flutter-plugins/packages/camera/camera_aurora/lib/camera_viewfinder.dart

// SPDX-FileCopyrightText: Copyright 2023 Open Mobile Platform LLC <community@omp.ru>
// SPDX-License-Identifier: BSD-3-Clause
import 'dart:async';
import 'dart:convert';

import 'package:camera_platform_interface/camera_platform_interface.dart';
import 'package:flutter/material.dart';
import 'package:flutter/services.dart';

import 'camera_aurora_method_channel.dart';
import 'camera_aurora_platform_interface.dart';

class CameraAurora extends CameraPlatform {
  /// Registers this class as the default instance of [CameraPlatform].
  static void registerWith() {
    CameraPlatform.instance = CameraAurora();
  }

  // The stream for vending frames to platform interface clients.
  StreamController<CameraImageData>? _frameStreamController;

  /// Completes with a list of available cameras.
  ///
  /// This method returns an empty list when no cameras are available.
  @override
  Future<List<CameraDescription>> availableCameras() =>
      CameraAuroraPlatform.instance.availableCameras();

  /// Creates an uninitialized camera instance and returns the cameraId.
  @override
  Future<int> createCamera(
    CameraDescription cameraDescription,
    ResolutionPreset? resolutionPreset, {
    bool enableAudio = false,
  }) {
    EventChannel(CameraAuroraEvents.cameraAuroraStreamedFrame.name)
        .receiveBroadcastStream()
        .listen((event) {
      debugPrint(event);
    });
    return CameraAuroraPlatform.instance.createCamera(cameraDescription.name);
  }

  /// Initializes the camera on the device.
  ///
  /// [imageFormatGroup] is used to specify the image formatting used.
  /// On Android this defaults to ImageFormat.YUV_420_888 and applies only to the imageStream.
  /// On iOS this defaults to kCVPixelFormatType_32BGRA.
  /// On Web this parameter is currently not supported.
  @override
  Future<void> initializeCamera(
    int cameraId, {
    ImageFormatGroup imageFormatGroup = ImageFormatGroup.unknown,
  }) async {
    // init
  }

  /// Releases the resources of this camera.
  @override
  Future<void> dispose(int cameraId) {
    return CameraAuroraPlatform.instance.dispose(cameraId);
  }

  /// Captures an image and returns the file where it was saved.
  @override
  Future<XFile> takePicture(int cameraId) =>
      CameraAuroraPlatform.instance.takePicture(cameraId);

  /// Starts a video recording.
  ///
  /// The length of the recording can be limited by specifying the [maxVideoDuration].
  /// By default no maximum duration is specified,
  /// meaning the recording will continue until manually stopped.
  /// With [maxVideoDuration] set the video is returned in a [VideoRecordedEvent]
  /// through the [onVideoRecordedEvent] stream when the set duration is reached.
  ///
  /// This method is deprecated in favour of [startVideoCapturing].
  @override
  Future<void> startVideoRecording(int cameraId,
          {Duration? maxVideoDuration}) =>
      CameraAuroraPlatform.instance.startVideoRecording(cameraId);

  /// Stops the video recording and returns the file where it was saved.
  @override
  Future<XFile> stopVideoRecording(int cameraId) =>
      CameraAuroraPlatform.instance.stopVideoRecording(cameraId);

  /// Pause video recording.
  @override
  Future<void> pauseVideoRecording(int cameraId) =>
      CameraAuroraPlatform.instance.pauseVideoRecording(cameraId);

  /// Resume video recording after pausing.
  @override
  Future<void> resumeVideoRecording(int cameraId) =>
      CameraAuroraPlatform.instance.resumeVideoRecording(cameraId);

  /// The ui orientation changed.
  ///
  /// Implementations for this:
  /// - Should support all 4 orientations.
  @override
  Stream<DeviceOrientationChangedEvent> onDeviceOrientationChanged() async* {
    yield const DeviceOrientationChangedEvent(DeviceOrientation.portraitUp);
  }

  /// The camera has been initialized.
  @override
  Stream<CameraInitializedEvent> onCameraInitialized(int cameraId) async* {
    yield CameraInitializedEvent(
      cameraId,
      // previewWidth
      400,
      // previewHeight
      400,
      // exposureMode
      ExposureMode.auto,
      // exposurePointSupported
      true,
      // focusMode
      FocusMode.auto,
      // focusPointSupported
      true,
    );
  }

  @override
  Stream<CameraImageData> onStreamedFrameAvailable(
    int cameraId, {
    CameraImageStreamOptions? options,
  }) {
    _frameStreamController = StreamController<CameraImageData>(
      onListen: () =>
          CameraAuroraPlatform.instance.streamedFrame(cameraId).listen((data) {
        _frameStreamController!.add(data);
      }),
      onPause: () => {},
      onResume: () => {},
      onCancel: () => {},
    );
    return _frameStreamController!.stream;
  }

  /// Returns a widget showing a live camera preview.
  @override
  Widget buildPreview(int cameraId) {
    return Center(
      child: Text(
        'Camera: $cameraId',
        style:
            const TextStyle(fontWeight: FontWeight.bold, color: Colors.white),
      ),
    );
  }
}