Re: Displaying typesetting information at compile time

[Richard Shann]

On Sun, 2022-03-20 at 20:09 +0100, Jean Abou Samra wrote:
> 
> 
> Le 20/03/2022 à 19:09, Richard Shann a écrit :
> > On Sun, 2022-03-20 at 18:43 +0100, Jean Abou Samra wrote:
> > > \version "2.22.2"
> > > 
> > > markWithPageInfo =
> > >     %% Must not get called before line breaking
> > >     \tweak X-extent #'(0 . 0)
> > >     \tweak Y-extent #'(0 . 0)
> > >     \tweak horizontal-skylines
> > >       #(ly:make-unpure-pure-container ly:grob::simple-horizontal-
> > > skylines-from-extents)
> > >     \tweak vertical-skylines
> > >       #(ly:make-unpure-pure-container ly:grob::simple-vertical-
> > > skylines-from-extents)
> > >     \tweak stencil
> > >       #(lambda (grob)
> > >          (let* ((sys (ly:grob-system grob))
> > >                 ;; No broken pieces for systems ...
> > >                 (alignment (ly:grob-object sys 'vertical-
> > > alignment))
> > >                 (all-alignments (ly:spanner-broken-into (ly:grob-
> > > original alignment)))
> > >                 (all-systems (map ly:grob-system all-alignments))
> > >                 (n-systems (length all-systems))
> > >                 (all-pages (map (lambda (s) (ly:grob-property s
> > > 'page-
> > > number))
> > >                                 all-systems))
> > >                 (n-pages (1+ (- (apply max all-pages)
> > >                                 (apply min all-pages))))
> > >                 (layout (ly:grob-layout grob))
> > >                 (defs (append `((n-systems . ,(number->string n-
> > > systems))
> > >                                 (n-pages . ,(number->string n-
> > > pages)))
> > >                               (ly:output-def-lookup layout 'text-
> > > font-
> > > defaults)))
> > >                 (props (ly:grob-alist-chain grob defs))
> > >                 (text (ly:grob-property grob 'text)))
> > >            (interpret-markup layout props text)))
> > >     \mark \etc
> > > 
> > > {
> > >     \markWithPageInfo \markup { Have \fromproperty #'n-systems
> > > systems
> > > on \fromproperty #'n-pages pages }
> > >     \repeat unfold 20 { 1 1 \break }
> > > }
> > Wow! That goes beyond what I had in mind - it actually outputs the
> > information within the typeset (I guess the stuff with skylining
> > might
> > be to avoid the typesetting of this information affecting the
> > number of
> > pages/systems??).
> 
> 
> 
> Sort of, yes. Normally, the RehearsalMark is drawn before line
> breaking 
> is done, and its width and height are accounted for during page
> breaking 
> and page spacing. At that time, there is obviously no number of pages
> or 
> systems available. So I'm giving it predetermined extents and
> skylines, 
> which are used for page breaking and page spacing purposes, only
> after 
> which the RehearsalMark's stencil is computed. The drawback is that
> it 
> could collide with something on top of it.
> 
> However, there was a flaw in that code. When you have several scores
> in 
> a bookpart, page-count and system-count override the total numbers
> for 
> the whole bookpart, but I was counting them per score. Here is a
> fixed 
> version:
> 
> \version "2.22.2"
> 
> \paper {
>    page-post-process =
>      #(lambda (paper pages)
>         (let ((n-systems 0)
>               (page-min #f)
>               (page-max #f))
>           (for-each
>            (lambda (page)
>              (for-each
>               (lambda (line)
>                 (let ((sys (ly:prob-property line 'system-grob)))
>                   (if (ly:grob? sys)
>                       (let ((sys-page (ly:grob-property sys 'page-
> number)))
>                        (set! n-systems (1+ n-systems))
>                        (set! page-min (if page-min
>                                           (min page-min sys-page)
>                                           sys-page))
>                        (set! page-max (if page-max
>                                           (max page-max sys-page)
>                                           sys-page))))))
>               (ly:prob-property page 'lines)))
>            pages)
>           (ly:output-def-set-variable! paper 'n-systems n-systems)
>           (ly:output-def-set-variable! paper 'n-pages (1+ (- page-max
> page-min)))))
> }
> 
> #(define-markup-command (page-info layout props arg) (markup?)
>     (ly:make-stencil
>      `(delay-stencil-evaluation
>        ,(delay
>          (let* ((n-systems (ly:output-def-lookup layout 'n-systems))
>                 (n-pages (ly:output-def-lookup layout 'n-pages)))
>                  (ly:stencil-expr
>                   (interpret-markup
>                    layout
>                    (cons `((n-systems . ,(number->string n-systems))
>                            (n-pages . ,(number->string n-pages)))
>                          props)
>                    arg)))))
>      '(0 . 0)
>      '(0 . 0)))
> 
> \header {
>    subsubtitle = \markup \page-info \line {
>      Have \fromproperty #'n-systems systems
>      on \fromproperty #'n-pages pages
>    }
> }
> 
> \book {
>    \bookpart {
>      \repeat unfold 10 { 1 1 \break }
>      \repeat unfold 10 { 1 1 \break }
>    }
>    \bookpart {
>      \repeat unfold 20 { 1 1 \break }
>      \repeat unfold 20 { 1 1 \break }
>    }
> }

Thanks again - I think I would prefer the information on the terminal
though so I modified your code to do that:

8><8><8><8><8><8><8><8><8><8><8><8><8><8><8><8><8><8><8><8><8><8><8><
\version "2.22.1"

\paper {
   page-post-process =
     #(lambda (paper pages)
        (let ((n-systems 0)
              (page-min #f)
              (page-max #f))
          (for-each
           (lambda (page)
             (for-each
              (lambda (line)
                (let ((sys (ly:prob-property line 'system-grob)))
                  (if (ly:grob? sys)
                      (let ((sys-page (ly:grob-property sys 'page-
number)))
                       (set! n-systems (1+ n-systems))
                       (set! page-min (if page-min
                                          (min page-min sys-page)
                                          sys-page))
                       (set! page-max (if page-max
                                          (max page-max sys-page)
                                          sys-page))))))
              (ly:prob-property page 'lines)))
           pages)
          (ly:output-def-set-variable! paper 'n-systems n-systems)
          (ly:output-def-set-variable! paper 'n-pages (1+ (- page-max 
page-min)))))
}

#(define-markup-command (page-info layout props) ()
    (ly:make-stencil
     `(delay-stencil-evaluation
       ,(delay
         (let* ((n-systems (ly:output-def-lookup layout 'n-systems))
                (n-pages (ly:output-def-lookup layout 'n-pages)))
                 (ly:stencil-expr
                  (interpret-markup
                   layout
                   (cons `((n-systems . ,(number->string n-systems))
                           (n-pages . ,(number->string n-pages)))
                         props)
                   ""))
                 (format #t "pages ~s systems ~s" n-pages n-systems))))
     '(0 . 0)
     '(0 . 0)))
\markup \page-info
\score 
  {
    { \repeat unfold 10 { 1 1 \break }
     \repeat unfold 13 { 1 1 \break }}
   }
8><8><8><8><8><8><8><8><8><8><8><8><8><8><8><8><8><8><8><8><8><8><8><

However this looks like strange calling \markup just to get the side
effect of outputting the pages and systems info during the page-info
call. But define-markup-command gets the layout parameter while define-
scheme-command does not ... perhaps there is something altogether
simpler?

Richard