3 texidoc = "overriding the molecule callback can also be used to draw a
4 box around arbitrary grobs.
6 TODO: check whether the corners are really correct.
10 #(define (box-molecule xext yext)
12 (list 'filledbox (- (car xext)) (cdr xext)
13 (- (car yext)) (cdr yext))
17 #(define (widen-interval iv amount)
18 (cons (- (car iv) amount)
22 #(define (make-molecule-boxer callback)
23 (define (molecule-boxer grob)
28 (x-ext (widen-interval (ly-get-molecule-extent mol 0) box-padding))
29 (y-ext (widen-interval (ly-get-molecule-extent mol 1) box-padding))
31 (x-rule (box-molecule (widen-interval x-ext rule-thick)
33 (y-rule (box-molecule (cons 0 rule-thick) y-ext))
36 (set! mol (ly-combine-molecule-at-edge mol 0 1 y-rule (* 0.5 box-padding)))
37 (set! mol (ly-combine-molecule-at-edge mol 0 -1 y-rule (* 0.5 box-padding)))
38 (set! mol (ly-combine-molecule-at-edge mol 1 1 x-rule 0.0))
39 (set! mol (ly-combine-molecule-at-edge mol 1 -1 x-rule 0.0))
49 \property Voice.TextScript \override #'molecule-callback =
50 #(make-molecule-boxer Text_item::brew_molecule)
54 \property Voice.Stem \override #'molecule-callback =
55 #(make-molecule-boxer Stem::brew_molecule)