maybeOf static method

AdvancedNavigatorState? maybeOf(BuildContext context, { bool rootNavigator = false, int skip = 0, String? tag, })

The navigator state from the closest instance of this class that encloses the given context, if any.

Typical usage is as follows:

AdvancedNavigatorState? navigator = AdvancedNavigator.maybeOf(context);
if (navigator != null) {
  navigator
    ..pop()
    ..pop()
    ..pushNamed('/settings');
}

The skip argument denominates the number of instances to be skipped when searching up the widget tree for an instance of AdvancedNavigator.

With the tag argument specified, only navigators with a matching tag will be considered. Should multiple navigators carry a matching tag, the closest instance after skipping skip instances will be returned.

If rootNavigator is set to true, both skip and tag are ignored and the state from the furthest instance of this class is given instead. Useful for pushing contents above all subsequent instances of AdvancedNavigator.

Will return null if there is no matching ancestor AdvancedNavigator in the context.

Implementation

static AdvancedNavigatorState? maybeOf(
  BuildContext context, {
  bool rootNavigator = false,
  int skip = 0,
  String? tag,
}) {
  assert(rootNavigator || skip >= 0);
  AdvancedNavigatorState? navigator;
  // Handles the case where the input context is a navigator element.
  if (context is StatefulElement && context.state is AdvancedNavigatorState) {
    navigator = context.state as AdvancedNavigatorState;
  }
  if (rootNavigator) {
    navigator = context.findRootAncestorStateOfType<AdvancedNavigatorState>();
  } else {
    context.visitAncestorElements((element) {
      if (element is StatefulElement) {
        var state = element.state;
        if (state is AdvancedNavigatorState) {
          if (tag == null || tag == state.tag) {
            if (skip == 0) {
              navigator = state;
              return false;
            }
            skip--;
          }
        }
      }
      return true;
    });
  }
  return navigator;
}