Add getter for floatingActionButtonLocation in ScaffoldState

[kacpmu]

Use case

During development of custom bottom app bar I ran into the issue where I need to place items differently based on Scaffold's FAB location.

My current workaround:

class NewScaffold extends Scaffold {
  const NewScaffold({
    super.key, 
    super.appBar,
    super.body,
    super.floatingActionButton,
    // ... and so on, truncated for readability
  });

  @override
  ScaffoldState createState() => NewScaffoldState();

  static NewScaffoldState of(BuildContext context) {
    final NewScaffoldState? result = context.findAncestorStateOfType<NewScaffoldState>();
    if (result != null) {
      return result;
    }
    throw Exception();
  }
}

class NewScaffoldState extends ScaffoldState {
  NewScaffoldState() : super();

  FloatingActionButtonLocation get floatingActionButtonLocation
      => widget.floatingActionButtonLocation ?? FloatingActionButtonLocation.endFloat;
}

Then:

final fabLocation = NewScaffold.of(context).floatingActionButtonLocation;

Which is just fine, because as of today, the internal _floatingActionButtonLocation changes only if widget.floatingActionButtonLocation is changed.

Of course I could simply pass current FAB location to my custom bottom app bar, but it's not the point.

Proposal

Add getter to ScaffoldState:

FloatingActionButtonLocation get floatingActionButtonLocation
      => _floatingActionButtonLocation!; // if widget.floatingActionButtonLocation is null, then it has a value of _kDefaultFloatingActionButtonLocation

[Piinks]

Hi @kacpmu, the ScaffoldState should not be needed to access the FloatingActionButtonLocation. By default it is FloatingActionButtonLocation.endFloat, otherwise it is whatever location you have provided to Scaffold.floatingActionButtonLocation. Is there a case that requires getting that value from the state of the Scaffold?

[kacpmu]

By getting that value from the Scaffold's state I could provide very easy to use and more responsive implementation that does not require setup. Of course, I could pass current FAB location directly into the bottom app bar, but I would like to obtain this info without doing so, since it requires yet another state in your app to be properly managed or at least another place you need to put this info for your widget. On the other hand, Scaffold's state is already out there and may be utilized.