Is there a magic method that accepts two views and returns how close they are to one another (perhaps the x and y distances)? Or is this something that must be done manually?
Manually. As long as there is no transform applied to the views, it shouldn't be that hard to write some code that would calculate the distance between the 2 view's frame rectangles.
Thinking out loud here:
If you can't draw a vertical and horizontal line in the space between the 2 views frame rectangles, the distance will be the x distance or y distance between the nearest sides.
If you can draw both a horizontal line and a vertical line between the views (they don't overlap in either the x dimension or the y dimension) then the distance between the 2 views will be the pythagorean distance between their nearest corners.