onPopPage method Null safety

  1. @visibleForTesting
bool onPopPage(
  1. Route<Object?> route,
  2. [Object? result]
)

Callback to handle imperative pop or operating system pop event.

route request to be be pop/removed. result provided with the request to pop the route.

Implementation

@visibleForTesting
bool onPopPage(Route<Object?> route, [Object? result]) {
  final bool popSucceeded = route.didPop(result);
  // In the imperative pop, the route can decline to be pop so we
  // need to only update the page if the route has agreed to be pop.
  if (popSucceeded) {
    // the navigator pop always remove the top most page but for safety
    // i prefer to look for the page before popping it.
    DBPage? foundPage;

    for (final DBPage page in _pages) {
      if (page.name == route.settings.name) {
        foundPage = page;
        break;
      }
    }

    _pages.remove(foundPage);

    notifyListeners();
    // if someone is waiting for the result, we remove it and signal
    // the completion.
    final Completer<Object?>? tracker =
        _popResultTracker.remove(foundPage?.name);

    if (tracker?.isCompleted == false) {
      tracker?.complete(result);
    }
  }

  return popSucceeded;
}