Add Notification module

lib/notification.js

Index: lib/notification.js
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+/*
+ * This file is part of Adblock Plus <http://adblockplus.org/>,
+ * Copyright (C) 2006-2013 Eyeo GmbH
+ *
+ * Adblock Plus is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 3 as
+ * published by the Free Software Foundation.
+ *
+ * Adblock Plus is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with Adblock Plus.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+/**
+ * @fileOverview Handles notifications.
+ */
+
+Cu.import("resource://gre/modules/Services.jsm");
+
+let {Prefs} = require("prefs");
+
+function compareSeverity(notification1, notification2)
+{
+  let levels = {information: 0, critical: 1};
+  return levels[notification1.severity] - levels[notification2.severity];
+}
+
+/**
+ * Regularly fetches notifications and decides which to show.
+ * @class
+ */
+let Notification = exports.Notification =
+{
+  /**
+   * Determines which notification is to be shown next.
+   * @param {Array of Object} notifications active notifications
+   * @return {Object} notification to be shown, or null if there is none
+   */
+  getNextToShow: function(notifications)
+  {
+    if (!Prefs.shownNotifications)
+      Prefs.shownNotifications = [];
+
+    let notificationToShow;
+    for each (let notification in notifications)
+    {
+      if (notification.severity === "information"
+          && Prefs.shownNotifications.indexOf(notification.timestamp) !== -1)
+        continue;
+
+      let info = require("info");
+      let platform = info.application;
+      let version = info.addonVersion;
+
+      if ("platforms" in notification
+          && notification.platforms.indexOf("chrome") === -1)
+        continue;
+
+      if ("minVersion" in notification
+          && Services.vc.compare(version, notification.minVersion) < 0)
+        continue;
+
+      if ("maxVersion" in notification
+          && Services.vc.compare(version, notification.maxVersion) > 0)
+        continue;
+
+      if (!notificationToShow
+          || compareSeverity(notification, notificationToShow) > 0)
+        notificationToShow = notification;
+    }
+
+    if (notificationToShow && "timestamp" in notificationToShow)
+      Prefs.shownNotifications.push(notificationToShow.timestamp);
+
+    return notificationToShow;
+  }
+};