Re: Defining new contexts

[Thomas Morley]

2015-02-23 9:56 GMT+01:00 Jim Long <address@hidden>:
> I'm experimenting with defining and using custom contexts.
>
> I have not succeeded in applying the example at:
>
> http://lilypond.org/doc/v2.18/Documentation/notation/defining-new-contexts
>
> to my tiny example below attempting the creation of a custom
> ChordNames context.  The '\new XChords' line throws a warning:
>
> GNU LilyPond 2.18.2
> Processing `foo.ly'
> Parsing...
> Interpreting music...
> Preprocessing graphical objects...
> Interpreting music...
> warning: cannot find or create new `XChords'
> Preprocessing graphical objects...
> Finding the ideal number of pages...
> Fitting music on 1 page...
> Drawing systems...
> Layout output to `foo.ps'...
> Converting to `./foo.pdf'...
> Success: compilation successfully completed
>
>
> How can I modify the second score's source to have the scores
> engrave the same in the output file?
>
> Thank you!
>
> Jim
>
>
> \version "2.18.2"
>
> \score {
>   \layout {
>     \context {
>       \ChordNames
>         \override ChordName.font-size = #12
>     } % context
>   } % layout
>   <<
>     \new ChordNames \chordmode { c1 }
>     \new Staff      \chordmode { c1 }
>   >>
> }
>
>
> \score {
>   \layout {
>     \context {
>       \name XChords
>         \alias ChordNames
>         \override ChordName.font-size = #12
>         \type "Engraver_group"
>     } % context
>   } % layout
>   <<
>     \new XChords \chordmode { c1 }
>     \new Staff   \chordmode { c1 }
>   >>
> }



Try the following, comments inline:

\score {
  <<
    \new XChords \chordmode { c1 }
    \new Staff   \chordmode { c1 }
  >>
  \layout {
    \context {
      %% copies settings from ChordNames
      %% No need to create a new context from scratch
      \ChordNames
      \name XChords
      \alias ChordNames
      \override ChordName.font-size = #12
    }
    %% let Score accept XChords, likely need to let it be accepted by other
    %% context as well. I.e. do the same for Pianostaff, GrandStaff, ChoirStaff,
    %% maybe more, have a look in engraver-init.ly to see which contexts
    %% accept the default ChordNames
    \context {
            \Score
            \accepts XChords
    }
  } % layout
}

HTH,
  Harm