aves/lib/widgets/fullscreen/image_view.dart
Thibault Deckers c9fb94f326 svg sizing
2020-12-18 11:44:07 +09:00

252 lines
8.7 KiB
Dart

import 'dart:async';
import 'package:aves/image_providers/thumbnail_provider.dart';
import 'package:aves/image_providers/uri_picture_provider.dart';
import 'package:aves/model/image_entry.dart';
import 'package:aves/model/settings/settings.dart';
import 'package:aves/theme/icons.dart';
import 'package:aves/widgets/collection/empty.dart';
import 'package:aves/widgets/common/magnifier/controller/controller.dart';
import 'package:aves/widgets/common/magnifier/controller/state.dart';
import 'package:aves/widgets/common/magnifier/magnifier.dart';
import 'package:aves/widgets/common/magnifier/scale/scale_level.dart';
import 'package:aves/widgets/common/magnifier/scale/scalestate_controller.dart';
import 'package:aves/widgets/common/magnifier/scale/state.dart';
import 'package:aves/widgets/fullscreen/tiled_view.dart';
import 'package:aves/widgets/fullscreen/video_view.dart';
import 'package:flutter/foundation.dart';
import 'package:flutter/material.dart';
import 'package:flutter_ijkplayer/flutter_ijkplayer.dart';
import 'package:flutter_svg/flutter_svg.dart';
import 'package:provider/provider.dart';
import 'package:tuple/tuple.dart';
class ImageView extends StatefulWidget {
final ImageEntry entry;
final Object heroTag;
final MagnifierTapCallback onTap;
final List<Tuple2<String, IjkMediaController>> videoControllers;
final VoidCallback onDisposed;
const ImageView({
Key key,
@required this.entry,
this.heroTag,
@required this.onTap,
@required this.videoControllers,
this.onDisposed,
}) : super(key: key);
@override
_ImageViewState createState() => _ImageViewState();
}
class _ImageViewState extends State<ImageView> {
final MagnifierController _magnifierController = MagnifierController();
final MagnifierScaleStateController _magnifierScaleStateController = MagnifierScaleStateController();
final ValueNotifier<ViewState> _viewStateNotifier = ValueNotifier(ViewState.zero);
StreamSubscription<MagnifierState> _subscription;
Size _magnifierChildSize;
static const initialScale = ScaleLevel(ref: ScaleReference.contained);
static const minScale = ScaleLevel(ref: ScaleReference.contained);
static const maxScale = ScaleLevel(factor: 2.0);
ImageEntry get entry => widget.entry;
MagnifierTapCallback get onTap => widget.onTap;
@override
void initState() {
super.initState();
_subscription = _magnifierController.outputStateStream.listen(_onViewChanged);
_magnifierChildSize = entry.displaySize;
}
@override
void dispose() {
_subscription.cancel();
_subscription = null;
widget.onDisposed?.call();
super.dispose();
}
@override
Widget build(BuildContext context) {
Widget child;
if (entry.isVideo) {
if (entry.width > 0 && entry.height > 0) {
child = _buildVideoView();
}
} else if (entry.isSvg) {
child = _buildSvgView();
} else if (entry.canDecode) {
child = _buildRasterView();
}
child ??= ErrorChild(onTap: () => onTap?.call(null));
// no hero for videos, as a typical video first frame is different from its thumbnail
return widget.heroTag != null && !entry.isVideo
? Hero(
tag: widget.heroTag,
transitionOnUserGestures: true,
child: child,
)
: child;
}
ImageProvider get fastThumbnailProvider => ThumbnailProvider(ThumbnailProviderKey.fromEntry(entry));
// this loading builder shows a transition image until the final image is ready
// if the image is already in the cache it will show the final image, otherwise the thumbnail
// in any case, we should use `Center` + `AspectRatio` + `BoxFit.fill` so that the transition image
// is laid the same way as the final image when `contained`
Widget _loadingBuilder(BuildContext context, ImageProvider imageProvider) {
return Center(
child: AspectRatio(
// enforce original aspect ratio, as some thumbnails aspect ratios slightly differ
aspectRatio: entry.displayAspectRatio,
child: Image(
image: imageProvider,
fit: BoxFit.fill,
),
),
);
}
Widget _buildRasterView() {
return Magnifier(
// key includes size and orientation to refresh when the image is rotated
key: ValueKey('${entry.rotationDegrees}_${entry.isFlipped}_${entry.width}_${entry.height}_${entry.path}'),
child: Selector<MediaQueryData, Size>(
selector: (context, mq) => mq.size,
builder: (context, mqSize, child) {
// When the scale state is cycled to be in its `initial` state (i.e. `contained`), and the device is rotated,
// `Magnifier` keeps the scale state as `contained`, but the controller does not update or notify the new scale value.
// We cannot monitor scale state changes as a workaround, because the scale state is updated before animating the scale,
// so we keep receiving scale updates after the scale state update.
// Instead we check the scale state here when the constraints change, so we can reset the obsolete scale value.
if (_magnifierScaleStateController.scaleState.state == ScaleState.initial) {
final value = MagnifierState(position: Offset.zero, scale: 0, source: ChangeSource.internal);
WidgetsBinding.instance.addPostFrameCallback((_) => _onViewChanged(value));
}
return TiledImageView(
entry: entry,
viewportSize: mqSize,
viewStateNotifier: _viewStateNotifier,
baseChild: _loadingBuilder(context, fastThumbnailProvider),
errorBuilder: (context, error, stackTrace) => ErrorChild(onTap: () => onTap?.call(null)),
);
},
),
childSize: entry.displaySize,
controller: _magnifierController,
scaleStateController: _magnifierScaleStateController,
maxScale: maxScale,
minScale: minScale,
initialScale: initialScale,
onTap: (c, d, s, childPosition) => onTap?.call(childPosition),
applyScale: false,
);
}
Widget _buildSvgView() {
final colorFilter = ColorFilter.mode(Color(settings.svgBackground), BlendMode.dstOver);
return Magnifier(
child: SvgPicture(
UriPicture(
uri: entry.uri,
mimeType: entry.mimeType,
colorFilter: colorFilter,
),
),
childSize: entry.displaySize,
controller: _magnifierController,
minScale: minScale,
initialScale: initialScale,
scaleStateCycle: _vectorScaleStateCycle,
onTap: (c, d, s, childPosition) => onTap?.call(childPosition),
);
}
Widget _buildVideoView() {
final videoController = widget.videoControllers.firstWhere((kv) => kv.item1 == entry.uri, orElse: () => null)?.item2;
return Magnifier(
child: videoController != null
? AvesVideo(
entry: entry,
controller: videoController,
)
: SizedBox(),
childSize: entry.displaySize,
controller: _magnifierController,
maxScale: maxScale,
minScale: minScale,
initialScale: initialScale,
onTap: (c, d, s, childPosition) => onTap?.call(childPosition),
);
}
void _onViewChanged(MagnifierState v) {
final viewState = ViewState(v.position, v.scale, _magnifierChildSize);
_viewStateNotifier.value = viewState;
ViewStateNotification(entry.uri, viewState).dispatch(context);
}
static ScaleState _vectorScaleStateCycle(ScaleState actual) {
switch (actual) {
case ScaleState.initial:
return ScaleState.covering;
default:
return ScaleState.initial;
}
}
}
class ViewState {
final Offset position;
final double scale;
final Size size;
static const ViewState zero = ViewState(Offset(0.0, 0.0), 0, null);
const ViewState(this.position, this.scale, this.size);
@override
String toString() => '$runtimeType#${shortHash(this)}{position=$position, scale=$scale, size=$size}';
}
class ViewStateNotification extends Notification {
final String uri;
final ViewState viewState;
const ViewStateNotification(this.uri, this.viewState);
@override
String toString() => '$runtimeType#${shortHash(this)}{uri=$uri, viewState=$viewState}';
}
class ErrorChild extends StatelessWidget {
final VoidCallback onTap;
const ErrorChild({@required this.onTap});
@override
Widget build(BuildContext context) {
return GestureDetector(
onTap: () => onTap?.call(),
// use a `Container` with a dummy color to make it expand
// so that we can also detect taps around the title `Text`
child: Container(
color: Colors.transparent,
child: EmptyContent(
icon: AIcons.error,
text: 'Oops!',
alignment: Alignment.center,
),
),
);
}
}
typedef MagnifierTapCallback = void Function(Offset childPosition);