resolve method

InheritedProperties resolve(BuildContext context)

Resolves an InheritedProperties by calling callbacks on top of parent's values.

If the parent's values are unchanged, the cached resolved set will be used.

Implementation

InheritedProperties resolve(BuildContext context) {
  final parentResolved = parent?.resolve(context) ??
      const InheritedProperties._(null, [], TextStyle());
  final scopedCallbacks = _callbacks;
  if (scopedCallbacks == null) {
    return parentResolved;
  }

  final cache = _cachedResolved;
  if (cache != null && identical(parentResolved, _cachedParent)) {
    return cache;
  }

  var resolving = parentResolved.copyWith(parent: parentResolved);
  for (final callback in scopedCallbacks) {
    resolving = callback(context, resolving);
    assert(
      identical(resolving.parent, parentResolved),
      'The inherited properties set should be modified by calling copyWith() '
      'to preserve parent reference.',
    );
  }

  // performance critical
  // keep track of both the parent's and the resolved set -> skip resolving if possible
  // under normal circumstances, the root properties shouldn't be invalidated a lot
  _cachedParent = parentResolved;
  _cachedResolved = resolving;

  return resolving;
}