redesign Sound Hardware Preferences

[Be]

In 2.0 and 2.1 many more options were added to the Sound Hardware Preferences but the design grew to be unwieldy. It could really use a redesign. There is lots of legacy code for this part of the preferences, so it could be somewhat tricky. I have a few ideas for improving the design:

* Replace Output and Input tabs with Internal Mixing and External Mixing tabs, each with an Output and Input section.
* Add descriptive text for each input and output explaining what they do so users should not need to refer to the manual for basic setup
* Move options that are currently in a huge list of comboboxes above the I/O selection next to the input or output they affect. For example, the Master Output Mode combobox could be replaced with a checkbox labeled "Downmix to Mono" next to the Master output selection; the Master, Headphone, and Booth delay spinboxes could be next to their respective outputs; and the Microphone monitor mode and latency compensation options could be moved by the Microphone section

[Be (be.ing)]

Anyone want to volunteer to do this for 2.2?

[Be (be.ing)]

Links to the manual should be added where appropriate. I'm especially thinking about the Microphone latency compensation option.

[Sébastien BLAISOT (sblaisot)]

regarding links to the manual, we need some sort of permalink to avoid broken links in the future.

[Be (be.ing)]

Sean, do you want to do this for 2.2? If so, please assign yourself to this.

[ronso0 (ronso0)]

this is one the project proposals for Outreachy 2020/21

[Swiftb0y (swiftb0y)]

Mixxx now uses GitHub for bug tracking. This bug has been migrated to:
https://github.com/mixxxdj/mixxx/issues/9065