Re: Color tweaks (edition engraver)

[David Nalesnik]

Hi Kieren,

On Tue, May 5, 2015 at 8:57 AM, Kieren MacMillan <address@hidden> wrote:

Hi David,

> And it works with that editionEngraver example.

It definitely works with a minimal EE example… Nice work!

However, I added it to my current (definitely non-minimal!) score, and it fails with:

  In procedure ly:music-property in _expression_ (ly:music-property (ly:event-property cause #) (quote tweaks)):
  [file-path here] Wrong type argument in position 1 (expecting Music): ()

That line is

#(define (mark-tweak grob)
     [%%%SNIP%%%]
     (if (null? diff)
         (let* ((cause (event-cause grob))
                (tweaks (and cause
                             (ly:music-property    %%%%%%  THIS ONE!!!!
                              (ly:event-property cause 'music-cause)
                              'tweaks))))

Can’t spend time tracking down the issue further now, but wanted you to know.

Thanks!

The fix here is no problem.  Quoting just mark-tweak:

 #(define (mark-tweak grob)

   "Color @var{grob} if it has been tweaked.  The color to use is stored

in the global variables @var{override-color} and @var{tweak-color}."

   (let* ((default (assoc-get (grob::name grob) all-grob-descriptions)) 

          (props (ly:grob-basic-properties grob))

          ;; Our procedure has been added to the head of grob's basic

          ;; properties.  Let's not count it as a tweak!

          (props

           (remove

            (lambda (p)

              (and (procedure? (cdr p))

                   (eq? (procedure-name (cdr p)) 'mark-tweak)))

            props))

          ;; We're using after-line-breaking to set color of stencil, but

          ;; let's preserve its last setting

          (after-line-return (assoc-get 'after-line-breaking props))

          ;; Clef.glyph doesn't appear in all-grob-descriptions, but it

          ;; is set at some point automatically.  Don't mark it unless

          ;; it genuinely is a user override.  There may be other

          ;; such grobs.

          (props

           (if (eq? (grob::name grob) 'Clef)

               (reverse (remove-first 'glyph (reverse props)))

               props))

          (diff (lset-difference eq? props default)))

     ;; Tweaks will not appear in the "basic properties" alist of our grob, but

     ;; we can find them through the music event which led to the grob.  This

     ;; is available through the stream-event which caused our grob.

     (if (null? diff)

         (let* ((cause (event-cause grob))

                (music-cause

                 (if (ly:stream-event? cause)

                     (ly:event-property cause 'music-cause)

                     #f))

                (tweaks (and (ly:music? music-cause)

                             (ly:music-property

                              music-cause

                              'tweaks))))

           (if (pair? tweaks)

               (set! (ly:grob-property grob 'color) tweak-color)))

         (set! (ly:grob-property grob 'color) override-color))

     

     ;; Return any default setting of after-line-breaking.

     after-line-return))

%%%

Thanks for pointing this out!

David