new engraver for spacing in chordlyrics

private_includes/base/verses_with_chords.ily

@@ -253,6 +253,88 @@
                                     (make-pad-right-markup -0.1 (make-tied-lyric-markup text))
                                     text))))
 
+Chord_lyrics_spacing_engraver =
+#(lambda (ctx)
+   (let ((last-lyric-syllable #f)
+         (last-lyric-syllable-width 0)
+         (lyric-width-since-last-chord 0)
+         (last-printed-chord #f)
+         (chord-width-since-last-lyric 0)
+         (lyrics-seen-since-break #f)
+         (have-a-rest #f))
+     (make-engraver
+      (listeners
+       ((multi-measure-rest-event engraver event)
+        (set! have-a-rest #t)
+        )
+       ((rest-event engraver event)
+        (set! have-a-rest #t)
+        )
+       ((lyric-event engraver event)
+        (set! have-a-rest #f)
+        )
+       ((break-event engraver event)
+        (set! last-lyric-syllable #f)
+        (set! last-lyric-syllable-width 0)
+        (set! lyric-width-since-last-chord 0)
+        (set! last-printed-chord #f)
+        (set! chord-width-since-last-lyric 0)
+        (set! lyrics-seen-since-break #f)
+        ))
+      (acknowledgers
+       ((lyric-syllable-interface this-engraver grob source-engraver)
+        (let ((syllable-width (interval-length (ly:grob-extent grob grob X))))
+          (set! lyric-width-since-last-chord (+ lyric-width-since-last-chord syllable-width))
+          (set! last-lyric-syllable-width syllable-width)
+          )
+        (if (> chord-width-since-last-lyric 0)
+            (if lyrics-seen-since-break
+                (ly:grob-set-property! grob 'extra-spacing-width
+                                       (cons (- chord-width-since-last-lyric) (cdr (ly:grob-property grob 'extra-spacing-width '(0 . 0)))))
+                (if last-printed-chord
+                    (let ((last-printed-chord-width (interval-length (ly:grob-extent last-printed-chord last-printed-chord X))))
+                      (ly:grob-set-parent! grob X last-printed-chord)
+                      (ly:grob-set-property! grob 'X-offset last-printed-chord-width)
+                      )))
+            )
+        (set! last-lyric-syllable grob)
+        (set! chord-width-since-last-lyric 0)
+        (set! lyrics-seen-since-break #t)
+        )
+       ((chord-name-interface this-engraver grob source-engraver)
+        (if (not (and
+                  (boolean? (ly:grob-property grob 'begin-of-line-visible))
+                  (ly:grob-property grob 'begin-of-line-visible)))
+            (let* ((last-printed-chord-width (if last-printed-chord (interval-length (ly:grob-extent last-printed-chord last-printed-chord X)) 0))
+                   (chord-overwidth (- last-printed-chord-width lyric-width-since-last-chord))
+                   (chord-gap 0.5))
+              (if have-a-rest
+                  (let ((chord-width (interval-length (ly:grob-extent grob grob X))))
+                    (if last-lyric-syllable
+                        (begin
+                         (ly:grob-set-parent! grob X last-lyric-syllable)
+                         (ly:grob-set-property! grob 'X-offset last-lyric-syllable-width)
+                         )
+                        (if last-printed-chord
+                            (begin
+                             (ly:grob-set-parent! grob X last-printed-chord)
+                             (ly:grob-set-property! grob 'X-offset (+ chord-gap last-printed-chord-width))
+                             )))
+                    (set! chord-width-since-last-lyric (+ chord-width-since-last-lyric chord-width chord-gap))
+                    ))
+              (if (and last-lyric-syllable last-printed-chord (> chord-overwidth 0))
+                      (ly:grob-set-property! last-lyric-syllable 'extra-spacing-width
+                                             (cons (car (ly:grob-property last-lyric-syllable 'extra-spacing-width '(0 . 0))) (+ chord-gap chord-overwidth)))
+                      )
+              (set! last-printed-chord grob)
+              (set! last-lyric-syllable #f)
+              (set! lyric-width-since-last-chord 0)
+              )
+            )
+        )
+       )
+      )))
+
 #(define-markup-command (chordlyrics layout props lyrics) (ly:music?)
    #:properties ((verse-chords #{#})
                  (verse-reference-voice #{#})
@@ -296,9 +378,11 @@
             \context {
               \Score
               \override PaperColumn.keep-inside-line = ##f
-             % \override SpacingSpanner.strict-note-spacing = ##t
+              % \override SpacingSpanner.strict-note-spacing = ##t
               \override SpacingSpanner.uniform-stretching = ##t
               \override SpacingSpanner.spacing-increment = 0
+              % \override SpacingSpanner.packed-spacing = ##t
+              \consists \Chord_lyrics_spacing_engraver
               \remove Bar_number_engraver
               \remove Mark_engraver
               \remove Jump_engraver
@@ -328,14 +412,6 @@
               \remove Note_heads_engraver
               \remove Script_engraver
             }
-            \context {
-              \NullVoice
-              \consists Rest_engraver
-              \omit Rest
-              \undo \omit NoteHead
-              \hide NoteHead
-              \override NoteHead.X-extent = #'(0 . 0)
-            }
           }
         }
       }