Re: Determine \voiceXXX implicitly

[David Kastrup]

address@hidden writes:

> Hi,
>
> I recall that we had such a discussion some years ago when we worked
> at the Layout Control Options for Frescobaldi. IIRC there wasn't a
> viable solution, but maybe things have changed and maybe I know more
> today ...
>
> Is it possible to determine from inspecting a grob whether its
> properties have been set automatically or by explicit voice
> attribution? Concretely I'm talking about attribution through the << {
> } \\ { } >> construct.
>
> When dealing with a Tie or Slur object I can see its 'direction
> property, but I can't see if that has been calculated automatically,
> manually overridden through \override or \tweak, or set through a
> \voiceXXX command or the polyphony construct.
>
> But *is* there a way to determine such a situation? I think the
> \voiceXXX commands only set a number of properties, but there's no
> information about that "act", right? What I could imagine is adding a
> custom grob property and set this by redefining \voiceXXX. But can I
> do something comparable for the temporary polyphony construct?
>
> I need this because in my current project I need to place ties not
> according to LilyPond's algorithms but always opposite of the stem
> direction - but only in a \oneVoice context. With \voiceOne also ties
> have to go upwards, just like usual.
>
> Any suggestions?

Put the corresponding direction callback override at Staff level or
anywhere outside of Voice, then it will be overriden by \voice... or
{ \\ }.

-- 
David Kastrup