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stream-chat-flutter/lib/src/message_search_list_view.dart
T

375 lines
12 KiB
Dart

import 'dart:convert';
import 'package:flutter/material.dart';
import 'package:stream_chat/stream_chat.dart';
import 'package:stream_chat_flutter/src/message_search_item.dart';
import '../stream_chat_flutter.dart';
import 'lazy_load_scroll_view.dart';
import 'message_search_bloc.dart';
/// Callback called when tapping on a user
typedef MessageSearchItemTapCallback = void Function(GetMessageResponse);
/// Builder used to create a custom [ListUserItem] from a [User]
typedef MessageSearchItemBuilder = Widget Function(
BuildContext, GetMessageResponse);
/// Builder used when [MessageSearchListView] is empty
typedef EmptyMessageSearchBuilder = Widget Function(
BuildContext context, String searchQuery);
///
/// It shows the list of searched messages.
///
/// ```dart
/// class MessageSearchPage extends StatelessWidget {
/// @override
/// Widget build(BuildContext context) {
/// return Scaffold(
/// body: MessageSearchListView(
/// messageQuery: _channelQuery,
/// filters: {
/// 'members': {
/// r'$in': [user.id]
/// }
/// },
/// paginationParams: PaginationParams(limit: 20),
/// ),
/// );
/// }
/// }
/// ```
///
///
/// Make sure to have a [MessageSearchBloc] ancestor in order to provide the information about the messages.
/// The widget uses a [ListView.separated] to render the list of messages.
///
/// The widget components render the ui based on the first ancestor of type [StreamChatTheme].
/// Modify it to change the widget appearance.
class MessageSearchListView extends StatefulWidget {
/// Instantiate a new MessageSearchListView
const MessageSearchListView({
Key key,
@required this.messageQuery,
@required this.filters,
this.sortOptions,
this.paginationParams,
this.emptyBuilder,
this.errorBuilder,
this.separatorBuilder,
this.itemBuilder,
this.onItemTap,
this.showResultCount = true,
}) : super(key: key);
/// Message String to search on
final String messageQuery;
/// The query filters to use.
/// You can query on any of the custom fields you've defined on the [Channel].
/// You can also filter other built-in channel fields.
final Map<String, dynamic> filters;
/// The sorting used for the channels matching the filters.
/// Sorting is based on field and direction, multiple sorting options can be provided.
/// You can sort based on last_updated, last_message_at, updated_at, created_at or member_count.
/// Direction can be ascending or descending.
final List<SortOption> sortOptions;
/// Pagination parameters
/// limit: the number of users to return (max is 30)
/// offset: the offset (max is 1000)
/// message_limit: how many messages should be included to each channel
final PaginationParams paginationParams;
/// Builder used to create a custom item preview
final MessageSearchItemBuilder itemBuilder;
/// Function called when tapping on a [MessageSearchItem]
final MessageSearchItemTapCallback onItemTap;
/// The builder used when the channel list is empty.
final EmptyMessageSearchBuilder emptyBuilder;
/// The builder that will be used in case of error
final Widget Function(Error error) errorBuilder;
/// Builder used to create a custom item separator
final IndexedWidgetBuilder separatorBuilder;
/// Set it to false to hide total results text
final bool showResultCount;
@override
_MessageSearchListViewState createState() => _MessageSearchListViewState();
}
class _MessageSearchListViewState extends State<MessageSearchListView> {
@override
void initState() {
super.initState();
final messageSearchBloc = MessageSearchBloc.of(context);
messageSearchBloc.search(
filter: widget.filters,
sort: widget.sortOptions,
query: widget.messageQuery,
pagination: widget.paginationParams,
);
}
@override
Widget build(BuildContext context) {
final messageSearchBloc = MessageSearchBloc.of(context);
return _buildListView(messageSearchBloc);
}
Widget _separatorBuilder(BuildContext context, int index) {
return Container(
height: 1,
color: Theme.of(context).brightness == Brightness.dark
? StreamChatTheme.of(context).colorTheme.white.withOpacity(0.1)
: StreamChatTheme.of(context).colorTheme.black.withOpacity(0.1),
);
}
Widget _listItemBuilder(
BuildContext context, GetMessageResponse getMessageResponse) {
if (widget.itemBuilder != null) {
return widget.itemBuilder(context, getMessageResponse);
}
return MessageSearchItem(
getMessageResponse: getMessageResponse,
onTap: () => widget.onItemTap(getMessageResponse),
);
}
Widget _buildQueryProgressIndicator(
context, MessageSearchBlocState messageSearchBloc) {
return StreamBuilder<bool>(
stream: messageSearchBloc.queryMessagesLoading,
initialData: false,
builder: (context, snapshot) {
if (snapshot.hasError) {
return Container(
color: StreamChatTheme.of(context)
.colorTheme
.accentRed
.withOpacity(.2),
child: Padding(
padding: const EdgeInsets.symmetric(vertical: 16.0),
child: Center(
child: Text('Error loading messages'),
),
),
);
}
return Container(
height: 100,
padding: EdgeInsets.all(32),
child: Center(
child: snapshot.data ? CircularProgressIndicator() : Container(),
),
);
});
}
Widget _buildListView(MessageSearchBlocState messageSearchBloc) {
return StreamBuilder<List<GetMessageResponse>>(
stream: messageSearchBloc.messagesStream,
builder: (context, snapshot) {
if (snapshot.hasError) {
if (snapshot.error is Error) {
print((snapshot.error as Error).stackTrace);
}
if (widget.errorBuilder != null) {
return widget.errorBuilder(snapshot.error);
}
var message = snapshot.error.toString();
if (snapshot.error is DioError) {
final dioError = snapshot.error as DioError;
if (dioError.type == DioErrorType.RESPONSE) {
message = dioError.message;
} else {
message = 'Check your connection and retry';
}
}
return Center(
child: Column(
mainAxisAlignment: MainAxisAlignment.center,
children: <Widget>[
Text.rich(
TextSpan(
children: [
WidgetSpan(
child: Padding(
padding: const EdgeInsets.only(
right: 2.0,
),
child: Icon(Icons.error_outline),
),
),
TextSpan(text: 'Error loading messages'),
],
),
style: Theme.of(context).textTheme.headline6,
),
Padding(
padding: const EdgeInsets.only(
top: 16.0,
),
child: Text(message),
),
FlatButton(
onPressed: () {
messageSearchBloc.search(
filter: widget.filters,
sort: widget.sortOptions,
query: widget.messageQuery,
pagination: widget.paginationParams,
);
},
child: Text('Retry'),
),
],
),
);
}
if (!snapshot.hasData) {
return LayoutBuilder(
builder: (context, viewportConstraints) {
return SingleChildScrollView(
physics: AlwaysScrollableScrollPhysics(),
child: ConstrainedBox(
constraints: BoxConstraints(
minHeight: viewportConstraints.maxHeight,
),
child: Center(
child: CircularProgressIndicator(),
),
),
);
},
);
}
final items = snapshot.data;
if (items.isEmpty) {
if (widget.emptyBuilder != null) {
return widget.emptyBuilder(context, widget.messageQuery);
}
return LayoutBuilder(
builder: (context, viewportConstraints) {
return SingleChildScrollView(
physics: AlwaysScrollableScrollPhysics(),
child: ConstrainedBox(
constraints: BoxConstraints(
minHeight: viewportConstraints.maxHeight,
),
child: Center(
child: Text('There are no messages currently'),
),
),
);
},
);
}
Widget child;
child = LazyLoadScrollView(
onEndOfPage: () => messageSearchBloc.search(
filter: widget.filters,
sort: widget.sortOptions,
pagination: widget.paginationParams.copyWith(
offset: messageSearchBloc.messageResponses?.length ?? 0,
),
query: widget.messageQuery,
),
child: ListView.separated(
physics: AlwaysScrollableScrollPhysics(),
itemCount: items.isNotEmpty ? items.length + 1 : items.length,
separatorBuilder: (_, index) {
if (widget.separatorBuilder != null) {
return widget.separatorBuilder(context, index);
}
return _separatorBuilder(context, index);
},
itemBuilder: (context, index) {
if (index < items.length) {
return _listItemBuilder(context, items[index]);
}
return _buildQueryProgressIndicator(context, messageSearchBloc);
},
),
);
if (widget.showResultCount) {
child = Column(
children: [
Container(
width: double.maxFinite,
decoration: BoxDecoration(
gradient: LinearGradient(
begin: Alignment.centerLeft,
end: Alignment.centerRight,
colors: [
StreamChatTheme.of(context)
.colorTheme
.black
.withOpacity(0.02),
StreamChatTheme.of(context)
.colorTheme
.white
.withOpacity(0.05),
],
stops: [0, 1],
),
),
child: Padding(
padding: const EdgeInsets.symmetric(
vertical: 8,
horizontal: 8,
),
child: Text(
'${items.length} results',
style: TextStyle(
color: StreamChatTheme.of(context)
.colorTheme
.black
.withOpacity(0.5),
),
),
),
),
Expanded(child: child),
],
);
}
return child;
},
);
}
@override
void didUpdateWidget(MessageSearchListView oldWidget) {
super.didUpdateWidget(oldWidget);
if (widget.filters?.toString() != oldWidget.filters?.toString() ||
jsonEncode(widget.sortOptions) != jsonEncode(oldWidget.sortOptions) ||
widget.paginationParams?.toJson()?.toString() !=
oldWidget.paginationParams?.toJson()?.toString() ||
widget.messageQuery?.toString() != oldWidget.messageQuery?.toString()) {
final messageSearchBloc = MessageSearchBloc.of(context);
messageSearchBloc.search(
filter: widget.filters,
sort: widget.sortOptions,
query: widget.messageQuery,
pagination: widget.paginationParams,
);
}
}
}