From: Mike Solomon <mike@apollinemike.com>
Date: Wed, 28 Dec 2011 09:22:39 +0000 (+0100)
Subject: Centers tremoli on double stems in TabVoice contexts.
X-Git-Tag: release/2.15.24-1~30
X-Git-Url: https://git.donarmstrong.com/?a=commitdiff_plain;ds=inline;h=297e9f6f16be3a451f2381c00e7f44ac61232154;p=lilypond.git

Centers tremoli on double stems in TabVoice contexts.
---

diff --git a/input/regression/tablature-double-stem-tremolo.ly b/input/regression/tablature-double-stem-tremolo.ly
new file mode 100644
index 0000000000..fd76588ac9
--- /dev/null
+++ b/input/regression/tablature-double-stem-tremolo.ly
@@ -0,0 +1,11 @@
+\version "2.15.24"
+
+\header {
+  texidoc = "Tremoli applied to double stems in a @code{TabVoice}
+should be centered on the double stem.
+"
+}
+\new TabVoice \relative c' {
+  \tabFullNotation
+  a2:32
+}
\ No newline at end of file
diff --git a/ly/property-init.ly b/ly/property-init.ly
index 3f0c1185f0..37a68917e7 100644
--- a/ly/property-init.ly
+++ b/ly/property-init.ly
@@ -448,6 +448,7 @@ tabFullNotation = {
   \revert TabVoice.Stem #'transparent
   \revert TabVoice.Flag #'transparent
   \override TabVoice.Stem #'stencil = #tabvoice::draw-double-stem-for-half-notes
+  \override TabVoice.Stem #'X-extent = #tabvoice::make-double-stem-width-for-half-notes
   \set autoBeaming = ##t
   \revert NoteColumn #'ignore-collision
   % beams, dots
diff --git a/scm/define-grobs.scm b/scm/define-grobs.scm
index 157055779a..35d82c3f37 100644
--- a/scm/define-grobs.scm
+++ b/scm/define-grobs.scm
@@ -1997,9 +1997,16 @@
 	(stencil . ,ly:stem-tremolo::print)
 	(style . ,ly:stem-tremolo::calc-style)
 	(X-extent . ,ly:stem-tremolo::width)
+	(X-offset . ,(ly:make-simple-closure
+		      `(,+
+			,(ly:make-simple-closure
+			  (list ly:self-alignment-interface::centered-on-x-parent))
+			,(ly:make-simple-closure
+			  (list ly:self-alignment-interface::x-aligned-on-self)))))
 	(Y-offset . ,ly:stem-tremolo::calc-y-offset)
 	(meta . ((class . Item)
-		 (interfaces . (stem-tremolo-interface))))))
+		 (interfaces . (self-alignment-interface
+                                stem-tremolo-interface))))))
 
     (StringNumber
      . (
diff --git a/scm/tablature.scm b/scm/tablature.scm
index c26af257c8..5dd774aac8 100644
--- a/scm/tablature.scm
+++ b/scm/tablature.scm
@@ -78,6 +78,16 @@
 
 ;; if stems are drawn, it is nice to have a double stem for
 ;; (dotted) half notes to distinguish them from quarter notes:
+(define-public (tabvoice::make-double-stem-width-for-half-notes grob)
+  (let ((X-extent (ly:stem::width grob)))
+
+    ;; is the note a (dotted) half note?
+    (if (= 1 (ly:grob-property grob 'duration-log))
+        ;; yes -> return double stem width
+        (cons (car X-extent) (+ 0.5 (* 2 (cdr X-extent))))
+        ;; no -> return simple stem width
+        X-extent)))
+
 (define-public (tabvoice::draw-double-stem-for-half-notes grob)
   (let ((stem (ly:stem::print grob)))