Re: Translator todos

[Erik Sandberg]

On Wednesday 04 October 2006 13:53, Han-Wen Nienhuys wrote:
> Erik Sandberg schreef:
> > OK. Should I try to do the same for created grobs, too? It shouldn't be
> > that difficult, just add some code to the make_item macro, which
> > registers an init function that adds the symbol to a list. There will be
> > problems with a few engravers (piano-pedal and system-start-delimiter),
> > but those should be solvable.
>
> Hi,
>
> I had a brief thought over this. It would be possible to do this, by
> changing the mechanics of creating grobs. Rather than doing
>
>    clef = make_item("Clef", cause)
>
> we should use C++ function that have a similar mechanism to listners and
> acknowledgers, ie.
>
>
>    DECLARE_CREATOR(clef);
>
>
>    ..
>
>    clef = make_clef (cause);
>    ..
>
> using some layers, make_clef will call
>
>    Grob *
>    Clef_engraver::create_clef (SCM cause)
>    {
>      return make_item ("Clef", cause);
>    }
>
> Of course, this is the standard, default case, which would be
>        done with a IMPLEMENT_DEFAULT_CREATOR() macro.
>
> However, if we have this, it would be feasible to register/override
> Scheme functions for creation, eg.
>
>    \set Staff.clefEngraverClefCreator =
>    #(lambda (context cause . other_args)
>      (let*
>       ((c (ly:context-make-grob context 'Clef)))
>
>       (ly:grob-set-property! c 'cause cause)
>       c))
>
> this would make it possible to softcode loads of functionality, in terms
> of connecting grobs and setting grob properties.

This sounds very cool; I can look into it after 2.10 if you like.

-- 
Erik