Re: GDP: Rhythms: add-grace-property

[Jonathan Kulp]

Ok thanks everyone for responding to this.  What I gather is the following:

1. The "add-grace-property" example currently appearing in NR does not 
work anymore. --#(add-grace-property 'Voice 'Stem 'direction '())  It 
needs to be removed or changed

2. The way to accomplish the same thing is to use the new 
remove-grace-property or Neil's ly:stem::calc-direction instead of '() 
as the direction argument. I got Neil's solution to work but haven't 
grabbed the new file from git to try Carl's.  Will do that tonight.

So, the question is whether it's worth introducing add-grace-property 
and/or remove-grace-property at that point in NR, since it already shows 
how to alter stem direction using \stemDown in a different example right 
before it.  Is it sufficiently abnormal that it should belong to a 
snippet instead of appearing in the main text?  Should I create an 
example that works and then move it to the @snippets area?  This 
question is probably for Carl :)

Jon

Neil Puttock wrote:
> 2008/8/11 Neil Puttock <address@hidden>:
> > Hi Jonathan,
> >
> > 2008/8/11 Jonathan Kulp <address@hidden>:
> >
> > > "The layout of grace expressions can be changed throughout the
> > > music using the function @code{add-grace-property}.  The following
> > > example undefines the @code{Stem} direction for this grace, so
> > > that stems do not always point up."
> > >
> > > @example
> > > \new Staff @{
> > >  #(add-grace-property 'Voice 'Stem 'direction '())
> > >  @dots{}
> > > @}
> > > @end example
> > I suspect this is something that worked many moons ago, but as you've
> > found out, you can't set 'direction to an empty list, or indeed to
> > CENTER.
> >
> > The correct method to make grace notes behave like normal notes would
> > be to use the same 'direction setting callback which the Stem grob
> > uses:
> >
> > #(add-grace-property 'Voice 'Stem ly:stem::calc-direction)
>
> Of course, I completely ballsed this up, since 'direction is missing. :)
>
> #(add-grace-property 'Voice 'Stem 'direction ly:stem::calc-direction)
>
> Though now you can just use Carl's remove-grace-property function
> instead, which will do the same thing without having to worry about
> grob callbacks.
>
> Regards,
> Neil

--
Jonathan Kulp
http://www.jonathankulp.com