From d5766025a1573c709dfa3c9663c1c6b903abec24 Mon Sep 17 00:00:00 2001
From: Neil Puttock <n.puttock@gmail.com>
Date: Thu, 7 Jul 2011 20:10:20 +0100
Subject: [PATCH] Add display method for \tweak.

* input/regression/display-lily-tests.ly:

  add tests for \tweak

* scm/define-music-display-methods.scm

  (scheme-expr->lily-string): don't funnel booleans through pretty-print
  (EventChord): treat simple_element with 'tweaks list as note_chord_element
                to preserve < > around tweaked note

* scm/display-lily.scm (music->lily-string):

  process 'tweaks via new function tweaks->lily-string
---
 input/regression/display-lily-tests.ly |  8 +++++++-
 scm/define-music-display-methods.scm   |  7 +++++--
 scm/display-lily.scm                   | 14 ++++++++++++--
 3 files changed, 24 insertions(+), 5 deletions(-)

diff --git a/input/regression/display-lily-tests.ly b/input/regression/display-lily-tests.ly
index 08a13bdc78..620289dda3 100644
--- a/input/regression/display-lily-tests.ly
+++ b/input/regression/display-lily-tests.ly
@@ -1,4 +1,4 @@
-\version "2.14.0"
+\version "2.15.5"
 #(use-modules (srfi srfi-13)
               (ice-9 format))
 
@@ -241,6 +241,12 @@ stderr of this run."
 %% \ottava
 \test "" ##[ \ottava #1 #] % OttavaMusic
 
+%% \tweak
+\test "" ##[ < \tweak #'duration-log #2 c > #]
+\test "" ##[ < c \tweak #'transparent ##t e > #]
+\test "" ##[ < \tweak #'color #'(1.0 0.0 0.0) \tweak #'duration-log #2 c > #]
+\test "" ##[ c-\tweak #'font-size #3 -> #]
+
 %% end test.
 
 #(read-hash-extend #\[ #f) %{ ] %}
diff --git a/scm/define-music-display-methods.scm b/scm/define-music-display-methods.scm
index 3ecfce5aaf..c0041ba2a9 100644
--- a/scm/define-music-display-methods.scm
+++ b/scm/define-music-display-methods.scm
@@ -16,7 +16,8 @@
 ;;;
 (define (scheme-expr->lily-string scm-arg)
   (cond ((or (number? scm-arg)
-	     (string? scm-arg))
+             (string? scm-arg)
+             (boolean? scm-arg))
 	 (format #f "~s" scm-arg))
 	((or (symbol? scm-arg)
 	     (list? scm-arg))
@@ -466,7 +467,9 @@ Otherwise, return #f."
 		 ;; as a note_chord_element to prevent spurious output, e.g.,
 		 ;; \displayLilyMusic < c-1\4 >8 -> c-1\48
 		 (null? (filter post-event?
-				(ly:music-property (car simple-elements) 'articulations))))
+				(ly:music-property (car simple-elements) 'articulations)))
+		 ;; same for simple_element with \tweak
+		 (null? (ly:music-property (car simple-elements) 'tweaks)))
 	    ;; simple_element : note | figure | rest | mmrest | lyric_element | skip
 	    (let* ((simple-element (car simple-elements))
 		   (duration (ly:music-property simple-element 'duration))
diff --git a/scm/display-lily.scm b/scm/display-lily.scm
index 6fc933499d..302259fa23 100644
--- a/scm/display-lily.scm
+++ b/scm/display-lily.scm
@@ -79,6 +79,15 @@ display method will be called."
 		 (format #f "~a\\tag #'~a" (if post-event? "-" "") tag))
 	       (ly:music-property expr 'tags))))
 
+(define* (tweaks->lily-string expr #:optional (post-event? #f))
+  (format #f "~{~a ~}"
+          (map (lambda (tweak)
+                 (format #f "~a\\tweak #'~a #~a"
+                         (if post-event? "-" "")
+                         (car tweak)
+                         (scheme-expr->lily-string (cdr tweak))))
+               (ly:music-property expr 'tweaks))))
+
 (define-public (music->lily-string expr parser)
   "Print @var{expr}, a music expression, in LilyPond syntax."
   (if (ly:music? expr)
@@ -90,8 +99,9 @@ display method will be called."
 					      (proc expr parser))
 					    procs))))
 	(if result-string
-	    (format #f "~a~a" 
-		    (tag->lily-string expr (post-event? expr))
+	    (format #f "~a~a~a"
+                    (tag->lily-string expr (post-event? expr))
+                    (tweaks->lily-string expr (post-event? expr))
 		    result-string)
 	    (format #f "%{ Print method not implemented for music type ~a %}"
 		    music-type)))
-- 
2.39.2