[Denemo-devel] Tidying up the main structures

[Richard Shann]

This is long overdue. As an example of the problems the preferences are
attached to the DenemoScore structure, yet they belong at the very top
level (above DenemoGUI) since if you have two denemo windows open and
change the preferences in each then as you quit each window the
preferences get overwritten - which you get next time you start Denemo
depends on the order you quit the windows. And there is a global list
called "displays" which lurks rather in the code - it is really the root
structure in Denemo.
I propose to replace the global variable "displays" with a structure
DenemoRoot containing the list of DenemoGUI and the preferences. The
DenemoGUI corresponds to a Denemo file on disk as at present. It all the
GUI stuff together with stuff that applies to the whole piece of music -
a list of DenemoScore representing movements in the piece and the
DenemoScore si pointer to the current movement and the header data that
applies to the whole piece. The DenemoScore corresponds to a single
\score {} block in the output LilyPond, ie to a single movement (as at
present, but currently Denemo is limited to one movement).
This will actually be quite painless in terms of the code changes. The
names of the structures are a little unfortunate - ultimately stemming
from LilyPond's name \score for a single movement in what is normally
called a score. But I think we can live with that.

Comments please,

Richard