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<ChatController>(
key: const Key('ChatView'),
init: ChatController(
id,
Get.find(),
Get.find(),
Get.find(),
Get.find(),
Get.find(),
Get.find(),
itemId: itemId,
onContext: () => context,
),
tag: id.val,
global: !Get.isRegistered<ChatController>(tag: id.val),
builder: (c) {
// Opens [Routes.chatInfo] or [Routes.user] page basing on the
// [Chat.isGroup] indicator.
void onDetailsTap() {
final Chat? chat = c.chat?.chat.value;
if (chat != null) {
if (chat.isGroup || chat.isMonolog) {
router.chatInfo(chat.id, push: true);
} else if (chat.members.isNotEmpty) {
router.user(
chat.members
.firstWhereOrNull((e) => e.user.id != c.me)
?.user
.id ??
chat.members.first.user.id,
push: true,
);
}
}
}
return Obx(() {
if (c.status.value.isEmpty) {
return Scaffold(
appBar: AppBar(),
body: Center(child: Text('label_no_chat_found'.l10n)),
);
} else if (!c.status.value.isSuccess) {
return Scaffold(
appBar: const CustomAppBar(
padding: EdgeInsets.only(left: 4, right: 20),
leading: [StyledBackButton()],
),
body: const Center(child: CustomProgressIndicator.primary()),
bottomNavigationBar: _bottomBar(c, context),
);
}
final bool isMonolog = c.chat!.chat.value.isMonolog;
return CustomDropTarget(
key: Key('ChatView_$id'),
onPerformDrop: c.dropFiles,
builder: (dragging) => GestureDetector(
onTap: () => FocusManager.instance.primaryFocus?.unfocus(),
child: Stack(
children: [
Scaffold(
resizeToAvoidBottomInset: true,
appBar: CustomAppBar(
title: Obx(() {
if (c.searching.value) {
return 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,
hint: 'label_search'.l10n,
maxLines: 1,
filled: false,
dense: true,
padding: const EdgeInsets.symmetric(
vertical: 8,
),
style:
style.fonts.medium.regular.onBackground,
onChanged: () {
c.query.value = c.search.text;
if (c.search.text.isEmpty) {
c.switchToMessages();
}
},
),
),
),
);
}
return Row(
children: [
WidgetButton(
onPressed: onDetailsTap,
child: Center(
child: AvatarWidget.fromRxChat(
c.chat,
radius: AvatarRadius.medium,
),
),
),
const SizedBox(width: 10),
Flexible(
child: InkWell(
splashFactory: NoSplash.splashFactory,
hoverColor: style.colors.transparent,
highlightColor: style.colors.transparent,
onTap: onDetailsTap,
child: DefaultTextStyle.merge(
maxLines: 1,
overflow: TextOverflow.ellipsis,
child: Column(
mainAxisAlignment: MainAxisAlignment.center,
crossAxisAlignment:
CrossAxisAlignment.start,
children: [
Row(
children: [
Flexible(
child: Obx(() {
return Text(
c.chat!.title,
style: style
.fonts
.big
.regular
.onBackground,
overflow: TextOverflow.ellipsis,
maxLines: 1,
);
}),
),
Obx(() {
if (c.chat?.chat.value.muted ==
null) {
return const SizedBox();
}
return const Padding(
padding: EdgeInsets.only(left: 5),
child: SvgIcon(SvgIcons.muted),
);
}),
],
),
if (!isMonolog)
ChatSubtitle(c.chat!, c.me),
],
),
),
),
),
const SizedBox(width: 10),
],
);
}),
padding: const EdgeInsets.only(left: 4),
leading: [
Obx(() {
if (c.searching.value) {
return const Padding(
padding: EdgeInsets.only(left: 16),
child: SvgIcon(SvgIcons.search),
);
}
return const StyledBackButton();
}),
],
border:
(c.searching.value ||
c.search.isFocused.value == true ||
c.query.value?.isNotEmpty == true)
? Border.all(color: style.colors.primary, width: 2)
: null,
actions: [
Obx(() {
if (c.searching.value) {
return WidgetButton(
onPressed: () {
if (c.searching.value) {
if (c.search.text.isNotEmpty) {
c.search.clear();
c.search.focus.requestFocus();
c.switchToMessages();
} else {
c.toggleSearch();
}
} else {
c.toggleSearch();
}
},
child: Padding(
padding: const EdgeInsets.fromLTRB(8, 8, 21, 8),
child: c.search.isEmpty.value
? const SvgIcon(SvgIcons.closePrimary)
: const SvgIcon(SvgIcons.clearSearch),
),
);
}
final bool blocked = c.chat?.blocked == true;
final bool inCall = c.chat?.inCall.value ?? false;
final List<Widget> children;
// Display the join/end call button, if [Chat] has an
// [OngoingCall] happening in it.
if (c.chat!.chat.value.ongoingCall != null) {
final Widget child;
if (inCall) {
child = Container(
key: const Key('Drop'),
height: 32,
width: 32,
decoration: BoxDecoration(
color: style.colors.danger,
shape: BoxShape.circle,
),
child: const Center(
child: SvgIcon(SvgIcons.callEnd),
),
);
} else {
child = Container(
key: const Key('Join'),
height: 32,
width: 32,
decoration: BoxDecoration(
color: style.colors.primary,
shape: BoxShape.circle,
),
child: const Center(
child: SvgIcon(SvgIcons.callStart),
),
);
}
children = [
AnimatedButton(
key: const Key('ActiveCallButton'),
onPressed: inCall ? c.dropCall : c.joinCall,
child: SafeAnimatedSwitcher(
duration: 300.milliseconds,
child: child,
),
),
];
} else if (!blocked) {
children = [
if (c.callPosition == null ||
c.callPosition ==
CallButtonsPosition.appBar) ...[
AnimatedButton(
onPressed: () => c.call(true),
child: const SvgIcon(SvgIcons.chatVideoCall),
),
const SizedBox(width: 28),
AnimatedButton(
key: const Key('AudioCall'),
onPressed: () => c.call(false),
child: const SvgIcon(SvgIcons.chatAudioCall),
),
const SizedBox(width: 10),
],
];
} else {
// [Chat]-dialog is blocked, therefore no call
// buttons should be displayed.
children = [];
}
return Row(
children: [
...children,
Obx(() {
final bool muted =
c.chat?.chat.value.muted != null;
final bool dialog =
c.chat?.chat.value.isDialog == true;
final bool isLocal =
c.chat?.chat.value.id.isLocal == true;
final bool monolog =
c.chat?.chat.value.isMonolog == true;
final bool favorite =
c.chat?.chat.value.favoritePosition != null;
// TODO: Uncomment, when contacts are
// implemented.
// final bool contact =
// c.user?.user.value.contacts.isNotEmpty ??
// false;
final Widget child;
if (c.selecting.value) {
child = AnimatedButton(
key: const Key('CancelSelecting'),
onPressed: c.selecting.toggle,
child: Container(
padding: const EdgeInsets.only(left: 10),
height: double.infinity,
child: const Padding(
padding: EdgeInsets.fromLTRB(
10,
0,
21,
0,
),
child: SvgIcon(SvgIcons.closePrimary),
),
),
);
} else {
child = ContextMenuRegion(
key: c.moreKey,
selector: c.moreKey,
alignment: Alignment.topRight,
enablePrimaryTap: true,
margin: const EdgeInsets.only(
bottom: 4,
right: 10,
),
actions: [
if (c.callPosition ==
CallButtonsPosition.contextMenu) ...[
ContextMenuButton(
label: 'btn_audio_call'.l10n,
onPressed: blocked || inCall
? null
: () => c.call(false),
trailing: SvgIcon(
blocked || inCall
? SvgIcons.makeAudioCallDisabled
: SvgIcons.makeAudioCall,
),
inverted: const SvgIcon(
SvgIcons.makeAudioCallWhite,
),
),
ContextMenuButton(
label: 'btn_video_call'.l10n,
onPressed: blocked || inCall
? null
: () => c.call(true),
trailing: SvgIcon(
blocked || inCall
? SvgIcons.makeVideoCallDisabled
: SvgIcons.makeVideoCall,
),
inverted: const SvgIcon(
SvgIcons.makeVideoCallWhite,
),
),
],
ContextMenuButton(
key: const Key('SearchItemsButton'),
label: 'label_search'.l10n,
onPressed: c.toggleSearch,
trailing: const SvgIcon(
SvgIcons.search,
),
inverted: const SvgIcon(
SvgIcons.searchWhite,
),
),
// TODO: Uncomment, when contacts are implemented.
// if (dialog)
// ContextMenuButton(
// key: Key(
// contact
// ? 'DeleteFromContactsButton'
// : 'AddToContactsButton',
// ),
// label: contact
// ? 'btn_delete_from_contacts'.l10n
// : 'btn_add_to_contacts'.l10n,
// trailing: SvgIcon(
// contact
// ? SvgIcons.deleteContact
// : SvgIcons.addContact,
// ),
// inverted: SvgIcon(
// contact
// ? SvgIcons.deleteContactWhite
// : SvgIcons.addContactWhite,
// ),
// onPressed: contact
// ? () => _removeFromContacts(
// c,
// context,
// )
// : c.addToContacts,
// ),
ContextMenuButton(
key: Key(
favorite
? 'UnfavoriteChatButton'
: 'FavoriteChatButton',
),
label: favorite
? 'btn_delete_from_favorites'.l10n
: 'btn_add_to_favorites'.l10n,
trailing: SvgIcon(
favorite
? SvgIcons.favoriteSmall
: SvgIcons.unfavoriteSmall,
),
inverted: SvgIcon(
favorite
? SvgIcons.favoriteSmallWhite
: SvgIcons.unfavoriteSmallWhite,
),
onPressed: favorite
? c.unfavoriteChat
: c.favoriteChat,
),
if (!isLocal) ...[
if (!monolog)
ContextMenuButton(
key: Key(
muted
? 'UnmuteChatButton'
: 'MuteChatButton',
),
label: muted
? PlatformUtils.isMobile
? 'btn_unmute'.l10n
: 'btn_unmute_chat'.l10n
: PlatformUtils.isMobile
? 'btn_mute'.l10n
: 'btn_mute_chat'.l10n,
trailing: SvgIcon(
muted
? SvgIcons.unmuteSmall
: SvgIcons.muteSmall,
),
inverted: SvgIcon(
muted
? SvgIcons.unmuteSmallWhite
: SvgIcons.muteSmallWhite,
),
onPressed: muted
? c.unmuteChat
: c.muteChat,
),
ContextMenuButton(
key: const Key('ClearHistoryButton'),
label: 'btn_clear_history'.l10n,
trailing: const SvgIcon(
SvgIcons.cleanHistory,
),
inverted: const SvgIcon(
SvgIcons.cleanHistoryWhite,
),
onPressed: () =>
_clearChat(c, context),
),
],
if (!monolog && !dialog)
ContextMenuButton(
key: const Key('LeaveGroupButton'),
label: 'btn_leave_group'.l10n,
trailing: const SvgIcon(
SvgIcons.leaveGroup,
),
inverted: const SvgIcon(
SvgIcons.leaveGroupWhite,
),
onPressed: () =>
_leaveGroup(c, context),
),
if (!isLocal || monolog)
ContextMenuButton(
key: const Key('HideChatButton'),
label: 'btn_delete_chat'.l10n,
trailing: const SvgIcon(
SvgIcons.delete19,
),
inverted: const SvgIcon(
SvgIcons.delete19White,
),
onPressed: () =>
_hideChat(c, context),
),
if (dialog)
ContextMenuButton(
key: Key(
blocked ? 'Unblock' : 'Block',
),
label: blocked
? 'btn_unblock'.l10n
: 'btn_block'.l10n,
trailing: const SvgIcon(
SvgIcons.block,
),
inverted: const SvgIcon(
SvgIcons.blockWhite,
),
onPressed: blocked
? c.unblock
: () => _blockUser(c, context),
),
ContextMenuButton(
label: 'btn_select_messages'.l10n,
onPressed: c.selecting.toggle,
trailing: const SvgIcon(
SvgIcons.select,
),
inverted: const SvgIcon(
SvgIcons.selectWhite,
),
),
],
child: Container(
key: const Key('MoreButton'),
padding: const EdgeInsets.only(
left: 20,
right: 21,
),
height: double.infinity,
child: const SvgIcon(SvgIcons.more),
),
);
}
return AnimatedButton(
child: SafeAnimatedSwitcher(
duration: 250.milliseconds,
child: child,
),
);
}),
],
);
}),
],
),
body: Stack(
children: [
// Required for the [Stack] to take [Scaffold]'s
// size.
IgnorePointer(
child: ObscuredMenuInterceptor(child: Container()),
),
Obx(() {
final Widget child = FlutterListView(
key: const Key('MessagesList'),
controller: c.listController,
physics: c.isDraggingItem.value
? const NeverScrollableScrollPhysics()
: const BouncingScrollPhysics(),
reverse: true,
delegate: FlutterListViewDelegate(
(context, i) => _listElement(context, c, i),
// ignore: invalid_use_of_protected_member
childCount: c.elements.value.length,
stickyAtTailer: true,
keepPosition: true,
keepPositionOffset: c.active.isTrue
? c.keepPositionOffset.value
: 1,
onItemKey: (i) =>
c.elements.values.elementAt(i).id.toString(),
onItemSticky: (i) =>
c.elements.values.elementAt(i)
is DateTimeElement,
initIndex: c.initIndex,
initOffset: c.initOffset,
initOffsetBasedOnBottom: true,
disableCacheItems: kDebugMode ? true : false,
),
);
if (PlatformUtils.isMobile) {
if (!PlatformUtils.isWeb) {
return Scrollbar(
controller: c.listController,
child: child,
);
} else {
return child;
}
}
return ObscuredSelectionArea(
key: Key('${c.selecting.value}'),
onSelectionChanged: (a) => c.selection.value = a,
contextMenuBuilder: (_, __) => const SizedBox(),
selectionControls: EmptyTextSelectionControls(),
child: ObscuredMenuInterceptor(child: child),
);
}),
Obx(() {
if (c.searching.value) {
if (c.status.value.isLoadingMore) {
return const Center(
child: CustomProgressIndicator(),
);
}
// ignore: invalid_use_of_protected_member
else if (c.elements.value.isEmpty) {
return Center(
child: SystemInfoPrompt(
key: const Key('NoMessages'),
'label_no_messages'.l10n,
),
);
}
}
if ((c.chat!.status.value.isSuccess ||
c.chat!.status.value.isEmpty) &&
c.chat!.messages.isEmpty) {
final Widget? welcome = _welcomeMessage(context, c);
if (welcome != null) {
return Center(
child: ListView(
shrinkWrap: true,
children: [
Align(
alignment: Alignment.centerLeft,
child: ConstrainedBox(
constraints: const BoxConstraints(
maxWidth: 550,
),
child: Padding(
padding: const EdgeInsets.only(
right: 48,
),
child: welcome,
),
),
),
],
),
);
}
if (isMonolog) {
return Center(
key: const Key('NoMessages'),
child: NotesBlock(),
);
}
return Center(
child: SystemInfoPrompt(
key: const Key('NoMessages'),
'label_no_messages'.l10n,
),
);
}
if (c.status.value.isLoading) {
return const Center(
child: CustomProgressIndicator(),
);
}
return const SizedBox();
}),
if (c.callPosition == CallButtonsPosition.top ||
c.callPosition == CallButtonsPosition.bottom)
Positioned(
top: c.callPosition == CallButtonsPosition.top
? 8
: null,
bottom: c.callPosition == CallButtonsPosition.bottom
? 8
: null,
right: 12,
child: Obx(() {
final bool inCall = c.chat?.inCall.value ?? false;
return Column(
mainAxisSize: MainAxisSize.min,
children: [
const SizedBox(height: 8),
CircleButton(
inCall
? SvgIcons.chatAudioCallDisabled
: SvgIcons.chatAudioCall,
onPressed: inCall
? null
: () => c.call(false),
),
const SizedBox(height: 8),
CircleButton(
inCall
? SvgIcons.chatVideoCallDisabled
: SvgIcons.chatVideoCall,
onPressed: inCall
? null
: () => c.call(true),
),
const SizedBox(height: 8),
],
);
}),
),
],
),
floatingActionButton: Obx(() {
return SizedBox(
width: 50,
height: 50,
child: SafeAnimatedSwitcher(
duration: 200.milliseconds,
child: c.canGoBack.isTrue
? FloatingActionButton.small(
onPressed: c.animateToBack,
child: const Icon(Icons.arrow_upward),
)
: c.canGoDown.isTrue
? FloatingActionButton.small(
onPressed: c.animateToBottom,
child: const Icon(Icons.arrow_downward),
)
: const SizedBox(),
),
);
}),
bottomNavigationBar: _bottomBar(c, context),
),
IgnorePointer(
child: SafeAnimatedSwitcher(
duration: 200.milliseconds,
child: dragging
? Container(
color: style.colors.onBackgroundOpacity27,
child: Center(
child: AnimatedDelayedScale(
duration: const Duration(milliseconds: 300),
beginScale: 1,
endScale: 1.06,
child: ConditionalBackdropFilter(
borderRadius: BorderRadius.circular(16),
child: Container(
decoration: BoxDecoration(
borderRadius: BorderRadius.circular(16),
color:
style.colors.onBackgroundOpacity27,
),
child: const Padding(
padding: EdgeInsets.all(16),
child: SvgIcon(SvgIcons.addBigger),
),
),
),
),
),
)
: null,
),
),
],
),
),
);
});
},
);
}