SliverStickyHeaderBuilder: add isPinned parameter

[dsparber]

Is it possible to add an additional paramater to the builder function? I.e. to indicate if the header is currently fixed at the top or positioned normally within the scroll view:

For this example isPinned would be true for Header#10 and false for any other visible header.

[letsar]

Hi @DanielSparber.
I will work on this this week-end. I'll keep you posted.

[letsar]

I've got something working in the branch: https://github.com/letsar/flutter_sticky_header/tree/feature/pinned-state.

If this what you had in mind I will publish it.

[dsparber]

Yes, it's exactly what I had in mind. Thanks a lot!

[letsar]

Merged and published, have fun!