[Discussions] Selection Text

[dath7]

Content

Content

Hi,
I use flutter_scrollview_observer for rendering list messages, and my case is after i select some texts and new message appear, the selection of text lost.

I have followed wiki.

I think the problem is my reversed list. Can you give me some recommend to solve this problem ? Thanks a lot.

My snippet code below:

ListViewObserver(
      controller: observerController,
      child:CustomSelectionArea(
            child: ListView.builder(
              physics: ChatObserverClampingScrollPhysics(observer: chatObserver),
              shrinkWrap: true,
              controller: widget.scrollController,
              reverse: true,
              itemCount: data.length,
              itemBuilder: (context, index) {
                  final message = data[index];
                  return ChatItem(message: message)
              }))

[LinXunFeng]

This should be a bug of SelectionArea.
Related issue: flutter/flutter#124787

[dath7]

Sorry for my late reply.
I think that related issue isn't same as my case. In my case, when new item appears, it's inserted at 0 so entire list has to rebuild and the selection of item lost.

Can you give me some recommend to solve this problem? Thanks a lot.

Example

Screen.Recording.2024-07-22.at.08.17.00.mov

[LinXunFeng]

I think you can pause the update of ListView when selecting text.

bool canUpdateListView = true;

Widget resultWidget = ChatItemWidget(
  ...
);
resultWidget = SelectionArea(
  child: resultWidget,
  onSelectionChanged: (value) {
    canUpdateListView = value?.plainText == null;
    // The text is no longer selected. Update the ListView to display all the latest messages.
    if (canUpdateListView) {
      setState(() {});
    }
  },
);
return resultWidget;

_addMessage(int count) {
  chatObserver.standby(changeCount: count);
  needIncrementUnreadMsgCount = true;
  for (var i = 0; i < count; i++) {
    chatModels.insert(0, ChatDataHelper.createChatModel());
  }

  // Currently selecting text.
  if (!canUpdateListView) return;
  setState(() {});
}

[dath7]

Let me try.
Thanks a lot!