Adding attribution control and attribution.

src/ol/control/Attribution.js

@@ -0,0 +1,83 @@
+goog.provide('ol.control.Attribution');
+
+goog.require('ol.event');
+goog.require('ol.control.Control');
+
+goog.require('goog.dom');
+
+
+/**
+ * @constructor
+ * @extends {ol.control.Control}
+ * @param {boolean|undefined} opt_autoActivate
+ */
+ol.control.Attribution = function(opt_autoActivate) {
+
+    goog.base(this, opt_autoActivate);
+    
+    /**
+     * @type {Node}
+     */
+    this.container_ = null;
+
+    /**
+     * Activate this control when it is added to a map.  Default is true.
+     *
+     * @type {boolean} autoActivate
+     */
+    this.autoActivate_ =
+        goog.isDef(opt_autoActivate) ? opt_autoActivate : true;
+    
+};
+goog.inherits(ol.control.Attribution, ol.control.Control);
+
+/**
+ * @param {ol.Map} map
+ */
+ol.control.Attribution.prototype.setMap = function(map) {
+    this.container_ = goog.dom.createDom('div', 'ol-control-attribution');
+    var staticOverlay = map.getStaticOverlay();
+    if (!goog.isNull(this.container_) && !goog.isNull(staticOverlay)) {
+        goog.dom.append(staticOverlay, this.container_);
+    }
+    goog.base(this, 'setMap', map);
+};
+
+/** @inheritDoc */
+ol.control.Attribution.prototype.activate = function() {
+    var active = goog.base(this, 'activate');
+    if (active) {
+        this.map_.getEvents().register('addlayer', this.update, this);
+        this.update();
+    }
+    return active;
+};
+
+/** @inheritDoc */
+ol.control.Attribution.prototype.deactivate = function() {
+    var inactive = goog.base(this, 'deactivate');
+    if (inactive) {
+        this.map_.getEvents().unregister('addlayer', this.update, this);
+    }
+    return inactive;
+};
+
+ol.control.Attribution.prototype.update = function() {
+    var attribution = [],
+        layers = this.map_.getLayers(), layerAttribution;
+    for (var i=0, ii=layers.length; i<ii; ++i) {
+        layerAttribution = layers[i].getAttribution();
+        if (layerAttribution &&
+           !~goog.array.indexOf(attribution, layerAttribution)) {
+            attribution.push(layerAttribution);
+        }
+    }
+    this.container_.innerHTML = attribution.join(', ');
+};
+
+ol.control.Attribution.prototype.destroy = function() {
+    goog.dom.removeNode(this.container_);
+    goog.base(this, 'destroy');
+};
+
+ol.control.addControl('attribution', ol.control.Attribution);