of static method

ArnaScaffoldState of(BuildContext context)

Finds the ArnaScaffoldState from the closest instance of this class that encloses the given context.

If no instance of this class encloses the given context, will cause an assert in debug mode, and throw an exception in release mode.

This method can be expensive (it walks the element tree).

A more efficient solution is to split your build function into several widgets. This introduces a new context from which you can obtain the ArnaScaffold. In this solution, you would have an outer widget that creates the ArnaScaffold populated by instances of your new inner widgets, and then in these inner widgets you would use ArnaScaffold.of.

A less elegant but more expedient solution is assign a GlobalKey to the ArnaScaffold, then use the key.currentState property to obtain the ArnaScaffoldState rather than using the ArnaScaffold.of function.

If there is no ArnaScaffold in scope, then this will throw an exception. To return null if there is no ArnaScaffold, use maybeOf instead.

Implementation

static ArnaScaffoldState of(BuildContext context) {
  final ArnaScaffoldState? result =
      context.findAncestorStateOfType<ArnaScaffoldState>();
  if (result != null) {
    return result;
  }
  throw FlutterError.fromParts(<DiagnosticsNode>[
    ErrorSummary(
      'ArnaScaffold.of() called with a context that does not contain an ArnaScaffold.',
    ),
    ErrorDescription(
      'No ArnaScaffold ancestor could be found starting from the context that was passed to ArnaScaffold.of(). '
      'This usually happens when the context provided is from the same StatefulWidget as that '
      'whose build function actually creates the ArnaScaffold widget being sought.',
    ),
    ErrorHint(
      'There are several ways to avoid this problem. The simplest is to use a Builder to get a '
      'context that is "under" the ArnaScaffold. For an example of this, please see the '
      'documentation for ArnaScaffold.of().',
    ),
    ErrorHint(
      'A more efficient solution is to split your build function into several widgets. This '
      'introduces a new context from which you can obtain the ArnaScaffold. In this solution, '
      'you would have an outer widget that creates the ArnaScaffold populated by instances of '
      'your new inner widgets, and then in these inner widgets you would use ArnaScaffold.of().\n'
      'A less elegant but more expedient solution is assign a GlobalKey to the ArnaScaffold, '
      'then use the key.currentState property to obtain the ArnaScaffoldState rather than '
      'using the ArnaScaffold.of() function.',
    ),
    context.describeElement('The context used was'),
  ]);
}