The handle of the Split widget should have a minimum hit area

[s3thi]

You can only interact with the handle of the Split widget if you place your cursor exactly within its bounds. On some operating systems -- for example macOS -- you can place your cursor a tiny bit outside the bounds of the splitter handle and still be able to interact with it.

It would be useful to have this feature in Druid's Split widget as well. This would allow you to make your splitter barely visible -- say only 4px wide -- but still let users interact with it if they place their cursor 2px to the left or right of the visible area.

A good way to do this would be to specify a minimum hit area for the splitter handle. If you ask for a handle that has a width less than the minimum hit area, the widget will still capture events that occur within the minimum area.