new engraver for spacing in chordlyrics

private_includes/base/verses_with_chords.ily

@@ -255,85 +255,110 @@
 
 Chord_lyrics_spacing_engraver =
 #(lambda (ctx)
-   (let ((last-lyric-syllable #f)
+   (let ((last-note-head #f)
+         (note-head-extended #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))
+         (notes-on-syllable-count 0)
+         (last-chord-name #f)
+         (remaining-chord-width 0)
+         (last-rest #f)
+         (rest-count 0)
+         (multi-measure-rest-count 0)
+         (stanza-shift 0))
      (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)
+        (set! multi-measure-rest-count (+ multi-measure-rest-count 1))
         )
        ((break-event engraver event)
-        (set! last-lyric-syllable #f)
+        (set! last-note-head #f)
+        (set! note-head-extended #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)
+        (set! notes-on-syllable-count 0)
+        (set! last-chord-name #f)
+        (set! remaining-chord-width 0)
+        (set! last-rest #f)
+        (set! rest-count 0)
+        (set! multi-measure-rest-count 0)
+        (set! stanza-shift 0)
         ))
       (acknowledgers
+       ((note-head-interface this-engraver grob source-engraver)
+        (if (and (> rest-count 0) (not last-note-head))
+            (let ((rest-spacing-on-line-start 1.2))
+              (ly:grob-set-property! grob 'minimum-X-extent (cons (- rest-spacing-on-line-start) 0))
+              (set! stanza-shift rest-spacing-on-line-start)
+              ))
+        (set! notes-on-syllable-count (+ 1 notes-on-syllable-count))
+        (set! last-note-head grob)
+        (set! note-head-extended #f)
+        (set! last-rest #f)
+        (set! rest-count 0)
+        (set! multi-measure-rest-count 0)
+        )
        ((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)
+        (set! remaining-chord-width (max 0 (- remaining-chord-width lyric-width-since-last-chord)))
+        (set! last-lyric-syllable-width (- (cdr (ly:grob-extent grob grob X)) 0.2))
+        (set! lyric-width-since-last-chord (+ lyric-width-since-last-chord last-lyric-syllable-width))
+        (if last-note-head (set! notes-on-syllable-count 1))
         )
        ((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
+            (let ((on-a-rest (> rest-count 0)))
+              (if (not on-a-rest)
+                  (set! notes-on-syllable-count (- notes-on-syllable-count 1)))
+              (if (and last-chord-name (= multi-measure-rest-count 1) (> lyric-width-since-last-chord remaining-chord-width))
+                  (ly:grob-set-property! last-chord-name 'extra-spacing-width (cons -0.1 (+ 0.1 (- lyric-width-since-last-chord remaining-chord-width)))))
+              (if last-note-head
+                  (let* ((last-note-min-x-extent (ly:grob-property last-note-head 'minimum-X-extent))
+                         (last-note-min-x-lower (if (pair? last-note-min-x-extent) (car last-note-min-x-extent) 0))
+                         (last-note-min-x-upper (if (pair? last-note-min-x-extent) (cdr last-note-min-x-extent) 0)))
+                    (if on-a-rest
                         (begin
-                         (ly:grob-set-parent! grob X last-lyric-syllable)
-                         (ly:grob-set-property! grob 'X-offset last-lyric-syllable-width)
+                         (if (not note-head-extended)
+                             (begin
+                              (ly:grob-set-property! last-note-head 'minimum-X-extent
+                                                     (cons last-note-min-x-lower (- last-lyric-syllable-width -2 (* 2.2 rest-count))))
+                              (set! note-head-extended #t)
+                              ))
+                         (ly:grob-set-property! last-rest 'minimum-X-extent (cons 0 2))
                          )
-                        (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)
+                        (if (and (> lyric-width-since-last-chord 0)
+                                 (> remaining-chord-width lyric-width-since-last-chord))
+                            (ly:grob-set-property! last-note-head 'minimum-X-extent
+                                                   (cons (- -1.2 (- remaining-chord-width lyric-width-since-last-chord)) last-note-min-x-upper))
+                            (let* ((width-per-note-head 0.5)
+                                   (note-width-since-last-chord (* width-per-note-head notes-on-syllable-count)))
+                              (if (> remaining-chord-width note-width-since-last-chord)
+                                  (ly:grob-set-property! last-note-head 'minimum-X-extent
+                                                         (cons (- note-width-since-last-chord remaining-chord-width) last-note-min-x-upper))
+                                  )
+                              )
+                            )
+                        )))
+              (set! last-chord-name grob)
+              (set! remaining-chord-width
+                    (if (and on-a-rest (equal? (ly:prob-property (ly:grob-property grob 'cause) 'duration) (ly:prob-property (ly:grob-property last-rest 'cause) 'duration)))
+                        0
+                        (cdr (ly:grob-extent grob grob X))))
               (set! lyric-width-since-last-chord 0)
-              )
-            )
+              (set! notes-on-syllable-count (if on-a-rest 0 1))
+              ))
         )
-       )
-      )))
+       ((rest-interface this-engraver grob source-engraver)
+        (set! rest-count (+ 1 rest-count))
+        (set! last-rest grob)
+        (set! multi-measure-rest-count 0)
+        )
+       ((stanza-number-interface this-engraver grob source-engraver)
+        (ly:grob-set-property! grob 'padding (+ 1 stanza-shift)))
+       ))))
+
+%#(ly:set-option 'debug-skylines #t)
 
 #(define-markup-command (chordlyrics layout props lyrics) (ly:music?)
    #:properties ((verse-chords #{#})
@@ -378,10 +403,10 @@ Chord_lyrics_spacing_engraver =
             \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
+              %\override SpacingSpanner.packed-spacing = ##t
               \consists \Chord_lyrics_spacing_engraver
               \remove Bar_number_engraver
               \remove Mark_engraver
@@ -412,6 +437,15 @@ Chord_lyrics_spacing_engraver =
               \remove Note_heads_engraver
               \remove Script_engraver
             }
+            \context {
+              \NullVoice
+              \consists Rest_engraver
+              \omit Rest
+              \override Rest.X-extent = #'(0 . 0)
+              \undo \omit NoteHead
+              \hide NoteHead
+              \override NoteHead.X-extent = #'(0 . 0.5)
+            }
           }
         }
       }