tiling: task management

debug: task queue overlay

lib/services/image_file_service.dart

@@ -193,9 +193,11 @@ class ImageFileService {
     }
   }
 
+  static bool cancelRegion(Object taskKey) => servicePolicy.pause(taskKey, [ServiceCallPriority.getRegion]);
+
   static bool cancelThumbnail(Object taskKey) => servicePolicy.pause(taskKey, [ServiceCallPriority.getFastThumbnail, ServiceCallPriority.getSizedThumbnail]);
 
-  static Future<T> resumeThumbnail<T>(Object taskKey) => servicePolicy.resume<T>(taskKey);
+  static Future<T> resumeLoading<T>(Object taskKey) => servicePolicy.resume<T>(taskKey);
 
   static Stream<ImageOpEvent> delete(Iterable<ImageEntry> entries) {
     try {

lib/services/service_policy.dart

@@ -7,10 +7,13 @@ import 'package:tuple/tuple.dart';
 final ServicePolicy servicePolicy = ServicePolicy._private();
 
 class ServicePolicy {
+  final StreamController<QueueState> _queueStreamController = StreamController<QueueState>.broadcast();
   final Map<Object, Tuple2<int, _Task>> _paused = {};
   final SplayTreeMap<int, Queue<_Task>> _queues = SplayTreeMap();
   _Task _running;
 
+  Stream<QueueState> get queueStream => _queueStreamController.stream;
+
   ServicePolicy._private();
 
   Future<T> call<T>(
@@ -60,6 +63,7 @@ class ServicePolicy {
   Queue<_Task> _getQueue(int priority) => _queues.putIfAbsent(priority, () => Queue<_Task>());
 
   void _pickNext() {
+    _notifyQueueState();
     if (_running != null) return;
     final queue = _queues.entries.firstWhere((kv) => kv.value.isNotEmpty, orElse: () => null)?.value;
     _running = queue?.removeFirst();
@@ -90,6 +94,13 @@ class ServicePolicy {
   }
 
   bool isPaused(Object key) => _paused.containsKey(key);
+
+  void _notifyQueueState() {
+    if (!_queueStreamController.hasListener) return;
+
+    final queueByPriority = Map.fromEntries(_queues.entries.map((kv) => MapEntry(kv.key, kv.value.length)));
+    _queueStreamController.add(QueueState(queueByPriority));
+  }
 }
 
 class _Task {
@@ -110,3 +121,9 @@ class ServiceCallPriority {
   static const int getMetadata = 1000;
   static const int getLocation = 1000;
 }
+
+class QueueState {
+  final Map<int, int> queueByPriority;
+
+  const QueueState(this.queueByPriority);
+}

lib/widgets/collection/thumbnail/raster.dart

@@ -71,8 +71,6 @@ class _ThumbnailRasterImageState extends State<ThumbnailRasterImage> {
     _pauseProvider();
   }
 
-  bool get isSupported => entry.canDecode;
-
   void _initProvider() {
     if (!entry.canDecode) return;
 

lib/widgets/common/image_providers/region_provider.dart

@@ -0,0 +1,124 @@
+import 'dart:async';
+import 'dart:ui' as ui show Codec;
+
+import 'package:aves/model/image_entry.dart';
+import 'package:aves/services/image_file_service.dart';
+import 'package:flutter/foundation.dart';
+import 'package:flutter/material.dart';
+
+class RegionProvider extends ImageProvider<RegionProviderKey> {
+  final RegionProviderKey key;
+
+  RegionProvider(this.key) : assert(key != null);
+
+  @override
+  Future<RegionProviderKey> obtainKey(ImageConfiguration configuration) {
+    return SynchronousFuture<RegionProviderKey>(key);
+  }
+
+  @override
+  ImageStreamCompleter load(RegionProviderKey key, DecoderCallback decode) {
+    return MultiFrameImageStreamCompleter(
+      codec: _loadAsync(key, decode),
+      scale: key.scale,
+      informationCollector: () sync* {
+        yield ErrorDescription('uri=${key.uri}, rect=${key.rect}');
+      },
+    );
+  }
+
+  Future<ui.Codec> _loadAsync(RegionProviderKey key, DecoderCallback decode) async {
+    final uri = key.uri;
+    final mimeType = key.mimeType;
+    try {
+      final bytes = await ImageFileService.getRegion(
+        uri,
+        mimeType,
+        key.rotationDegrees,
+        key.isFlipped,
+        key.sampleSize,
+        key.rect,
+        taskKey: key,
+      );
+      if (bytes == null) {
+        throw StateError('$uri ($mimeType) region loading failed');
+      }
+      return await decode(bytes);
+    } catch (error) {
+      debugPrint('$runtimeType _loadAsync failed with mimeType=$mimeType, uri=$uri, error=$error');
+      throw StateError('$mimeType region decoding failed');
+    }
+  }
+
+  @override
+  void resolveStreamForKey(ImageConfiguration configuration, ImageStream stream, RegionProviderKey key, ImageErrorListener handleError) {
+    ImageFileService.resumeLoading(key);
+    super.resolveStreamForKey(configuration, stream, key, handleError);
+  }
+
+  void pause() => ImageFileService.cancelRegion(key);
+}
+
+class RegionProviderKey {
+  final String uri, mimeType;
+  final int rotationDegrees, sampleSize;
+  final bool isFlipped;
+  final Rect rect;
+  final double scale;
+
+  const RegionProviderKey({
+    @required this.uri,
+    @required this.mimeType,
+    @required this.rotationDegrees,
+    @required this.isFlipped,
+    @required this.sampleSize,
+    @required this.rect,
+    this.scale = 1.0,
+  })  : assert(uri != null),
+        assert(mimeType != null),
+        assert(rotationDegrees != null),
+        assert(isFlipped != null),
+        assert(sampleSize != null),
+        assert(rect != null),
+        assert(scale != null);
+
+  // do not store the entry as it is, because the key should be constant
+  // but the entry attributes may change over time
+  factory RegionProviderKey.fromEntry(
+    ImageEntry entry, {
+    @required int sampleSize,
+    @required Rect rect,
+  }) {
+    return RegionProviderKey(
+      uri: entry.uri,
+      mimeType: entry.mimeType,
+      rotationDegrees: entry.rotationDegrees,
+      isFlipped: entry.isFlipped,
+      sampleSize: sampleSize,
+      rect: rect,
+    );
+  }
+
+  @override
+  bool operator ==(Object other) {
+    if (other.runtimeType != runtimeType) return false;
+    return other is RegionProviderKey && other.uri == uri && other.mimeType == mimeType && other.rotationDegrees == rotationDegrees && other.isFlipped == isFlipped && other.sampleSize == sampleSize && other.rect == rect && other.scale == scale;
+  }
+
+  @override
+  int get hashCode => hashValues(
+        uri,
+        mimeType,
+        rotationDegrees,
+        isFlipped,
+        mimeType,
+        sampleSize,
+        rect,
+        scale,
+      );
+
+  @override
+  String toString() {
+    return 'RegionProviderKey(uri=$uri, mimeType=$mimeType, rotationDegrees=$rotationDegrees, isFlipped=$isFlipped, sampleSize=$sampleSize, rect=$rect, scale=$scale)';
+  }
+}

lib/widgets/common/image_providers/thumbnail_provider.dart

@@ -30,8 +30,8 @@ class ThumbnailProvider extends ImageProvider<ThumbnailProviderKey> {
   }
 
   Future<ui.Codec> _loadAsync(ThumbnailProviderKey key, DecoderCallback decode) async {
-    var uri = key.uri;
+    final uri = key.uri;
-    var mimeType = key.mimeType;
+    final mimeType = key.mimeType;
     try {
       final bytes = await ImageFileService.getThumbnail(
         uri,
@@ -55,7 +55,7 @@ class ThumbnailProvider extends ImageProvider<ThumbnailProviderKey> {
 
   @override
   void resolveStreamForKey(ImageConfiguration configuration, ImageStream stream, ThumbnailProviderKey key, ImageErrorListener handleError) {
-    ImageFileService.resumeThumbnail(key);
+    ImageFileService.resumeLoading(key);
     super.resolveStreamForKey(configuration, stream, key, handleError);
   }
 
@@ -105,7 +105,15 @@ class ThumbnailProviderKey {
   }
 
   @override
-  int get hashCode => hashValues(uri, mimeType, dateModifiedSecs, rotationDegrees, isFlipped, extent, scale);
+  int get hashCode => hashValues(
+        uri,
+        mimeType,
+        dateModifiedSecs,
+        rotationDegrees,
+        isFlipped,
+        extent,
+        scale,
+      );
 
   @override
   String toString() {

lib/widgets/common/image_providers/uri_region_provider.dart

@@ -1,81 +0,0 @@
-import 'dart:async';
-import 'dart:ui' as ui show Codec;
-
-import 'package:aves/services/image_file_service.dart';
-import 'package:flutter/foundation.dart';
-import 'package:flutter/material.dart';
-import 'package:pedantic/pedantic.dart';
-
-class UriRegion extends ImageProvider<UriRegion> {
-  const UriRegion({
-    @required this.uri,
-    @required this.mimeType,
-    @required this.rotationDegrees,
-    @required this.isFlipped,
-    @required this.sampleSize,
-    @required this.rect,
-    this.scale = 1.0,
-  })  : assert(uri != null),
-        assert(scale != null);
-
-  final String uri, mimeType;
-  final int rotationDegrees, sampleSize;
-  final bool isFlipped;
-  final Rect rect;
-  final double scale;
-
-  @override
-  Future<UriRegion> obtainKey(ImageConfiguration configuration) {
-    return SynchronousFuture<UriRegion>(this);
-  }
-
-  @override
-  ImageStreamCompleter load(UriRegion key, DecoderCallback decode) {
-    final chunkEvents = StreamController<ImageChunkEvent>();
-
-    return MultiFrameImageStreamCompleter(
-      codec: _loadAsync(key, decode, chunkEvents),
-      scale: key.scale,
-      chunkEvents: chunkEvents.stream,
-      informationCollector: () sync* {
-        yield ErrorDescription('uri=$uri, mimeType=$mimeType');
-      },
-    );
-  }
-
-  Future<ui.Codec> _loadAsync(UriRegion key, DecoderCallback decode, StreamController<ImageChunkEvent> chunkEvents) async {
-    assert(key == this);
-
-    try {
-      final bytes = await ImageFileService.getRegion(
-        uri,
-        mimeType,
-        rotationDegrees,
-        isFlipped,
-        sampleSize,
-        rect,
-      );
-      if (bytes == null) {
-        throw StateError('$uri ($mimeType) loading failed');
-      }
-      return await decode(bytes);
-    } catch (error) {
-      debugPrint('$runtimeType _loadAsync failed with mimeType=$mimeType, uri=$uri, error=$error');
-      throw StateError('$mimeType decoding failed');
-    } finally {
-      unawaited(chunkEvents.close());
-    }
-  }
-
-  @override
-  bool operator ==(Object other) {
-    if (other.runtimeType != runtimeType) return false;
-    return other is UriRegion && other.uri == uri && other.sampleSize == sampleSize && other.rect == rect && other.scale == scale;
-  }
-
-  @override
-  int get hashCode => hashValues(uri, sampleSize, rect, scale);
-
-  @override
-  String toString() => '${objectRuntimeType(this, 'UriRegion')}(uri=$uri, mimeType=$mimeType, scale=$scale)';
-}

lib/widgets/debug/app_debug_page.dart

@@ -6,6 +6,7 @@ import 'package:aves/widgets/debug/android_env.dart';
 import 'package:aves/widgets/debug/cache.dart';
 import 'package:aves/widgets/debug/database.dart';
 import 'package:aves/widgets/debug/firebase.dart';
+import 'package:aves/widgets/debug/overlay.dart';
 import 'package:aves/widgets/debug/settings.dart';
 import 'package:aves/widgets/debug/storage.dart';
 import 'package:aves/widgets/fullscreen/info/common.dart';
@@ -26,6 +27,8 @@ class AppDebugPage extends StatefulWidget {
 class AppDebugPageState extends State<AppDebugPage> {
   List<ImageEntry> get entries => widget.source.rawEntries;
 
+  static OverlayEntry _taskQueueOverlayEntry;
+
   @override
   Widget build(BuildContext context) {
     return MediaQueryDataProvider(
@@ -70,6 +73,22 @@ class AppDebugPageState extends State<AppDebugPage> {
           divisions: 9,
           label: '$timeDilation',
         ),
+        SwitchListTile(
+          value: _taskQueueOverlayEntry != null,
+          onChanged: (v) {
+            _taskQueueOverlayEntry?.remove();
+            if (v) {
+              _taskQueueOverlayEntry = OverlayEntry(
+                builder: (context) => DebugTaskQueueOverlay(),
+              );
+              Overlay.of(context).insert(_taskQueueOverlayEntry);
+            } else {
+              _taskQueueOverlayEntry = null;
+            }
+            setState(() {});
+          },
+          title: Text('Show tasks overlay'),
+        ),
         Divider(),
         Padding(
           padding: EdgeInsets.only(left: 8, right: 8, bottom: 8),

lib/widgets/debug/overlay.dart

@@ -0,0 +1,39 @@
+import 'package:aves/services/service_policy.dart';
+import 'package:flutter/material.dart';
+
+class DebugTaskQueueOverlay extends StatelessWidget {
+  @override
+  Widget build(BuildContext context) {
+    return IgnorePointer(
+      child: DefaultTextStyle(
+        style: TextStyle(),
+        child: Align(
+          alignment: AlignmentDirectional.bottomStart,
+          child: SafeArea(
+            child: Container(
+              color: Colors.indigo[900].withAlpha(0xCC),
+              margin: EdgeInsets.only(
+                bottom: MediaQuery.of(context).viewInsets.bottom,
+              ),
+              padding: EdgeInsets.all(8),
+              child: StreamBuilder<QueueState>(
+                  stream: servicePolicy.queueStream,
+                  builder: (context, snapshot) {
+                    if (snapshot.hasError) return SizedBox.shrink();
+                    final queuedEntries = (snapshot.hasData ? snapshot.data.queueByPriority.entries.toList() : []);
+                    queuedEntries.sort((a, b) => a.key.compareTo(b.key));
+                    return Column(
+                      mainAxisSize: MainAxisSize.min,
+                      crossAxisAlignment: CrossAxisAlignment.stretch,
+                      children: [
+                        Text(queuedEntries.map((kv) => '${kv.key}: ${kv.value}').join(', ')),
+                      ],
+                    );
+                  }),
+            ),
+          ),
+        ),
+      ),
+    );
+  }
+}

lib/widgets/fullscreen/tiled_view.dart

@@ -2,7 +2,7 @@ import 'dart:math';
 
 import 'package:aves/model/image_entry.dart';
 import 'package:aves/utils/math_utils.dart';
-import 'package:aves/widgets/common/image_providers/uri_region_provider.dart';
+import 'package:aves/widgets/common/image_providers/region_provider.dart';
 import 'package:aves/widgets/fullscreen/image_view.dart';
 import 'package:flutter/foundation.dart';
 import 'package:flutter/material.dart';
@@ -99,7 +99,7 @@ class _TiledImageViewState extends State<TiledImageView> {
           );
           final viewRect = (viewOrigin & viewportSize).inflate(preFetchMargin);
 
-          final tiles = <Widget>[];
+          final tiles = <RegionTile>[];
           var minSampleSize = min(_sampleSizeForScale(scale), _maxSampleSize);
           for (var sampleSize = _maxSampleSize; sampleSize >= minSampleSize; sampleSize = (sampleSize / 2).floor()) {
             final layerRegionSize = Size.square(_tileSide * sampleSize);
@@ -159,7 +159,7 @@ class _TiledImageViewState extends State<TiledImageView> {
   }
 }
 
-class RegionTile extends StatelessWidget {
+class RegionTile extends StatefulWidget {
   final ImageEntry entry;
 
   // `tileRect` uses Flutter view coordinates
@@ -174,35 +174,67 @@ class RegionTile extends StatelessWidget {
     @required this.sampleSize,
   });
 
+  @override
+  _RegionTileState createState() => _RegionTileState();
+}
+
+class _RegionTileState extends State<RegionTile> {
+  RegionProvider _provider;
+
+  ImageEntry get entry => widget.entry;
+
+  @override
+  void initState() {
+    super.initState();
+    _registerWidget(widget);
+  }
+
+  @override
+  void didUpdateWidget(RegionTile oldWidget) {
+    super.didUpdateWidget(oldWidget);
+    if (oldWidget.entry != widget.entry || oldWidget.tileRect != widget.tileRect || oldWidget.sampleSize != widget.sampleSize || oldWidget.sampleSize != widget.sampleSize) {
+      _unregisterWidget(oldWidget);
+      _registerWidget(widget);
+    }
+  }
+
+  @override
+  void dispose() {
+    _unregisterWidget(widget);
+    super.dispose();
+  }
+
+  void _registerWidget(RegionTile widget) {
+    _initProvider();
+  }
+
+  void _unregisterWidget(RegionTile widget) {
+    _pauseProvider();
+  }
+
+  void _initProvider() {
+    if (!entry.canDecode) return;
+
+    _provider = RegionProvider(RegionProviderKey.fromEntry(
+      entry,
+      sampleSize: widget.sampleSize,
+      rect: widget.regionRect,
+    ));
+  }
+
+  void _pauseProvider() => _provider?.pause();
+
   @override
   Widget build(BuildContext context) {
+    final tileRect = widget.tileRect;
+
     Widget child = Image(
-      image: UriRegion(
+      image: _provider,
-        uri: entry.uri,
-        mimeType: entry.mimeType,
-        rotationDegrees: entry.rotationDegrees,
-        isFlipped: entry.isFlipped,
-        sampleSize: sampleSize,
-        rect: regionRect,
-      ),
       width: tileRect.width,
       height: tileRect.height,
       fit: BoxFit.fill,
-      // TODO TLAD remove when done with tiling
-      // color: Color.fromARGB((0xff / sampleSize).floor(), 0, 0, 0xff),
-      // colorBlendMode: BlendMode.color,
     );
 
-    // child = Container(
-    //   foregroundDecoration: BoxDecoration(
-    //     border: Border.all(
-    //       color: Colors.cyan,
-    //     ),
-    //   ),
-    //   // child: Text('$sampleSize'),
-    //   child: child,
-    // );
-
     // apply EXIF orientation
     final quarterTurns = entry.rotationDegrees ~/ 90;
     if (entry.isFlipped) {
@@ -230,4 +262,12 @@ class RegionTile extends StatelessWidget {
       child: child,
     );
   }
+
+  @override
+  void debugFillProperties(DiagnosticPropertiesBuilder properties) {
+    super.debugFillProperties(properties);
+    properties.add(IntProperty('contentId', widget.entry.contentId));
+    properties.add(IntProperty('sampleSize', widget.sampleSize));
+    properties.add(DiagnosticsProperty<Rect>('regionRect', widget.regionRect));
+  }
 }

pubspec.yaml

@@ -33,6 +33,9 @@ version: 1.2.5+31
 # - does not support AC3 (by default, but possible by custom build)
 # - can play if only the video or audio stream is supported
 
+environment:
+  sdk: ">=2.7.0 <3.0.0"
+
 dependencies:
   flutter:
     sdk: flutter