CallKit minimal demo

callkit/.gitattributes

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+*.png filter=lfs diff=lfs merge=lfs -text

callkit/.gitignore

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+# Xcode
+#
+# gitignore contributors: remember to update Global/Xcode.gitignore, Objective-C.gitignore & Swift.gitignore
+
+## User settings
+xcuserdata/
+
+## Obj-C/Swift specific
+*.hmap
+
+## App packaging
+*.ipa
+*.dSYM.zip
+*.dSYM
+
+## Playgrounds
+timeline.xctimeline
+playground.xcworkspace
+
+# Swift Package Manager
+#
+# Add this line if you want to avoid checking in source code from Swift Package Manager dependencies.
+# Packages/
+# Package.pins
+# Package.resolved
+# *.xcodeproj
+#
+# Xcode automatically generates this directory with a .xcworkspacedata file and xcuserdata
+# hence it is not needed unless you have added a package configuration file to your project
+# .swiftpm
+
+.build/
+
+# CocoaPods
+#
+# We recommend against adding the Pods directory to your .gitignore. However
+# you should judge for yourself, the pros and cons are mentioned at:
+# https://guides.cocoapods.org/using/using-cocoapods.html#should-i-check-the-pods-directory-into-source-control
+#
+# Pods/
+#
+# Add this line if you want to avoid checking in source code from the Xcode workspace
+# *.xcworkspace
+
+# Carthage
+#
+# Add this line if you want to avoid checking in source code from Carthage dependencies.
+# Carthage/Checkouts
+
+Carthage/Build/
+
+# fastlane
+#
+# It is recommended to not store the screenshots in the git repo.
+# Instead, use fastlane to re-generate the screenshots whenever they are needed.
+# For more information about the recommended setup visit:
+# https://docs.fastlane.tools/best-practices/source-control/#source-control
+
+fastlane/report.xml
+fastlane/Preview.html
+fastlane/screenshots/**/*.png
+fastlane/test_output

callkit/.swift-version

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+5.9

callkit/.swiftformat

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+--exclude Sources/LiveKit/Protos
+--header "/*\n * Copyright {year} LiveKit\n *\n * Licensed under the Apache License, Version 2.0 (the \"License\");\n * you may not use this file except in compliance with the License.\n * You may obtain a copy of the License at\n *\n *     http://www.apache.org/licenses/LICENSE-2.0\n *\n * Unless required by applicable law or agreed to in writing, software\n * distributed under the License is distributed on an \"AS IS\" BASIS,\n * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.\n * See the License for the specific language governing permissions and\n * limitations under the License.\n */"
+--ifdef no-indent
+--disable modifiersOnSameLine

callkit/README.md

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+# CallKit + PushKit example
+
+This example demonstrates how to use the LiveKit Swift SDK with CallKit and PushKit.
+
+### Testing remote VoIP pushes
+
+Use the [Push Notification Console](https://developer.apple.com/documentation/usernotifications/testing-notifications-using-the-push-notification-console) to send a `VoIP` push to your token.
+
+You can obtain the push token by running the example app on a device.
+
+### Key points when integrating LiveKit SDK with CallKit
+
+CallKit on iOS sets AVAudioSession active automatically at specific timings.
+By default, the LiveKit Swift SDK also configures the AVAudioSession automatically, which will interfere with CallKit.
+
+We should ensure proper timing when configuring `AVAudioSession` and starting the SDK's internal `AVAudioEngine` between
+[provider(_:didActivate:)](https://developer.apple.com/documentation/callkit/cxproviderdelegate/provider(_:didactivate:)) and [provider(_:didDeactivate:)](https://developer.apple.com/documentation/callkit/cxproviderdelegate/provider(_:diddeactivate:)).
+
+Early in the process, we should disable automatic AVAudioSession configuration:
+```swift
+AudioManager.shared.audioSession.isAutomaticConfigurationEnabled = false
+```
+
+We should also ensure the SDK's internal `AVAudioEngine` will not start, even when subscribing to remote audio or publishing microphone:
+```swift
+try AudioManager.shared.setEngineAvailability(.none)
+```
+
+Now, in the `CXProviderDelegate`, we want to ensure `AVAudioSession.category` is set to `.playAndRecord` (if you will publish microphone).
+We also want to allow the SDK's internal `AVAudioEngine` to start within the `didActivate` ~ `didDeactivate` window.
+```swift
+func provider(_: CXProvider, didActivate session: AVAudioSession) {
+  do {
+    try session.setCategory(.playAndRecord, mode: .voiceChat, options: [.mixWithOthers])
+    try AudioManager.shared.setEngineAvailability(.default)
+  } catch {
+    // Error
+  }
+}
+
+func provider(_: CXProvider, didDeactivate _: AVAudioSession) {
+  do {
+    try AudioManager.shared.setEngineAvailability(.none)
+  } catch {
+    // Error
+  }
+}
+```
+> **NOTE:** We don't call `session.setActive(true)` since CallKit already activates it and Apple doesn't recommend calling it again.
+
+With this setup, you can connect, publish, and subscribe to audio at timings convenient to your implementation and requirements. See the source code of this example for details.
+
+### CallKit lock screen / background issues
+
+These are issues I've encountered while implementing this example. Please let me know if there are better workarounds or if I'm incorrect.
+
+1. [reportNewIncomingCall(with:update:completion:)](https://developer.apple.com/documentation/callkit/cxprovider/reportnewincomingcall(with:update:completion:)) must be invoked on the same thread as [pushRegistry(_:didReceiveIncomingPushWith:for:completion:)](https://developer.apple.com/documentation/pushkit/pkpushregistrydelegate/pushregistry(_:didreceiveincomingpushwith:for:completion:)), otherwise it will silently fail and not show the incoming call UI on the lock screen. Therefore, the async version may not work as intended.
+
+2. You may need to set `AVAudioSession.category` to `.playAndRecord` before calling [reportNewIncomingCall(with:update:completion:)](https://developer.apple.com/documentation/callkit/cxprovider/reportnewincomingcall(with:update:completion:)) when your app is woken up in the background by [pushRegistry(_:didReceiveIncomingPushWith:for:completion:)](https://developer.apple.com/documentation/pushkit/pkpushregistrydelegate/pushregistry(_:didreceiveincomingpushwith:for:completion:)).
+
+### References
+
+[Responding to VoIP Notifications from PushKit](https://developer.apple.com/documentation/pushkit/responding-to-voip-notifications-from-pushkit)
+[Developer Forums: CallKit does not activate audio session](https://developer.apple.com/forums/thread/783870)