"MIDI From" dropdowns within MIDI Mappings

[ltackett]

Binding should be able to be filtered by device, so that we don't have to rely on Channel so much for multi-controller bindings.

Consider the following mockup:



Values for Channel should also be a dropdown.

[toeman]

my wish is to ALSO be able to select ONLY CERTAIN notes you want as midi-in, so you can automate seperate notes!