Codeshare between ExpansionTile and its Cupertino variant #163552
Description
Document Link
flutter.dev/go/expansible-state-mixin
What problem are you solving?
This issue contains a proposal to add a CupertinoCollapsible widget, an animated container that can be expanded or collapsed.
The behavior of this CupertinoCollapsible is very similar to ExpansionTile, which sits nicely in the Material library.
Due to their similarity, it makes sense for CupertinoCollapsible to codeshare with ExpansionTile, instead of having its own independent implementation. This would also make it easier for developers to build components that require expanding/collapsing behavior.
WIP PRs:
Approach 1: ExpansibleStateMixin
Approach 2: Expansible