
                while (r-- >= 0) {
                    if (this.is_empty(tcol, r) && !this.is_placeholder_in(tcol, r)) {
                        urc[tcol].push(r);
                    } else {
                        break;
                    }
                }

                if (!urc[tcol].length) {
                    result = false;
                    return true;
                }

            });

            if (!result) {
                return false;
            }

            /* get common rows starting from upper position in all the columns
             * that widget occupies */
            r = row;
            for ( r = 1; r < actual_row; r++) {
                var common = true;

                for (var uc = 0, ucl = urc.length; uc < ucl; uc++) {
                    if (urc[uc] && $.inArray(r, urc[uc]) === -1) {
                        common = false;
                    }
                }

                if (common === true) {
                    result = r;
                    break;
                }
            }

            return result;
        };

        fn.displacement_diff = function(widget_grid_data, parent_bgd, y_units) {
            var actual_row = widget_grid_data.row;
            var diffs = [];
            var parent_max_y = parent_bgd.row + parent_bgd.size_y;

            this.for_each_column_occupied(widget_grid_data, function(col) {
                var temp_y_units = 0;

                for (var r = parent_max_y; r < actual_row; r++) {
                    if (this.is_empty(col, r)) {
                        temp_y_units = temp_y_units + 1;
                    }
                }

                diffs.push(temp_y_units);
            });

            var max_diff = Math.max.apply(Math, diffs);
            y_units = (y_units - max_diff);

            return y_units > 0 ? y_units : 0;
        };

        /**
         * Get widgets below a widget.
         *
         * @method widgets_below
         * @param {HTMLElement} $el The jQuery wrapped HTMLElement.
         * @return {HTMLElements} A jQuery collection of HTMLElements.
         */
        fn.widgets_below = function($el) {
            var el_grid_data = $.isPlainObject($el) ? $el : $el.coords().grid;
            //if (!el_grid_data || !el_grid_data.row)
            //    return $([]);

            var self = this;
            var ga = this.gridmap;
            var next_row = el_grid_data.row + el_grid_data.size_y - 1;
            var $nexts = $([]);

            this.for_each_column_occupied(el_grid_data, function(col) {
                self.for_each_widget_below(col, next_row, function(tcol, trow) {
                    if (!self.is_player(this) && $.inArray(this, $nexts) === -1) {
                        $nexts = $nexts.add(this);
                        return true;
                        // break
                    }
                });
            });

            return this.sort_by_row_asc($nexts);
        };

        /**
         * Update the array of mapped positions with the new player position.
         *
         * @method set_cells_player_occupies
         * @param {Number} col The new player col.
         * @param {Number} col The new player row.
         * @return {Class} Returns the instance of the Gridster Class.
         */
        fn.set_cells_player_occupies = function(col, row) {
            this.remove_from_gridmap(this.placeholder_grid_data);
            this.placeholder_grid_data.col = col;
            this.placeholder_grid_data.row = row;
            this.add_to_gridmap(this.placeholder_grid_data, this.$player);
            return this;
        };

        /**
         * Remove from the array of mapped positions the reference to the player.
         *
         * @method empty_cells_player_occupies
         * @return {Class} Returns the instance of the Gridster Class.
         */
        fn.empty_cells_player_occupies = function() {
            this.remove_from_gridmap(this.placeholder_grid_data);
            return this;
        };

        fn.can_go_down = function($el) {
            var can_go_down = true;
            var $gr = this;

            if ($el.hasClass(this.options.static_class)) {
                can_go_down = false;
            }

            this.widgets_below($el).each(function() {
                if ($(this).hasClass($gr.options.static_class)) {
                    can_go_down = false;
                }
            })

            return can_go_down;
        }

        fn.can_go_up = function($el) {
            var el_grid_data = $el.coords().grid;
            var initial_row = el_grid_data.row;
            var prev_row = initial_row - 1;
            var ga = this.gridmap;
            var upper_rows_by_column = [];

            var result = true;
            if (initial_row === 1) {
                return false;
            }

            this.for_each_column_occupied(el_grid_data, function(col) {
                var $w = this.is_widget(col, prev_row);

                if (this.is_occupied(col, prev_row) || this.is_player(col, prev_row) || this.is_placeholder_in(col, prev_row) || this.is_player_in(col, prev_row)) {
                    result = false;
                    return true;
                    //break
                }
            });

            return result;
        };

        /**
         * Check if it's possible to move a widget to a specific col/row. It takes
         * into account the dimensions (`size_y` and `size_x` attrs. of the grid
         *  coords object) the widget occupies.
         *
         * @method can_move_to
         * @param {Object} widget_grid_data The grid coords object that represents
         *  the widget.
         * @param {Object} col The col to check.
         * @param {Object} row The row to check.
         * @param {Number} [max_row] The max row allowed.
         * @return {Boolean} Returns true if all cells are empty, else return false.
         */
        fn.can_move_to = function(widget_grid_data, col, row, max_row) {
            var ga = this.gridmap;
            var $w = widget_grid_data.el;
            var future_wd = {
                size_y : widget_grid_data.size_y,
                size_x : widget_grid_data.size_x,
                col : col,
                row : row
            };
            var result = true;

            //Prevents widgets go out of the grid
            var right_col = col + widget_grid_data.size_x - 1;
            if (right_col > this.cols) {
                return false;
            }

            if (max_row && max_row < row + widget_grid_data.size_y - 1) {
                return false;
            }

            this.for_each_cell_occupied(future_wd, function(tcol, trow) {
                var $tw = this.is_widget(tcol, trow);
                if ($tw && (!widget_grid_data.el || $tw.is($w))) {
                    result = false;
                }
            });

            return result;
        };

        /**
         * Given the leftmost column returns all columns that are overlapping
         *  with the player.
         *
         * @method get_targeted_columns
         * @param {Number} [from_col] The leftmost column.
         * @return {Array} Returns an array with column numbers.
         */
        fn.get_targeted_columns = function(from_col) {
            var max = (from_col || this.player_grid_data.col) + (this.player_grid_data.size_x - 1);
            var cols = [];
            for (var col = from_col; col <= max; col++) {
                cols.push(col);
            }
            return cols;
        };

        /**
         * Given the upper row returns all rows that are overlapping with the player.
         *
         * @method get_targeted_rows
         * @param {Number} [from_row] The upper row.
         * @return {Array} Returns an array with row numbers.
         */
        fn.get_targeted_rows = function(from_row) {
            var max = (from_row || this.player_grid_data.row) + (this.player_grid_data.size_y - 1);
            var rows = [];
            for (var row = from_row; row <= max; row++) {
                rows.push(row);
            }
            return rows;
        };

        /**
         * Get all columns and rows that a widget occupies.
         *
         * @method get_cells_occupied
         * @param {Object} el_grid_data The grid coords object of the widget.
         * @return {Object} Returns an object like `{ cols: [], rows: []}`.
         */
        fn.get_cells_occupied = function(el_grid_data) {
            var cells = {
                cols : [],
                rows : []
            };
            var i;
            if (arguments[1] instanceof jQuery) {
                el_grid_data = arguments[1].coords().grid;
            }

            for ( i = 0; i < el_grid_data.size_x; i++) {
                var col = el_grid_data.col + i;
                cells.cols.push(col);
            }

            for ( i = 0; i < el_grid_data.size_y; i++) {
                var row = el_grid_data.row + i;
                cells.rows.push(row);
            }

            return cells;
        };

        /**
         * Iterate over the cells occupied by a widget executing a function for
         * each one.
         *
         * @method for_each_cell_occupied
         * @param {Object} el_grid_data The grid coords object that represents the
         *  widget.
         * @param {Function} callback The function to execute on each column
         *  iteration. Column and row are passed as arguments.
         * @return {Class} Returns the instance of the Gridster Class.
         */
        fn.for_each_cell_occupied = function(grid_data, callback) {
            this.for_each_column_occupied(grid_data, function(col) {
                this.for_each_row_occupied(grid_data, function(row) {
                    callback.call(this, col, row);
                });
            });
            return this;
        };

        /**
         * Iterate over the columns occupied by a widget executing a function for
         * each one.
         *
         * @method for_each_column_occupied
         * @param {Object} el_grid_data The grid coords object that represents
         *  the widget.
         * @param {Function} callback The function to execute on each column
         *  iteration. The column number is passed as first argument.
         * @return {Class} Returns the instance of the Gridster Class.
         */
        fn.for_each_column_occupied = function(el_grid_data, callback) {
            //if (!el_grid_data)
            //return;
            for (var i = 0; i < el_grid_data.size_x; i++) {
                var col = el_grid_data.col + i;
                callback.call(this, col, el_grid_data);
            }
        };

        /**
         * Iterate over the rows occupied by a widget executing a function for
         * each one.
         *
         * @method for_each_row_occupied
         * @param {Object} el_grid_data The grid coords object that represents
         *  the widget.
         * @param {Function} callback The function to execute on each column
         *  iteration. The row number is passed as first argument.
         * @return {Class} Returns the instance of the Gridster Class.
         */
        fn.for_each_row_occupied = function(el_grid_data, callback) {
            for (var i = 0; i < el_grid_data.size_y; i++) {
                var row = el_grid_data.row + i;
                callback.call(this, row, el_grid_data);
            }
        };

        fn.clean_up_changed = function() {
            $gr = this;
            $gr.$changed.each(function() {
                if ($gr.options.shift_larger_widgets_down) {
                    $gr.move_widget_up($(this));
                }
            });
        }

        fn._traversing_widgets = function(type, direction, col, row, callback) {
            var ga = this.gridmap;
            if (!ga[col]) {
                return;
            }

            var cr, max;
            var action = type + '/' + direction;
            if (arguments[2] instanceof jQuery) {
                var el_grid_data = arguments[2].coords().grid;
                col = el_grid_data.col;
                row = el_grid_data.row;
                callback = arguments[3];
            }
            var matched = [];
            var trow = row;

            var methods = {
                'for_each/above' : function() {
                    while (--trow >= 0) {
                        if (trow > 0 && this.is_widget(col, trow) && $.inArray(ga[col][trow], matched) === -1) {
                            cr = callback.call(ga[col][trow], col, trow);
                            matched.push(ga[col][trow]);
                            if (cr) {
                                break;
                            }
                        }
                    }
                },
                'for_each/below' : function() {
                    for ( trow = row + 1, max = ga[col].length; trow < max; trow += 0.5) {
                        if (this.is_widget(col, trow) && $.inArray(ga[col][trow], matched) === -1) {
                            cr = callback.call(ga[col][trow], col, trow);
                            matched.push(ga[col][trow]);
                            //break was causing problems, leaving for testing.
                            //if (cr) { break; }
                        }
                    }
                }
            };

            if (methods[action]) {
                methods[action].call(this);
            }
        };

        /**
         * Iterate over each widget above the column and row specified.
         *
         * @method for_each_widget_above
         * @param {Number} col The column to start iterating.
         * @param {Number} row The row to start iterating.
         * @param {Function} callback The function to execute on each widget
         *  iteration. The value of `this` inside the function is the jQuery
         *  wrapped HTMLElement.
         * @return {Class} Returns the instance of the Gridster Class.
         */
        fn.for_each_widget_above = function(col, row, callback) {
            this._traversing_widgets('for_each', 'above', col, row, callback);
            return this;
        };

        /**
         * Iterate over each widget below the column and row specified.
         *
         * @method for_each_widget_below
         * @param {Number} col The column to start iterating.
         * @param {Number} row The row to start iterating.
         * @param {Function} callback The function to execute on each widget
         *  iteration. The value of `this` inside the function is the jQuery wrapped
         *  HTMLElement.
         * @return {Class} Returns the instance of the Gridster Class.
         */
        fn.for_each_widget_below = function(col, row, callback) {
            this._traversing_widgets('for_each', 'below', col, row, callback);
            return this;
        };

        /**
         * Returns the highest occupied cell in the grid.
         *
         * @method get_highest_occupied_cell
         * @return {Object} Returns an object with `col` and `row` numbers.
         */
        fn.get_highest_occupied_cell = function() {
            var r;
            var gm = this.gridmap;
            var rows = [];
            var row_in_col = [];
            for (var c = gm.length - 1; c >= 1; c--) {
                for ( r = gm[c].length - 1; r >= 1; r--) {
                    if (this.is_widget(c, r)) {
                        rows.push(r);
                        row_in_col[r] = c;
                        break;
                    }
                }
            }

            var highest_row = Math.max.apply(Math, rows);

            this.highest_occupied_cell = {
                col : row_in_col[highest_row],
                row : highest_row
            };

            return this.highest_occupied_cell;
        };

        fn.get_widgets_from = function(col, row) {
            var ga = this.gridmap;
            var $widgets = $();

            if (col) {
                $widgets = $widgets.add(this.$widgets.filter(function() {
                    var tcol = $(this).attr('data-col');
                    return (tcol === col || tcol > col);
                }));
            }

            if (row) {
                $widgets = $widgets.add(this.$widgets.filter(function() {
                    var trow = $(this).attr('data-row');
                    return (trow === row || trow > row);
                }));
            }

            return $widgets;
        };

        /**
         * Set the current height of the parent grid.
         *
         * @method set_dom_grid_height
         * @return {Object} Returns the instance of the Gridster class.
         */
        fn.set_dom_grid_height = function() {
            var maxPosY = 0;
            var $liMaxPosY = $();
            
            var self = this;            
            this.$widgets.each(function() {
                var $li = $(this);
                var posY = parseFloat($li.attr('data-row')) + parseFloat($li.attr('data-sizey'));
                if(maxPosY < posY) {
                    maxPosY = posY;
                    $liMaxPosY = $li;
                }
            });
            
            var blockHeight = this.options.widget_base_dimensions[1] + this.options.widget_margins[1] * 2;
            var newHeight = ( parseFloat($liMaxPosY.attr('data-row')) - 1 + parseFloat($liMaxPosY.attr('data-sizey')) ) * blockHeight;
            
            this.$el.height(newHeight);
            return this;
        };

        /**
         * It generates the neccessary styles to position the widgets.
         *
         * @method generate_stylesheet
         * @param {Number} rows Number of columns.
         * @param {Number} cols Number of rows.
         * @return {Object} Returns the instance of the Gridster class.
         */
        fn.generate_stylesheet = function(opts) {
            var styles = '';
            var max_size_x = this.options.max_size_x;
            var max_rows = 0;
            var max_cols = 0;
            var i;
            var rules;

            opts || ( opts = {});
            opts.cols || (opts.cols = this.cols);
            opts.rows || (opts.rows = this.rows);
            opts.namespace || (opts.namespace = this.options.namespace);
            opts.widget_base_dimensions || (opts.widget_base_dimensions = this.options.widget_base_dimensions);
            opts.widget_margins || (opts.widget_margins = this.options.widget_margins);
            opts.min_widget_width = (opts.widget_margins[0] * 2) + opts.widget_base_dimensions[0];
            opts.min_widget_height = (opts.widget_margins[1] * 2) + opts.widget_base_dimensions[1];

            // don't duplicate stylesheets for the same configuration
            var serialized_opts = $.param(opts);
            //if ($.inArray(serialized_opts, Gridster.generated_stylesheets) >= 0) {
            //    return false;
            // }

            Gridster.generated_stylesheets.push(serialized_opts);

            /* generate CSS styles for cols */
            for ( i = opts.cols; i >= 0; i--) {
                styles += (opts.namespace + ' [data-col="' + (i + 1) + '"] { left:' + ((i * opts.widget_base_dimensions[0]) + (i * opts.widget_margins[0]) + ((i + 1) * opts.widget_margins[0])) + 'px;} ');

                styles += (opts.namespace + ' [data-col="' + (i + 1) + '.5"] { left:' + (((i + 0.5) * opts.widget_base_dimensions[0]) + ((i + 0.5) * opts.widget_margins[0]) + (((i + 0.5) + 1) * opts.widget_margins[0])) + 'px;} ');
            }

            /* generate CSS styles for rows */
            for ( i = opts.rows; i >= 0; i--) {
                styles += (opts.namespace + ' [data-row="' + (i + 1) + '"] { top:' + ((i * opts.widget_base_dimensions[1]) + (i * opts.widget_margins[1]) + ((i + 1) * opts.widget_margins[1]) ) + 'px;} ');

                styles += (opts.namespace + ' [data-row="' + (i + 1) + '.5"] { top:' + (((i + 0.5) * opts.widget_base_dimensions[1]) + ((i + 0.5) * opts.widget_margins[1]) + (((i + 0.5) + 1) * opts.widget_margins[1]) ) + 'px;} ');
            }

            for (var y = 1; y <= opts.rows; y++) {
                styles += (opts.namespace + ' [data-sizey="' + y + '"] { height:' + (y * opts.widget_base_dimensions[1] + (y - 1) * (opts.widget_margins[1] * 2)) + 'px;}');

                styles += (opts.namespace + ' [data-sizey="' + y + '.5"] { height:' + ((y + 0.5) * opts.widget_base_dimensions[1] + ((y + 0.5) - 1) * (opts.widget_margins[1] * 2)) + 'px;}');
            }

            for (var x = 1; x <= max_size_x; x++) {
                styles += (opts.namespace + ' [data-sizex="' + x + '"] { width:' + (x * opts.widget_base_dimensions[0] + (x - 1) * (opts.widget_margins[0] * 2)) + 'px;}');

                styles += (opts.namespace + ' [data-sizex="' + x + '.5"] { width:' + ((x + 0.5) * opts.widget_base_dimensions[0] + ((x + 0.5) - 1) * (opts.widget_margins[0] * 2)) + 'px;}');
            }

            return this.add_style_tag(styles);
        };

        /**
         * Injects the given CSS as string to the head of the document.
         *
         * @method add_style_tag
         * @param {String} css The styles to apply.
         * @return {Object} Returns the instance of the Gridster class.
         */
        fn.add_style_tag = function(css) {

            $('style#gridster-style').remove();

            var d = document;
            var tag = d.createElement('style');

            tag.setAttribute('id', 'gridster-style');
            tag.setAttribute('type', 'text/css');
            d.getElementsByTagName('head')[0].appendChild(tag);

            if (tag.styleSheet) {
                tag.styleSheet.cssText = css;
            } else {
                tag.appendChild(document.createTextNode(css));
            }

            return this;
        };

        /**
         * Generates a faux grid to collide with it when a widget is dragged and
         * detect row or column that we want to go.
         *
         * @method generate_faux_grid
         * @param {Number} rows Number of columns.
         * @param {Number} cols Number of rows.
         * @return {Object} Returns the instance of the Gridster class.
         */
        fn.generate_faux_grid = function(rows, cols) {
            this.faux_grid = [];
            this.gridmap = [];
            var col;
            var row;
            for ( col = cols; col > 0; col--) {
                this.gridmap[col] = [];
                for ( row = rows; row > 0; row--) {
                    this.add_faux_cell(row, col);
                }
            }
            return this;
        };

        /**
         * Add cell to the faux grid.
         *
         * @method add_faux_cell
         * @param {Number} row The row for the new faux cell.
         * @param {Number} col The col for the new faux cell.
         * @return {Object} Returns the instance of the Gridster class.
         */
        fn.add_faux_cell = function(row, col) {
            var coords = $({
                left : this.baseX + ((col - 1) * this.min_widget_width),
                top : this.baseY + (row - 1) * this.min_widget_height,
                width : this.min_widget_width,
                height : this.min_widget_height,
                col : col,
                row : row,
                original_col : col,
                original_row : row
            }).coords();

            if (!$.isArray(this.gridmap[col])) {
                this.gridmap[col] = [];
            }

            this.gridmap[col][row] = false;
            this.faux_grid.push(coords);

            return this;
        };

        /**
         * Add rows to the faux grid.
         *
         * @method add_faux_rows
         * @param {Number} rows The number of rows you want to add to the faux grid.
         * @return {Object} Returns the instance of the Gridster class.
         */
        fn.add_faux_rows = function(rows) {
            var actual_rows = this.rows;
            var max_rows = actual_rows + (rows || 1);

            for (var r = max_rows; r > actual_rows; r--) {
                for (var c = this.cols; c >= 1; c--) {
                    this.add_faux_cell(r, c);
                }
            }

            this.rows = max_rows;

            if (this.options.autogenerate_stylesheet) {
                this.generate_stylesheet();
            }

            return this;
        };

        /**
         * Add cols to the faux grid.
         *
         * @method add_faux_cols
         * @param {Number} cols The number of cols you want to add to the faux grid.
         * @return {Object} Returns the instance of the Gridster class.
         */
        fn.add_faux_cols = function(cols) {
            var actual_cols = this.cols;
            var max_cols = actual_cols + (cols || 1);

            for (var c = actual_cols; c < max_cols; c++) {
                for (var r = this.rows; r >= 1; r--) {
                    this.add_faux_cell(r, c);
                }
            }

            this.cols = max_cols;

            if (this.options.autogenerate_stylesheet) {
                this.generate_stylesheet();
            }

            return this;
        };

        /**
         * Recalculates the offsets for the faux grid. You need to use it when
         * the browser is resized.
         *
         * @method recalculate_faux_grid
         * @return {Object} Returns the instance of the Gridster class.
         */
        fn.recalculate_faux_grid = function() {
            var aw = this.$wrapper.width();
            this.baseX = ($(window).width() - aw) / 2;
            this.baseY = this.$wrapper.offset().top;

            $.each(this.faux_grid, $.proxy(function(i, coords) {
                this.faux_grid[i] = coords.update({
                    left : this.baseX + (coords.data.col - 1) * this.min_widget_width,
                    top : this.baseY + (coords.data.row - 1) * this.min_widget_height
                });

            }, this));

            return this;
        };

        /**
         * Get all widgets in the DOM and register them.
         *
         * @method get_widgets_from_DOM
         * @return {Object} Returns the instance of the Gridster class.
         */
        fn.get_widgets_from_DOM = function() {
            this.$widgets.each($.proxy(function(i, widget) {
                this.register_widget($(widget));
            }, this));
            return this;
        };

        /**
         * Calculate columns and rows to be set based on the configuration
         *  parameters, grid dimensions, etc ...
         *
         * @method generate_grid_and_stylesheet
         * @return {Object} Returns the instance of the Gridster class.
         */
        fn.generate_grid_and_stylesheet = function() {
            var aw = this.$wrapper.width();
            var ah = this.$wrapper.height();

            var cols = Math.floor(aw / this.min_widget_width) + this.options.extra_cols;

            var actual_cols = this.$widgets.map(function() {
                return $(this).attr('data-col');
            });
            actual_cols = Array.prototype.slice.call(actual_cols, 0);
            //needed to pass tests with phantomjs
            actual_cols.length || ( actual_cols = [0]);

            var min_cols = Math.max.apply(Math, actual_cols);

            // get all rows that could be occupied by the current widgets
            var max_rows = this.options.extra_rows;
            this.$widgets.each(function(i, w) {
                max_rows += (+$(w).attr('data-sizey'));
            });

            this.cols = Math.max(min_cols, cols, this.options.min_cols);
            var max_cols = this.options.max_cols;
            if (max_cols >= -1 && max_cols >= min_cols) {
                if (max_cols < this.cols) {
                    this.cols = max_cols;
                }
            }
            //this.rows = Math.max(max_rows, this.options.min_rows);
            this.rows = this.options.max_rows;

            this.baseX = ($(window).width() - aw) / 2;
            this.baseY = this.$wrapper.offset().top;

            if (this.options.autogenerate_stylesheet) {
                this.generate_stylesheet();
            }

            return this.generate_faux_grid(this.rows, this.cols);
        };

        //jQuery adapter
        $.fn.gridster = function(options) {
            return this.each(function() {
                if (!$(this).data('gridster')) {
                    $(this).data('gridster', new Gridster(this, options));
                }
            });
        };

        $.Gridster = fn;

    }(jQuery, window, document));