Don't de-activate audio sesion when other audio activities are happening

// FREEBIE

Signal.xcodeproj/project.pbxproj

@@ -248,6 +248,7 @@
 		4523149E1F7E916B003A428C /* SlideOffAnimatedTransition.swift in Sources */ = {isa = PBXBuildFile; fileRef = 4523149D1F7E916B003A428C /* SlideOffAnimatedTransition.swift */; };
 		452314A01F7E9E18003A428C /* DirectionalPanGestureRecognizer.swift in Sources */ = {isa = PBXBuildFile; fileRef = 4523149F1F7E9E18003A428C /* DirectionalPanGestureRecognizer.swift */; };
 		452C468F1E427E200087B011 /* OutboundCallInitiator.swift in Sources */ = {isa = PBXBuildFile; fileRef = 452C468E1E427E200087B011 /* OutboundCallInitiator.swift */; };
+		452C7CA72037628B003D51A5 /* Weak.swift in Sources */ = {isa = PBXBuildFile; fileRef = 45F170D51E315310003FC1F2 /* Weak.swift */; };
 		452D1EE81DCA90D100A57EC4 /* MesssagesBubblesSizeCalculatorTest.swift in Sources */ = {isa = PBXBuildFile; fileRef = 452D1EE71DCA90D100A57EC4 /* MesssagesBubblesSizeCalculatorTest.swift */; };
 		452EA09E1EA7ABE00078744B /* AttachmentPointerView.swift in Sources */ = {isa = PBXBuildFile; fileRef = 452EA09D1EA7ABE00078744B /* AttachmentPointerView.swift */; };
 		452ECA4D1E087E7200E2F016 /* MessageFetcherJob.swift in Sources */ = {isa = PBXBuildFile; fileRef = 452ECA4C1E087E7200E2F016 /* MessageFetcherJob.swift */; };
@@ -308,7 +309,6 @@
 		45E5A6991F61E6DE001E4A8A /* MarqueeLabel.swift in Sources */ = {isa = PBXBuildFile; fileRef = 45E5A6981F61E6DD001E4A8A /* MarqueeLabel.swift */; };
 		45E7A6A81E71CA7E00D44FB5 /* DisplayableTextFilterTest.swift in Sources */ = {isa = PBXBuildFile; fileRef = 45E7A6A61E71CA7E00D44FB5 /* DisplayableTextFilterTest.swift */; };
 		45F170BB1E2FC5D3003FC1F2 /* CallAudioService.swift in Sources */ = {isa = PBXBuildFile; fileRef = 45F170BA1E2FC5D3003FC1F2 /* CallAudioService.swift */; };
-		45F170D61E315310003FC1F2 /* Weak.swift in Sources */ = {isa = PBXBuildFile; fileRef = 45F170D51E315310003FC1F2 /* Weak.swift */; };
 		45F59A082028E4FB00E8D2B0 /* OWSAudioSession.swift in Sources */ = {isa = PBXBuildFile; fileRef = 45F170AB1E2F0351003FC1F2 /* OWSAudioSession.swift */; };
 		45F59A0A2029140500E8D2B0 /* OWSVideoPlayer.swift in Sources */ = {isa = PBXBuildFile; fileRef = 45F59A092029140500E8D2B0 /* OWSVideoPlayer.swift */; };
 		45F659731E1BD99C00444429 /* CallKitCallUIAdaptee.swift in Sources */ = {isa = PBXBuildFile; fileRef = 45F659721E1BD99C00444429 /* CallKitCallUIAdaptee.swift */; };
@@ -1138,6 +1138,7 @@
 				346129BE1FD2068600532771 /* ThreadUtil.m */,
 				B97940251832BD2400BD66CB /* UIUtil.h */,
 				B97940261832BD2400BD66CB /* UIUtil.m */,
+				45F170D51E315310003FC1F2 /* Weak.swift */,
 				346129751FD1E0B500532771 /* WeakTimer.swift */,
 			);
 			path = utils;
@@ -1756,7 +1757,6 @@
 				FCFA64B11A24F29E0007FB87 /* UI Categories */,
 				FCC81A961A44558300DFEC7D /* UIDevice+TSHardwareVersion.h */,
 				FCC81A971A44558300DFEC7D /* UIDevice+TSHardwareVersion.m */,
-				45F170D51E315310003FC1F2 /* Weak.swift */,
 			);
 			path = util;
 			sourceTree = "<group>";
@@ -2803,6 +2803,7 @@
 				3478506B1FD9B78A007B8332 /* NoopCallMessageHandler.swift in Sources */,
 				451F8A3D1FD713CA005CB9DA /* ThreadViewHelper.m in Sources */,
 				346129AD1FD1F34E00532771 /* ImageCache.swift in Sources */,
+				452C7CA72037628B003D51A5 /* Weak.swift in Sources */,
 				451F8A341FD710C3005CB9DA /* ConversationSearcher.swift in Sources */,
 				346129341FD1A88700532771 /* OWSSwiftUtils.swift in Sources */,
 				346129FE1FD5F31400532771 /* OWS106EnsureProfileComplete.swift in Sources */,
@@ -2977,7 +2978,6 @@
 				4574A5D61DD6704700C6B692 /* CallService.swift in Sources */,
 				34B3F8721E8DF1700035BE1A /* AdvancedSettingsTableViewController.m in Sources */,
 				3461299C1FD1EA9E00532771 /* NotificationsManager.m in Sources */,
-				45F170D61E315310003FC1F2 /* Weak.swift in Sources */,
 				4521C3C01F59F3BA00B4C582 /* TextFieldHelper.swift in Sources */,
 				34B3F8891E8DF1700035BE1A /* OWSConversationSettingsViewController.m in Sources */,
 				34B3F87E1E8DF1700035BE1A /* InboxTableViewCell.m in Sources */,

Signal/src/ViewControllers/ConversationView/ConversationViewController.m

@@ -151,6 +151,7 @@ typedef NS_ENUM(NSInteger, MessagesRangeSizeMode) {
 
 @property (nonatomic) TSThread *thread;
 @property (nonatomic) YapDatabaseConnection *editingDatabaseConnection;
+@property (nonatomic, readonly) AudioActivity *voiceNoteAudioActivity;
 
 // These two properties must be updated in lockstep.
 //
@@ -277,6 +278,8 @@ typedef NS_ENUM(NSInteger, MessagesRangeSizeMode) {
     _networkManager = [TSNetworkManager sharedManager];
     _blockingManager = [OWSBlockingManager sharedManager];
     _contactsViewHelper = [[ContactsViewHelper alloc] initWithDelegate:self];
+    NSString *audioActivityDescription = [NSString stringWithFormat:@"%@ voice note", self.logTag];
+    _voiceNoteAudioActivity = [[AudioActivity alloc] initWithAudioDescription:audioActivityDescription];
 }
 
 - (void)addNotificationListeners
@@ -3173,7 +3176,7 @@ typedef NS_ENUM(NSInteger, MessagesRangeSizeMode) {
     NSURL *fileURL = [NSURL fileURLWithPath:filepath];
 
     // Setup audio session
-    BOOL configuredAudio = [OWSAudioSession.shared setRecordCategory];
+    BOOL configuredAudio = [OWSAudioSession.shared setRecordCategoryWithAudioActivity:self.voiceNoteAudioActivity];
     if (!configuredAudio) {
         OWSFail(@"%@ Couldn't configure audio session", self.logTag);
         [self cancelVoiceMemo];
@@ -3278,7 +3281,7 @@ typedef NS_ENUM(NSInteger, MessagesRangeSizeMode) {
 - (void)stopRecording
 {
     [self.audioRecorder stop];
-    [OWSAudioSession.shared endAudioActivity];
+    [OWSAudioSession.shared endAudioActivity:self.voiceNoteAudioActivity];
 }
 
 - (void)cancelRecordingVoiceMemo

Signal/src/call/NonCallKitCallUIAdaptee.swift

@@ -15,6 +15,7 @@ class NonCallKitCallUIAdaptee: NSObject, CallUIAdaptee {
 
     let notificationsAdapter: CallNotificationsAdapter
     let callService: CallService
+    let audioActivity: AudioActivity
 
     // Starting/Stopping incoming call ringing is our apps responsibility for the non CallKit interface.
     let hasManualRinger = true
@@ -24,6 +25,7 @@ class NonCallKitCallUIAdaptee: NSObject, CallUIAdaptee {
 
         self.callService = callService
         self.notificationsAdapter = notificationsAdapter
+        self.audioActivity = AudioActivity(audioDescription: "[NonCallKitCallUIAdaptee]")
 
         super.init()
 
@@ -89,7 +91,7 @@ class NonCallKitCallUIAdaptee: NSObject, CallUIAdaptee {
             return
         }
 
-        OWSAudioSession.shared.isRTCAudioEnabled = true
+        OWSAudioSession.shared.enableRTCAudio(audioActivity: audioActivity)
         self.callService.handleAnswerCall(call)
     }
 
@@ -123,7 +125,7 @@ class NonCallKitCallUIAdaptee: NSObject, CallUIAdaptee {
     func recipientAcceptedCall(_ call: SignalCall) {
         AssertIsOnMainThread()
 
-        OWSAudioSession.shared.isRTCAudioEnabled = true
+        OWSAudioSession.shared.enableRTCAudio(audioActivity: audioActivity)
     }
 
     func localHangupCall(_ call: SignalCall) {

Signal/src/call/SignalCall.swift

@@ -1,5 +1,5 @@
 //
-//  Copyright (c) 2017 Open Whisper Systems. All rights reserved.
+//  Copyright (c) 2018 Open Whisper Systems. All rights reserved.
 //
 
 import Foundation
@@ -148,7 +148,6 @@ protocol CallObserver: class {
         self.signalingId = signalingId
         self.state = state
         self.remotePhoneNumber = remotePhoneNumber
-
         self.thread = TSContactThread.getOrCreateThread(contactId: remotePhoneNumber)
     }
 

Signal/src/call/Speakerbox/CallKitCallUIAdaptee.swift

@@ -25,6 +25,7 @@ final class CallKitCallUIAdaptee: NSObject, CallUIAdaptee, CXProviderDelegate {
     internal let notificationsAdapter: CallNotificationsAdapter
     internal let contactsManager: OWSContactsManager
     private let provider: CXProvider
+    private let audioActivity: AudioActivity
 
     // CallKit handles incoming ringer stop/start for us. Yay!
     let hasManualRinger = false
@@ -60,6 +61,7 @@ final class CallKitCallUIAdaptee: NSObject, CallUIAdaptee, CXProviderDelegate {
         self.contactsManager = contactsManager
         self.notificationsAdapter = notificationsAdapter
         self.provider = CXProvider(configuration: type(of: self).providerConfiguration)
+        self.audioActivity = AudioActivity(audioDescription: "CallKitCallUIAdaptee audio")
 
         super.init()
 
@@ -343,16 +345,15 @@ final class CallKitCallUIAdaptee: NSObject, CallUIAdaptee, CXProviderDelegate {
     func provider(_ provider: CXProvider, didActivate audioSession: AVAudioSession) {
         AssertIsOnMainThread()
 
-        Logger.debug("\(TAG) Received \(#function)")
+        Logger.debug("\(TAG) in \(#function)")
-
+        OWSAudioSession.shared.enableRTCAudio(audioActivity: audioActivity)
-        OWSAudioSession.shared.isRTCAudioEnabled = true
     }
 
     func provider(_ provider: CXProvider, didDeactivate audioSession: AVAudioSession) {
         AssertIsOnMainThread()
 
-        Logger.debug("\(TAG) Received \(#function)")
+        Logger.debug("\(TAG) in \(#function)")
-        OWSAudioSession.shared.isRTCAudioEnabled = false
+        OWSAudioSession.shared.disableRTCAudio(audioActivity: audioActivity)
     }
 
     // MARK: - Util

SignalMessaging/attachments/OWSAudioAttachmentPlayer.m

@@ -15,6 +15,7 @@ NS_ASSUME_NONNULL_BEGIN
 @property (nonatomic, readonly) NSURL *mediaUrl;
 @property (nonatomic, nullable) AVAudioPlayer *audioPlayer;
 @property (nonatomic, nullable) NSTimer *audioPlayerPoller;
+@property (nonatomic, readonly) AudioActivity *audioActivity;
 
 @end
 
@@ -35,6 +36,9 @@ NS_ASSUME_NONNULL_BEGIN
     _delegate = delegate;
     _mediaUrl = mediaUrl;
 
+    NSString *audioActivityDescription = [NSString stringWithFormat:@"%@ %@", self.logTag, self.mediaUrl];
+    _audioActivity = [[AudioActivity alloc] initWithAudioDescription:audioActivityDescription];
+
     [[NSNotificationCenter defaultCenter] addObserver:self
                                              selector:@selector(applicationDidEnterBackground:)
                                                  name:OWSApplicationDidEnterBackgroundNotification
@@ -65,7 +69,7 @@ NS_ASSUME_NONNULL_BEGIN
     OWSAssert(self.mediaUrl);
     OWSAssert([self.delegate audioPlaybackState] != AudioPlaybackState_Playing);
 
-    [OWSAudioSession.shared setPlaybackCategory];
+    [OWSAudioSession.shared setPlaybackCategoryWithAudioActivity:self.audioActivity];
 
     [self.audioPlayerPoller invalidate];
 
@@ -111,7 +115,7 @@ NS_ASSUME_NONNULL_BEGIN
     [self.audioPlayerPoller invalidate];
     [self.delegate setAudioProgress:[self.audioPlayer currentTime] duration:[self.audioPlayer duration]];
 
-    [OWSAudioSession.shared endAudioActivity];
+    [OWSAudioSession.shared endAudioActivity:self.audioActivity];
     [DeviceSleepManager.sharedInstance removeBlockWithBlockObject:self];
 }
 
@@ -124,7 +128,7 @@ NS_ASSUME_NONNULL_BEGIN
     [self.audioPlayerPoller invalidate];
     [self.delegate setAudioProgress:0 duration:0];
 
-    [OWSAudioSession.shared endAudioActivity];
+    [OWSAudioSession.shared endAudioActivity:self.audioActivity];
     [DeviceSleepManager.sharedInstance removeBlockWithBlockObject:self];
 }
 

SignalMessaging/attachments/OWSVideoPlayer.swift

@@ -15,12 +15,14 @@ protocol OWSVideoPlayerDelegate: class {
 public class OWSVideoPlayer: NSObject {
 
     let avPlayer: AVPlayer
+    let audioActivity: AudioActivity
 
     weak var delegate: OWSVideoPlayerDelegate?
 
     @available(iOS 9.0, *)
     init(url: URL) {
         self.avPlayer = AVPlayer(url: url)
+        self.audioActivity = AudioActivity(audioDescription:  "[OWSVideoPlayer] url:\(url)")
 
         super.init()
 
@@ -35,12 +37,12 @@ public class OWSVideoPlayer: NSObject {
     @available(iOS 9.0, *)
     public func pause() {
         avPlayer.pause()
-        OWSAudioSession.shared.endAudioActivity()
+        OWSAudioSession.shared.endAudioActivity(self.audioActivity)
     }
 
     @available(iOS 9.0, *)
     public func play() {
-        OWSAudioSession.shared.setPlaybackCategory()
+        OWSAudioSession.shared.setPlaybackCategory(audioActivity: self.audioActivity)
 
         guard let item = avPlayer.currentItem else {
             owsFail("\(logTag) video player item was unexpectedly nil")
@@ -67,6 +69,6 @@ public class OWSVideoPlayer: NSObject {
     @available(iOS 9.0, *)
     private func playerItemDidPlayToCompletion(_ notification: Notification) {
         self.delegate?.videoPlayerDidPlayToCompletion(self)
-        OWSAudioSession.shared.endAudioActivity()
+        OWSAudioSession.shared.endAudioActivity(self.audioActivity)
     }
 }

SignalMessaging/environment/OWSAudioSession.swift

@@ -5,6 +5,24 @@
 import Foundation
 import WebRTC
 
+@objc
+public class AudioActivity: NSObject {
+    let audioDescription: String
+
+    override public var description: String {
+        return "<\(self.logTag) audioDescription: \"\(audioDescription)\">"
+    }
+
+    public
+    init(audioDescription: String) {
+        self.audioDescription = audioDescription
+    }
+
+    deinit {
+        OWSAudioSession.shared.ensureAudioSessionActivationState()
+    }
+}
+
 @objc
 public class OWSAudioSession: NSObject {
 
@@ -13,14 +31,18 @@ public class OWSAudioSession: NSObject {
     private override init() {}
     private let avAudioSession = AVAudioSession.sharedInstance()
 
+    private var currentActivities: [Weak<AudioActivity>] = []
+
     // Ignores hardware mute switch, plays through external speaker
-    public func setPlaybackCategory() {
+    public func setPlaybackCategory(audioActivity: AudioActivity) {
         Logger.debug("\(logTag) in \(#function)")
 
         // In general, we should have put the audio session back to it's default
         // category when we were done with whatever activity required it to be modified
         assert(avAudioSession.category == AVAudioSessionCategorySoloAmbient)
 
+        startAudioActivity(audioActivity)
+
         do {
             try avAudioSession.setCategory(AVAudioSessionCategoryPlayback)
         } catch {
@@ -28,7 +50,7 @@ public class OWSAudioSession: NSObject {
         }
     }
 
-    public func setRecordCategory() -> Bool {
+    public func setRecordCategory(audioActivity: AudioActivity) -> Bool {
         Logger.debug("\(logTag) in \(#function)")
 
         // In general, we should have put the audio session back to it's default
@@ -37,6 +59,8 @@ public class OWSAudioSession: NSObject {
 
         assert(avAudioSession.recordPermission() == .granted)
 
+        startAudioActivity(audioActivity)
+
         do {
             try avAudioSession.setCategory(AVAudioSessionCategoryRecord)
             return true
@@ -46,8 +70,38 @@ public class OWSAudioSession: NSObject {
         }
     }
 
-    public func endAudioActivity() {
+    private func startAudioActivity(_ audioActivity: AudioActivity) {
-        Logger.debug("\(logTag) in \(#function)")
+        Logger.debug("\(logTag) in \(#function) with \(audioActivity)")
+
+        self.currentActivities.append(Weak(value: audioActivity))
+    }
+
+    public func endAudioActivity(_ audioActivity: AudioActivity) {
+        Logger.debug("\(logTag) in \(#function) with audioActivity: \(audioActivity)")
+
+        currentActivities = currentActivities.filter { return $0.value != audioActivity }
+        ensureAudioSessionActivationState()
+    }
+
+    fileprivate func ensureAudioSessionActivationState() {
+        // Cull any stale activities
+        currentActivities = currentActivities.flatMap { oldActivity in
+            guard oldActivity.value != nil else {
+                // Normally we should be explicitly stopping an audio activity, but this allows
+                // for recovery if the owner of the AudioAcivity was GC'd without ending it's
+                // audio activity
+                Logger.warn("\(logTag) an old activity has been gc'd")
+                return nil
+            }
+
+            // return any still-active activities
+            return oldActivity
+        }
+
+        guard currentActivities.count == 0 else {
+            Logger.debug("\(logTag) not deactivating due to currentActivities: \(currentActivities)")
+            return
+        }
 
         do {
             try avAudioSession.setCategory(AVAudioSessionCategorySoloAmbient)
@@ -88,14 +142,15 @@ public class OWSAudioSession: NSObject {
 
     /**
      * Because we useManualAudio with our RTCAudioSession, we have to start/stop the recording audio session ourselves.
-     * See header for details on  manual audio.
+     * See "WebRTC Audio" comment for details on manual audio.
      */
-    public var isRTCAudioEnabled: Bool {
+    public func enableRTCAudio(audioActivity: AudioActivity) {
-        get {
+        startAudioActivity(audioActivity)
-            return rtcAudioSession.isAudioEnabled
+        rtcAudioSession.isAudioEnabled = true
-        }
+    }
-        set {
+
-            rtcAudioSession.isAudioEnabled = newValue
+    public func disableRTCAudio(audioActivity: AudioActivity) {
-        }
+        rtcAudioSession.isAudioEnabled = false
+        endAudioActivity(audioActivity)
     }
 }

SignalMessaging/utils/Weak.swift

@@ -1,20 +1,19 @@
 //
-//  Copyright © 2017 Open Whisper Systems. All rights reserved.
+//  Copyright (c) 2018 Open Whisper Systems. All rights reserved.
 //
 
 /**
  * Container for a weakly referenced object.
  *
  * Only use this for |T| with reference-semantic entities
- * e.g. inheriting from AnyObject or Class-only protocols, but not structs or enums.
+ * That is - <T> should inherit from AnyObject or Class-only protocols, but not structs or enums.
- *
  *
  * Based on https://devforums.apple.com/message/981472#981472, but also supports class-only protocols
  */
-struct Weak<T> {
+public struct Weak<T> {
     private weak var _value: AnyObject?
 
-    var value: T? {
+    public var value: T? {
         get {
             return _value as? T
         }
@@ -23,7 +22,7 @@ struct Weak<T> {
         }
     }
 
-    init(value: T) {
+    public init(value: T) {
         self.value = value
     }
 }