[camera_avfoundation] Implementation swift migration - part 4 (flutter#9219)

Migrates camera implementation as part of flutter/flutter#119109

This PR migrates a part of `FLTCam` class to Swift. To avoid migrating the whole huge class to Swift at once and a refactor that we don't have a budget for we are extending the `FLTCam` class in swift (`DefaultCamera`). We will now migrate the methods in smaller chunks.

This PR includes the first chunk:
- `captureOutput` (from `AVCaptureVideoDataOutputSampleBufferDelegate`, `AVCaptureAudioDataOutputSampleBufferDelegate` protocols)
- `copyPixelBuffer` (from `FlutterTexture` protocol)

Some properties of the `FLTCam` have to be temporarily made public so that they are accessible in `DefaultCamera`.

The `DefaultCamera` class conforms to the new `Camera` protocol. A few properties defined in `FLTCam` are now marked  `nullable` to match the `Camera` protocol and the reality.

## Pre-Review Checklist

[^1]: Regular contributors who have demonstrated familiarity with the repository guidelines only need to comment if the PR is not auto-exempted by repo tooling.

Author: RobertOdrowaz

packages/camera/camera_avfoundation/CHANGELOG.md

@@ -1,3 +1,9 @@
+## 0.9.19+2
+
+* Adds the `Camera` Swift protocol.
+* Adds `DefaultCamera`, a `FLTCam`-based implementation of the `Camera` protocol.
+* Migrates sample buffer delegates and `FlutterTexture` protocol implementations to `DefaultCamera`.
+
 ## 0.9.19+1
 
 * Adds `audioCaptureDeviceFactory` to `FLTCamConfiguration`.

packages/camera/camera_avfoundation/example/ios/RunnerTests/CameraTestUtils.swift

@@ -4,11 +4,11 @@
 
 import XCTest
 
+@testable import camera_avfoundation
+
 // Import Objectice-C part of the implementation when SwiftPM is used.
 #if canImport(camera_avfoundation_objc)
   import camera_avfoundation_objc
-#else
-  import camera_avfoundation
 #endif
 
 /// Utils for creating default class instances used in tests
@@ -81,16 +81,16 @@ enum CameraTestUtils {
     return configuration
   }
 
-  static func createTestCamera(_ configuration: FLTCamConfiguration) -> FLTCam {
-    return FLTCam(configuration: configuration, error: nil)
+  static func createTestCamera(_ configuration: FLTCamConfiguration) -> DefaultCamera {
+    return DefaultCamera(configuration: configuration, error: nil)
   }
 
-  static func createTestCamera() -> FLTCam {
+  static func createTestCamera() -> DefaultCamera {
     return createTestCamera(createTestCameraConfiguration())
   }
 
   static func createCameraWithCaptureSessionQueue(_ captureSessionQueue: DispatchQueue)
-    -> FLTCam
+    -> DefaultCamera
   {
     let configuration = createTestCameraConfiguration()
     configuration.captureSessionQueue = captureSessionQueue

packages/camera/camera_avfoundation/example/ios/RunnerTests/FLTCamExposureTests.swift

@@ -12,7 +12,7 @@ import XCTest
 #endif
 
 final class FLTCamExposureTests: XCTestCase {
-  private func createCamera() -> (FLTCam, MockCaptureDevice, MockDeviceOrientationProvider) {
+  private func createCamera() -> (Camera, MockCaptureDevice, MockDeviceOrientationProvider) {
     let mockDevice = MockCaptureDevice()
     let mockDeviceOrientationProvider = MockDeviceOrientationProvider()
 

packages/camera/camera_avfoundation/example/ios/RunnerTests/FLTCamFocusTests.swift

@@ -13,7 +13,7 @@ import XCTest
 #endif
 
 final class FLTCamSetFocusModeTests: XCTestCase {
-  private func createCamera() -> (FLTCam, MockCaptureDevice, MockDeviceOrientationProvider) {
+  private func createCamera() -> (Camera, MockCaptureDevice, MockDeviceOrientationProvider) {
     let mockDevice = MockCaptureDevice()
     let mockDeviceOrientationProvider = MockDeviceOrientationProvider()
 

packages/camera/camera_avfoundation/example/ios/RunnerTests/FLTCamSetDeviceOrientationTests.swift

@@ -13,7 +13,7 @@ import XCTest
 #endif
 
 final class FLTCamSetDeviceOrientationTests: XCTestCase {
-  private func createCamera() -> (FLTCam, MockCaptureConnection, MockCaptureConnection) {
+  private func createCamera() -> (Camera, MockCaptureConnection, MockCaptureConnection) {
     let camera = CameraTestUtils.createTestCamera()
 
     let mockCapturePhotoOutput = MockCapturePhotoOutput()

packages/camera/camera_avfoundation/example/ios/RunnerTests/FLTCamSetFlashModeTests.swift

@@ -13,7 +13,7 @@ import XCTest
 #endif
 
 final class FLTCamSetFlashModeTests: XCTestCase {
-  private func createCamera() -> (FLTCam, MockCaptureDevice, MockCapturePhotoOutput) {
+  private func createCamera() -> (Camera, MockCaptureDevice, MockCapturePhotoOutput) {
     let mockDevice = MockCaptureDevice()
     let mockCapturePhotoOutput = MockCapturePhotoOutput()
 

packages/camera/camera_avfoundation/example/ios/RunnerTests/FLTCamZoomTests.swift

@@ -13,7 +13,7 @@ import XCTest
 #endif
 
 final class FLTCamZoomTests: XCTestCase {
-  private func createCamera() -> (FLTCam, MockCaptureDevice) {
+  private func createCamera() -> (Camera, MockCaptureDevice) {
     let mockDevice = MockCaptureDevice()
 
     let configuration = CameraTestUtils.createTestCameraConfiguration()

packages/camera/camera_avfoundation/example/ios/RunnerTests/Mocks/MockCamera.swift

@@ -2,14 +2,14 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-import camera_avfoundation
+@testable import camera_avfoundation
 
 // Import Objectice-C part of the implementation when SwiftPM is used.
 #if canImport(camera_avfoundation_objc)
   import camera_avfoundation_objc
 #endif
 
-final class MockCamera: FLTCam {
+final class MockCamera: NSObject, Camera {
   var setDartApiStub: ((FCPCameraEventApi?) -> Void)?
   var setOnFrameAvailableStub: (((() -> Void)?) -> Void)?
   var getMinimumExposureOffsetStub: (() -> CGFloat)?
@@ -42,7 +42,7 @@ final class MockCamera: FLTCam {
   var startImageStreamStub: ((FlutterBinaryMessenger) -> Void)?
   var stopImageStreamStub: (() -> Void)?
 
-  override var dartAPI: FCPCameraEventApi {
+  var dartAPI: FCPCameraEventApi? {
     get {
       preconditionFailure("Attempted to access unimplemented property: dartAPI")
     }
@@ -51,7 +51,7 @@ final class MockCamera: FLTCam {
     }
   }
 
-  override var onFrameAvailable: (() -> Void) {
+  var onFrameAvailable: (() -> Void)? {
     get {
       preconditionFailure("Attempted to access unimplemented property: onFrameAvailable")
     }
@@ -60,147 +60,149 @@ final class MockCamera: FLTCam {
     }
   }
 
-  override var minimumExposureOffset: CGFloat {
+  var videoFormat: FourCharCode = kCVPixelFormatType_32BGRA
+
+  var isPreviewPaused: Bool = false
+
+  var minimumExposureOffset: CGFloat {
     return getMinimumExposureOffsetStub?() ?? 0
   }
 
-  override var maximumExposureOffset: CGFloat {
+  var maximumExposureOffset: CGFloat {
     return getMaximumExposureOffsetStub?() ?? 0
   }
 
-  override var minimumAvailableZoomFactor: CGFloat {
+  var minimumAvailableZoomFactor: CGFloat {
     return getMinimumAvailableZoomFactorStub?() ?? 0
   }
 
-  override var maximumAvailableZoomFactor: CGFloat {
+  var maximumAvailableZoomFactor: CGFloat {
     return getMaximumAvailableZoomFactorStub?() ?? 0
   }
 
-  override func setUpCaptureSessionForAudioIfNeeded() {
+  func setUpCaptureSessionForAudioIfNeeded() {
     setUpCaptureSessionForAudioIfNeededStub?()
   }
 
-  override func reportInitializationState() {}
+  func reportInitializationState() {}
 
-  override func receivedImageStreamData() {
+  func receivedImageStreamData() {
     receivedImageStreamDataStub?()
   }
 
-  override func start() {
+  func start() {
     startStub?()
   }
 
-  override func stop() {}
+  func stop() {}
 
-  override func startVideoRecording(
+  func startVideoRecording(
     completion: @escaping (FlutterError?) -> Void,
     messengerForStreaming messenger: FlutterBinaryMessenger?
   ) {
     startVideoRecordingStub?(completion, messenger)
   }
 
-  override func pauseVideoRecording() {
+  func pauseVideoRecording() {
     pauseVideoRecordingStub?()
   }
 
-  override func resumeVideoRecording() {
+  func resumeVideoRecording() {
     resumeVideoRecordingStub?()
   }
 
-  override func stopVideoRecording(completion: @escaping (String?, FlutterError?) -> Void) {
+  func stopVideoRecording(completion: @escaping (String?, FlutterError?) -> Void) {
     stopVideoRecordingStub?(completion)
   }
 
-  override func captureToFile(completion: @escaping (String?, FlutterError?) -> Void) {
+  func captureToFile(completion: @escaping (String?, FlutterError?) -> Void) {
     captureToFileStub?(completion)
   }
 
-  override func setDeviceOrientation(_ orientation: UIDeviceOrientation) {
+  func setDeviceOrientation(_ orientation: UIDeviceOrientation) {
     setDeviceOrientationStub?(orientation)
   }
 
-  override func lockCaptureOrientation(_ orientation: FCPPlatformDeviceOrientation) {
+  func lockCaptureOrientation(_ orientation: FCPPlatformDeviceOrientation) {
     lockCaptureOrientationStub?(orientation)
   }
 
-  override func unlockCaptureOrientation() {
+  func unlockCaptureOrientation() {
     unlockCaptureOrientationStub?()
   }
 
-  override func setImageFileFormat(_ fileFormat: FCPPlatformImageFileFormat) {
+  func setImageFileFormat(_ fileFormat: FCPPlatformImageFileFormat) {
     setImageFileFormatStub?(fileFormat)
   }
 
-  override func setExposureMode(_ mode: FCPPlatformExposureMode) {
+  func setExposureMode(_ mode: FCPPlatformExposureMode) {
     setExposureModeStub?(mode)
   }
 
-  override func setExposureOffset(_ offset: Double) {
+  func setExposureOffset(_ offset: Double) {
     setExposureOffsetStub?(offset)
   }
 
-  override func setExposurePoint(
+  func setExposurePoint(
     _ point: FCPPlatformPoint?, withCompletion: @escaping (FlutterError?) -> Void
   ) {
     setExposurePointStub?(point, withCompletion)
   }
 
-  override func setFocusMode(_ mode: FCPPlatformFocusMode) {
+  func setFocusMode(_ mode: FCPPlatformFocusMode) {
     setFocusModeStub?(mode)
   }
 
-  override func setFocusPoint(
-    _ point: FCPPlatformPoint?, completion: @escaping (FlutterError?) -> Void
-  ) {
+  func setFocusPoint(_ point: FCPPlatformPoint?, completion: @escaping (FlutterError?) -> Void) {
     setFocusPointStub?(point, completion)
   }
 
-  override func setZoomLevel(
+  func setZoomLevel(
     _ zoom: CGFloat,
     withCompletion completion: @escaping (FlutterError?) -> Void
   ) {
     setZoomLevelStub?(zoom, completion)
   }
 
-  override func setFlashMode(
+  func setFlashMode(
     _ mode: FCPPlatformFlashMode,
     withCompletion completion: @escaping (FlutterError?) -> Void
   ) {
     setFlashModeStub?(mode, completion)
   }
 
-  override func pausePreview() {
+  func pausePreview() {
     pausePreviewStub?()
   }
 
-  override func resumePreview() {
+  func resumePreview() {
     resumePreviewStub?()
   }
 
-  override func setDescriptionWhileRecording(
+  func setDescriptionWhileRecording(
     _ cameraName: String,
     withCompletion completion: @escaping (FlutterError?) -> Void
   ) {
     setDescriptionWhileRecordingStub?(cameraName, completion)
   }
 
-  override func startImageStream(with messenger: FlutterBinaryMessenger) {
+  func startImageStream(with messenger: FlutterBinaryMessenger) {
     startImageStreamStub?(messenger)
   }
 
-  override func stopImageStream() {
+  func stopImageStream() {
     stopImageStreamStub?()
   }
 
-  override func captureOutput(
+  func captureOutput(
     _ output: AVCaptureOutput,
     didOutput sampleBuffer: CMSampleBuffer,
     from connection: AVCaptureConnection
   ) {}
 
-  override func close() {}
+  func close() {}
 
-  override func copyPixelBuffer() -> Unmanaged<CVPixelBuffer>? {
+  func copyPixelBuffer() -> Unmanaged<CVPixelBuffer>? {
     return nil
   }
 }

packages/camera/camera_avfoundation/example/ios/RunnerTests/PhotoCaptureTests.swift

@@ -14,7 +14,7 @@ import XCTest
 
 /// Includes test cases related to photo capture operations for FLTCam class.
 final class PhotoCaptureTests: XCTestCase {
-  private func createCam(with captureSessionQueue: DispatchQueue) -> FLTCam {
+  private func createCam(with captureSessionQueue: DispatchQueue) -> DefaultCamera {
     let configuration = CameraTestUtils.createTestCameraConfiguration()
     configuration.captureSessionQueue = captureSessionQueue
     return CameraTestUtils.createTestCamera(configuration)

packages/camera/camera_avfoundation/example/ios/RunnerTests/SampleBufferTests.swift

@@ -69,7 +69,7 @@ private class FakeMediaSettingsAVWrapper: FLTCamMediaSettingsAVWrapper {
 /// Includes test cases related to sample buffer handling for FLTCam class.
 final class CameraSampleBufferTests: XCTestCase {
   private func createCamera() -> (
-    FLTCam,
+    DefaultCamera,
     MockAssetWriter,
     MockAssetWriterInputPixelBufferAdaptor,
     MockAssetWriterInput