Re: Defining 'not-last-page'

[Nick Payne]

On 15/07/11 10:20, Matthew Collett wrote:
> titling-init.ly contains the following definitions:
>
> #(define (first-page layout props arg)
>    (if (book-first-page? layout props)
>        (interpret-markup layout props arg)
>        empty-stencil))
>
> #(define (last-page layout props arg)
>    (if (book-last-page? layout props)
>        (interpret-markup layout props arg)
>        empty-stencil))
>
> #(define (not-first-page layout props arg)
>    (if (not (book-first-page? layout props))
>        (interpret-markup layout props arg)
>        empty-stencil))
>
> Given these, it would seem to be trivial to complete the set by defining
>
> #(define (not-last-page layout props arg)
>    (if (not (book-last-page? layout props))
>        (interpret-markup layout props arg)
>        empty-stencil))
>
> However, any attempt to _use_ this results in 'ERROR: Unbound variable: 
> book-last-page?'.  This is extremely Schemely puzzling, since in exactly the 
> same context 'last-page' works fine, even though it references the same 
> putatively AWOL variable. For example,
>
> \paper {
>    oddHeaderMarkup = \markup { \fill-line {
>      \null
>      \fromproperty #'page:page-number-string
>      {
>        \on-the-fly #not-last-page { "More ..." }
>        \on-the-fly #last-page { "No more." }
>      }
>    }}
>    evenHeaderMarkup =  \oddHeaderMarkup
> }
> \markup{}
> \pageBreak
> \markup{}
>
> works as expected with the 'not-last-page' line commented out.  What is really 
> going on here, and how can I get 'not-last-page' to work?

 This works for me:

\paper {
    #(define (print-positive-page-number layout props arg)
        (if (> (chain-assoc-get 'page:page-number props -1) 0)
            (create-page-number-stencil layout props arg)
                empty-stencil))

    %% cf. ly/titling-init.ly
    #(define (not-last-page layout props arg)
        (if (and (chain-assoc-get 'page:is-bookpart-last-page props #f)
            (chain-assoc-get 'page:is-last-bookpart props #f))
            empty-stencil
            (interpret-markup layout props arg)))

    oddHeaderMarkup = \markup \fill-line { " " }
    evenHeaderMarkup = \markup \fill-line { " " }
    oddFooterMarkup = \markup \fill-line { \column { \fontsize #-1
        \on-the-fly #not-first-page \on-the-fly #not-last-page 
\on-the-fly #print-positive-page-number
        \fromproperty #'page:page-number-string \on-the-fly #last-page 
\fromproperty #'header:tagline
    } }
    evenFooterMarkup = \markup \fill-line { \column { \fontsize #-1
        \on-the-fly #not-first-page \on-the-fly #not-last-page 
\on-the-fly #print-positive-page-number
        \fromproperty #'page:page-number-string \on-the-fly #last-page 
\fromproperty #'header:tagline
    } }
}


Nick