be honest: the graphical display is output, not input.
Yes, certainly, but
If you are using a toolkit that has a data flow of the
following:
pointer motion->graphical display->values->application->output
Well, basically that is broken as you have a flow that is
input->output->input->application->output
I believe it's
input -- output (graphical display)
|_ application -> output (audio)
Once the slider is drawn to the screen, it does not feed back into the
application, so
input->application->output
is, in fact, part of the flow. The two components of output that you
mention are provided independently in parallel branches.