Instrument calls to ensure audio session is maintained

// FREEBIE

Signal/src/call/CallService.swift

@@ -1501,6 +1501,8 @@ protocol CallServiceObserver: class {
 
         self.call?.removeAllObservers()
         self.call = nil
+        self.callUIAdapter.didTerminateCall(self.call)
+
         self.sendIceUpdatesImmediately = true
         Logger.info("\(self.logTag) clearing pendingIceUpdateMessages")
         self.pendingIceUpdateMessages = []

Signal/src/call/NonCallKitCallUIAdaptee.swift

@@ -37,6 +37,9 @@ class NonCallKitCallUIAdaptee: NSObject, CallUIAdaptee {
 
         let call = SignalCall.outgoingCall(localId: UUID(), remotePhoneNumber: handle)
 
+        // make sure we don't terminate audio session during call
+        OWSAudioSession.shared.startAudioActivity(call.audioActivity)
+
         self.callService.handleOutgoingCall(call).then {
             Logger.debug("\(self.TAG) handleOutgoingCall succeeded")
         }.catch { error in

Signal/src/call/SignalCall.swift

@@ -106,6 +106,8 @@ protocol CallObserver: class {
         }
     }
 
+    let audioActivity: AudioActivity
+
     var audioSource: AudioSource? = nil {
         didSet {
             AssertIsOnMainThread()
@@ -149,6 +151,7 @@ protocol CallObserver: class {
         self.state = state
         self.remotePhoneNumber = remotePhoneNumber
         self.thread = TSContactThread.getOrCreateThread(contactId: remotePhoneNumber)
+        self.audioActivity = AudioActivity(audioDescription: "[SignalCall] with \(remotePhoneNumber)")
     }
 
     // A string containing the three identifiers for this call.

Signal/src/call/Speakerbox/CallKitCallUIAdaptee.swift

@@ -78,6 +78,9 @@ final class CallKitCallUIAdaptee: NSObject, CallUIAdaptee, CXProviderDelegate {
 
         let call = SignalCall.outgoingCall(localId: UUID(), remotePhoneNumber: handle)
 
+        // make sure we don't terminate audio session during call
+        OWSAudioSession.shared.startAudioActivity(call.audioActivity)
+
         // Add the new outgoing call to the app's list of calls.
         // So we can find it in the provider delegate callbacks.
         callManager.addCall(call)

Signal/src/call/UserInterface/CallUIAdapter.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
@@ -111,6 +111,9 @@ extension CallUIAdaptee {
     internal func reportIncomingCall(_ call: SignalCall, thread: TSContactThread) {
         AssertIsOnMainThread()
 
+        // make sure we don't terminate audio session during call
+        OWSAudioSession.shared.startAudioActivity(call.audioActivity)
+
         let callerName = self.contactsManager.displayName(forPhoneIdentifier: call.remotePhoneNumber)
         adaptee.reportIncomingCall(call, callerName: callerName)
     }
@@ -153,6 +156,14 @@ extension CallUIAdaptee {
         adaptee.declineCall(call)
     }
 
+    internal func didTerminateCall(_ call: SignalCall?) {
+        AssertIsOnMainThread()
+
+        if let call = call {
+            OWSAudioSession.shared.endAudioActivity(call.audioActivity)
+        }
+    }
+
     internal func startAndShowOutgoingCall(recipientId: String) {
         AssertIsOnMainThread()
 

SignalMessaging/environment/OWSAudioSession.swift

@@ -70,7 +70,7 @@ public class OWSAudioSession: NSObject {
         }
     }
 
-    private func startAudioActivity(_ audioActivity: AudioActivity) {
+    public func startAudioActivity(_ audioActivity: AudioActivity) {
         Logger.debug("\(logTag) in \(#function) with \(audioActivity)")
 
         self.currentActivities.append(Weak(value: audioActivity))