Timer to ensure call screen shown

// FREEBIE

Signal/src/call/CallService.swift

@@ -894,7 +894,7 @@ protocol CallServiceObserver: class {
      * For incoming call, when the local user has chosen to accept the call.
      */
     func handleConnectedCall(_ call: SignalCall) {
-        Logger.debug("\(TAG) in \(#function)")
+        Logger.info("\(TAG) in \(#function)")
         AssertIsOnMainThread()
 
         guard let peerConnectionClient = self.peerConnectionClient else {
@@ -911,6 +911,8 @@ protocol CallServiceObserver: class {
 
         call.state = .connected
 
+        self.startActiveCallTimer(call: call)
+
         // We don't risk transmitting any media until the remote client has admitted to being connected.
         peerConnectionClient.setAudioEnabled(enabled: !call.isMuted)
         peerConnectionClient.setLocalVideoEnabled(enabled: shouldHaveLocalVideoTrack())
@@ -1430,6 +1432,7 @@ protocol CallServiceObserver: class {
 
         self.call?.removeAllObservers()
         self.call = nil
+        self.stopAnyActiveCallTimer()
         self.sendIceUpdatesImmediately = true
         Logger.info("\(TAG) clearing pendingIceUpdateMessages")
         self.pendingIceUpdateMessages = []
@@ -1567,6 +1570,52 @@ protocol CallServiceObserver: class {
                                                  remoteVideoTrack:remoteVideoTrack)
         }
     }
+
+    // MARK: CallViewController Timer
+
+    var activeCallTimer: Timer?
+    func startActiveCallTimer(call: SignalCall) {
+        AssertIsOnMainThread()
+        assert(call.state == .connected)
+
+        if self.activeCallTimer != nil {
+            owsFail("\(TAG) activeCallTimer should only be set once per call")
+            self.activeCallTimer!.invalidate()
+            self.activeCallTimer = nil
+        }
+
+        self.activeCallTimer = WeakTimer.scheduledTimer(timeInterval: 1, target: self, userInfo: nil, repeats: true) { [weak self] timer in
+            guard let strongSelf = self else {
+                return
+            }
+
+            guard call == strongSelf.call else {
+                owsFail("\(strongSelf.TAG) call has since ended. Timer should have been invalidated.")
+                timer.invalidate()
+                return
+            }
+
+            strongSelf.ensureCallScreenVisible(call: call)
+        }
+    }
+
+    func ensureCallScreenVisible(call: SignalCall) {
+        guard nil != UIApplication.shared.frontmostViewController as? CallViewController else {
+            owsFail("\(TAG) in \(#function) CallViewController should already be visible.")
+            self.callUIAdapter.showCall(call)
+            return
+        }
+
+        Logger.debug("\(TAG) in \(#function) already visible.")
+    }
+
+    func stopAnyActiveCallTimer() {
+        AssertIsOnMainThread()
+        assert(self.call == nil)
+
+        self.activeCallTimer?.invalidate()
+        self.activeCallTimer = nil
+    }
 }
 
 fileprivate extension MessageSender {

Signal/src/call/NonCallKitCallUIAdaptee.swift

@@ -31,7 +31,7 @@ class NonCallKitCallUIAdaptee: CallUIAdaptee {
             Logger.debug("\(self.TAG) handleOutgoingCall succeeded")
         }.catch { error in
             Logger.error("\(self.TAG) handleOutgoingCall failed with error: \(error)")
-        }
+        }.retainUntilComplete()
 
         return call
     }

Signal/src/call/UserInterface/CallUIAdapter.swift

@@ -34,7 +34,7 @@ extension CallUIAdaptee {
     internal func showCall(_ call: SignalCall) {
         AssertIsOnMainThread()
 
-        let callViewController = CallViewController(call:call)
+        let callViewController = CallViewController(call: call)
         callViewController.modalTransitionStyle = .crossDissolve
 
         guard let presentingViewController = Environment.getCurrent().signalsViewController else {