Issue 2420 - Move notification show logic to core

lib/notification.js

Index: lib/notification.js
===================================================================
--- a/lib/notification.js
+++ b/lib/notification.js
@@ -30,13 +30,15 @@
 let INITIAL_DELAY = 12 * MILLIS_IN_MINUTE;
 let CHECK_INTERVAL = 1 * MILLIS_IN_HOUR;
 let EXPIRATION_INTERVAL = 1 * MILLIS_IN_DAY;
+let STARTUP_SHOW_DELAY = 3 * MILLIS_IN_MINUTE;
 let TYPE = {
   information: 0,
   question: 1,
   critical: 2
 };
 
-let listeners = {};
+let showListeners = [];
+let questionListeners = {};
 
 function getNumericalSeverity(notification)
 {
@@ -81,14 +83,16 @@
   init: function()
   {
     downloader = new Downloader(this._getDownloadables.bind(this), INITIAL_DELAY, CHECK_INTERVAL);
-    onShutdown.add(function()
-    {
-      downloader.cancel();
-    });
-
     downloader.onExpirationChange = this._onExpirationChange.bind(this);
     downloader.onDownloadSuccess = this._onDownloadSuccess.bind(this);
     downloader.onDownloadError = this._onDownloadError.bind(this);
+    onShutdown.add(() => downloader.cancel());
+
+    notificationTimer = Cc["@mozilla.org/timer;1"].createInstance(Ci.nsITimer);
+    notificationTimer.initWithCallback(Notification.showNext.bind(this),
+                                       STARTUP_SHOW_DELAY,
+                                       Ci.nsITimer.TYPE_ONE_SHOT);
+    onShutdown.add(() => notificationTimer.cancel());
   },
 
   /**
@@ -158,11 +162,33 @@
   },
 
   /**
+   * Adds a listener for notifications to be shown.
+   * @param {Function} listener Listener to be invoked when a notification is
+   *                   to be shown
+   */
+  addShowListener: function(listener)
+  {
+    if (showListeners.indexOf(listener) == -1)
+      showListeners.push(listener);
+  },
+
+  /**
+   * Removes the supplied listener.
+   * @param {Function} listener Listener that was added via addShowListener()
+   */
+  removeShowListener: function(listener)
+  {
+    let index = showListeners.indexOf(listener);
+    if (index != -1)
+      showListeners.splice(index, 1);
+  },
+
+  /**
    * Determines which notification is to be shown next.
    * @param {String} url URL to match notifications to (optional)
    * @return {Object} notification to be shown, or null if there is none
    */
-  getNextToShow: function(url)
+  _getNextToShow: function(url)
   {
     function checkTarget(target, parameter, name, version)
     {
@@ -234,15 +260,26 @@
         notificationToShow = notification;
     }
 
-    if (notificationToShow && "id" in notificationToShow)
-    {
-      if (notificationToShow.type !== "question")
-        this.markAsShown(notificationToShow.id);
-    }
-
     return notificationToShow;
   },
 
+  /**
+   * Invokes the listeners added via addShowListener() with the next
+   * notification to be shown.
+   * @param {String} url URL to match notifications to (optional)
+   */
+  showNext: function(url)
+  {
+    let notification = Notification._getNextToShow(url);
+    if (notification)
+      for (let showListener of showListeners)
+        showListener(notification);
+  },
+
+  /**
+   * Marks a notification as shown.
+   * @param {String} id ID of the notification to be marked as shown
+   */
   markAsShown: function(id)
   {
     if (Prefs.notificationdata.shown.indexOf(id) > -1)
@@ -303,10 +340,10 @@
    */
   addQuestionListener: function(/**string*/ id, /**function(approved)*/ listener)
   {
-    if (!(id in listeners))
-      listeners[id] = [];
-    if (listeners[id].indexOf(listener) === -1)
-      listeners[id].push(listener);
+    if (!(id in questionListeners))
+      questionListeners[id] = [];
+    if (questionListeners[id].indexOf(listener) === -1)
+      questionListeners[id].push(listener);
   },
 
   /**
@@ -314,26 +351,26 @@
    */
   removeQuestionListener: function(/**string*/ id, /**function(approved)*/ listener)
   {
-    if (!(id in listeners))
+    if (!(id in questionListeners))
       return;
-    let index = listeners[id].indexOf(listener);
+    let index = questionListeners[id].indexOf(listener);
     if (index > -1)
-      listeners[id].splice(index, 1);
-    if (listeners[id].length === 0)
-      delete listeners[id];
+      questionListeners[id].splice(index, 1);
+    if (questionListeners[id].length === 0)
+      delete questionListeners[id];
   },
 
   /**
-   * Notifies listeners about interactions with a notification
+   * Notifies question listeners about interactions with a notification
    * @param {String} id notification ID
    * @param {Boolean} approved indicator whether notification has been approved or not
    */
   triggerQuestionListeners: function(id, approved)
   {
-    if (!(id in listeners))
+    if (!(id in questionListeners))
       return;
-    let questionListeners = listeners[id];
-    for (let listener of questionListeners)
+    let listeners = questionListeners[id];
+    for (let listener of listeners)
       listener(approved);
   },