Issue 1357 in lilypond: Enhancement: autochange improvements

[lilypond]

Status: Accepted
Owner: v.villenave
Labels: Type-Enhancement Priority-Low autochange Frog

New issue 1357 by v.villenave: Enhancement: autochange improvements
http://code.google.com/p/lilypond/issues/detail?id=1357

Here are a couple of ideas of what I intend to implement in the autochange  
function.

First off, the pitch that acts as a "turning point" to change between  
staves should be customizable.  I have already posted a workaround on  
-user-fr:
http://lists.gnu.org/archive/html/lilypond-user-fr/2010-10/msg00188.html
but I plan to make it easier to use, possibly by adding at a  
new 'autoChangePitch context-property (that would default to the middle C,  
but could be modified on-the-fly as well).

Secondly, the autochange iterator currently relies on two hard-coded Staff  
contexts named "up" and "down". It's rather ugly and should be  
user-settable instead. My plan is to add the contexts' names as an argument  
to the \autochange macro. Then we could write a convert-rule that would  
turn the old
\autochange { music }
syntax, into something like
\autochange #'("up" . "down") { music }

The second part is more involved coding-wise, but that's a long-term plan.  
(Of course, I certainly won't mind if someone else steps in before I do,  
possibly a Frog and preferably with better ideas! :-)