Currently, a bottom sheet can either be dragged or have a scrollable child, but not both.
I've implemented support for this in the linked PR. However, in order to do so I'm requiring that the child of a bottom sheet have a scrollable widget with primary set to true. This allows a bottom sheet to be dragged vertically and scroll its child when it reaches full height. As currently implemented, an assertion will be thrown if you try to show a bottom sheet that does not have a scrollable child. A simple way to fix this is to wrap your existing child in a SingleChildScrollView with primary set to true. If it is already a ListView or GridView, you should add "primary: true" to the arguments of the constructor.
I'm very open to feedback on this - if there's a work around that allows us to achieve the following without adding this requirement I think it'd be great:
- Support dragging the bottom sheet vertically
- Support scrolling the interior contents of the bottom sheet if its contents overflow the height of the screen (or otherwise overflow the max height of the bottom sheet)
- Support all gestures as expected for children of the bottom sheet