So maybe I'm just reading into this wrong but to me the way this function is named and the values this is returning this makes me think the purpose is to determine which side the `draggingView` is coming from.

When I was trying this locally and looking at the values of all your diffs I noticed when dragging from the right onto another trackevent it doesn't hit this condition where you return `right` but actually where you return `left`.

Am I crazy for thinking this function should be refactored to follow that "flow"?