How to override the minimum height in SliverAppBar

Question

I am having a problem where I can't decrease the SliverAppBar as I need. I found out that it has some kind of minHeight constraint that has to deal with some animation and layout stuff. I have a TextButton.icon and some Text in it which don't take up much space. I need the behavior of the SliverAppBar of floating. Is there a way to decrease the height freely without any constraints?

Answer 1

You can use SliverToBoxAdapter and then use a Sizedbox or for more flexibility you can use SliverPersistentHeader.

class MySliverAppBarDelegant extends SliverPersistentHeaderDelegate {
  @override
  Widget build(
      BuildContext context, double shrinkOffset, bool overlapsContent) {
    return Container();
  }

  @override
  double get maxExtent => 40; //use same for fixed height
  @override
  double get minExtent => 30;

  @override
  bool shouldRebuild(covariant SliverPersistentHeaderDelegate oldDelegate) =>
      false;
}

And use like

SliverPersistentHeader(
  delegate: MySliverAppBarDelegant(),
  pinned: true,
)