How to resize a page when the keyboard appears without rebuilding it in the flutter?

Question

I have a chatroom page that has listview, when focusing on textfield keyboard is appear and the page is rebuilt and requests to server and fetch data again when avoiding the rebuild page, when the keyboard appears not to scroll to the end and the keyboard appears on the listview I want to when the keyboard is appearing, not rebuild the page and auto scroll to bottom (resize), how can do it?

class ChatPrivate extends StatefulWidget {
  String code;
  String name;
  String imgPath;
  String username;

  ChatPrivate({
    Key? key,
    required this.code,
    required this.name,
    required this.imgPath,
    required this.username,
  }) : super(key: key);

  static const String ChatPrivateName = "/ChatPrivateName";

  @override
  State<ChatPrivate> createState() => _ChatPrivateState();
}

class _ChatPrivateState extends State<ChatPrivate> {
  late BuildContext ctx;

  bool isVisible = false;
  

  @override
  void initState() {
    super.initState();
  }

  Widget? listBuild;
  int page = 2;

  @override
  Widget build(BuildContext context) {
    
    if (listBuild == null) {
      listBuild = pageBuild();
    }

    return listBuild!;
  }

  pageBuild() {
    ctx = context;
    context.read<ChatHistoryCubit>().getChatHistory(widget.code);
    return Scaffold(
      appBar: ChatAppBar()
          .appBarPages(widget.name, widget.imgPath, widget.username, context),
      body: GestureDetector(
        onTap: (){
          FocusScopeNode currentFocus = FocusScope.of(context);
          if (!currentFocus.hasPrimaryFocus) {
            currentFocus.unfocus();
          }
        },
        child: Container(
            child: SafeArea(
              child: Stack(
                children: [
                  Image.asset(
                    "assets/images/chat_bg.jpg",
                    width: MediaQuery.of(context).size.width,
                    height: MediaQuery.of(context).size.height,
                    fit: BoxFit.cover,
                  ),
                  Padding(
                    padding: const EdgeInsets.only(
                      left: 8.0,
                      right: 8,
                      bottom: 50,
                    ),
                    child: BodyContent(),
                  ),
                ],
              ),
            )),
      ),
      bottomSheet: SendMessage(
        code: widget.code,
      ),
    );
  }
}

and BodyContent is

class BodyContent extends StatelessWidget {
  BodyContent({Key? key}) : super(key: key);

  // final late List<DataModel> data;
  static final ScrollController controller = ScrollController();

  @override
  Widget build(BuildContext context) {
    return bodyContent();
  }

  Widget bodyContent() {
    List<DataModel> data = [];
    return BlocConsumer<ChatHistoryCubit, ChatHistoryState>(
      listener: (context, state) {},
      builder: (context, state) {
      
        if (state is ChatHistoryLoading) {
          return Container(
              width: MediaQuery
                  .of(context)
                  .size
                  .width,
              child: Center(child: Loading.loadingPage()));
        }
        if (state is ChatHistoryFetch) {
          data = state.data!;
          return showList(
              true, data
          );
        }
      
        if (state is ChatListUpdated) {
          data.addAll(state.data!);
          return showList(false, data);
        }

        return showList(true, data);
      },
    );
  }

  Widget showList(bool toBottom, List<DataModel> data, {String? cast}) {
    if (toBottom) {
      try {
        Timer(Duration(milliseconds: 500),
                () => controller.jumpTo(controller.position.maxScrollExtent));
      } catch (e) {}
    }

    return ListView.builder(
      controller: controller,
      physics: ScrollPhysics(),
      itemBuilder: (BuildContext ctx, int index) {
        if (index == data.length) {
          return Container(height: 60,);
        }
        return ChatItem(data: data[data.length - index - 1], cast: cast);
      },
      itemCount: data.length + 1,
    );
  }
}

Answer 1

Try moving your code that runs the refetching of the chats into init state

  @override
  void initState() {
    context.read<ChatHistoryCubit>().getChatHistory(widget.code);
    super.initState();
  }

Then remove context.read<ChatHistoryCubit>().getChatHistory(widget.code); from pageBuild()