Sorry. I did a little more testing and it turns out there was a little error in calculating the grab area for vertical sliders (my program only uses horizontal). Upper/Lower wasn't very clear in this case when "upper" (the extent value) actually has a lower y then the "lower" (normal value). Hopefully this new naming convention makes things a little more clear regardless of the orientation.
Sorry. I did a little more testing and it turns out there was a little error in calculating the grab area for vertical sliders (my program only uses horizontal). Upper/Lower wasn't very clear in this case when "upper" (the extent value) actually has a lower y then the "lower" (normal value). Hopefully this new naming convention makes things a little more clear regardless of the orientation.
Take care.