1 files changed, 134 insertions, 0 deletions
diff --git a/tools/addon-sdk-1.12/lib/sdk/deprecated/observer-service.js b/tools/addon-sdk-1.12/lib/sdk/deprecated/observer-service.js
new file mode 100644
index 0000000..6a25109
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+++ b/tools/addon-sdk-1.12/lib/sdk/deprecated/observer-service.js
@@ -0,0 +1,134 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+
+module.metadata = {
+  "stability": "deprecated"
+};
+
+const { Cc, Ci } = require("chrome");
+const { when: unload } = require("../system/unload");
+const { ns } = require("../core/namespace");
+const { on, off, emit, once } = require("../system/events");
+const { id } = require("../self");
+
+const subscribers = ns();
+const cache = [];
+
+/**
+ * Topics specifically available to Jetpack-generated extensions.
+ *
+ * Using these predefined consts instead of the platform strings is good:
+ *   - allows us to scope topics specifically for Jetpacks
+ *   - addons aren't dependent on strings nor behavior of core platform topics
+ *   - the core platform topics are not clearly named
+ *
+ */
+exports.topics = {
+  /**
+   * A topic indicating that the application is in a state usable
+   * by add-ons.
+   */
+  APPLICATION_READY: id + "_APPLICATION_READY"
+};
+
+function Listener(callback, target) {
+  return function listener({ subject, data }) {
+    callback.call(target || callback, subject, data);
+  }
+}
+
+/**
+ * Register the given callback as an observer of the given topic.
+ *
+ * @param   topic       {String}
+ *          the topic to observe
+ *
+ * @param   callback    {Object}
+ *          the callback; an Object that implements nsIObserver or a Function
+ *          that gets called when the notification occurs
+ *
+ * @param   target  {Object}  [optional]
+ *          the object to use as |this| when calling a Function callback
+ *
+ * @returns the observer
+ */
+function add(topic, callback, target) {
+  let listeners = subscribers(callback);
+  if (!(topic in listeners)) {
+    let listener = Listener(callback, target);
+    listeners[topic] = listener;
+
+    // Cache callback unless it's already cached.
+    if (!~cache.indexOf(callback))
+      cache.push(callback);
+
+    on(topic, listener);
+  }
+};
+exports.add = add;
+
+/**
+ * Unregister the given callback as an observer of the given topic.
+ *
+ * @param   topic       {String}
+ *          the topic being observed
+ *
+ * @param   callback    {Object}
+ *          the callback doing the observing
+ *
+ * @param   target  {Object}  [optional]
+ *          the object being used as |this| when calling a Function callback
+ */
+function remove(topic, callback, target) {
+  let listeners = subscribers(callback);
+  if (topic in listeners) {
+    let listener = listeners[topic];
+    delete listeners[topic];
+
+    // If no more observers are registered and callback is still in cache
+    // then remove it.
+    let index = cache.indexOf(callback);
+    if (~index && !Object.keys(listeners).length)
+      cache.splice(index, 1)
+
+    off(topic, listener);
+  }
+};
+exports.remove = remove;
+
+/**
+ * Notify observers about something.
+ *
+ * @param topic   {String}
+ *        the topic to notify observers about
+ *
+ * @param subject {Object}  [optional]
+ *        some information about the topic; can be any JS object or primitive
+ *
+ * @param data    {String}  [optional] [deprecated]
+ *        some more information about the topic; deprecated as the subject
+ *        is sufficient to pass all needed information to the JS observers
+ *        that this module targets; if you have multiple values to pass to
+ *        the observer, wrap them in an object and pass them via the subject
+ *        parameter (i.e.: { foo: 1, bar: "some string", baz: myObject })
+ */
+function notify(topic, subject, data) {
+  emit(topic, {
+    subject: subject === undefined ? null : subject,
+    data: data === undefined ? null : data
+  });
+}
+exports.notify = notify;
+
+unload(function() {
+  // Make a copy of cache first, since cache will be changing as we
+  // iterate through it.
+  cache.slice().forEach(function(callback) {
+    Object.keys(subscribers(callback)).forEach(function(topic) {
+      remove(topic, callback);
+    });
+  });
+})