usually when elements (incl. controls) are loaded they are all present when the xml
is being transformed into the runtime element tree. during this process each interact
method is being resolved, tracing all controllers from top to bottom leading a list
of controller instances for each method.
This returns an informational String containing all elements that Nifty is aware of that
could handle mouse events with the ones currently hovering the mouse sorted from top to
bottom.
one value: [applied to all]
two values: [top and bottom], [left and right]
three values: [top], [left and right], [bottom]
four values: [top], [right], [bottom], [left]
Deprecated.This implementation only exists for legacy reasons and is likely
to be dropped in future versions. Better use the implementations
in the package de.lessvoid.nifty.spi.time.impl