build method
- BuildContext context
override
Describes the part of the user interface represented by this widget.
The framework calls this method when this widget is inserted into the tree in a given BuildContext and when the dependencies of this widget change (e.g., an InheritedWidget referenced by this widget changes). This method can potentially be called in every frame and should not have any side effects beyond building a widget.
The framework replaces the subtree below this widget with the widget returned by this method, either by updating the existing subtree or by removing the subtree and inflating a new subtree, depending on whether the widget returned by this method can update the root of the existing subtree, as determined by calling Widget.canUpdate.
Typically implementations return a newly created constellation of widgets that are configured with information from this widget's constructor and from the given BuildContext.
The given BuildContext contains information about the location in the tree at which this widget is being built. For example, the context provides the set of inherited widgets for this location in the tree. A given widget might be built with multiple different BuildContext arguments over time if the widget is moved around the tree or if the widget is inserted into the tree in multiple places at once.
The implementation of this method must only depend on:
- the fields of the widget, which themselves must not change over time, and
- any ambient state obtained from the
contextusing BuildContext.dependOnInheritedWidgetOfExactType.
If a widget's build method is to depend on anything else, use a StatefulWidget instead.
See also:
- StatelessWidget, which contains the discussion on performance considerations.
Implementation
@override
Widget build(BuildContext context) {
final style = Theme.of(context).style;
return GetBuilder(
key: const Key('ContactsTab'),
init: ContactsTabController(
Get.find(),
Get.find(),
Get.find(),
Get.find(),
Get.find(),
),
builder:
(ContactsTabController c) => Obx(() {
return Scaffold(
appBar: CustomAppBar(
border:
c.search.value != null || c.selecting.value
? Border.all(color: style.colors.primary, width: 2)
: null,
title: Obx(() {
final Widget child;
if (c.search.value != null) {
child = Theme(
data: MessageFieldView.theme(context),
child: Padding(
padding: const EdgeInsets.symmetric(horizontal: 10),
child: Transform.translate(
offset: const Offset(0, 1),
child: ReactiveTextField(
key: const Key('SearchField'),
state: c.search.value!.search,
hint: 'label_search'.l10n,
maxLines: 1,
filled: false,
dense: true,
padding: const EdgeInsets.symmetric(vertical: 8),
style: style.fonts.medium.regular.onBackground,
onChanged:
() =>
c.search.value?.query.value =
c.search.value?.search.text ?? '',
),
),
),
);
} else if (c.selecting.value) {
child = Text('label_select_contacts'.l10n);
} else {
final Widget synchronization;
if (c.fetching.value == null &&
c.status.value.isLoadingMore) {
synchronization = Padding(
padding: const EdgeInsets.only(top: 2),
child: Center(
child: Text(
'label_synchronization'.l10n,
style: style.fonts.small.regular.secondary,
),
),
);
} else {
synchronization = const SizedBox.shrink();
}
child = Align(
alignment: Alignment.centerLeft,
child: Column(
mainAxisSize: MainAxisSize.min,
crossAxisAlignment: CrossAxisAlignment.start,
children: [
Text('label_contacts'.l10n),
AnimatedSizeAndFade(
sizeDuration: const Duration(milliseconds: 300),
fadeDuration: const Duration(milliseconds: 300),
child: synchronization,
),
],
),
);
}
return SafeAnimatedSwitcher(
duration: 250.milliseconds,
child: child,
);
}),
actions: [
Obx(() {
final Widget? child;
if (c.search.value != null) {
if (c.search.value?.search.isEmpty.value == false) {
child = const SvgIcon(
SvgIcons.clearSearch,
key: Key('CloseSearch'),
);
} else {
child = const SvgIcon(
SvgIcons.closePrimary,
key: Key('CloseSearch'),
);
}
} else {
child =
c.selecting.value
? const SvgIcon(
SvgIcons.closePrimary,
key: Key('CloseGroupSearching'),
)
: null;
}
if (child != null) {
return AnimatedButton(
key:
c.search.value != null
? const Key('CloseSearchButton')
: c.selecting.value
? const Key('CloseSelectingButton')
: null,
onPressed: () {
if (c.search.value != null) {
if (c.search.value?.search.isEmpty.value == false) {
c.search.value?.search.clear();
c.search.value?.query.value = '';
c.search.value?.search.focus.requestFocus();
}
} else if (c.selecting.value) {
c.toggleSelecting();
}
},
decorator: (child) {
return Container(
padding: const EdgeInsets.only(left: 12, right: 16),
height: double.infinity,
child: child,
);
},
child: SizedBox(
width: 29.17,
child: AnimatedSwitcher(
duration: 250.milliseconds,
child: child,
),
),
);
}
return Row(
mainAxisSize: MainAxisSize.min,
children: [
AnimatedButton(
key: const Key('ChatsButton'),
onPressed: () => router.tab = HomeTab.chats,
decorator: (child) {
return Container(
padding: const EdgeInsets.only(
left: 20,
right: 8,
),
height: double.infinity,
child: child,
);
},
child: const SvgIcon(SvgIcons.chatsSwitch),
),
AnimatedButton(
key: const Key('SearchButton'),
onPressed: () => c.toggleSearch(),
decorator:
(child) => Container(
padding: const EdgeInsets.only(
left: 20,
right: 12,
),
height: double.infinity,
child: child,
),
child: const SvgIcon(
SvgIcons.search,
key: Key('Search'),
),
),
ContextMenuRegion(
key: const Key('ContactsMenu'),
alignment: Alignment.topRight,
enablePrimaryTap: true,
enableLongTap: false,
enableSecondaryTap: false,
selector: c.moreKey,
margin: const EdgeInsets.only(bottom: 4),
actions: [
ContextMenuButton(
key: const Key('SelectContactsButton'),
label: 'btn_select_and_delete'.l10n,
onPressed: c.toggleSelecting,
trailing: const SvgIcon(SvgIcons.select),
inverted: const SvgIcon(SvgIcons.selectWhite),
),
],
child: AnimatedButton(
decorator:
(child) => Container(
key: c.moreKey,
padding: const EdgeInsets.only(
left: 12,
right: 18,
),
height: double.infinity,
child: Padding(
padding: const EdgeInsets.fromLTRB(
10,
0,
10,
0,
),
child: child,
),
),
child: const SvgIcon(SvgIcons.more),
),
),
],
);
}),
],
leading: [
Obx(() {
if (c.selecting.value) {
final bool selected =
c.contacts.isNotEmpty &&
c.contacts.every(
(e) => c.selectedContacts.any((m) => m == e.id),
);
return AnimatedButton(
onPressed: () {
bool selected = c.contacts.every(
(e) => c.selectedContacts.any((m) => m == e.id),
);
if (selected) {
c.selectedContacts.clear();
} else {
for (var e in c.contacts) {
if (!c.selectedContacts.contains(e.id)) {
c.selectContact(e.rx);
}
}
}
},
decorator:
(child) => Container(
padding: const EdgeInsets.only(
left: 20,
right: 6,
),
height: double.infinity,
child: child,
),
child: SelectedDot(
selected: selected,
inverted: false,
outlined: !selected,
size: 21,
),
);
}
if (c.search.value == null) {
return const SizedBox(width: 21);
}
return AnimatedButton(
key: const Key('CloseSearchButton'),
onPressed: () => c.toggleSearch(false),
decorator: (child) {
return Container(
padding: const EdgeInsets.only(left: 20, right: 6),
height: double.infinity,
child: child,
);
},
child: const SvgIcon(SvgIcons.search),
);
}),
],
),
extendBodyBehindAppBar: true,
body: Obx(() {
final RxStatus? searchStatus =
c.search.value?.searchStatus.value;
if (c.status.value.isLoading) {
return const Center(child: CustomProgressIndicator.primary());
}
final Widget? child;
if (c.search.value?.search.isEmpty.value == false) {
if (c.search.value!.searchStatus.value.isLoading &&
c.elements.isEmpty) {
child = Center(
key: UniqueKey(),
child: ColoredBox(
key: const Key('Loading'),
color: style.colors.almostTransparent,
child: const CustomProgressIndicator(),
),
);
} else if (c.elements.isNotEmpty) {
child = SafeScrollbar(
controller: c.search.value!.scrollController,
child: AnimationLimiter(
key: const Key('Search'),
child: ListView.builder(
key: const Key('SearchScrollable'),
controller: c.search.value!.scrollController,
itemCount: c.elements.length,
itemBuilder: (_, i) {
ListElement? element;
if (i < c.elements.length) {
element = c.elements[i];
}
Widget child;
if (element is ContactElement) {
child = SearchUserTile(
key: Key('SearchContact_${element.contact.id}'),
contact: element.contact,
onTap:
() => router.user(
(element as ContactElement)
.contact
.user
.value!
.id,
),
);
} else if (element is UserElement) {
child = SearchUserTile(
key: Key('SearchUser_${element.user.id}'),
user: element.user,
onTap:
() => router.user(
(element as UserElement).user.id,
),
);
} else if (element is DividerElement) {
child = Center(
child: Container(
margin: const EdgeInsets.fromLTRB(
10,
2,
10,
2,
),
padding: const EdgeInsets.fromLTRB(
12,
10,
12,
6,
),
width: double.infinity,
child: Center(
child: Text(
element.category.name.capitalizeFirst!,
style:
style
.fonts
.normal
.regular
.onBackground,
),
),
),
);
} else {
child = const SizedBox();
}
if (i == c.elements.length - 1) {
if ((searchStatus?.isLoadingMore ?? false) ||
(searchStatus?.isLoading ?? false)) {
child = Column(
children: [
child,
const CustomProgressIndicator(),
],
);
}
}
return AnimationConfiguration.staggeredList(
position: i,
duration: const Duration(milliseconds: 375),
child: SlideAnimation(
horizontalOffset: 50,
child: FadeInAnimation(child: child),
),
);
},
),
),
);
} else {
child = AnimatedDelayedSwitcher(
key: UniqueKey(),
delay: const Duration(milliseconds: 300),
child: Center(
key: const Key('NothingFound'),
child: Text(
'label_nothing_found'.l10n,
style: style.fonts.small.regular.onBackground,
),
),
);
}
} else {
if (c.contacts.isEmpty) {
child = KeyedSubtree(
key: UniqueKey(),
child: Center(
key: const Key('NoContacts'),
child: Text('label_no_contacts'.l10n),
),
);
} else {
final List<ContactEntry> favorites = [];
final List<ContactEntry> contacts = [];
for (ContactEntry e in c.contacts) {
if (e.contact.value.favoritePosition != null) {
favorites.add(e);
} else {
contacts.add(e);
}
}
child = AnimationLimiter(
key: const Key('Contacts'),
child: SafeScrollbar(
controller: c.scrollController,
child: CustomScrollView(
controller: c.scrollController,
slivers: [
SliverPadding(
padding: const EdgeInsets.only(
top: CustomAppBar.height - 4,
left: 10,
right: 10,
),
sliver: SliverReorderableList(
onReorderStart:
(_) => c.reordering.value = true,
proxyDecorator: (child, _, animation) {
return AnimatedBuilder(
animation: animation,
builder: (_, Widget? child) {
final double t = Curves.easeInOut
.transform(animation.value);
final double elevation =
lerpDouble(0, 6, t)!;
final Color color =
Color.lerp(
style.colors.transparent,
style.colors.onBackgroundOpacity20,
t,
)!;
return Container(
decoration: BoxDecoration(
boxShadow: [
CustomBoxShadow(
color: color,
blurRadius: elevation,
),
],
borderRadius: style.cardRadius
.copyWith(
topLeft: Radius.circular(
style.cardRadius.topLeft.x *
1.75,
),
),
),
child: child,
);
},
child: child,
);
},
itemBuilder: (_, i) {
if (favorites.isEmpty) {
// This builder is invoked for some reason when
// deleting all favorite contacts, so put a
// guard for that case.
return const SizedBox.shrink(key: Key('0'));
}
final ContactEntry contact = favorites[i];
if (contact.hidden.value) {
return const SizedBox();
}
return KeyedSubtree(
key: Key(contact.id.val),
child: Obx(() {
final Widget child = _contact(
context,
contact,
c,
avatarBuilder: (child) {
if (PlatformUtils.isMobile) {
return ReorderableDelayedDragStartListener(
key: Key(
'ReorderHandle_${contact.id.val}',
),
index: i,
enabled: !c.selecting.value,
child: child,
);
}
return RawGestureDetector(
gestures: {
DisableSecondaryButtonRecognizer:
GestureRecognizerFactoryWithHandlers<
DisableSecondaryButtonRecognizer
>(
() =>
DisableSecondaryButtonRecognizer(),
(_) {},
),
},
child: ReorderableDragStartListener(
key: Key(
'ReorderHandle_${contact.id.val}',
),
index: i,
enabled: !c.selecting.value,
// Use a dummy
// [GestureDetector.onLongPress]
// callback for discarding long
// presses on the [child].
child: GestureDetector(
onLongPress: () {},
child: child,
),
),
);
},
);
// Ignore the animation, if there's an ongoing
// reordering happening.
if (c.reordering.value) {
return child;
}
return AnimationConfiguration.staggeredList(
position: i,
duration: const Duration(
milliseconds: 375,
),
child: SlideAnimation(
horizontalOffset: 50,
child: FadeInAnimation(child: child),
),
);
}),
);
},
itemCount: favorites.length,
onReorder: (a, b) {
c.reorderContact(a, b);
c.reordering.value = false;
},
),
),
SliverPadding(
padding: const EdgeInsets.only(
bottom: CustomNavigationBar.height,
left: 10,
right: 10,
),
sliver: SliverList(
delegate: SliverChildListDelegate.fixed([
...contacts.mapIndexed((i, e) {
if (e.hidden.value) {
return const SizedBox();
}
return AnimationConfiguration.staggeredList(
position: favorites.length + i,
duration: const Duration(
milliseconds: 375,
),
child: SlideAnimation(
horizontalOffset: 50,
child: FadeInAnimation(
child: _contact(context, e, c),
),
),
);
}),
if (c.hasNext.isTrue)
Center(
child: CustomProgressIndicator(
key: const Key('ContactsLoading'),
value:
Config.disableInfiniteAnimations
? 0
: null,
),
),
]),
),
),
],
),
),
);
}
}
return Stack(
children: [
Obx(() {
return AnimatedContainer(
duration: 200.milliseconds,
color:
c.search.value != null
? style.colors.secondaryHighlight
: style.colors.secondaryHighlight.withValues(
alpha: 0,
),
);
}),
ContextMenuInterceptor(
child: SlidableAutoCloseBehavior(
child: SafeAnimatedSwitcher(
duration: const Duration(milliseconds: 250),
child: child,
),
),
),
],
);
}),
bottomNavigationBar: Column(
mainAxisSize: MainAxisSize.min,
children: [
Obx(() {
final Widget child;
final action = c.dismissed.lastOrNull;
if (action == null) {
child = const SizedBox(key: Key('NoDismissed'));
} else {
child = Padding(
key: Key('Dismissed_${action.contact.id}'),
padding: EdgeInsets.fromLTRB(
10 + 10,
0,
10 + 10,
72 + router.context!.mediaQueryViewPadding.bottom,
),
child: WidgetButton(
key: const Key('Restore'),
onPressed: action.cancel,
child: Container(
key: Key('${action.contact.id}'),
decoration: BoxDecoration(
borderRadius: BorderRadius.circular(12),
color: style.colors.primary.withValues(alpha: .9),
boxShadow: [
CustomBoxShadow(
blurRadius: 8,
color: style.colors.onBackgroundOpacity13,
blurStyle: BlurStyle.outer.workaround,
),
],
),
height: CustomNavigationBar.height,
width: double.infinity,
padding: const EdgeInsets.all(16),
child: Stack(
alignment: Alignment.centerLeft,
children: [
Stack(
alignment: Alignment.center,
children: [
SizedBox(
width: 20,
height: 20,
child: CircularProgressIndicator(
value: action.remaining.value / 5000,
color: style.colors.onPrimary,
strokeWidth: 2,
),
),
Text(
'${action.remaining.value ~/ 1000 + 1}',
style:
style.fonts.small.regular.onPrimary,
),
],
),
Center(
child: Text(
'btn_undo_delete'.l10n,
style: style.fonts.big.regular.onPrimary,
),
),
],
),
),
),
);
}
return SafeAnimatedSwitcher(
duration: 200.milliseconds,
child: child,
);
}),
Obx(() {
if (c.selecting.value) {
return BottomPaddedRow(
children: [
ShadowedRoundedButton(
onPressed: c.toggleSelecting,
child: Text(
'btn_cancel'.l10n,
overflow: TextOverflow.ellipsis,
maxLines: 1,
style: style.fonts.medium.regular.onBackground,
),
),
ShadowedRoundedButton(
key: const Key('DeleteContacts'),
onPressed:
c.selectedContacts.isEmpty
? null
: () => _removeContacts(context, c),
color: style.colors.primary,
child: Text(
'btn_delete_count'.l10nfmt({
'count': c.selectedContacts.length,
}),
overflow: TextOverflow.ellipsis,
maxLines: 1,
style:
c.selectedContacts.isEmpty
? style.fonts.medium.regular.onBackground
: style.fonts.medium.regular.onPrimary,
),
),
],
);
}
return const SizedBox();
}),
],
),
);
}),
);
}