[camera_avfoundation] Implementation swift migration - part 8 (#9635)

Migrates camera implementation as part of flutter/flutter#119109

This PR migrates the 5th chunk of `FLTCam` class to Swift:
* `setVideoFormat`
* `stopVideoRecording`
* `stopImageStream`
* stopping accelerometer updates (`deinit`)
* `setDescriptionWhileRecording`
* `createConnection` (adds Swift implementation, FLTCam still depends on private non-static implementation)

NOTE:  `setDescriptionWhileRecording` is migrated close to verbatim, the [issue](flutter/flutter#168134) affecting it remains.

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

## 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 +1,10 @@
+## 0.9.20+4
+
+* Migrates `setVideoFormat`,`stopVideoRecording`, and `stopImageStream` methods to Swift.
+* Migrates stopping accelerometer updates to Swift.
+* Migrates `setDescriptionWhileRecording` method to Swift.
+* Adds `createConnection` method implementation to Swift.
+
 ## 0.9.20+3
 
 * Migrates `setZoomLevel` and `setFlashMode` methods to Swift.

packages/camera/camera_avfoundation/ios/camera_avfoundation/Sources/camera_avfoundation/DefaultCamera.swift

@@ -10,6 +10,14 @@ import CoreMotion
 #endif
 
 final class DefaultCamera: FLTCam, Camera {
+  override var videoFormat: FourCharCode {
+    didSet {
+      captureVideoOutput.videoSettings = [
+        kCVPixelBufferPixelFormatTypeKey as String: videoFormat
+      ]
+    }
+  }
+
   override var deviceOrientation: UIDeviceOrientation {
     get { super.deviceOrientation }
     set {
@@ -52,6 +60,34 @@ final class DefaultCamera: FLTCam, Camera {
       details: error.domain)
   }
 
+  private static func createConnection(
+    captureDevice: FLTCaptureDevice,
+    videoFormat: FourCharCode,
+    captureDeviceInputFactory: FLTCaptureDeviceInputFactory
+  ) throws -> (FLTCaptureInput, FLTCaptureVideoDataOutput, AVCaptureConnection) {
+    // Setup video capture input.
+    let captureVideoInput = try captureDeviceInputFactory.deviceInput(with: captureDevice)
+
+    // Setup video capture output.
+    let captureVideoOutput = FLTDefaultCaptureVideoDataOutput(
+      captureVideoOutput: AVCaptureVideoDataOutput())
+    captureVideoOutput.videoSettings = [
+      kCVPixelBufferPixelFormatTypeKey as String: videoFormat
+    ]
+    captureVideoOutput.alwaysDiscardsLateVideoFrames = true
+
+    // Setup video capture connection.
+    let connection = AVCaptureConnection(
+      inputPorts: captureVideoInput.ports,
+      output: captureVideoOutput.avOutput)
+
+    if captureDevice.position == .front {
+      connection.isVideoMirrored = true
+    }
+
+    return (captureVideoInput, captureVideoOutput, connection)
+  }
+
   func reportInitializationState() {
     // Get all the state on the current thread, not the main thread.
     let state = FCPPlatformCameraState.make(
@@ -96,6 +132,40 @@ final class DefaultCamera: FLTCam, Camera {
     isRecordingPaused = false
   }
 
+  func stopVideoRecording(completion: @escaping (String?, FlutterError?) -> Void) {
+    guard isRecording else {
+      let error = NSError(
+        domain: NSCocoaErrorDomain,
+        code: URLError.resourceUnavailable.rawValue,
+        userInfo: [NSLocalizedDescriptionKey: "Video is not recording!"]
+      )
+      completion(nil, DefaultCamera.flutterErrorFromNSError(error))
+      return
+    }
+
+    isRecording = false
+
+    // When `isRecording` is true `startWriting` was already called so `videoWriter.status`
+    // is always either `.writing` or `.failed` and `finishWriting` does not throw exceptions so
+    // there is no need to check `videoWriter.status`
+    videoWriter?.finishWriting { [weak self] in
+      guard let strongSelf = self else { return }
+
+      if strongSelf.videoWriter?.status == .completed {
+        strongSelf.updateOrientation()
+        completion(strongSelf.videoRecordingPath, nil)
+        strongSelf.videoRecordingPath = nil
+      } else {
+        completion(
+          nil,
+          FlutterError(
+            code: "IOError",
+            message: "AVAssetWriter could not finish writing!",
+            details: nil))
+      }
+    }
+  }
+
   func lockCaptureOrientation(_ pigeonOrientation: FCPPlatformDeviceOrientation) {
     let orientation = FCPGetUIDeviceOrientationForPigeonDeviceOrientation(pigeonOrientation)
     if lockedCaptureOrientation != orientation {
@@ -341,6 +411,94 @@ final class DefaultCamera: FLTCam, Camera {
     isPreviewPaused = false
   }
 
+  func setDescriptionWhileRecording(
+    _ cameraName: String, withCompletion completion: @escaping (FlutterError?) -> Void
+  ) {
+    guard isRecording else {
+      completion(
+        FlutterError(
+          code: "setDescriptionWhileRecordingFailed",
+          message: "Device was not recording",
+          details: nil))
+      return
+    }
+
+    captureDevice = captureDeviceFactory(cameraName)
+
+    let oldConnection = captureVideoOutput.connection(withMediaType: .video)
+
+    // Stop video capture from the old output.
+    captureVideoOutput.setSampleBufferDelegate(nil, queue: nil)
+
+    // Remove the old video capture connections.
+    videoCaptureSession.beginConfiguration()
+    videoCaptureSession.removeInput(captureVideoInput)
+    videoCaptureSession.removeOutput(captureVideoOutput.avOutput)
+
+    let newConnection: AVCaptureConnection
+
+    do {
+      (captureVideoInput, captureVideoOutput, newConnection) = try DefaultCamera.createConnection(
+        captureDevice: captureDevice,
+        videoFormat: videoFormat,
+        captureDeviceInputFactory: captureDeviceInputFactory)
+
+      captureVideoOutput.setSampleBufferDelegate(self, queue: captureSessionQueue)
+    } catch {
+      completion(
+        FlutterError(
+          code: "VideoError",
+          message: "Unable to create video connection",
+          details: nil))
+      return
+    }
+
+    // Keep the same orientation the old connections had.
+    if let oldConnection = oldConnection, newConnection.isVideoOrientationSupported {
+      newConnection.videoOrientation = oldConnection.videoOrientation
+    }
+
+    // Add the new connections to the session.
+    if !videoCaptureSession.canAddInput(captureVideoInput) {
+      completion(
+        FlutterError(
+          code: "VideoError",
+          message: "Unable to switch video input",
+          details: nil))
+    }
+    videoCaptureSession.addInputWithNoConnections(captureVideoInput)
+
+    if !videoCaptureSession.canAddOutput(captureVideoOutput.avOutput) {
+      completion(
+        FlutterError(
+          code: "VideoError",
+          message: "Unable to switch video output",
+          details: nil))
+    }
+    videoCaptureSession.addOutputWithNoConnections(captureVideoOutput.avOutput)
+
+    if !videoCaptureSession.canAddConnection(newConnection) {
+      completion(
+        FlutterError(
+          code: "VideoError",
+          message: "Unable to switch video connection",
+          details: nil))
+    }
+    videoCaptureSession.addConnection(newConnection)
+    videoCaptureSession.commitConfiguration()
+
+    completion(nil)
+  }
+
+  func stopImageStream() {
+    if isStreamingImages {
+      isStreamingImages = false
+      imageStreamHandler = nil
+    } else {
+      reportErrorMessage("Images from camera are not streaming!")
+    }
+  }
+
   func captureOutput(
     _ output: AVCaptureOutput,
     didOutput sampleBuffer: CMSampleBuffer,
@@ -591,4 +749,8 @@ final class DefaultCamera: FLTCam, Camera {
       }
     }
   }
+
+  deinit {
+    motionManager.stopAccelerometerUpdates()
+  }
 }

packages/camera/camera_avfoundation/ios/camera_avfoundation/Sources/camera_avfoundation_objc/FLTCam.m

@@ -5,7 +5,6 @@
 #import "./include/camera_avfoundation/FLTCam.h"
 #import "./include/camera_avfoundation/FLTCam_Test.h"
 
-@import CoreMotion;
 @import Flutter;
 #import <libkern/OSAtomic.h>
 
@@ -33,28 +32,21 @@ @interface FLTCam () <AVCaptureVideoDataOutputSampleBufferDelegate,
 @property(readonly, nonatomic) FCPPlatformMediaSettings *mediaSettings;
 @property(readonly, nonatomic) FLTCamMediaSettingsAVWrapper *mediaSettingsAVWrapper;
 
-@property(readonly, nonatomic) NSObject<FLTCaptureInput> *captureVideoInput;
 @property(readonly, nonatomic) CGSize captureSize;
 @property(strong, nonatomic)
     NSObject<FLTAssetWriterInputPixelBufferAdaptor> *assetWriterPixelBufferAdaptor;
 @property(strong, nonatomic) AVCaptureVideoDataOutput *videoOutput;
 @property(strong, nonatomic) AVCaptureAudioDataOutput *audioOutput;
-@property(strong, nonatomic) NSString *videoRecordingPath;
 @property(assign, nonatomic) BOOL isAudioSetup;
 
-@property(nonatomic) CMMotionManager *motionManager;
-/// All FLTCam's state access and capture session related operations should be on run on this queue.
-@property(strong, nonatomic) dispatch_queue_t captureSessionQueue;
 /// The queue on which captured photos (not videos) are written to disk.
 /// Videos are written to disk by `videoAdaptor` on an internal queue managed by AVFoundation.
 @property(strong, nonatomic) dispatch_queue_t photoIOQueue;
 /// A wrapper for CMVideoFormatDescriptionGetDimensions.
 /// Allows for alternate implementations in tests.
 @property(nonatomic, copy) VideoDimensionsForFormat videoDimensionsForFormat;
 /// A wrapper for AVCaptureDevice creation to allow for dependency injection in tests.
-@property(nonatomic, copy) CaptureDeviceFactory captureDeviceFactory;
 @property(nonatomic, copy) AudioCaptureDeviceFactory audioCaptureDeviceFactory;
-@property(readonly, nonatomic) NSObject<FLTCaptureDeviceInputFactory> *captureDeviceInputFactory;
 @property(nonatomic, copy) AssetWriterFactory assetWriterFactory;
 @property(nonatomic, copy) InputPixelBufferAdaptorFactory inputPixelBufferAdaptorFactory;
 /// Reports the given error message to the Dart side of the plugin.
@@ -193,12 +185,6 @@ - (AVCaptureConnection *)createConnection:(NSError **)error {
   return connection;
 }
 
-- (void)setVideoFormat:(OSType)videoFormat {
-  _videoFormat = videoFormat;
-  _captureVideoOutput.videoSettings =
-      @{(NSString *)kCVPixelBufferPixelFormatTypeKey : @(videoFormat)};
-}
-
 - (void)updateOrientation {
   if (_isRecording) {
     return;
@@ -426,10 +412,6 @@ - (BOOL)setCaptureSessionPreset:(FCPPlatformResolutionPreset)resolutionPreset
   return bestFormat;
 }
 
-- (void)dealloc {
-  [_motionManager stopAccelerometerUpdates];
-}
-
 /// Main logic to setup the video recording.
 - (void)setUpVideoRecordingWithCompletion:(void (^)(FlutterError *_Nullable))completion {
   NSError *error;
@@ -481,90 +463,6 @@ - (void)startVideoRecordingWithCompletion:(void (^)(FlutterError *_Nullable))com
   }
 }
 
-- (void)stopVideoRecordingWithCompletion:(void (^)(NSString *_Nullable,
-                                                   FlutterError *_Nullable))completion {
-  if (_isRecording) {
-    _isRecording = NO;
-
-    // when _isRecording is YES startWriting was already called so _videoWriter.status
-    // is always either AVAssetWriterStatusWriting or AVAssetWriterStatusFailed and
-    // finishWritingWithCompletionHandler does not throw exception so there is no need
-    // to check _videoWriter.status
-    [_videoWriter finishWritingWithCompletionHandler:^{
-      if (self->_videoWriter.status == AVAssetWriterStatusCompleted) {
-        [self updateOrientation];
-        completion(self->_videoRecordingPath, nil);
-        self->_videoRecordingPath = nil;
-      } else {
-        completion(nil, [FlutterError errorWithCode:@"IOError"
-                                            message:@"AVAssetWriter could not finish writing!"
-                                            details:nil]);
-      }
-    }];
-  } else {
-    NSError *error =
-        [NSError errorWithDomain:NSCocoaErrorDomain
-                            code:NSURLErrorResourceUnavailable
-                        userInfo:@{NSLocalizedDescriptionKey : @"Video is not recording!"}];
-    completion(nil, FlutterErrorFromNSError(error));
-  }
-}
-
-- (void)setDescriptionWhileRecording:(NSString *)cameraName
-                      withCompletion:(void (^)(FlutterError *_Nullable))completion {
-  if (!_isRecording) {
-    completion([FlutterError errorWithCode:@"setDescriptionWhileRecordingFailed"
-                                   message:@"Device was not recording"
-                                   details:nil]);
-    return;
-  }
-
-  _captureDevice = self.captureDeviceFactory(cameraName);
-
-  NSObject<FLTCaptureConnection> *oldConnection =
-      [_captureVideoOutput connectionWithMediaType:AVMediaTypeVideo];
-
-  // Stop video capture from the old output.
-  [_captureVideoOutput setSampleBufferDelegate:nil queue:nil];
-
-  // Remove the old video capture connections.
-  [_videoCaptureSession beginConfiguration];
-  [_videoCaptureSession removeInput:_captureVideoInput];
-  [_videoCaptureSession removeOutput:_captureVideoOutput.avOutput];
-
-  NSError *error = nil;
-  AVCaptureConnection *newConnection = [self createConnection:&error];
-  if (error) {
-    completion(FlutterErrorFromNSError(error));
-    return;
-  }
-
-  // Keep the same orientation the old connections had.
-  if (oldConnection && newConnection.isVideoOrientationSupported) {
-    newConnection.videoOrientation = oldConnection.videoOrientation;
-  }
-
-  // Add the new connections to the session.
-  if (![_videoCaptureSession canAddInput:_captureVideoInput])
-    completion([FlutterError errorWithCode:@"VideoError"
-                                   message:@"Unable switch video input"
-                                   details:nil]);
-  [_videoCaptureSession addInputWithNoConnections:_captureVideoInput];
-  if (![_videoCaptureSession canAddOutput:_captureVideoOutput.avOutput])
-    completion([FlutterError errorWithCode:@"VideoError"
-                                   message:@"Unable switch video output"
-                                   details:nil]);
-  [_videoCaptureSession addOutputWithNoConnections:_captureVideoOutput.avOutput];
-  if (![_videoCaptureSession canAddConnection:newConnection])
-    completion([FlutterError errorWithCode:@"VideoError"
-                                   message:@"Unable switch video connection"
-                                   details:nil]);
-  [_videoCaptureSession addConnection:newConnection];
-  [_videoCaptureSession commitConfiguration];
-
-  completion(nil);
-}
-
 - (void)startImageStreamWithMessenger:(NSObject<FlutterBinaryMessenger> *)messenger
                            completion:(void (^)(FlutterError *))completion {
   [self startImageStreamWithMessenger:messenger
@@ -612,15 +510,6 @@ - (void)startImageStreamWithMessenger:(NSObject<FlutterBinaryMessenger> *)messen
   }
 }
 
-- (void)stopImageStream {
-  if (_isStreamingImages) {
-    _isStreamingImages = NO;
-    _imageStreamHandler = nil;
-  } else {
-    [self reportErrorMessage:@"Images from camera are not streaming!"];
-  }
-}
-
 - (BOOL)setupWriterForPath:(NSString *)path {
   NSError *error = nil;
   NSURL *outputURL;