handleScrollNotification method

bool handleScrollNotification({ required ScrollNotification notification, required ScrollController scrollController, required ValueNotifier<bool> isCollapsedValueNotifier, CollapsingStateCallback? onCollapseStateChanged, })

Scrolling Notification listener

triggers haptic feedback and snaps the appbar to either collapse or expand depending on which state is closest to the current scrolling offset

Implementation

bool handleScrollNotification({
  required ScrollNotification notification,
  required ScrollController scrollController,
  required ValueNotifier<bool> isCollapsedValueNotifier,
  CollapsingStateCallback? onCollapseStateChanged,
}) {
  /// The position at which we either collapse or expand
  ///
  /// the threshold which if we exceed then we should expand
  /// otherwise we should collapse the appbar
  final double expandThresholdPosition =
      (expandedBarHeight - collapsedBarHeight) / 1.75;

  /// The current position of the scrolling
  final double currentScrollingPosition = scrollController.offset;

  /// sets the collapsed and expanded views as the user scrolls
  //region Update isCollapsed value as user scrolls
  _updateIsAppBarCollapsed(
    isCollapsed: isCollapsedValueNotifier,
    scrollController: scrollController,
    expandThresholdPosition: expandThresholdPosition,
    onCollapseStateChanged: onCollapseStateChanged,
  );
  //endregion

  //region
  if (notification is ScrollEndNotification) {
    _snapAppBar(
      currentScrollingPosition: currentScrollingPosition,
      expandThresholdPosition: expandThresholdPosition,
      scrollController: scrollController,
    );
  }
  //endregion

  return false;
}