Allow music in contextmods

[lilypond.git] / scm / lily-library.scm

diff --git a/scm/lily-library.scm b/scm/lily-library.scm
index 8d4e0a069fa5461b658678b344422d4ffe72bb37..514f5b40fb576f37ee1ad5321b0e4d83388dc74a 100644 (file)
--- a/scm/lily-library.scm
+++ b/scm/lily-library.scm
@@ -257,6 +257,48 @@ bookoutput function"
                      parser
                     music))
 
+(define-public (context-mod-from-music parser music)
+  (let ((warn #t) (mods (ly:make-context-mod)))
+    (let loop ((m music) (context #f))
+      (if (music-is-of-type? m 'layout-instruction-event)
+         (let ((symbol (cons context (ly:music-property m 'symbol))))
+           (ly:add-context-mod
+            mods
+            (case (ly:music-property m 'name)
+              ((PropertySet)
+               (list 'assign
+                     symbol
+                     (ly:music-property m 'value)))
+              ((PropertyUnset)
+               (list 'unset symbol))
+              ((OverrideProperty)
+               (cons* 'push
+                      symbol
+                      (ly:music-property m 'grob-value)
+                      (ly:music-property m 'grob-property-path)))
+              ((RevertProperty)
+               (cons* 'pop
+                      symbol
+                      (ly:music-property m 'grob-property-path))))))
+         (case (ly:music-property m 'name)
+           ((ApplyContext)
+            (ly:add-context-mod mods
+                                (list 'apply
+                                      (ly:music-property m 'procedure))))
+           ((SequentialMusic SimultaneousMusic)
+            (fold loop context (ly:music-property m 'elements)))
+           ((ContextSpeccedMusic)
+            (loop (ly:music-property m 'element)
+                  (ly:music-property m 'context-type)))
+           (else (if (and warn (ly:duration? (ly:music-property m 'duration)))
+                     (begin
+                       (ly:music-warning
+                        music
+                        (_ "Music unsuitable for context-mod"))
+                       (set! warn #f))))))
+      context)
+    mods))
+
 (define-public (context-defs-from-music parser output-def music)
   (let ((bottom 'Voice) (warn #t))
     (define (get-bottom sym)