ScrollablePositionedList: There seems to be a problem with the widget's state when back to the previous screen when if use listen. about flutter.widgets

[tarobins]

what's the + 2 for in that example?

[oseiasmribeiro]

@tarobins I found that the problem was in the future response from Navigator.push.Then () when I returned to the previous screen. I was erroneously told to clear a list in the Bloc, this made Flutter go through the entire widget tree again until it reached the ScrollablePositionedList, and as the list was empty, the bad state error occurred. But the question remains, didn't the ScrollablePositionedList have to predict this? An example repository follows to analyze where the bad state error occurs when returning. If this is not an error feel free to close the problem. Thank you!
https://github.com/oseiasmribeiro/scrollablepositionedlistbadstate.git

...
Navigator.push(
context,
MaterialPageRoute(builder: (context) => ReadingMessage()),
).then(
(isSearchBar){
_bloc.listTextParagraph.clear(); // PROBLEM IS HERE
_bloc.changeLongPressForShare(false);
FocusScope.of(context).requestFocus(FocusNode());
}
);
...

[oseiasmribeiro]

Today I have more understanding that the ScrollablePositionedList is not to blame for this problem.