Issue 4328: Add means to display objects accessible from a grob

[lilypond.git] / scm / output-lib.scm

diff --git a/scm/output-lib.scm b/scm/output-lib.scm
index 7f956a54d574549efbf360575efc782ad817fb67..a73e2c0324977e6046d45c8cfb736bd59ec4c644 100644 (file)
--- a/scm/output-lib.scm
+++ b/scm/output-lib.scm
@@ -30,6 +30,29 @@
   "Return the name of the grob @var{grob} as a symbol."
   (assq-ref (ly:grob-property grob 'meta) 'name))
 
+(define-public (grob::rhythmic-location grob)
+  "Return a pair consisting of the measure number and moment within
+   the measure of grob @var{grob}."
+  (let* (; all grobs support either spanner- or item-interface
+         (item (if (grob::has-interface grob 'spanner-interface)
+                   (ly:spanner-bound grob LEFT)
+                   grob))
+         (col (ly:item-get-column item)))
+    (if (ly:grob? col)
+        (ly:grob-property col 'rhythmic-location)
+        '())))
+
+(define-public (grob::when grob)
+  "Return the global timestep (a moment) of grob @var{grob}."
+  (let* (; all grobs support either spanner- or item-interface
+         (item (if (grob::has-interface grob 'spanner-interface)
+                   (ly:spanner-bound grob LEFT)
+                   grob))
+         (col (ly:item-get-column item)))
+    (if (ly:grob? col)
+        (ly:grob-property col 'when)
+        '())))
+
 (define-public (make-stencil-boxer thickness padding callback)
   "Return function that adds a box around the grob passed as argument."
   (lambda (grob)
@@ -107,6 +130,44 @@
 
     line-thickness))
 
+(define (grob::objects-from-interface grob iface)
+  "For grob @var{grob} return the name and contents of all properties
+ within interface @var{iface} having type @code{ly:grob?} or
+ @code{ly:grob-array?}."
+  (let* ((iface-entry (hashq-ref (ly:all-grob-interfaces) iface))
+         (props (if iface-entry (last iface-entry) '()))
+         (pointer-props
+          (filter
+           (lambda (prop)
+             (let ((type (object-property prop 'backend-type?)))
+               (or (eq? type ly:grob?)
+                   (eq? type ly:grob-array?))))
+           props)))
+    (if (null? pointer-props)
+        '()
+        (list iface
+          (map
+           (lambda (prop) (list prop (ly:grob-object grob prop)))
+           pointer-props)))))
+
+(define-public (grob::all-objects grob)
+  "Return a list of the names and contents of all properties having type
+ @code{ly:grob?} or @code{ly:grob-array?} for all interfaces supported by
+ grob @var{grob}."
+  (let loop ((ifaces (ly:grob-interfaces grob)) (result '()))
+    (if (null? ifaces)
+        (cons grob (list result))
+        (let ((entry (grob::objects-from-interface grob (car ifaces))))
+          (if (pair? entry)
+              (loop (cdr ifaces) (append result (list entry)))
+              (loop (cdr ifaces) result))))))
+
+(use-modules (ice-9 pretty-print))
+(define-public (grob::display-objects grob)
+  "Display all objects stored in properties of grob @var{grob}."
+  (pretty-print (grob::all-objects grob))
+  (newline))
+
 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 ;; beam slope
 
@@ -1164,8 +1225,19 @@ parent or the parent has no setting."
   (let* ((shift-when-alone (ly:grob-property grob 'toward-stem-shift 0.0))
          (shift-in-column (ly:grob-property grob 'toward-stem-shift-in-column))
          (script-column (ly:grob-object grob 'script-column))
-         (shift (if (and (ly:grob? script-column) (number? shift-in-column))
-                    shift-in-column shift-when-alone))
+         (shift
+           (if (and (ly:grob? script-column)
+                    (number? shift-in-column)
+                    ;; ScriptColumn can contain grobs other than Script.
+                    ;; These should not result in a shift.
+                    (any (lambda (s)
+                           (and (not (eq? s grob))
+                                (grob::has-interface s 'script-interface)
+                                (not (grob::has-interface s
+                                       'accidental-suggestion-interface))))
+                         (ly:grob-array->list
+                           (ly:grob-object script-column 'scripts))))
+               shift-in-column shift-when-alone))
          (note-head-location
           (ly:self-alignment-interface::aligned-on-x-parent grob))
          (note-head-grob (ly:grob-parent grob X))