Restoring notifications on startup

chrome/browser/resources/google_now/background.js

 // Copyright (c) 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 'use strict';
 
 /**
  * @fileoverview The event page for Google Now for Chrome implementation.
  * The Google Now event page gets Google Now cards from the server and shows
  * them as Chrome notifications.
  * The service performs periodic updating of Google Now cards.
  * Each updating of the cards includes 4 steps:
  * 1. Obtaining the location of the machine;
  * 2. Processing requests for cards dismissals that are not yet sent to the
  *    server;
  * 3. Making a server request based on that location;
  * 4. Showing the received cards as notifications.
  */
 
 // TODO(vadimt): Decide what to do in incognito mode.
 // TODO(vadimt): Figure out the final values of the constants.
 // TODO(vadimt): Remove 'console' calls.
-// TODO(vadimt): Consider sending JS stacks for malformed server responses.
 
 /**
  * Standard response code for successful HTTP requests. This is the only success
  * code the server will send.
  */
 var HTTP_OK = 200;
 var HTTP_NOCONTENT = 204;
 
 var HTTP_BAD_REQUEST = 400;
 var HTTP_UNAUTHORIZED = 401;
@@ skipping 40 matching lines @@
  */
 var DISMISS_RETENTION_TIME_MS = 20 * 60 * 1000;  // 20 minutes
 
 /**
  * Names for tasks that can be created by the extension.
  */
 var UPDATE_CARDS_TASK_NAME = 'update-cards';
 var DISMISS_CARD_TASK_NAME = 'dismiss-card';
 var RETRY_DISMISS_TASK_NAME = 'retry-dismiss';
 var STATE_CHANGED_TASK_NAME = 'state-changed';
+var SHOW_ON_START_TASK_NAME = 'show-cards-on-start';
 
 var LOCATION_WATCH_NAME = 'location-watch';
 
 var WELCOME_TOAST_NOTIFICATION_ID = 'enable-now-toast';
 
 /**
  * The indices of the buttons that are displayed on the welcome toast.
  * @enum {number}
  */
 var ToastButtonIndex = {YES: 0, NO: 1};
@@ skipping 216 matching lines @@
             var previousVersion = notifications[chromeNotificationId] &&
                                   notificationData &&
                                   notificationData.cardCreateInfo &&
                                   notificationData.cardCreateInfo.version;
             newNotificationsData[chromeNotificationId] = cardSet.update(
                 chromeNotificationId,
                 cards[chromeNotificationId],
                 previousVersion);
           }
 
-          recordEvent(GoogleNowEvent.CARDS_PARSE_SUCCESS);
-
           chrome.storage.local.set({
             notificationsData: newNotificationsData,
             recentDismissals: updatedRecentDismissals
           });
         });
       });
 }
 
 /**
  * Removes all cards and card state on Google Now close down.
@@ skipping 108 matching lines @@
 
   verify(nextPollTime != null, 'scheduleNextPoll: nextPollTime is null');
 
   var nextPollDelaySeconds = Math.max(
       (nextPollTime - Date.now()) / MS_IN_SECOND,
       MINIMUM_POLLING_PERIOD_SECONDS);
   updateCardsAttempts.start(nextPollDelaySeconds);
 }
 
 /**
+ * Merges notification groups into a set of Chrome notifications and shows them.
+ * @param {Object.<string, StorageGroup>} notificationGroups Map from group name
+ *     to group information.
+ */
+function mergeAndShowNotificationCards(notificationGroups) {
+  var mergedCards = {};
+
+  for (var groupName in notificationGroups)
+    mergeGroup(mergedCards, notificationGroups[groupName]);
+
+  showNotificationCards(mergedCards);
+}
+
+/**
  * Parses JSON response from the notification server, shows notifications and
  * schedules next update.
  * @param {string} response Server response.
  */
 function parseAndShowNotificationCards(response) {
   console.log('parseAndShowNotificationCards ' + response);
   var parsedResponse = JSON.parse(response);
 
-  var groups = parsedResponse.groups;
+  var receivedGroups = parsedResponse.groups;
 
   // Populate groups with corresponding cards.
   if (parsedResponse.notifications) {
     for (var i = 0; i != parsedResponse.notifications.length; ++i) {
       var card = parsedResponse.notifications[i];
-      var group = groups[card.groupName];
+      var group = receivedGroups[card.groupName];
       group.cards = group.cards || [];
       group.cards.push(card);
     }
   }
 
   instrumented.storage.local.get('notificationGroups', function(items) {
     console.log('parseAndShowNotificationCards-get ' + JSON.stringify(items));
     items = items || {};
     items.notificationGroups = items.notificationGroups || {};
 
     var now = Date.now();
 
-    // Build updated set of groups and merge cards from all groups into one set.
+    // Build updated set of groups.
     var updatedGroups = {};
-    var mergedCards = {};
 
-    for (var groupName in groups) {
-      var receivedGroup = groups[groupName];
+    for (var groupName in receivedGroups) {
+      var receivedGroup = receivedGroups[groupName];
       var storageGroup = items.notificationGroups[groupName] || {
         cards: [],
         cardsTimestamp: undefined,
         nextPollTime: now,
         rank: undefined
       };
 
       if (receivedGroup.requested)
         receivedGroup.cards = receivedGroup.cards || [];
 
       if (receivedGroup.cards) {
         storageGroup.cards = receivedGroup.cards;
         storageGroup.cardsTimestamp = now;
         storageGroup.rank = receivedGroup.rank;
       }
 
       if (receivedGroup.nextPollSeconds !== undefined) {
         storageGroup.nextPollTime =
             now + receivedGroup.nextPollSeconds * MS_IN_SECOND;
       }
 
       updatedGroups[groupName] = storageGroup;
-
-      mergeGroup(mergedCards, storageGroup);
     }
 
     scheduleNextPoll(updatedGroups);
-
     chrome.storage.local.set({notificationGroups: updatedGroups});
-
-    showNotificationCards(mergedCards);
+    mergeAndShowNotificationCards(updatedGroups);
+    recordEvent(GoogleNowEvent.CARDS_PARSE_SUCCESS);
   });
 }
 
 /**
  * Requests notification cards from the server.
  * @param {Location} position Location of this computer.
  */
 function requestNotificationCards(position) {
   console.log('requestNotificationCards ' + JSON.stringify(position) +
       ' from ' + NOTIFICATION_CARDS_URL);
@@ skipping 345 matching lines @@
   updateCardsAttempts.stop();
 
   removeAllCards();
 }
 
 /**
  * Initializes the event page on install or on browser startup.
  */
 function initialize() {
   recordEvent(GoogleNowEvent.EXTENSION_START);
-
-  // Alarms persist across chrome restarts. This is undesirable since it
-  // prevents us from starting up everything (alarms are a heuristic to
-  // determine if we are already running). To mitigate this, we will
-  // shut everything down on initialize before starting everything up.
-  stopPollingCards();
   onStateChange();
 }
 
 /**
  * Starts or stops the polling of cards.
  * @param {boolean} shouldPollCardsRequest true to start and
  *     false to stop polling cards.
  */
 function setShouldPollCards(shouldPollCardsRequest) {
   updateCardsAttempts.isRunning(function(currentValue) {
@@ skipping 183 matching lines @@
 
 instrumented.runtime.onInstalled.addListener(function(details) {
   console.log('onInstalled ' + JSON.stringify(details));
   if (details.reason != 'chrome_update') {
     initialize();
   }
 });
 
 instrumented.runtime.onStartup.addListener(function() {
   console.log('onStartup');
+
+  // Show notifications received by earlier polls. Doing this as early as
+  // possible to reduce latency of showing first notifications. This mimics how
+  // persistent notifications will work.
+  tasks.add(SHOW_ON_START_TASK_NAME, function() {
+    instrumented.storage.local.get('notificationGroups', function(items) {
+      console.log('onStartup-get ' + JSON.stringify(items));
+      items = items || {};
+      items.notificationGroups = items.notificationGroups || {};
+
+      mergeAndShowNotificationCards(items.notificationGroups);
+    });
+  });
+
   initialize();
 });
 
 instrumented.
     preferencesPrivate.
     googleGeolocationAccessEnabled.
     onChange.
     addListener(function(prefValue) {
       console.log('googleGeolocationAccessEnabled Pref onChange ' +
           prefValue.value);
@@ skipping 32 matching lines @@
 
 instrumented.location.onLocationUpdate.addListener(function(position) {
   recordEvent(GoogleNowEvent.LOCATION_UPDATE);
   updateNotificationsCards(position);
 });
 
 instrumented.omnibox.onInputEntered.addListener(function(text) {
   localStorage['server_url'] = NOTIFICATION_CARDS_URL = text;
   initialize();
 });