/files/gridster.js/0.1/jquery.gridster.js

/*! gridster.js - v0.1.0 - 2013-06-14
* http://gridster.net/
* Copyright (c) 2013 ducksboard; Licensed MIT */

;(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));

;(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_start, self.options.on_overlap_stop);
        }

        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);

;(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,
        container_width: 0  // 0 == auto
        // drag: function(e){},
        // start : function(e, ui){},
        // stop : function(e){}
    };

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

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

    fn.events = function() {
        this.$container.on('selectstart.gridster-draggable',
            $.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;
        });

        if (!isTouch) { 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();

        var container_width = this.options.container_width || this.$container.width();
        this.player_max_left = (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();

        this.$container.off('.gridster-draggable');
        this.$body.off('.gridster-draggable');
        $(window).off('.gridster-draggable');

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


}(jQuery, window, document));

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

    var defaults = {
        namespace: '',
        widget_selector: 'li',
        widget_margins: [10, 10],
        widget_base_dimensions: [400, 225],
        extra_rows: 0,
        extra_cols: 0,
        min_cols: 1,
        max_cols: null,
        min_rows: 15,
        max_size_x: 6,
        autogenerate_stylesheet: true,
        avoid_overlapped_widgets: 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
        }
    };

    /**
    * @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.max_cols] The maximum columns possible (set to null
    *     for no maximum).
    *    @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 = $([]);
        this.wrapper_width = this.$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.$style_tags = $([]);

        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();

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


    /**
    * 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();
        return this;
    };


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


    /**
    * 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 = $(html).attr({
                'data-col': pos.col,
                'data-row': pos.row,
                'data-sizex' : size_x,
                'data-sizey' : size_y
            }).addClass('gs_w').appendTo(this.$el).hide();

        this.$widgets = this.$widgets.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();

        return $w.fadeIn();
    };



     /**
    * 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.
    * @param {Function} callback Function executed when the widget is removed.
    * @return {HTMLElement} Returns $widget.
    */
    fn.resize_widget = function($widget, size_x, size_y, callback) {
        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);
        }

        if (callback) {
            callback.call(this, size_x, size_y);
        }

        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 = $(w).coords().grid;
            if (!(wgd.row <= (row + size_y - 1))) { return; }
            var diff =  (row + size_y) - wgd.row;
            this.move_widget_down($(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;
    };


    /**
    * 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.
    * @return {Class} Returns the instance of the Gridster Class.
    */
    fn.remove_widget = function(el, silent, callback) {
        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);

        $el.fadeOut($.proxy(function() {
            $el.remove();

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

            this.set_dom_grid_height();

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


    /**
    * 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) {
            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': parseInt($el.attr('data-col'), 10),
            'row': parseInt($el.attr('data-row'), 10),
            'size_x': parseInt($el.attr('data-sizex'), 10),
            'size_y': parseInt($el.attr('data-sizey'), 10),
            '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)
        ) {
            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) {
                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 = $.extend(true, {}, this.options.draggable, {
            offset_left: this.options.widget_margins[0],
            container_width: this.container_width,
            start: function(event, ui) {
                self.$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.drag(draggable_options).data('drag');
        return this;
    };


    /**
    * This function is executed when the player begins to be dragged.
    *
    * @method on_start_drag
    * @param {Event} event The original browser event
    * @param {Object} ui 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} event The original browser event
    * @param {Object} ui 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} event The original browser event
    * @param {Object} ui 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.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 this;
        }
        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} end_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 this;
        }
        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) {