;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; property setting music objs.
+(define-safe-public (check-grob-path path #:optional parser location
+ #:key
+ (start 0)
+ default
+ (min 1)
+ max)
+ "Check a grob path specification @var{path}, a symbol list (or a
+single symbol), for validity and possibly complete it. Returns the
+completed specification, or @code{#f} if invalid. If optional
+@var{parser} is given, a syntax error is raised in that case,
+optionally using @var{location}. If an optional keyword argument
+@code{#:start @var{start}} is given, the parsing starts at the given
+index in the sequence @samp{Context.Grob.property.sub-property...},
+with the default of @samp{0} implying the full path.
+
+If there is no valid first element of @var{path} fitting at the given
+path location, an optionally given @code{#:default @var{default}} is
+used as the respective element instead without checking it for
+validity at this position.
+
+The resulting path after possibly prepending @var{default} can be
+constrained in length by optional arguments @code{#:min @var{min}} and
+@code{#:max @var{max}}, defaulting to @samp{1} and unlimited,
+respectively."
+ (let ((path (if (symbol? path) (list path) path)))
+ ;; A Guile 1.x bug specific to optargs precludes moving the
+ ;; defines out of the let
+ (define (unspecial? s)
+ (not (or (object-property s 'is-grob?)
+ (object-property s 'backend-type?))))
+ (define (grob? s)
+ (object-property s 'is-grob?))
+ (define (property? s)
+ (object-property s 'backend-type?))
+ (define (check c p) (c p))
+
+ (let* ((checkers
+ (and (< start 3)
+ (drop (list unspecial? grob? property?) start)))
+ (res
+ (cond
+ ((null? path)
+ ;; tricky. Should we make use of the default when the
+ ;; list is empty? In most cases, this question should be
+ ;; academical as an empty list can only be generated by
+ ;; Scheme and is likely an error. We consider this a case
+ ;; of "no valid first element, and default given".
+ ;; Usually, invalid use cases should be caught later using
+ ;; the #:min argument, and if the user explicitly does not
+ ;; catch this, we just follow through.
+ (if default (list default) '()))
+ ((not checkers)
+ ;; no checkers, so we have a valid first element and just
+ ;; take the path as-is.
+ path)
+ (default
+ (if ((car checkers) (car path))
+ (and (every check (cdr checkers) (cdr path))
+ path)
+ (and (every check (cdr checkers) path)
+ (cons default path))))
+ (else
+ (and (every check checkers path)
+ path)))))
+ (if (and res
+ (if max (<= min (length res) max)
+ (<= min (length res))))
+ res
+ (begin
+ (if parser
+ (ly:parser-error parser
+ (format #f (_ "bad grob property path ~a")
+ path)
+ location))
+ #f)))))
+
(define-public (make-grob-property-set grob gprop val)
"Make a @code{Music} expression that sets @var{gprop} to @var{val} in
@var{grob}. Does a pop first, i.e., this is not an override."
(if (>= (length siblings) 2)
(helper siblings arg)
(car arg))))
+
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+;; measure counter
+
+(define (measure-counter-stencil grob)
+ "Print a number for a measure count. The number is centered using
+the extents of @code{BreakAlignment} grobs associated with
+@code{NonMusicalPaperColumn} grobs. In the case of an unbroken measure, these
+columns are the left and right bounds of a @code{MeasureCounter} spanner.
+Broken measures are numbered in parentheses."
+ (let* ((orig (ly:grob-original grob))
+ (siblings (ly:spanner-broken-into orig)) ; have we been split?
+ (bounds (ly:grob-array->list (ly:grob-object grob 'columns)))
+ (refp (ly:grob-system grob))
+ ; we use the first and/or last NonMusicalPaperColumn grob(s) of
+ ; a system in the event that a MeasureCounter spanner is broken
+ (all-cols (ly:grob-array->list (ly:grob-object refp 'columns)))
+ (all-cols
+ (filter
+ (lambda (col) (eq? #t (ly:grob-property col 'non-musical)))
+ all-cols))
+ (left-bound
+ (if (or (null? siblings) ; spanner is unbroken
+ (eq? grob (car siblings))) ; or the first piece
+ (car bounds)
+ (car all-cols)))
+ (right-bound
+ (if (or (null? siblings)
+ (eq? grob (car (reverse siblings))))
+ (car (reverse bounds))
+ (car (reverse all-cols))))
+ (elts-L (ly:grob-array->list (ly:grob-object left-bound 'elements)))
+ (elts-R (ly:grob-array->list (ly:grob-object right-bound 'elements)))
+ (break-alignment-L
+ (filter
+ (lambda (elt) (grob::has-interface elt 'break-alignment-interface))
+ elts-L))
+ (break-alignment-R
+ (filter
+ (lambda (elt) (grob::has-interface elt 'break-alignment-interface))
+ elts-R))
+ (break-alignment-L-ext (ly:grob-extent (car break-alignment-L) refp X))
+ (break-alignment-R-ext (ly:grob-extent (car break-alignment-R) refp X))
+ (num (markup (number->string (ly:grob-property grob 'count-from))))
+ (num
+ (if (or (null? siblings)
+ (eq? grob (car siblings)))
+ num
+ (make-parenthesize-markup num)))
+ (num (grob-interpret-markup grob num))
+ (num (ly:stencil-aligned-to num X (ly:grob-property grob 'self-alignment-X)))
+ (num
+ (ly:stencil-translate-axis
+ num
+ (+ (interval-length break-alignment-L-ext)
+ (* 0.5
+ (- (car break-alignment-R-ext)
+ (cdr break-alignment-L-ext))))
+ X)))
+ num))
projects / lilypond.git / blobdiff