class ChatList extends ConsumerStatefulWidget {
  final String recieverUserId;
  const ChatList({Key? key, required this.recieverUserId}) : super(key: key);
  @override
  ConsumerState<ConsumerStatefulWidget> createState() => _ChatListState();
}

class _ChatListState extends ConsumerState<ChatList> {
  final ScrollController messageController = ScrollController();

  @override
  void dispose() {
    super.dispose();
    messageController.dispose();
  }

  @override
  Widget build(BuildContext context) {
    return ref.read(chatMessagesProvider(widget.recieverUserId)).when(
      data: (data) {
        return ListView.builder(
          controller: messageController,
          physics: ClampingScrollPhysics(),
          itemCount: data.length,
          itemBuilder: (context, index) {
            WidgetsBinding.instance.addPostFrameCallback((_) {
              messageController
                  .jumpTo(messageController.position.maxScrollExtent);
            });
            final messageData = data[index];
            if (!messageData.isSeen &&
                messageData.recieverid == ref.watch(userProvider)!.uid) {
              ref.read(chatControllerProvider).setChatMessageSeen(
                  context, widget.recieverUserId, messageData.messageId);
            }
            if (ref.watch(userProvider)!.uid == messageData.senderId) {
              return MyMessageCard(
                isSeen: messageData.isSeen,
                type: messageData.type,
                message: messageData.text,
                date: DateFormat.Hm().format(messageData.timeSent),
              );
            }
            return SenderMessageCard(
              type: messageData.type,
              message: messageData.text,
              date: DateFormat.Hm().format(messageData.timeSent),
            );
          },
        );
      },
      error: (error, stackTrace) {
        return ErrorText(error: error.toString());
      },
      loading: () {
        return Loader();
      },
    );
  }
}

flutter goes all the way in listview automatically, but I can't scroll up I changed the physics property, I changed the location of addpostframecallback, but I still can't scroll the list up. I want it to scroll to the end when clicked on this conversation and then scroll up

CodePudding user response：

Try to go to end of list on condition. in your State class create a bool var shouldScrollDown = true

Then add condition to your postframe callback

if(shouldScrollDown) {
  WidgetsBinding.instance.addPostFrameCallback((_) {
    messageController.jumpTo(messageController.position.maxScrollExtent);
   });
   shouldScrollDown = false;
}