#1 A Flutter Widget for an AppBar that is initially flush with elevated when scrolled

appbar elevation

a flutter widget for an appbar that is initially flush with the body and elevated when scrolled.

usage

use the scrollactivatedappbarelevation widget to wrap a scaffold that contains
a scrollable view (e.g. listview, customscrollview). the widget uses a
notificationlistener to detect the scroll position and provides an
appbarelevation value to be used.

example

@override
widget build(buildcontext context) {
  return scrollactivatedappbarelevation(
    builder: (buildcontext context, double appbarelevation) {
      return scaffold(
        appbar: appbar(
          elevation: appbarelevation,
        ),
        body: listview(
          children: [
            // ...
          ],
        ),
      );
    },
  );
}

see example for full code.