Previously, the resulting distance was considered as a time value,
not a step value. For discrete time models, this coincidently does
the right thing, but for continuous time models this does not work as expected.
Technically, as engine.getPathSize() is a long and the value from the text box
is an int, the result is a long and that leads Java to prefer the a_backTrack(double)
and a_autoStep(double) variants of these methods. We cast to an int to ensure
that the int-parameter variants are taken.