Function scroll_handle 

pub fn scroll_handle(handle: &UniformListScrollHandle) -> ScrollHandle

The pixel-space scroll handle inside a UniformListScrollHandle.

uniform_list tracks its scrolling through this one, so it carries the offset, the maximum offset and the viewport that crate::scroll::thumb needs — a virtualized list takes the same bar as any other scroller, with no second implementation behind a trait.

The clone shares state rather than copying it: the returned handle is the list’s, and moving one moves the other.