control up/down arrows to navigate between staff layers and staves

[craigsapp]

Related to issue https://github.com/humdrum-tools/verovio-humdrum-viewer/issues/95, implement control-up/down arrows to navigate between layers on a staff and between staves.

[craigsapp]

And possibly to also navigate to other notes in a chord. (i.e., control-up/down could be to navigate vertically (harmonically) while regular up/down is for horizontal navigation (melodic navigation).

[craigsapp]

Also, once this is implemented, then perhaps make up/down and left/right navigation of notes by plain arrow keys, and then make pitch transposition be control-up/down arrows. (currently pitch transposition is plain up/down and control up/down has no meaning, other than the control key being ignored).

[craigsapp]

Implemented with commit https://github.com/humdrum-tools/verovio-humdrum-viewer/commit/84985a3a2ce4ecad8ccd46f0d5c2b47fe3b30efb

[craigsapp]

The method of graphically editing pitch has now changed, related to this feature addition: To change pitch, use shift-up/down arrows, and to transpose an octave use control-up/down arrows. To transpose up a fifth would be 5 then shift-up arrow.

Commit for this change: https://github.com/humdrum-tools/verovio-humdrum-viewer/commit/f3d0d33a1bde83f1f3baa72ef0e9162da3d4d7a6

The help menu is updated for these changes:

And the documentation page about graphical editing of pitch is update:

http://doc.verovio.humdrum.org/graphic/pitch

And specifically added a section about arrow-key navigation on the above page, with a video demo:

http://doc.verovio.humdrum.org/graphic/pitch/#graphical-notation-navigation

Probably shift-left/right can be mapped to jump to the next/previous measure or system on the page, and control-left/right can be mapped to moving to the next/previous page (regular left/right arrow keys will also be for moving by page when a note/rest is not being edited).

There are still some problems with editing notes in chords to deal with.