Re: space the width of key signature

[David Nalesnik]

On Mon, Jul 4, 2016 at 2:15 PM, Thomas Morley <address@hidden> wrote:

>
> thanks a lot for your research and findings.

You're welcome!

> Your suggestions are all implemented leading to geat simplifications.
> In `keep-at-line-begin' I added some fool-proof.
> Regrettable StanzaNumber does not respond correctly for 'break-visibility...

I did some further investigation.

break-visibility would work on StanzaNumber if it were associated with
a NonMusicalPaperColumn.  "Non-musical"  grobs such as Clef and
KeySignature are copied twice and exist in three forms per measure at
one point: one for beginning-of-line, one for mid-line, one-for
end-of-line, to be used or discarded when line breaks are decided --
lots of grobs are suicided.  The unneeded grobs are thrown out based
on the break-direction.

If you apply ly:item-break-dir to StanzaNumber you will always get 0 =
unbroken, so break-visibility is useless.  The extra copies aren't
made for "musical" items, anyway.

The trick I used was to locate a neighboring NonMusicalPaprtColumn,
which would have break-directions of -1, 0, or 1.  You could extend
the procedure for determining line beginnings by looking at
'right-column for line ends.

David