packages/camera/camera_android_camerax/lib/src/camera_info.dart

// Copyright 2013 The Flutter Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

import 'dart:async';

import 'package:flutter/services.dart' show BinaryMessenger;
import 'package:meta/meta.dart' show immutable;

import 'android_camera_camerax_flutter_api_impls.dart';
import 'camera_state.dart';
import 'camerax_library.g.dart';
import 'exposure_state.dart';
import 'instance_manager.dart';
import 'java_object.dart';
import 'live_data.dart';
import 'zoom_state.dart';

/// The metadata of a camera.
///
/// See https://developer.android.com/reference/androidx/camera/core/CameraInfo.
@immutable
class CameraInfo extends JavaObject {
  /// Constructs a [CameraInfo] that is not automatically attached to a native object.
  CameraInfo.detached(
      {BinaryMessenger? binaryMessenger, InstanceManager? instanceManager})
      : super.detached(
            binaryMessenger: binaryMessenger,
            instanceManager: instanceManager) {
    _api = _CameraInfoHostApiImpl(
        binaryMessenger: binaryMessenger, instanceManager: instanceManager);
    AndroidCameraXCameraFlutterApis.instance.ensureSetUp();
  }

  late final _CameraInfoHostApiImpl _api;

  /// Gets sensor orientation degrees of the camera.
  Future<int> getSensorRotationDegrees() =>
      _api.getSensorRotationDegreesFromInstance(this);

  /// Starts listening for the camera closing.
  Future<LiveData<CameraState>> getCameraState() =>
      _api.getCameraStateFromInstance(this);

  /// Gets the exposure state of the camera.
  Future<ExposureState> getExposureState() =>
      _api.getExposureStateFromInstance(this);

  /// Gets the live zoom state of the camera.
  Future<LiveData<ZoomState>> getZoomState() =>
      _api.getZoomStateFromInstance(this);
}

/// Host API implementation of [CameraInfo].
class _CameraInfoHostApiImpl extends CameraInfoHostApi {
  /// Constructs a [_CameraInfoHostApiImpl].
  _CameraInfoHostApiImpl(
      {super.binaryMessenger, InstanceManager? instanceManager}) {
    this.instanceManager = instanceManager ?? JavaObject.globalInstanceManager;
  }

  /// Maintains instances stored to communicate with native language objects.
  late final InstanceManager instanceManager;

  /// Gets sensor orientation degrees of the specified [CameraInfo] instance.
  Future<int> getSensorRotationDegreesFromInstance(
    CameraInfo instance,
  ) async {
    final int sensorRotationDegrees = await getSensorRotationDegrees(
        instanceManager.getIdentifier(instance)!);
    return sensorRotationDegrees;
  }

  /// Gets the [LiveData<CameraState>] that represents the state of the camera
  /// to which the CameraInfo [instance] pertains.
  Future<LiveData<CameraState>> getCameraStateFromInstance(
      CameraInfo instance) async {
    final int? identifier = instanceManager.getIdentifier(instance);
    final int liveCameraStateId = await getCameraState(identifier!);
    final LiveData<CameraState> liveCameraState =
        instanceManager.getInstanceWithWeakReference<LiveData<CameraState>>(
            liveCameraStateId)!;
    return liveCameraState;
  }

  /// Gets the [ExposureState] of the specified [CameraInfo] instance.
  Future<ExposureState> getExposureStateFromInstance(
      CameraInfo instance) async {
    final int? identifier = instanceManager.getIdentifier(instance);
    final int exposureStateIdentifier = await getExposureState(identifier!);
    return instanceManager
        .getInstanceWithWeakReference<ExposureState>(exposureStateIdentifier)!;
  }

  /// Gets the [LiveData<ZoomState>] of the specified [CameraInfo] instance.
  Future<LiveData<ZoomState>> getZoomStateFromInstance(
      CameraInfo instance) async {
    final int? identifier = instanceManager.getIdentifier(instance);
    final int zoomStateIdentifier = await getZoomState(identifier!);
    return instanceManager.getInstanceWithWeakReference<LiveData<ZoomState>>(
        zoomStateIdentifier)!;
  }
}

/// Flutter API implementation of [CameraInfo].
class CameraInfoFlutterApiImpl extends CameraInfoFlutterApi {
  /// Constructs a [CameraInfoFlutterApiImpl].
  ///
  /// If [binaryMessenger] is null, the default [BinaryMessenger] will be used,
  /// which routes to the host platform.
  ///
  /// An [instanceManager] is typically passed when a copy of an instance
  /// contained by an [InstanceManager] is being created. If left null, it
  /// will default to the global instance defined in [JavaObject].
  CameraInfoFlutterApiImpl({
    BinaryMessenger? binaryMessenger,
    InstanceManager? instanceManager,
  })  : _binaryMessenger = binaryMessenger,
        _instanceManager = instanceManager ?? JavaObject.globalInstanceManager;

  /// Receives binary data across the Flutter platform barrier.
  final BinaryMessenger? _binaryMessenger;

  /// Maintains instances stored to communicate with native language objects.
  final InstanceManager _instanceManager;

  @override
  void create(int identifier) {
    _instanceManager.addHostCreatedInstance(
      CameraInfo.detached(
          binaryMessenger: _binaryMessenger, instanceManager: _instanceManager),
      identifier,
      onCopy: (CameraInfo original) {
        return CameraInfo.detached(
            binaryMessenger: _binaryMessenger,
            instanceManager: _instanceManager);
      },
    );
  }
}