Multi device read receipts.

All the heavy lifting is in SignalServiceKit.

// FREEBIE

Podfile

@@ -3,8 +3,7 @@ source 'https://github.com/CocoaPods/Specs.git'
 
 target 'Signal' do
     pod 'SocketRocket',               :git => 'https://github.com/facebook/SocketRocket.git'
-    #pod 'SignalServiceKit',           :git => 'https://github.com/WhisperSystems/SignalServiceKit.git'
-    pod 'SignalServiceKit',           path: '../SignalServiceKit'
+    pod 'SignalServiceKit',           :git => 'https://github.com/WhisperSystems/SignalServiceKit.git', branch: 'dt'
     pod 'OpenSSL',                    '~> 1.0.208'
     pod 'PastelogKit',                '~> 1.3'
     pod 'FFCircularProgressView',     '~> 0.5'

Podfile.lock

@@ -33,7 +33,7 @@ PODS:
   - JSQMessagesViewController (7.3.4):
     - JSQSystemSoundPlayer (~> 2.0.1)
   - JSQSystemSoundPlayer (2.0.1)
-  - libPhoneNumber-iOS (0.8.15)
+  - libPhoneNumber-iOS (0.8.16)
   - Mantle (2.0.7):
     - Mantle/extobjc (= 2.0.7)
   - Mantle/extobjc (2.0.7)
@@ -119,16 +119,20 @@ DEPENDENCIES:
   - OpenSSL (~> 1.0.208)
   - PastelogKit (~> 1.3)
   - SCWaveformView (~> 1.0)
-  - SignalServiceKit (from `../SignalServiceKit`)
+  - SignalServiceKit (from `https://github.com/WhisperSystems/SignalServiceKit.git`, branch `dt`)
   - SocketRocket (from `https://github.com/facebook/SocketRocket.git`)
 
 EXTERNAL SOURCES:
   SignalServiceKit:
-    :path: "../SignalServiceKit"
+    :branch: dt
+    :git: https://github.com/WhisperSystems/SignalServiceKit.git
   SocketRocket:
     :git: https://github.com/facebook/SocketRocket.git
 
 CHECKOUT OPTIONS:
+  SignalServiceKit:
+    :commit: 80be2b6db99ceb5e8f77d84a219d0c2a9dd9f5a2
+    :git: https://github.com/WhisperSystems/SignalServiceKit.git
   SocketRocket:
     :commit: 8096fef47d582bff8ae3758c9ae7af1d55ea53d6
     :git: https://github.com/facebook/SocketRocket.git
@@ -143,7 +147,7 @@ SPEC CHECKSUMS:
   HKDFKit: c058305d6f64b84f28c50bd7aa89574625bcb62a
   JSQMessagesViewController: 39fed975e3c9f8eba7292071e29eeb541d105e66
   JSQSystemSoundPlayer: c5850e77a4363ffd374cd851154b9af93264ed8d
-  libPhoneNumber-iOS: 62a740e1ea5741060f5cec0f788b52071115cf31
+  libPhoneNumber-iOS: acb5805f67892db37adc3440290a367923672b51
   Mantle: bc40bb061d8c2c6fb48d5083e04d928c3b7f73d9
   OpenSSL: b187269d386b07452f56af273764ea0636dd5da8
   PastelogKit: 7b475be4cf577713506a943dd940bcc0499c8bca
@@ -158,6 +162,6 @@ SPEC CHECKSUMS:
   UnionFind: c33be5adb12983981d6e827ea94fc7f9e370f52d
   YapDatabase: 713d4018cfacbd6e77dd430710ca84730e450980
 
-PODFILE CHECKSUM: fa9416a71a75bf01fde5554c0505c69f88921ab7
+PODFILE CHECKSUM: bcac03a0ce180ba50c3467068062f8e55e11e778
 
 COCOAPODS: 1.0.1

Signal/src/AppDelegate.m

@@ -2,10 +2,10 @@
 #import "AppStoreRating.h"
 #import "CategorizingLogger.h"
 #import "CodeVerificationViewController.h"
-#import "OWSContactsManager.h"
 #import "DebugLogger.h"
 #import "Environment.h"
 #import "NotificationsManager.h"
+#import "OWSContactsManager.h"
 #import "PreferencesUtil.h"
 #import "PushManager.h"
 #import "Release.h"
@@ -15,6 +15,7 @@
 #import "TSSocketManager.h"
 #import "TextSecureKitEnv.h"
 #import "VersionMigrations.h"
+#import <SignalServiceKit/OWSReadReceiptObserver.h>
 
 static NSString *const kStoryboardName                  = @"Storyboard";
 static NSString *const kInitialViewControllerIdentifier = @"UserInitialViewController";
@@ -24,6 +25,7 @@ static NSString *const kURLHostVerifyPrefix             = @"verify";
 @interface AppDelegate ()
 
 @property (nonatomic, retain) UIWindow *screenProtectionWindow;
+@property (nonatomic) OWSReadReceiptObserver *readReceiptObserver;
 
 @end
 
@@ -117,6 +119,9 @@ static NSString *const kURLHostVerifyPrefix             = @"verify";
     [TextSecureKitEnv sharedEnv].contactsManager = [Environment getCurrent].contactsManager;
     [[TSStorageManager sharedManager] setupDatabase];
     [TextSecureKitEnv sharedEnv].notificationsManager = [[NotificationsManager alloc] init];
+    self.readReceiptObserver =
+        [[OWSReadReceiptObserver alloc] initWithMessagesManager:[TSMessagesManager sharedManager]];
+    [self.readReceiptObserver startObserving];
 }
 
 - (void)application:(UIApplication *)application