SliverPersistentHeaderDelegate Example

sliverPersistentHeaderDelegate.dart

/*
SliverPersistentHeader(
  pinned: true,
  floating: true,
  delegate: OurDelegate(
    toolBarHeight: MediaQuery.of(context).padding.top,
    openHeight: 250,
    closedHeight: 40,
  ),
),
*/

class OurDelegate extends SliverPersistentHeaderDelegate {
  double toolBarHeight;
  //toolBarHeight Included in both
  double closedHeight;
  double openHeight;

  OurDelegate({
    this.toolBarHeight,
    this.closedHeight,
    this.openHeight,
  });

  @override
  Widget build(BuildContext context, double shrinkOffset, bool overlapsContent){
    return Container(
      height: toolBarHeight + openHeight,
      color: Theme.of(context).primaryColorDark,
      child: SafeArea(
        child: Container(
          padding: EdgeInsets.symmetric(
            horizontal: 64,
          ),
          child: FittedBox(
            fit: BoxFit.contain,
            child: Text("Workouts"),
          ),
        ),
      ),
    );
  }

  @override
  double get maxExtent => toolBarHeight + openHeight;

  @override
  double get minExtent => toolBarHeight + closedHeight;

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