add is_area_empty API method

README.md

@@ -34,6 +34,7 @@ Inspired by [gridster.js](http://gridster.net). Built with love.
     - [disable()](#disable)
     - [enable()](#enable)
     - [get_cell_from_pixel(position)](#get_cell_from_pixelposition)
+    - [is_area_empty(x, y, width, height)](#is_area_emptyx-y-width-height)
     - [locked(el, val)](#lockedel-val)
     - [remove_widget(el)](#remove_widgetel)
     - [remove_all()](#remove_all)
@@ -274,6 +275,10 @@ Parameters :
 
 Returns an object with properties `x` and `y` i.e. the column and row in the grid.
 
+### is_area_empty(x, y, width, height)
+
+Checks if specified area is empty.
+
 ### locked(el, val)
 
 Locks/unlocks widget.
@@ -634,6 +639,7 @@ Changes
 
 #### v0.2.3 (development version)
 
+- add `is_area_empty` method
 - nested grids
 - add `batch_update`/`commit` methods
 - add `update` method

src/gridstack.js

@@ -107,6 +107,14 @@
         }
     };
 
+    GridStackEngine.prototype.is_area_empty = function (x, y, width, height) {
+        var nn = {x: x || 0, y: y || 0, width: width || 1, height: height || 1};
+        var collision_node = _.find(this.nodes, function (n) {
+            return Utils.is_intercepted(n, nn);
+        }, this);
+        return collision_node == null;
+    };
+
     GridStackEngine.prototype._sort_nodes = function (dir) {
         this.nodes = Utils.sort(this.nodes, dir, this.width);
     };
@@ -831,6 +839,10 @@
         this._update_container_height()
     };
 
+    GridStack.prototype.is_area_empty = function (x, y, width, height) {
+        return this.grid.is_area_empty(x, y, width, height);
+    };
+
     scope.GridStackUI = GridStack;
 
     scope.GridStackUI.Utils = Utils;