This file is indexed.

/usr/share/lilypond/2.18.2/scm/page.scm is in lilypond-data 2.18.2-4.

This file is owned by root:root, with mode 0o644.

The actual contents of the file can be viewed below.

  1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
;;;; This file is part of LilyPond, the GNU music typesetter.
;;;;
;;;; Copyright (C) 2006--2012 Han-Wen Nienhuys <hanwen@xs4all.nl>
;;;;
;;;; LilyPond is free software: you can redistribute it and/or modify
;;;; it under the terms of the GNU General Public License as published by
;;;; the Free Software Foundation, either version 3 of the License, or
;;;; (at your option) any later version.
;;;;
;;;; LilyPond is distributed in the hope that it will be useful,
;;;; but WITHOUT ANY WARRANTY; without even the implied warranty of
;;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
;;;; GNU General Public License for more details.
;;;;
;;;; You should have received a copy of the GNU General Public License
;;;; along with LilyPond.  If not, see <http://www.gnu.org/licenses/>.

(define-module (scm page)

  #:export (make-page
            page-property
            page-set-property!
            page-prev
            page-printable-height
            layout->page-init
            page-force
            page-penalty
            page-configuration
            page-lines
            page-page-number
            page-system-numbers
            page-stencil
            page-free-height
            page?
            ))

(use-modules (lily)
             (scm paper-system)
             (srfi srfi-1))


(define (annotate? layout)
  (eq? #t (ly:output-def-lookup layout 'annotate-spacing)))


(define page-module (current-module))

(define (make-page paper-book  . args)
  (let*
      ((p (apply ly:make-prob (append
                               (list 'page (layout->page-init (ly:paper-book-paper paper-book))
                                     'paper-book paper-book)
                               args))))

    (page-set-property! p 'head-stencil (page-header p))
    (page-set-property! p 'foot-stencil (page-footer p))

    p))

(define page-property ly:prob-property)
(define page-set-property! ly:prob-set-property!)
(define (page-property? page sym)
  (eq? #t (page-property page sym)))
(define (page? x)  (ly:prob-type? x 'page))


;; define accessors.
(for-each
 (lambda (j)
   (module-define!
    page-module
    (string->symbol (format #f "page-~a" j))
    (lambda (pg)
      (page-property pg j))))

 '(page-number prev lines force penalty lines))

(define (page-system-numbers page)
  (map (lambda (ps) (ly:prob-property ps 'number))
       (page-lines page)))

(define (page-translate-systems page)
  (for-each

   (lambda (sys-off)
     (let*
         ((sys (car sys-off))
          (off (cadr sys-off)))

       (if (not (number? (ly:prob-property sys 'Y-offset)))
           (ly:prob-set-property! sys 'Y-offset off))))

   (zip (page-property page 'lines)
        (page-property page 'configuration))))

(define (annotate-top-space first-system layout header-stencil stencil)
  (let* ((top-margin (ly:output-def-lookup layout 'top-margin))
         (sym (if (paper-system-title? first-system)
                  'top-markup-spacing
                  'top-system-spacing))
         (spacing-spec (ly:output-def-lookup layout sym))
         (X-offset (ly:prob-property first-system 'X-offset 5))
         (header-extent (ly:stencil-extent header-stencil Y)))

    (set! stencil
          (ly:stencil-add stencil
                          (ly:stencil-translate-axis
                           (annotate-spacing-spec layout
                                                  spacing-spec
                                                  (- top-margin)
                                                  (car header-extent)
                                                  #:base-color red)
                           X-offset X)))
    stencil))


(define (annotate-page layout stencil)
  (let ((top-margin (ly:output-def-lookup layout 'top-margin))
        (paper-height (ly:output-def-lookup layout 'paper-height))
        (bottom-margin (ly:output-def-lookup layout 'bottom-margin))
        (add-stencil (lambda (y)
                       (set! stencil
                             (ly:stencil-add stencil
                                             (ly:stencil-translate-axis y 6 X))))))
    (add-stencil
     (ly:stencil-translate-axis
      (annotate-y-interval layout "paper-height"
                           (cons (- paper-height) 0)
                           #t)
      1 X))
    (add-stencil
     (ly:stencil-translate-axis
      (annotate-y-interval layout "top-margin"
                           (cons (- top-margin) 0)
                           #t)
      2 X))
    (add-stencil
     (ly:stencil-translate-axis
      (annotate-y-interval layout "bottom-margin"
                           (cons (- paper-height) (- bottom-margin paper-height))
                           #t)
      2 X))
    stencil))

(define (annotate-space-left page)
  (let*
      ((paper-book (page-property page 'paper-book))
       (layout (ly:paper-book-paper paper-book))
       (arrow (annotate-y-interval layout
                                   "space left"
                                   (cons (- 0.0
                                            (page-property page 'bottom-edge)
                                            (let ((foot (page-property page 'foot-stencil)))
                                              (if (and (ly:stencil? foot)
                                                       (not (ly:stencil-empty? foot)))
                                                  (car (ly:stencil-extent foot Y))
                                                  0.0)))
                                         (page-property page  'bottom-system-edge))
                                   #t)))

    (set! arrow (ly:stencil-translate-axis arrow 8 X))

    arrow))


(define (page-header-or-footer page dir)
  (let*
      ((paper-book (page-property page 'paper-book))
       (layout (ly:paper-book-paper paper-book))
       (scopes (ly:paper-book-scopes paper-book))
       (number (page-page-number page))
       (is-last-bookpart (page-property page 'is-last-bookpart))
       (is-bookpart-last-page (page-property page 'is-bookpart-last-page))
       (sym (if (= dir UP)
                'make-header
                'make-footer))
       (header-proc (ly:output-def-lookup layout sym)))

    (if (procedure? header-proc)
        (header-proc layout scopes number is-last-bookpart is-bookpart-last-page)
        #f)))


(define (page-header page)
  (page-header-or-footer page UP))

(define (page-footer page)
  (page-header-or-footer page DOWN))

(define (layout->page-init layout)
  "Alist of settings for page layout"
  (let*
      ((paper-height (ly:output-def-lookup layout 'paper-height))
       (paper-width (ly:output-def-lookup layout 'paper-width))
       (left-margin (ly:output-def-lookup layout 'left-margin))
       (right-margin (ly:output-def-lookup layout 'right-margin))
       (bottom-edge (- paper-height
                       (ly:output-def-lookup layout 'bottom-margin)) )
       (top-margin (ly:output-def-lookup layout 'top-margin))
       )

    `((paper-height . ,paper-height)
      (paper-width . ,paper-width)
      (left-margin . ,left-margin)
      (right-margin . ,right-margin)
      (top-margin . ,top-margin)
      (bottom-edge . ,bottom-edge)
      )))

(define (make-page-stencil page)
  "Construct a stencil representing the page from PAGE."


  (page-translate-systems page)
  (let*
      ((paper-book (page-property page 'paper-book))
       (prop (lambda (sym) (page-property page sym)))
       (layout (ly:paper-book-paper paper-book))
       (scopes (ly:paper-book-scopes paper-book))
       (lines (page-lines page))
       (number (page-page-number page))

       ;; TODO: naming paper-height/paper-width not analogous to TeX.

       (system-xoffset (ly:output-def-lookup layout 'horizontal-shift 0.0))
       (system-separator-markup (ly:output-def-lookup layout 'system-separator-markup))
       (system-separator-stencil (if (markup? system-separator-markup)
                                     (interpret-markup layout
                                                       (layout-extract-page-properties layout)
                                                       system-separator-markup)
                                     #f))

       (page-stencil (ly:make-stencil '()))

       (last-system #f)
       (last-y 0.0)
       (add-to-page (lambda (stencil x y)
                      (set! page-stencil
                            (ly:stencil-add page-stencil
                                            (ly:stencil-translate stencil
                                                                  (cons
                                                                   (+ system-xoffset x)
                                                                   (- 0 y (prop 'top-margin)))

                                                                  )))))
       (add-system
        (lambda (system)
          (let* ((stencil (paper-system-stencil system))
                 (y (ly:prob-property system 'Y-offset 0))
                 (is-title (paper-system-title?
                            system)))
            (add-to-page stencil
                         (ly:prob-property system 'X-offset 0.0)
                         y)
            (if (and (ly:stencil? system-separator-stencil)
                     last-system
                     (not (paper-system-title? system))
                     (not (paper-system-title? last-system)))
                (add-to-page
                 system-separator-stencil
                 0
                 (average (- last-y
                             (car (paper-system-staff-extents last-system)))
                          (- y
                             (cdr (paper-system-staff-extents system))))))
            (set! last-system system)
            (set! last-y y))))
       (head (prop 'head-stencil))
       (foot (prop 'foot-stencil))
       )

    (if (and
         (ly:stencil? head)
         (not (ly:stencil-empty? head)))
        (begin
          ;; Ensure that the top of the header just touches the top margin.
          (set! head (ly:stencil-translate-axis head
                                                (- 0 (cdr (ly:stencil-extent head Y)) (prop 'top-margin)) Y))
          (set! page-stencil (ly:stencil-add page-stencil head))))

    (if (and
         (annotate? layout)
         (pair? lines))

        (begin
          (set! page-stencil (annotate-top-space (car lines) layout head page-stencil))

          (for-each (lambda (sys next-sys)
                      (paper-system-annotate sys next-sys layout))
                    lines
                    (append (cdr lines) (list #f)))
          (paper-system-annotate-last (car (last-pair lines)) layout)))

    (for-each add-system lines)


    (ly:prob-set-property! page 'bottom-system-edge
                           (car (ly:stencil-extent page-stencil Y)))
    (ly:prob-set-property! page 'space-left
                           (+ (prop 'bottom-edge)
                              (prop 'bottom-system-edge)
                              (if (and (ly:stencil? foot)
                                       (not (ly:stencil-empty? foot)))
                                  (car (ly:stencil-extent foot Y))
                                  0.0)))

    (if (annotate? layout)
        (set! page-stencil
              (ly:stencil-add page-stencil
                              (annotate-space-left page))))

    (if (and (ly:stencil? foot)
             (not (ly:stencil-empty? foot)))
        (set! page-stencil
              (ly:stencil-add
               page-stencil
               (ly:stencil-translate
                foot
                (cons 0
                      (+ (- (prop 'bottom-edge))
                         (- (car (ly:stencil-extent foot Y)))))))))

    (if (ly:output-def-lookup layout 'two-sided #f)
        (set! page-stencil
              (ly:stencil-translate page-stencil
                                    (cons (prop (if (even? number)
                                                    'left-margin
                                                    'right-margin))
                                          0)))
        (set! page-stencil
              (ly:stencil-translate page-stencil (cons (prop 'left-margin) 0))))

    ;; annotation.
    (if (annotate? layout)
        (set! page-stencil (annotate-page layout page-stencil)))

    page-stencil))


(define-public (page-stencil page)
  (if (not (ly:stencil? (page-property page 'stencil)))

      ;; todo: make tweakable.
      ;; via property + callbacks.

      (page-set-property! page 'stencil (make-page-stencil page)))
  (page-property page 'stencil))

(define (calc-printable-height page)
  "Printable area for music and titles; matches default-page-make-stencil."
  (let*
      ((paper-book (page-property page 'paper-book))
       (layout (ly:paper-book-paper paper-book))
       (h (- (ly:output-def-lookup layout 'paper-height)
             (ly:output-def-lookup layout 'top-margin)
             (ly:output-def-lookup layout 'bottom-margin)))

       (head (page-property page 'head-stencil))
       (foot (page-property page 'foot-stencil))
       (available
        (- h (if (ly:stencil? head)
                 (interval-length (ly:stencil-extent head Y))
                 0)
           (if (ly:stencil? foot)
               (interval-length (ly:stencil-extent foot Y))
               0))))

    ;; (display (list "\n available" available head foot))
    available))

(define (page-printable-height page)
  (if (not (number? (page-property page 'printable-height)))
      (page-set-property! page 'printable-height (calc-printable-height page)))

  (page-property page 'printable-height))