focusManager property Null safety

The object in charge of the focus tree.

Rarely used directly. Instead, consider using FocusScope.of to obtain the FocusScopeNode for a given BuildContext.

See FocusManager for more details.

This field will default to a FocusManager that has registered its global input handlers via FocusManager.registerGlobalHandlers. Callers wishing to avoid registering those handlers (and modifying the associated static state) can explicitly pass a focus manager to the BuildOwner.new constructor.