immich/mobile/lib/presentation/widgets/images/local_image_provider.dart

import 'dart:async';
import 'dart:ui';

import 'package:flutter/foundation.dart';
import 'package:flutter/widgets.dart';
import 'package:immich_mobile/infrastructure/repositories/asset_media.repository.dart';

class LocalThumbProvider extends ImageProvider<LocalThumbProvider> {
  static const _assetMediaRepository = AssetMediaRepository();

  final String id;
  final Size size;
  final DateTime? updatedAt;

  const LocalThumbProvider({
    required this.id,
    required this.size,
    this.updatedAt,
  });

  @override
  Future<LocalThumbProvider> obtainKey(ImageConfiguration configuration) {
    return SynchronousFuture(this);
  }

  @override
  ImageStreamCompleter loadImage(
    LocalThumbProvider key,
    ImageDecoderCallback decode,
  ) {
    return OneFrameImageStreamCompleter(
      _codec(key),
      informationCollector: () => <DiagnosticsNode>[
        DiagnosticsProperty<String>('Id', key.id),
        DiagnosticsProperty<DateTime>('Updated at', key.updatedAt),
        DiagnosticsProperty<Size>('Size', key.size),
      ],
    );
  }

  Future<ImageInfo> _codec(LocalThumbProvider key) async {
    final codec =
        await _assetMediaRepository.getLocalThumbnail(key.id, key.size);
    return ImageInfo(image: (await codec.getNextFrame()).image, scale: 1.0);
  }

  @override
  bool operator ==(Object other) {
    if (identical(this, other)) return true;
    if (other is LocalThumbProvider) {
      return id == other.id &&
          size == other.size &&
          updatedAt == other.updatedAt;
    }
    return false;
  }

  @override
  int get hashCode => id.hashCode ^ updatedAt.hashCode;
}

class LocalFullImageProvider extends ImageProvider<LocalFullImageProvider> {
  static const _assetMediaRepository = AssetMediaRepository();

  final String id;
  final Size size;

  const LocalFullImageProvider({required this.id, required this.size});

  @override
  Future<LocalFullImageProvider> obtainKey(ImageConfiguration configuration) {
    return SynchronousFuture(this);
  }

  @override
  ImageStreamCompleter loadImage(
    LocalFullImageProvider key,
    ImageDecoderCallback decode,
  ) {
    return OneFrameImageStreamCompleter(_codec(key));
  }

  Future<ImageInfo> _codec(LocalFullImageProvider key) async {
    final devicePixelRatio =
        PlatformDispatcher.instance.views.first.devicePixelRatio;
    final codec = await _assetMediaRepository.getLocalThumbnail(
      key.id,
      Size(size.width * devicePixelRatio, size.height * devicePixelRatio),
    );
    return ImageInfo(image: (await codec.getNextFrame()).image, scale: 1.0);
  }

  @override
  bool operator ==(Object other) {
    if (identical(this, other)) return true;
    if (other is LocalFullImageProvider) {
      return id == other.id && size == other.size;
    }
    return false;
  }

  @override
  int get hashCode => id.hashCode ^ size.hashCode;
}