doc: Added some docs for core code

packages/stream_chat_flutter_core/lib/src/channel_list_core.dart

@@ -11,14 +11,15 @@ import 'stream_chat_core.dart';
 /// ![screenshot](https://raw.githubusercontent.com/GetStream/stream-chat-flutter/master/screenshots/channel_list_view.png)
 /// ![screenshot](https://raw.githubusercontent.com/GetStream/stream-chat-flutter/master/screenshots/channel_list_view_paint.png)
 ///
-/// It shows the list of current channels.
+/// [ChannelListCore] is a simplified class that allows fetching a list of channels while exposing UI builders.
+/// A [ChannelListController] is used to reload and paginate data.
 ///
 /// ```dart
 /// class ChannelListPage extends StatelessWidget {
 ///   @override
 ///   Widget build(BuildContext context) {
 ///     return Scaffold(
-///       body: ChannelListView(
+///       body: ChannelListCore(
 ///         filter: {
 ///           'members': {
 ///             '\$in': [StreamChat.of(context).user.id],
@@ -28,7 +29,24 @@ import 'stream_chat_core.dart';
 ///         pagination: PaginationParams(
 ///           limit: 20,
 ///         ),
-///         channelWidget: ChannelPage(),
+///         errorBuilder: (err) {
+///           return Center(
+///             child: Text('An error has occured'),
+///           );
+///         },
+///         emptyBuilder: (context) {
+///           return Center(
+///             child: Text('Nothing here...'),
+///           );
+///         },
+///         emptyBuilder: (context) {
+///           return Center(
+///             child: CircularProgressIndicator(),
+///           );
+///         },
+///         listBuilder: (context, list) {
+///           return ChannelPage(list);
+///         }
 ///       ),
 ///     );
 ///   }
@@ -37,10 +55,6 @@ import 'stream_chat_core.dart';
 ///
 ///
 /// Make sure to have a [StreamChatCore] ancestor in order to provide the information about the channels.
-/// The widget uses a [ListView.custom] to render the list of channels.
-///
-/// The widget components render the ui based on the first ancestor of type [StreamChatTheme].
-/// Modify it to change the widget appearance.
 class ChannelListCore extends StatefulWidget {
   /// Instantiate a new ChannelListView
   ChannelListCore({
@@ -56,13 +70,17 @@ class ChannelListCore extends StatefulWidget {
     this.channelListController,
   }) : super(key: key);
 
+  /// A [ChannelListController] allows reloading and pagination.
+  /// Use [ChannelListController.loadData] and [ChannelListController.paginateData] respectively for reloading and pagination.
   final ChannelListController channelListController;
 
   /// The builder that will be used in case of error
   final Widget Function(Error error) errorBuilder;
 
+  /// The builder that will be used in case of loading
   final WidgetBuilder loadingBuilder;
 
+  /// The builder which is used when list of channels loads
   final Function(BuildContext, List<Channel>) listBuilder;
 
   /// The builder used when the channel list is empty.

packages/stream_chat_flutter_core/lib/src/message_list_core.dart

@@ -8,7 +8,8 @@ import 'stream_channel.dart';
 /// ![screenshot](https://raw.githubusercontent.com/GetStream/stream-chat-flutter/master/screenshots/message_listview.png)
 /// ![screenshot](https://raw.githubusercontent.com/GetStream/stream-chat-flutter/master/screenshots/message_listview_paint.png)
 ///
-/// It shows the list of messages of the current channel.
+/// [MessageListCore] is a simplified class that allows fetching a list of messages while exposing UI builders.
+/// A [MessageListController] is used to paginate data.
 ///
 /// ```dart
 /// class ChannelPage extends StatelessWidget {
@@ -19,19 +20,25 @@ import 'stream_channel.dart';
 ///   @override
 ///   Widget build(BuildContext context) {
 ///     return Scaffold(
-///       appBar: ChannelHeader(),
 ///       body: Column(
 ///         children: <Widget>[
 ///           Expanded(
-///             child: MessageListView(
+///             child: MessageListCore(
-///               threadBuilder: (_, parentMessage) {
+///         emptyBuilder: (context) {
-///                 return ThreadPage(
+///           return Center(
-///                   parent: parentMessage,
+///             child: Text('Nothing here...'),
-///                 );
+///           );
-///               },
+///         },
+///         emptyBuilder: (context) {
+///           return Center(
+///             child: CircularProgressIndicator(),
+///           );
+///         },
+///         messageListBuilder: (context, list) {
+///           return MessagesPage(list);
+///         }
 ///             ),
 ///           ),
-///           MessageInput(),
 ///         ],
 ///       ),
 ///     );
@@ -57,6 +64,8 @@ class MessageListCore extends StatefulWidget {
     this.messageListController,
   }) : super(key: key);
 
+  /// A [MessageListController] allows pagination.
+  /// Use [ChannelListController.paginateData] pagination.
   final MessageListController messageListController;
 
   final Widget Function(BuildContext, List<Message>) messageListBuilder;

packages/stream_chat_flutter_core/lib/src/message_search_list_core.dart

@@ -5,14 +5,15 @@ import 'package:stream_chat/stream_chat.dart';
 import 'message_search_bloc.dart';
 
 ///
-/// It shows the list of searched messages.
+/// [MessageSearchListCore] is a simplified class that allows searching for messages across channels while exposing UI builders.
+/// A [MessageSearchListController] is used to load and paginate data.
 ///
 /// ```dart
 /// class MessageSearchPage extends StatelessWidget {
 ///   @override
 ///   Widget build(BuildContext context) {
 ///     return Scaffold(
-///       body: MessageSearchListView(
+///       body: MessageSearchListCore(
 ///               messageQuery: _channelQuery,
 ///               filters: {
 ///                 'members': {
@@ -48,6 +49,8 @@ class MessageSearchListCore extends StatefulWidget {
     this.messageSearchListController,
   }) : super(key: key);
 
+  /// A [MessageSearchListController] allows reloading and pagination.
+  /// Use [MessageSearchListController.loadData] and [MessageSearchListController.paginateData] respectively for reloading and pagination.
   final MessageSearchListController messageSearchListController;
 
   /// Message String to search on
@@ -75,6 +78,7 @@ class MessageSearchListCore extends StatefulWidget {
   /// You can also filter other built-in channel fields.
   final Map<String, dynamic> messageFilters;
 
+  /// The builder that is used when the search messages are fetched
   final Widget Function(List<GetMessageResponse>) childBuilder;
 
   /// The builder used when the channel list is empty.
@@ -83,6 +87,7 @@ class MessageSearchListCore extends StatefulWidget {
   /// The builder that will be used in case of error
   final Widget Function(Error error) errorBuilder;
 
+  /// The builder that will be used in case of loading
   final WidgetBuilder loadingBuilder;
 
   @override

packages/stream_chat_flutter_core/lib/src/user_list_core.dart

@@ -5,14 +5,15 @@ import 'package:stream_chat/stream_chat.dart';
 import 'package:stream_chat_flutter_core/src/users_bloc.dart';
 
 ///
-/// It shows the list of current users.
+/// [UserListCore] is a simplified class that allows fetching users while exposing UI builders.
+/// A [UserListController] is used to load and paginate data.
 ///
 /// ```dart
 /// class UsersListPage extends StatelessWidget {
 ///   @override
 ///   Widget build(BuildContext context) {
 ///     return Scaffold(
-///       body: UsersListView(
+///       body: UsersListCore(
 ///         filter: {
 ///           'members': {
 ///             '\$in': [StreamChat.of(context).user.id],
@@ -22,7 +23,24 @@ import 'package:stream_chat_flutter_core/src/users_bloc.dart';
 ///         pagination: PaginationParams(
 ///           limit: 20,
 ///         ),
-///         channelWidget: ChannelPage(),
+///         errorBuilder: (err) {
+///           return Center(
+///             child: Text('An error has occured'),
+///           );
+///         },
+///         emptyBuilder: (context) {
+///           return Center(
+///             child: Text('Nothing here...'),
+///           );
+///         },
+///         emptyBuilder: (context) {
+///           return Center(
+///             child: CircularProgressIndicator(),
+///           );
+///         },
+///         listBuilder: (context, list) {
+///           return UsersPage(list);
+///         }
 ///       ),
 ///     );
 ///   }
@@ -51,6 +69,8 @@ class UserListCore extends StatefulWidget {
     this.userListController,
   }) : super(key: key);
 
+  /// A [UserListController] allows reloading and pagination.
+  /// Use [UserListController.loadData] and [UserListController.paginateData] respectively for reloading and pagination.
   final UserListController userListController;
 
   /// The builder that will be used in case of error