[camera] Reland implementation of flip camera while recording. App facing changes

packages/camera/camera/CHANGELOG.md

@@ -1,5 +1,6 @@
-## NEXT
+## 0.10.4
 
+* Allows camera to be switched while video recording.
 * Aligns Dart and Flutter SDK constraints.
 
 ## 0.10.3+2

packages/camera/camera/README.md

@@ -70,7 +70,7 @@ void didChangeAppLifecycleState(AppLifecycleState state) {
   if (state == AppLifecycleState.inactive) {
     cameraController.dispose();
   } else if (state == AppLifecycleState.resumed) {
-    onNewCameraSelected(cameraController.description);
+    _initializeCameraController(cameraController.description);
   }
 }
 ```

packages/camera/camera/example/integration_test/camera_test.dart

@@ -265,6 +265,49 @@ void main() {
     return completer.future;
   }
 
+  testWidgets('Set description while recording', (WidgetTester tester) async {
+    final List<CameraDescription> cameras = await availableCameras();
+    if (cameras.length < 2) {
+      return;
+    }
+
+    final CameraController controller = CameraController(
+      cameras[0],
+      ResolutionPreset.low,
+      enableAudio: false,
+    );
+
+    await controller.initialize();
+    await controller.prepareForVideoRecording();
+
+    await controller.startVideoRecording();
+    sleep(const Duration(milliseconds: 500));
+    await controller.setDescription(cameras[1]);
+    sleep(const Duration(milliseconds: 500));
+
+    expect(controller.description, cameras[1]);
+  });
+
+  testWidgets('Set description', (WidgetTester tester) async {
+    final List<CameraDescription> cameras = await availableCameras();
+    if (cameras.length < 2) {
+      return;
+    }
+
+    final CameraController controller = CameraController(
+      cameras[0],
+      ResolutionPreset.low,
+      enableAudio: false,
+    );
+
+    await controller.initialize();
+    sleep(const Duration(milliseconds: 500));
+    await controller.setDescription(cameras[1]);
+    sleep(const Duration(milliseconds: 500));
+
+    expect(controller.description, cameras[1]);
+  });
+
   testWidgets(
     'iOS image streaming with imageFormatGroup',
     (WidgetTester tester) async {

packages/camera/camera/example/lib/main.dart

@@ -120,7 +120,7 @@ class _CameraExampleHomeState extends State<CameraExampleHome>
     if (state == AppLifecycleState.inactive) {
       cameraController.dispose();
     } else if (state == AppLifecycleState.resumed) {
-      onNewCameraSelected(cameraController.description);
+      _initializeCameraController(cameraController.description);
     }
   }
   // #enddocregion AppLifecycle
@@ -597,10 +597,7 @@ class _CameraExampleHomeState extends State<CameraExampleHome>
               title: Icon(getCameraLensIcon(cameraDescription.lensDirection)),
               groupValue: controller?.description,
               value: cameraDescription,
-              onChanged:
-                  controller != null && controller!.value.isRecordingVideo
-                      ? null
-                      : onChanged,
+              onChanged: onChanged,
             ),
           ),
         );
@@ -633,17 +630,15 @@ class _CameraExampleHomeState extends State<CameraExampleHome>
   }
 
   Future<void> onNewCameraSelected(CameraDescription cameraDescription) async {
-    final CameraController? oldController = controller;
-    if (oldController != null) {
-      // `controller` needs to be set to null before getting disposed,
-      // to avoid a race condition when we use the controller that is being
-      // disposed. This happens when camera permission dialog shows up,
-      // which triggers `didChangeAppLifecycleState`, which disposes and
-      // re-creates the controller.
-      controller = null;
-      await oldController.dispose();
+    if (controller != null) {
+      return controller!.setDescription(cameraDescription);
+    } else {
+      return _initializeCameraController(cameraDescription);
     }
+  }
 
+  Future<void> _initializeCameraController(
+      CameraDescription cameraDescription) async {
     final CameraController cameraController = CameraController(
       cameraDescription,
       kIsWeb ? ResolutionPreset.max : ResolutionPreset.medium,

packages/camera/camera/lib/src/camera_controller.dart

@@ -49,14 +49,15 @@ class CameraValue {
     required this.exposurePointSupported,
     required this.focusPointSupported,
     required this.deviceOrientation,
+    required this.description,
     this.lockedCaptureOrientation,
     this.recordingOrientation,
     this.isPreviewPaused = false,
     this.previewPauseOrientation,
   }) : _isRecordingPaused = isRecordingPaused;
 
   /// Creates a new camera controller state for an uninitialized controller.
-  const CameraValue.uninitialized()
+  const CameraValue.uninitialized(CameraDescription description)
       : this(
           isInitialized: false,
           isRecordingVideo: false,
@@ -70,6 +71,7 @@ class CameraValue {
           focusPointSupported: false,
           deviceOrientation: DeviceOrientation.portraitUp,
           isPreviewPaused: false,
+          description: description,
         );
 
   /// True after [CameraController.initialize] has completed successfully.
@@ -143,6 +145,9 @@ class CameraValue {
   /// The orientation of the currently running video recording.
   final DeviceOrientation? recordingOrientation;
 
+  /// The properties of the camera device controlled by this controller.
+  final CameraDescription description;
+
   /// Creates a modified copy of the object.
   ///
   /// Explicitly specified fields get the specified value, all other fields get
@@ -164,6 +169,7 @@ class CameraValue {
     Optional<DeviceOrientation>? lockedCaptureOrientation,
     Optional<DeviceOrientation>? recordingOrientation,
     bool? isPreviewPaused,
+    CameraDescription? description,
     Optional<DeviceOrientation>? previewPauseOrientation,
   }) {
     return CameraValue(
@@ -188,6 +194,7 @@ class CameraValue {
           ? this.recordingOrientation
           : recordingOrientation.orNull,
       isPreviewPaused: isPreviewPaused ?? this.isPreviewPaused,
+      description: description ?? this.description,
       previewPauseOrientation: previewPauseOrientation == null
           ? this.previewPauseOrientation
           : previewPauseOrientation.orNull,
@@ -211,7 +218,8 @@ class CameraValue {
         'lockedCaptureOrientation: $lockedCaptureOrientation, '
         'recordingOrientation: $recordingOrientation, '
         'isPreviewPaused: $isPreviewPaused, '
-        'previewPausedOrientation: $previewPauseOrientation)';
+        'previewPausedOrientation: $previewPauseOrientation, '
+        'description: $description)';
   }
 }
 
@@ -225,14 +233,14 @@ class CameraValue {
 class CameraController extends ValueNotifier<CameraValue> {
   /// Creates a new camera controller in an uninitialized state.
   CameraController(
-    this.description,
+    CameraDescription description,
     this.resolutionPreset, {
     this.enableAudio = true,
     this.imageFormatGroup,
-  }) : super(const CameraValue.uninitialized());
+  }) : super(CameraValue.uninitialized(description));
 
   /// The properties of the camera device controlled by this controller.
-  final CameraDescription description;
+  CameraDescription get description => value.description;
 
   /// The resolution this controller is targeting.
   ///
@@ -274,7 +282,12 @@ class CameraController extends ValueNotifier<CameraValue> {
   /// Initializes the camera on the device.
   ///
   /// Throws a [CameraException] if the initialization fails.
-  Future<void> initialize() async {
+  Future<void> initialize() => _initializeWithDescription(description);
+
+  /// Initializes the camera on the device with the specified description.
+  ///
+  /// Throws a [CameraException] if the initialization fails.
+  Future<void> _initializeWithDescription(CameraDescription description) async {
     if (_isDisposed) {
       throw CameraException(
         'Disposed CameraController',
@@ -313,6 +326,7 @@ class CameraController extends ValueNotifier<CameraValue> {
 
       value = value.copyWith(
         isInitialized: true,
+        description: description,
         previewSize: await initializeCompleter.future
             .then((CameraInitializedEvent event) => Size(
                   event.previewWidth,
@@ -380,6 +394,18 @@ class CameraController extends ValueNotifier<CameraValue> {
     }
   }
 
+  /// Sets the description of the camera.
+  ///
+  /// Throws a [CameraException] if setting the description fails.
+  Future<void> setDescription(CameraDescription description) async {
+    if (value.isRecordingVideo) {
+      await CameraPlatform.instance.setDescriptionWhileRecording(description);
+      value = value.copyWith(description: description);
+    } else {
+      await _initializeWithDescription(description);
+    }
+  }
+
   /// Captures an image and returns the file where it was saved.
   ///
   /// Throws a [CameraException] if the capture fails.

packages/camera/camera/pubspec.yaml

@@ -4,7 +4,7 @@ description: A Flutter plugin for controlling the camera. Supports previewing
   Dart.
 repository: https://github.com/flutter/packages/tree/main/packages/camera/camera
 issue_tracker: https://github.com/flutter/flutter/issues?q=is%3Aissue+is%3Aopen+label%3A%22p%3A+camera%22
-version: 0.10.3+2
+version: 0.10.4
 
 environment:
   sdk: ">=2.17.0 <3.0.0"
@@ -21,9 +21,9 @@ flutter:
         default_package: camera_web
 
 dependencies:
-  camera_android: ^0.10.1
-  camera_avfoundation: ^0.9.9
-  camera_platform_interface: ^2.3.2
+  camera_android: ^0.10.5
+  camera_avfoundation: ^0.9.13
+  camera_platform_interface: ^2.4.0
   camera_web: ^0.3.1
   flutter:
     sdk: flutter

packages/camera/camera/test/camera_preview_test.dart

@@ -11,7 +11,10 @@ import 'package:flutter_test/flutter_test.dart';
 
 class FakeController extends ValueNotifier<CameraValue>
     implements CameraController {
-  FakeController() : super(const CameraValue.uninitialized());
+  FakeController() : super(const CameraValue.uninitialized(fakeDescription));
+
+  static const CameraDescription fakeDescription = CameraDescription(
+      name: '', lensDirection: CameraLensDirection.back, sensorOrientation: 0);
 
   @override
   Future<void> dispose() async {
@@ -29,10 +32,6 @@ class FakeController extends ValueNotifier<CameraValue>
   @override
   void debugCheckIsDisposed() {}
 
-  @override
-  CameraDescription get description => const CameraDescription(
-      name: '', lensDirection: CameraLensDirection.back, sensorOrientation: 0);
-
   @override
   bool get enableAudio => false;
 
@@ -117,6 +116,12 @@ class FakeController extends ValueNotifier<CameraValue>
 
   @override
   Future<void> resumePreview() async {}
+
+  @override
+  Future<void> setDescription(CameraDescription description) async {}
+
+  @override
+  CameraDescription get description => value.description;
 }
 
 void main() {