Add geom.Collection & geom.collection.

Also make MultiPoint and multipoint inherit from Collection/collection
respectively.

src/api/geom/collection.js

@@ -0,0 +1,133 @@
+goog.provide('ol.geom.collection'); 
+
+goog.require('ol.geom.Collection');
+goog.require('ol.geom.point'); 
+goog.require('ol.projection');
+
+/**
+ * @export
+ * @param {Array.<ol.geom.Geometry>} opt_arg Components.
+ * @return {ol.geom.Collection} Collection.
+ */
+ol.geom.collection = function(opt_arg){
+    
+    if (opt_arg instanceof ol.geom.Collection) {
+        return opt_arg;
+    }
+    
+    var components = [];
+    if (arguments.length == 1 && goog.isDef(opt_arg)) {
+        if (goog.isArray(opt_arg)) {
+            var allValid = goog.array.every(opt_arg, function(geom){
+                if (geom instanceof ol.geom.Geometry) {
+                    components.push(geom);
+                    return true;
+                } else {
+                    return false;
+                }
+            });
+            if (!allValid) {
+                var msg = 'ol.geom.collection: at least one component '
+                    + 'definition was no geometry.';
+                throw new Error(msg);
+            }
+        } else {
+            throw new Error('ol.geom.collection');
+        }
+    }
+    
+    var c = new ol.geom.Collection(components);
+    return c;
+};
+goog.inherits(ol.geom.collection, ol.geom.geometry);
+
+/**
+ * @export
+ * @param {Array.<ol.geom.Geometry>=} opt_arg An array of point specifications.
+ * @return {Array.<ol.geom.Geometry>|ol.geom.Collection|undefined} Result.
+ */
+ol.geom.Collection.prototype.components = function(opt_arg){
+    if (arguments.length == 1 && goog.isDef(opt_arg)) {
+        var components = [],
+            allValid = false;
+            
+        allValid = goog.array.every(opt_arg, function(geom){
+            if (geom instanceof ol.geom.Geometry) {
+                components.push(geom);
+                return true;
+            } else {
+                return false;
+            }
+        });
+        if (!allValid) {
+            components = [];
+        }
+        this.setComponents(components);
+        return this;
+    }
+    else {
+        return this.getComponents();
+    }
+};
+
+/**
+ * @export
+ * @param {ol.geom.Geometry} geom A geometry.
+ * @param {number=} opt_index An optional index to add the point(s) at. If not
+ *     provided, the point(s) will be added to the end of the list of components.
+ * @return {ol.geom.Collection} The Collection instance.
+ */
+ol.geom.Collection.prototype.add = function(geom, opt_index){
+    var index = this.components_.length;
+    if (arguments.length == 2 && goog.isDef(opt_index)) {
+        index = opt_index;
+    }
+    this.addComponent(geom, index);
+    return this;
+};
+
+/**
+ * @export
+ * @param {Array.<ol.geom.Geometry>} components Some point specifications.
+ * @param {number=} opt_index An optional index to add the components at. If not
+ *     provided, the components will be added to the end of the list of 
+ *     components.
+ * @return {ol.geom.Collection} The Collection instance.
+ */
+ol.geom.Collection.prototype.addAll = function(components, opt_index){
+    var index = this.components_.length;
+    
+    if (arguments.length == 2 && goog.isDef(opt_index)) {
+        index = opt_index;
+    }
+    
+    goog.array.every(components, function(c){
+        this.addComponent(c, index);
+        index++;
+        return true;
+    }, this);
+    
+    return this;
+};
+
+/**
+ * @export
+ * @param {(ol.geom.Geometry|Array.<ol.geom.Geometry>)} components A point specification or
+ *     an array of point specifications.
+ * @return {ol.geom.Collection} The Collection instance.
+ */
+ol.geom.Collection.prototype.remove = function(components){
+    var compArr = [];
+    if (!goog.isArray(components)) {
+        compArr.push(components);
+    } else {
+        compArr = components;
+    }
+
+    goog.array.every(compArr, function(c){
+        this.removeComponent(c);
+        return true;
+    }, this);
+    
+    return this;
+};