Re: vert. spacing: Rename properties (lily, scm). (issue3031041)

[markpolesky]

On 2010/11/12 21:53:41, Mark Polesky wrote:
> I might like to keep staff-staff-spacing for the StaffGrouper
> prop. I'm thinking it over, and I'll get back to you.

Guys, I'd rather not change StaffGrouper's
'staff-staff-spacing to 'default-staff-staff-spacing.  The
big reason for me is that it is no more a "default spacing"
than its companion property 'staffgroup-staff-spacing, and
it would be very weird to call that one
'default-staffgroup-staff-spacing.

One way of seeing the interaction between the involved
properties is as a cascade of fallback options, with
VerticalAxisGroup's 'staff-staff-spacing being the first one
to consult, and VerticalAxisGroup's
'default-staff-staff-spacing being the last resort when
nothing else is available:

1)  Staff.VerticalAxisGroup #'staff-staff-spacing
    - distance between this staff and the one below it in
      the same system.

2a) StaffGroup.StaffGrouper #'staff-staff-spacing
    - the settings to use for #1 when unset, for all staves
      in the staff-group except the last one.

2b) StaffGroup.StaffGrouper #'staffgroup-staff-spacing
    - the settings to use for #1 when unset, for the last
      staff in the staff-group.

3)  Staff.VerticalAxisGroup #'default-staff-staff-spacing
    - the settings to use for #1 when none of the above are
      available.

Viewed in this way, it's clear that the StaffGrouper
properties are on the same "cascade level", each applying to
one of two cases within the staff-group (last-staff or
not-last-staff).  So I think we should reserve the word
"default" for #3, which is the real end of the line, as I
see it.

If you're okay with that logic, then all that remains is to
find a better way to explain both #1 and #2a using a single
property-description, since they share the same name.  I
propose this:

staff-staff-spacing

When applied to a staff-group's StaffGrouper grob, this
spacing alist controls the distance between consecutive
staves within the staff-group.  When applied to a staff's
VerticalAxisGroup grob, it controls the distance between the
staff and the nearest staff below it, replacing any settings
inherited from the StaffGrouper grob of the containing
staff-group, if there is one.

What do you think?

Thanks.
- Mark

http://codereview.appspot.com/3031041/