94 lines
2.9 KiB
Dart
94 lines
2.9 KiB
Dart
import 'dart:async';
|
|
import 'dart:math';
|
|
import 'dart:ui' as ui;
|
|
|
|
import 'package:aves/services/common/services.dart';
|
|
import 'package:equatable/equatable.dart';
|
|
import 'package:flutter/foundation.dart';
|
|
import 'package:flutter/widgets.dart';
|
|
|
|
class RegionProvider extends ImageProvider<RegionProviderKey> {
|
|
final RegionProviderKey key;
|
|
|
|
RegionProvider(this.key);
|
|
|
|
@override
|
|
Future<RegionProviderKey> obtainKey(ImageConfiguration configuration) {
|
|
return SynchronousFuture<RegionProviderKey>(key);
|
|
}
|
|
|
|
@override
|
|
ImageStreamCompleter loadImage(RegionProviderKey key, ImageDecoderCallback decode) {
|
|
return MultiFrameImageStreamCompleter(
|
|
codec: _loadAsync(key, decode),
|
|
scale: 1.0,
|
|
informationCollector: () sync* {
|
|
yield ErrorDescription('uri=${key.uri}, pageId=${key.pageId}, mimeType=${key.mimeType}, region=${key.region}');
|
|
},
|
|
);
|
|
}
|
|
|
|
Future<ui.Codec> _loadAsync(RegionProviderKey key, ImageDecoderCallback decode) async {
|
|
final uri = key.uri;
|
|
final mimeType = key.mimeType;
|
|
final pageId = key.pageId;
|
|
try {
|
|
final bytes = await mediaFetchService.getRegion(
|
|
uri,
|
|
mimeType,
|
|
key.rotationDegrees,
|
|
key.isFlipped,
|
|
key.sampleSize,
|
|
key.region,
|
|
key.imageSize,
|
|
pageId: pageId,
|
|
sizeBytes: key.sizeBytes,
|
|
taskKey: key,
|
|
);
|
|
if (bytes.isEmpty) {
|
|
throw StateError('$uri ($mimeType) region loading failed');
|
|
}
|
|
final buffer = await ui.ImmutableBuffer.fromUint8List(bytes);
|
|
return await decode(buffer);
|
|
} catch (error) {
|
|
// loading may fail if the provided MIME type is incorrect (e.g. the Media Store may report a JPEG as a TIFF)
|
|
debugPrint('$runtimeType _loadAsync failed with mimeType=$mimeType, uri=$uri, error=$error');
|
|
throw StateError('$mimeType region decoding failed (page $pageId)');
|
|
}
|
|
}
|
|
|
|
@override
|
|
void resolveStreamForKey(ImageConfiguration configuration, ImageStream stream, RegionProviderKey key, ImageErrorListener handleError) {
|
|
mediaFetchService.resumeLoading(key);
|
|
super.resolveStreamForKey(configuration, stream, key, handleError);
|
|
}
|
|
|
|
void pause() => mediaFetchService.cancelRegion(key);
|
|
}
|
|
|
|
@immutable
|
|
class RegionProviderKey extends Equatable {
|
|
// do not store the entry as it is, because the key should be constant
|
|
// but the entry attributes may change over time
|
|
final String uri, mimeType;
|
|
final int? pageId, sizeBytes;
|
|
final int rotationDegrees, sampleSize;
|
|
final bool isFlipped;
|
|
final Rectangle<int> region;
|
|
final Size imageSize;
|
|
|
|
@override
|
|
List<Object?> get props => [uri, pageId, rotationDegrees, isFlipped, sampleSize, region, imageSize];
|
|
|
|
const RegionProviderKey({
|
|
required this.uri,
|
|
required this.mimeType,
|
|
required this.pageId,
|
|
required this.sizeBytes,
|
|
required this.rotationDegrees,
|
|
required this.isFlipped,
|
|
required this.sampleSize,
|
|
required this.region,
|
|
required this.imageSize,
|
|
});
|
|
}
|