This PR contains:
- 3 instances of `colorScheme.background` â `colorScheme.surface`
- and a whole bunch of `MaterialState` â `WidgetState`
As of yet, no changes have been made to example test files or the [examples/api/lib/material/material_state/](0b2a8e589e/examples/api/lib/material/material_state) directory.
(related: #151373)
A sliver that shows its [child] when the user scrolls forward and hides it when the user scrolls backwards. Similar headers can be found in Google Photos and Facebook.
This sliver is preferable to the general purpose SliverPersistentHeader for its relatively narrow use case because there's no need to create a SliverPersistentHeaderDelegate or to predict the header's size.
https://github.com/flutter/flutter/assets/1377460/82b67dfb-5d38-4adf-9415-fc8527d0eb9f