Imports cased like the filename

src/ol/Observable.js

@@ -0,0 +1,156 @@
+goog.provide('ol.Observable');
+
+goog.require('ol');
+goog.require('ol.events');
+goog.require('ol.events.EventTarget');
+goog.require('ol.events.EventType');
+
+
+/**
+ * @classdesc
+ * Abstract base class; normally only used for creating subclasses and not
+ * instantiated in apps.
+ * An event target providing convenient methods for listener registration
+ * and unregistration. A generic `change` event is always available through
+ * {@link ol.Observable#changed}.
+ *
+ * @constructor
+ * @extends {ol.events.EventTarget}
+ * @fires ol.events.Event
+ * @struct
+ * @api
+ */
+ol.Observable = function() {
+
+  ol.events.EventTarget.call(this);
+
+  /**
+   * @private
+   * @type {number}
+   */
+  this.revision_ = 0;
+
+};
+ol.inherits(ol.Observable, ol.events.EventTarget);
+
+
+/**
+ * Removes an event listener using the key returned by `on()` or `once()`.
+ * @param {ol.EventsKey|Array.<ol.EventsKey>} key The key returned by `on()`
+ *     or `once()` (or an array of keys).
+ * @api
+ */
+ol.Observable.unByKey = function(key) {
+  if (Array.isArray(key)) {
+    for (var i = 0, ii = key.length; i < ii; ++i) {
+      ol.events.unlistenByKey(key[i]);
+    }
+  } else {
+    ol.events.unlistenByKey(/** @type {ol.EventsKey} */ (key));
+  }
+};
+
+
+/**
+ * Increases the revision counter and dispatches a 'change' event.
+ * @api
+ */
+ol.Observable.prototype.changed = function() {
+  ++this.revision_;
+  this.dispatchEvent(ol.events.EventType.CHANGE);
+};
+
+
+/**
+ * Dispatches an event and calls all listeners listening for events
+ * of this type. The event parameter can either be a string or an
+ * Object with a `type` property.
+ *
+ * @param {{type: string,
+ *     target: (EventTarget|ol.events.EventTarget|undefined)}|ol.events.Event|
+ *     string} event Event object.
+ * @function
+ * @api
+ */
+ol.Observable.prototype.dispatchEvent;
+
+
+/**
+ * Get the version number for this object.  Each time the object is modified,
+ * its version number will be incremented.
+ * @return {number} Revision.
+ * @api
+ */
+ol.Observable.prototype.getRevision = function() {
+  return this.revision_;
+};
+
+
+/**
+ * Listen for a certain type of event.
+ * @param {string|Array.<string>} type The event type or array of event types.
+ * @param {function(?): ?} listener The listener function.
+ * @param {Object=} opt_this The object to use as `this` in `listener`.
+ * @return {ol.EventsKey|Array.<ol.EventsKey>} Unique key for the listener. If
+ *     called with an array of event types as the first argument, the return
+ *     will be an array of keys.
+ * @api
+ */
+ol.Observable.prototype.on = function(type, listener, opt_this) {
+  if (Array.isArray(type)) {
+    var len = type.length;
+    var keys = new Array(len);
+    for (var i = 0; i < len; ++i) {
+      keys[i] = ol.events.listen(this, type[i], listener, opt_this);
+    }
+    return keys;
+  } else {
+    return ol.events.listen(
+        this, /** @type {string} */ (type), listener, opt_this);
+  }
+};
+
+
+/**
+ * Listen once for a certain type of event.
+ * @param {string|Array.<string>} type The event type or array of event types.
+ * @param {function(?): ?} listener The listener function.
+ * @param {Object=} opt_this The object to use as `this` in `listener`.
+ * @return {ol.EventsKey|Array.<ol.EventsKey>} Unique key for the listener. If
+ *     called with an array of event types as the first argument, the return
+ *     will be an array of keys.
+ * @api
+ */
+ol.Observable.prototype.once = function(type, listener, opt_this) {
+  if (Array.isArray(type)) {
+    var len = type.length;
+    var keys = new Array(len);
+    for (var i = 0; i < len; ++i) {
+      keys[i] = ol.events.listenOnce(this, type[i], listener, opt_this);
+    }
+    return keys;
+  } else {
+    return ol.events.listenOnce(
+        this, /** @type {string} */ (type), listener, opt_this);
+  }
+};
+
+
+/**
+ * Unlisten for a certain type of event.
+ * @param {string|Array.<string>} type The event type or array of event types.
+ * @param {function(?): ?} listener The listener function.
+ * @param {Object=} opt_this The object which was used as `this` by the
+ * `listener`.
+ * @api
+ */
+ol.Observable.prototype.un = function(type, listener, opt_this) {
+  if (Array.isArray(type)) {
+    for (var i = 0, ii = type.length; i < ii; ++i) {
+      ol.events.unlisten(this, type[i], listener, opt_this);
+    }
+    return;
+  } else {
+    ol.events.unlisten(this, /** @type {string} */ (type), listener, opt_this);
+  }
+};