yubioath-flutter/lib/app/views/app_page.dart
2024-08-13 16:35:09 +02:00

1010 lines
34 KiB
Dart
Executable File

/*
* Copyright (C) 2022 Yubico.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
import 'dart:async';
import 'dart:io';
import 'package:flutter/gestures.dart';
import 'package:flutter/material.dart';
import 'package:flutter_gen/gen_l10n/app_localizations.dart';
import 'package:flutter_riverpod/flutter_riverpod.dart';
import 'package:material_symbols_icons/symbols.dart';
import 'package:shared_preferences/shared_preferences.dart';
import '../../core/state.dart';
import '../../management/models.dart';
import '../../widgets/delayed_visibility.dart';
import '../../widgets/file_drop_target.dart';
import '../message.dart';
import '../shortcuts.dart';
import 'fs_dialog.dart';
import 'keys.dart';
import 'navigation.dart';
final _navigationVisibilityProvider =
StateNotifierProvider<_VisibilityNotifier, bool>((ref) =>
_VisibilityNotifier('NAVIGATION_VISIBILITY', ref.watch(prefProvider)));
final _detailViewVisibilityProvider =
StateNotifierProvider<_VisibilityNotifier, bool>((ref) =>
_VisibilityNotifier('DETAIL_VIEW_VISIBILITY', ref.watch(prefProvider)));
class _VisibilityNotifier extends StateNotifier<bool> {
final String _key;
final SharedPreferences _prefs;
_VisibilityNotifier(this._key, this._prefs)
: super(_prefs.getBool(_key) ?? true);
void toggleExpanded() {
final newValue = !state;
state = newValue;
_prefs.setBool(_key, newValue);
}
}
// We use global keys here to maintain the content between AppPages,
// and keep track of what has been scrolled under AppBar
final _navKey = GlobalKey();
final _navExpandedKey = GlobalKey();
final _sliverTitleGlobalKey = GlobalKey();
final _sliverTitleWrapperGlobalKey = GlobalKey();
final _headerSliverGlobalKey = GlobalKey();
final _detailsViewGlobalKey = GlobalKey();
final _mainContentGlobalKey = GlobalKey();
class AppPage extends ConsumerStatefulWidget {
final String? title;
final String? alternativeTitle;
final String? footnote;
final Widget Function(BuildContext context, bool expanded) builder;
final Widget Function(BuildContext context)? detailViewBuilder;
final List<Widget> Function(BuildContext context, bool expanded)?
actionsBuilder;
final Widget Function(BuildContext context)? keyActionsBuilder;
final bool keyActionsBadge;
final bool centered;
final bool delayedContent;
final Widget Function(BuildContext context)? actionButtonBuilder;
final Widget? fileDropOverlay;
final Function(File file)? onFileDropped;
final List<Capability>? capabilities;
final Widget? headerSliver;
const AppPage(
{super.key,
this.title,
this.alternativeTitle,
this.footnote,
required this.builder,
this.centered = false,
this.keyActionsBuilder,
this.detailViewBuilder,
this.actionButtonBuilder,
this.actionsBuilder,
this.fileDropOverlay,
this.capabilities,
this.onFileDropped,
this.delayedContent = false,
this.keyActionsBadge = false,
this.headerSliver})
: assert(!(onFileDropped != null && fileDropOverlay == null),
'Declaring onFileDropped requires declaring a fileDropOverlay');
@override
ConsumerState<ConsumerStatefulWidget> createState() => _AppPageState();
}
class _AppPageState extends ConsumerState<AppPage> {
final _VisibilityController _sliverTitleController = _VisibilityController();
final _VisibilityController _headerSliverController = _VisibilityController();
final _VisibilityController _navController = _VisibilityController();
final _VisibilityController _detailsController = _VisibilityController();
late _VisibilitiesController _scrolledUnderController;
final ScrollController _sliverTitleScrollController = ScrollController();
@override
void initState() {
super.initState();
_scrolledUnderController = _VisibilitiesController(
[_sliverTitleController, _navController, _detailsController]);
}
@override
void dispose() {
_sliverTitleController.dispose();
_headerSliverController.dispose();
_navController.dispose();
_detailsController.dispose();
_scrolledUnderController.dispose();
super.dispose();
}
@override
Widget build(BuildContext context) {
return LayoutBuilder(
builder: (context, constraints) {
final width = constraints.maxWidth;
if (width < 400 ||
(isAndroid && width < 600 && width < constraints.maxHeight)) {
return _buildScaffold(context, true, false, false);
}
if (width < 800) {
return _buildScaffold(context, true, true, false);
}
if (width < 1000) {
return _buildScaffold(context, true, true, true);
} else {
// Fully expanded layout, close existing drawer if open
final scaffoldState = scaffoldGlobalKey.currentState;
if (scaffoldState?.isDrawerOpen == true) {
scaffoldState?.closeDrawer();
}
return _buildScaffold(context, false, true, true);
}
},
);
}
Widget _buildLogo(BuildContext context) {
final color =
Theme.of(context).brightness == Brightness.dark ? 'white' : 'green';
return Padding(
padding: const EdgeInsets.only(top: 16, bottom: 12),
child: Image.asset(
'assets/graphics/yubico-$color.png',
alignment: Alignment.centerLeft,
height: 28,
filterQuality: FilterQuality.medium,
),
);
}
Widget _buildDrawer(BuildContext context) {
return Drawer(
child: SafeArea(
child: SingleChildScrollView(
child: Column(
children: [
Row(
mainAxisAlignment: MainAxisAlignment.spaceBetween,
children: [
Padding(
padding: const EdgeInsets.only(left: 16),
child: CloseButton(
color: Theme.of(context).colorScheme.onSurface),
),
_buildLogo(context),
const SizedBox(width: 48),
],
),
Material(
type: MaterialType.transparency,
child: NavigationContent(key: _navExpandedKey, extended: true)),
],
),
),
));
}
void _scrollElement(
BuildContext context,
ScrollController scrollController,
_ScrollDirection direction,
_VisibilityController controller,
GlobalKey targetKey,
GlobalKey? anchorKey) {
if (direction != _ScrollDirection.idle) {
final currentContext = targetKey.currentContext;
if (currentContext == null) return;
final RenderBox renderBox =
currentContext.findRenderObject() as RenderBox;
final RenderBox? anchorRenderBox = anchorKey != null
? anchorKey.currentContext?.findRenderObject() as RenderBox?
: null;
final anchorHeight = anchorRenderBox != null
? anchorRenderBox.size.height
: Scaffold.of(context).appBarMaxHeight!;
final targetHeight = renderBox.size.height;
final positionOffset = anchorRenderBox != null
? Offset(0, -anchorRenderBox.localToGlobal(Offset.zero).dy)
: Offset.zero;
final position = renderBox.localToGlobal(positionOffset);
if (direction == _ScrollDirection.up) {
var offset = scrollController.position.pixels +
(targetHeight - (anchorHeight - position.dy));
if (offset > scrollController.position.maxScrollExtent) {
offset = scrollController.position.maxScrollExtent;
}
Timer.run(() {
scrollController.animateTo(offset,
duration: const Duration(milliseconds: 100), curve: Curves.ease);
});
} else {
var offset =
scrollController.position.pixels - (anchorHeight - position.dy);
if (offset < scrollController.position.minScrollExtent) {
offset = scrollController.position.minScrollExtent;
}
if (controller.visibility != _Visibility.visible) {
Timer.run(() {
scrollController.animateTo(offset,
duration: const Duration(milliseconds: 100),
curve: Curves.ease);
});
}
}
}
}
Widget _buildTitle(BuildContext context) {
return ListenableBuilder(
listenable: _sliverTitleController,
builder: (context, child) {
_scrollElement(
context,
_sliverTitleScrollController,
_sliverTitleController.scrollDirection,
_sliverTitleController,
_sliverTitleWrapperGlobalKey,
null);
return Row(
mainAxisAlignment: MainAxisAlignment.spaceBetween,
children: [
Flexible(
child: Text(
key: _sliverTitleGlobalKey,
widget.alternativeTitle ?? widget.title!,
style: Theme.of(context).textTheme.displaySmall!.copyWith(
color: widget.alternativeTitle != null
? Theme.of(context)
.colorScheme
.onSurfaceVariant
.withOpacity(0.4)
: Theme.of(context)
.colorScheme
.primary
.withOpacity(0.9),
),
overflow: TextOverflow.ellipsis,
),
),
if (widget.capabilities != null && widget.alternativeTitle == null)
Wrap(
spacing: 4.0,
runSpacing: 8.0,
children: [
...widget.capabilities!.map((c) => CapabilityBadge(c))
],
)
],
);
},
);
}
double _getTitleHeight(BuildContext context) {
final Size size = (TextPainter(
text: TextSpan(
text: widget.title,
style: Theme.of(context)
.textTheme
.displaySmall), // Same style as title
maxLines: 1,
textScaler: MediaQuery.textScalerOf(context),
textDirection: TextDirection.ltr)
..layout())
.size;
return size.height;
}
Widget? _buildAppBarTitle(
BuildContext context, bool hasRail, bool hasManage, bool fullyExpanded) {
final showNavigation = ref.watch(_navigationVisibilityProvider);
final showDetailView = ref.watch(_detailViewVisibilityProvider);
EdgeInsets padding;
if (fullyExpanded) {
padding = EdgeInsets.only(
left: showNavigation ? 280 : 72, right: showDetailView ? 320 : 0.0);
} else if (!hasRail && hasManage) {
padding = const EdgeInsets.only(right: 320);
} else if (hasRail && hasManage) {
padding = EdgeInsets.only(left: 72, right: showDetailView ? 320 : 0.0);
} else if (hasRail && !hasManage) {
padding = const EdgeInsets.only(left: 72);
} else {
padding = const EdgeInsets.all(0);
}
if (widget.title != null) {
return ListenableBuilder(
listenable: _sliverTitleController,
builder: (context, child) {
final visible =
_sliverTitleController.visibility == _Visibility.scrolledUnder;
return Padding(
padding: padding,
child: AnimatedOpacity(
duration: const Duration(milliseconds: 300),
opacity: visible ? 1 : 0,
child: Text(widget.alternativeTitle ?? widget.title!),
),
);
},
);
}
return null;
}
Widget _buildMainContent(BuildContext context, bool expanded) {
final showDetailView = ref.watch(_detailViewVisibilityProvider);
final actions =
widget.actionsBuilder?.call(context, expanded && showDetailView) ?? [];
final content = Column(
mainAxisSize: MainAxisSize.min,
crossAxisAlignment: widget.centered
? CrossAxisAlignment.center
: CrossAxisAlignment.start,
children: [
widget.builder(context, expanded && showDetailView),
if (actions.isNotEmpty)
Align(
alignment:
widget.centered ? Alignment.center : Alignment.centerLeft,
child: Padding(
padding: const EdgeInsets.only(
top: 16, bottom: 0, left: 16, right: 16),
child: Wrap(
spacing: 8,
runSpacing: 4,
children: actions,
),
),
),
if (widget.footnote != null)
Padding(
padding:
const EdgeInsets.only(bottom: 16, top: 33, left: 16, right: 16),
child: Opacity(
opacity: 0.6,
child: Text(
widget.footnote!,
style: Theme.of(context).textTheme.bodySmall,
),
),
),
],
);
final safeArea = SafeArea(
child: widget.delayedContent
? DelayedVisibility(
key: GlobalKey(), // Ensure we reset the delay on rebuild
delay: const Duration(milliseconds: 400),
child: content,
)
: content,
);
if (widget.centered) {
return Stack(children: [
if (widget.title != null)
Positioned.fill(
child: Align(
alignment: Alignment.topLeft,
child: Padding(
padding: const EdgeInsets.only(
left: 16.0, right: 8.0, bottom: 24.0, top: 4.0),
child: _buildTitle(context),
),
),
),
Positioned.fill(
// Header height = title height + vertical padding
top: widget.title != null ? _getTitleHeight(context) + 24 : 0,
child: Align(
alignment: Alignment.center,
child: ScrollConfiguration(
behavior:
ScrollConfiguration.of(context).copyWith(scrollbars: false),
child: SingleChildScrollView(
physics: isAndroid
? const ClampingScrollPhysics(
parent: AlwaysScrollableScrollPhysics())
: null,
child: safeArea,
),
),
),
)
]);
}
if (widget.title != null) {
return _VisibilityListener(
targetKey: _sliverTitleGlobalKey,
controller: _sliverTitleController,
subTargetKey:
widget.headerSliver != null ? _headerSliverGlobalKey : null,
subController:
widget.headerSliver != null ? _headerSliverController : null,
subAnchorKey:
widget.headerSliver != null ? _sliverTitleWrapperGlobalKey : null,
child: CustomScrollView(
physics: isAndroid
? const ClampingScrollPhysics(
parent: AlwaysScrollableScrollPhysics())
: null,
controller: _sliverTitleScrollController,
key: _mainContentGlobalKey,
slivers: [
SliverMainAxisGroup(
slivers: [
SliverPersistentHeader(
pinned: true,
delegate: _SliverTitleDelegate(
child: ColoredBox(
color: Theme.of(context).colorScheme.surface,
child: Padding(
key: _sliverTitleWrapperGlobalKey,
padding: const EdgeInsets.only(
left: 16.0, right: 8.0, bottom: 12.0, top: 4.0),
child: _buildTitle(context),
),
),
// Header height = title height + vertical padding
height: _getTitleHeight(context) + 16,
),
),
if (widget.headerSliver != null)
SliverToBoxAdapter(
child: ListenableBuilder(
listenable: _headerSliverController,
builder: (context, child) {
_scrollElement(
context,
_sliverTitleScrollController,
_headerSliverController.scrollDirection,
_headerSliverController,
_headerSliverGlobalKey,
_sliverTitleWrapperGlobalKey);
return Container(
key: _headerSliverGlobalKey,
child: widget.headerSliver);
},
))
],
),
SliverToBoxAdapter(child: safeArea)
],
),
);
}
return SingleChildScrollView(
physics: isAndroid
? const ClampingScrollPhysics(parent: AlwaysScrollableScrollPhysics())
: null,
primary: false,
child: safeArea,
);
}
Scaffold _buildScaffold(
BuildContext context, bool hasDrawer, bool hasRail, bool hasManage) {
final l10n = AppLocalizations.of(context)!;
final fullyExpanded = !hasDrawer && hasRail && hasManage;
final showNavigation = ref.watch(_navigationVisibilityProvider);
final showDetailView = ref.watch(_detailViewVisibilityProvider);
final hasDetailsOrKeyActions =
widget.detailViewBuilder != null || widget.keyActionsBuilder != null;
var body = _buildMainContent(context, hasManage);
var navigationText = showNavigation
? (fullyExpanded
? l10n.s_collapse_navigation
: MaterialLocalizations.of(context).openAppDrawerTooltip)
: l10n.s_expand_navigation;
if (widget.onFileDropped != null) {
body = FileDropTarget(
onFileDropped: widget.onFileDropped!,
overlay: widget.fileDropOverlay!,
child: body,
);
}
if (hasRail || hasManage) {
body = GestureDetector(
behavior: HitTestBehavior.deferToChild,
onTap: () {
Actions.invoke(context, const EscapeIntent());
FocusManager.instance.primaryFocus?.unfocus();
},
child: Row(
crossAxisAlignment: CrossAxisAlignment.stretch,
children: [
if (hasRail && (!fullyExpanded || !showNavigation))
SizedBox(
width: 72,
child: _VisibilityListener(
targetKey: _navKey,
controller: _navController,
child: SingleChildScrollView(
child: NavigationContent(
key: _navKey,
shouldPop: false,
extended: false,
),
),
),
),
if (fullyExpanded && showNavigation)
SizedBox(
width: 280,
child: _VisibilityListener(
controller: _navController,
targetKey: _navExpandedKey,
child: SingleChildScrollView(
child: Material(
type: MaterialType.transparency,
child: NavigationContent(
key: _navExpandedKey,
shouldPop: false,
extended: true,
),
),
),
)),
const SizedBox(width: 8),
Expanded(child: body),
if (hasManage &&
!hasDetailsOrKeyActions &&
widget.capabilities != null &&
widget.capabilities?.first != Capability.u2f)
// Add a placeholder for the Manage/Details column. Exceptions are:
// - the "Security Key" because it does not have any actions/details.
// - pages without Capabilities
const SizedBox(width: 336), // simulate column
if (hasManage && hasDetailsOrKeyActions && showDetailView)
_VisibilityListener(
controller: _detailsController,
targetKey: _detailsViewGlobalKey,
child: SingleChildScrollView(
child: Padding(
padding: const EdgeInsets.symmetric(horizontal: 8),
child: SizedBox(
width: 320,
child: Column(
key: _detailsViewGlobalKey,
children: [
if (widget.detailViewBuilder != null)
widget.detailViewBuilder!(context),
if (widget.keyActionsBuilder != null)
widget.keyActionsBuilder!(context),
],
),
),
),
),
),
],
),
);
}
return Scaffold(
key: scaffoldGlobalKey,
appBar: _GestureDetectorAppBar(
onTap: () {
Actions.invoke(context, const EscapeIntent());
FocusManager.instance.primaryFocus?.unfocus();
},
appBar: AppBar(
bottom: PreferredSize(
preferredSize: const Size.fromHeight(1.0),
child: ListenableBuilder(
listenable: _scrolledUnderController,
builder: (context, child) {
final visible = _scrolledUnderController.someIsScrolledUnder;
return AnimatedOpacity(
opacity: visible ? 1 : 0,
duration: const Duration(milliseconds: 300),
child: Container(
color: Theme.of(context).hoverColor,
height: 1.0,
),
);
},
),
),
scrolledUnderElevation: 0.0,
leadingWidth: hasRail ? 84 : null,
backgroundColor: Theme.of(context).colorScheme.surface,
title: _buildAppBarTitle(
context,
hasRail,
hasManage,
fullyExpanded,
),
centerTitle: true,
leading: hasRail
? Row(
mainAxisAlignment: MainAxisAlignment.spaceAround,
children: [
Expanded(
child: Padding(
padding: const EdgeInsets.symmetric(horizontal: 8),
child: IconButton(
icon: Icon(Symbols.menu, semanticLabel: navigationText),
tooltip: navigationText,
onPressed: fullyExpanded
? () {
ref
.read(
_navigationVisibilityProvider.notifier)
.toggleExpanded();
}
: () {
scaffoldGlobalKey.currentState?.openDrawer();
},
),
)),
const SizedBox(width: 12),
],
)
: Builder(
builder: (context) {
// Need to wrap with builder to get Scaffold context
return IconButton(
onPressed: () => Scaffold.of(context).openDrawer(),
icon: const Icon(Symbols.menu),
);
},
),
actions: [
if (widget.actionButtonBuilder == null &&
(widget.keyActionsBuilder != null &&
(!hasManage || !showDetailView)))
Padding(
padding: const EdgeInsets.only(left: 4),
child: IconButton(
key: actionsIconButtonKey,
onPressed: () {
showBlurDialog(
context: context,
barrierColor: Colors.transparent,
builder: (context) => FsDialog(
child: Padding(
padding: const EdgeInsets.only(top: 32),
child: widget.keyActionsBuilder!(context),
),
),
);
},
icon: widget.keyActionsBadge
? Badge(
child: Icon(Symbols.more_vert,
semanticLabel: l10n.s_configure_yk),
)
: Icon(Symbols.more_vert,
semanticLabel: l10n.s_configure_yk),
iconSize: 24,
tooltip: l10n.s_configure_yk,
padding: const EdgeInsets.all(12),
),
),
if (hasManage &&
(widget.keyActionsBuilder != null ||
widget.detailViewBuilder != null))
Padding(
padding: const EdgeInsets.only(left: 4),
child: IconButton(
key: toggleDetailViewIconButtonKey,
onPressed: () {
ref
.read(_detailViewVisibilityProvider.notifier)
.toggleExpanded();
},
icon: const Icon(Symbols.view_sidebar),
iconSize: 24,
tooltip: showDetailView
? l10n.s_collapse_sidebar
: l10n.s_expand_sidebar,
padding: const EdgeInsets.all(12),
),
),
if (widget.actionButtonBuilder != null)
Padding(
padding: const EdgeInsets.only(right: 12),
child: widget.actionButtonBuilder!.call(context),
),
],
),
),
drawer: hasDrawer ? _buildDrawer(context) : null,
body: body,
);
}
}
class _GestureDetectorAppBar extends StatelessWidget
implements PreferredSizeWidget {
final AppBar appBar;
final void Function() onTap;
const _GestureDetectorAppBar({required this.appBar, required this.onTap});
@override
Widget build(BuildContext context) {
return GestureDetector(
behavior: HitTestBehavior.deferToChild, onTap: onTap, child: appBar);
}
@override
Size get preferredSize => const Size.fromHeight(kToolbarHeight);
}
class CapabilityBadge extends StatelessWidget {
final Capability capability;
const CapabilityBadge(this.capability, {super.key});
@override
Widget build(BuildContext context) {
final l10n = AppLocalizations.of(context)!;
final colorScheme = Theme.of(context).colorScheme;
return Badge(
backgroundColor: colorScheme.secondaryContainer,
textColor: colorScheme.onSecondaryContainer,
padding: const EdgeInsets.symmetric(horizontal: 6),
largeSize: MediaQuery.of(context).textScaler.scale(20),
label: Text(
capability.getDisplayName(l10n),
),
);
}
}
enum _Visibility { visible, topScrolledUnder, halfScrolledUnder, scrolledUnder }
enum _ScrollDirection { idle, up, down }
class _VisibilityController with ChangeNotifier {
_Visibility _visibility = _Visibility.visible;
_ScrollDirection _scrollDirection = _ScrollDirection.idle;
void setVisibility(_Visibility visibility) {
if (visibility != _visibility) {
_visibility = visibility;
if (_visibility != _Visibility.visible) {
_scrollDirection = _ScrollDirection.idle;
}
notifyListeners();
}
}
void notifyScroll(_ScrollDirection scrollDirection) {
if (visibility != _Visibility.scrolledUnder) {
_scrollDirection = scrollDirection;
notifyListeners();
}
}
_ScrollDirection get scrollDirection => _scrollDirection;
_Visibility get visibility => _visibility;
}
class _VisibilitiesController with ChangeNotifier {
final List<_VisibilityController> controllers;
bool someIsScrolledUnder = false;
_VisibilitiesController(this.controllers) {
for (var element in controllers) {
element.addListener(() {
_setScrolledUnder();
});
}
}
void _setScrolledUnder() {
final val =
controllers.any((element) => element.visibility != _Visibility.visible);
if (val != someIsScrolledUnder) {
someIsScrolledUnder = val;
notifyListeners();
}
}
}
class _VisibilityListener extends StatefulWidget {
final _VisibilityController controller;
final Widget child;
final GlobalKey targetKey;
final _VisibilityController? subController;
final GlobalKey? subTargetKey;
final GlobalKey? subAnchorKey;
const _VisibilityListener(
{required this.controller,
required this.child,
required this.targetKey,
this.subController,
this.subTargetKey,
this.subAnchorKey})
: assert(
(subController == null &&
subTargetKey == null &&
subAnchorKey == null) ||
(subController != null &&
subTargetKey != null &&
subAnchorKey != null),
'Declaring requires subTargetKey and subAnchorKey, and vice versa',
);
@override
State<_VisibilityListener> createState() => _VisibilityListenerState();
}
class _VisibilityListenerState extends State<_VisibilityListener> {
bool disableScroll = false;
@override
Widget build(BuildContext context) => Listener(
onPointerDown: (event) {
setState(() {
disableScroll = true;
});
},
onPointerUp: (event) {
setState(() {
disableScroll = false;
});
},
onPointerSignal: (event) {
if (event is PointerScrollEvent) {
if (!disableScroll) {
setState(() {
disableScroll = true;
});
Timer(const Duration(seconds: 1), () {
if (mounted) {
setState(() {
disableScroll = false;
});
}
});
}
}
},
child: NotificationListener(
onNotification: (notification) {
if (notification is ScrollMetricsNotification ||
notification is ScrollUpdateNotification) {
_handleScrollUpdate(context);
}
if (notification is ScrollEndNotification &&
widget.child is CustomScrollView) {
// Disable auto scrolling for mouse wheel and scrollbar
_handleScrollEnd(context);
}
return false;
},
child: widget.child,
),
);
void _handleScrollUpdate(
BuildContext context,
) {
widget.controller
.setVisibility(_scrolledUnderState(context, widget.targetKey, null));
if (widget.subController != null) {
widget.subController!.setVisibility(_scrolledUnderState(
context, widget.subTargetKey!, widget.subAnchorKey));
}
}
void _handleScrollEnd(
BuildContext context,
) {
if (!disableScroll) {
widget.controller.notifyScroll(_getScrollDirection(
_scrolledUnderState(context, widget.targetKey, null)));
if (widget.subController != null) {
widget.subController!.notifyScroll(_getScrollDirection(
_scrolledUnderState(
context, widget.subTargetKey!, widget.subAnchorKey)));
}
}
}
_ScrollDirection _getScrollDirection(_Visibility visibility) {
if (visibility == _Visibility.halfScrolledUnder) {
return _ScrollDirection.up;
} else if (visibility == _Visibility.topScrolledUnder) {
return _ScrollDirection.down;
} else {
return _ScrollDirection.idle;
}
}
_Visibility _scrolledUnderState(
BuildContext context,
GlobalKey targetKey,
GlobalKey? anchorKey,
) {
final currentContext = targetKey.currentContext;
if (currentContext == null) return _Visibility.visible;
final RenderBox renderBox = currentContext.findRenderObject() as RenderBox;
final RenderBox? anchorRenderBox = anchorKey != null
? anchorKey.currentContext?.findRenderObject() as RenderBox?
: null;
final anchorHeight = anchorRenderBox != null
? anchorRenderBox.size.height
: Scaffold.of(context).appBarMaxHeight!;
final targetHeight = renderBox.size.height;
final positionOffset = anchorRenderBox != null
? Offset(0, -anchorRenderBox.localToGlobal(Offset.zero).dy)
: Offset.zero;
final position = renderBox.localToGlobal(positionOffset);
if (anchorHeight - position.dy > targetHeight - 10) {
return _Visibility.scrolledUnder;
} else if (anchorHeight - position.dy > targetHeight / 2) {
return _Visibility.halfScrolledUnder;
} else if (anchorHeight - position.dy > 0) {
return _Visibility.topScrolledUnder;
} else {
return _Visibility.visible;
}
}
}
class _SliverTitleDelegate extends SliverPersistentHeaderDelegate {
_SliverTitleDelegate({
required this.height,
required this.child,
});
final double height;
final Widget child;
@override
double get minExtent => height;
@override
double get maxExtent => height;
@override
Widget build(
BuildContext context, double shrinkOffset, bool overlapsContent) {
return child;
}
@override
bool shouldRebuild(_SliverTitleDelegate oldDelegate) => true;
}