Add ability to customize PDF metadata for pdf-dc%

draw-doc/scribblings/draw/ps-setup-class.scrbl

@@ -272,4 +272,81 @@ Sets the scaling factor for PostScript output. See
 Sets the translation (from the bottom left corner) for PostScript
  output. See @method[ps-setup% get-translation].
 
+}
+
+@section{Customizing PDF metadata}
+
+The @racket[ps-setup%] object allows customizing PDF metadata in
+ conjunction with @racket[pdf-dc%], including the document title,
+ author, and other fields. Any newly constructed instance of
+ @racket[pdf-dc%] will apply the following metadata fields to the
+ output PDF from @racket[current-ps-setup] if specified. For
+ PostScript output, these properties are ignored.
+
+@defmethod[(get-title) (or/c string? #f)]{
+Returns the title metadata field, specifying the title of a
+ document.
+}
+
+@defmethod[(get-author) (or/c string? #f)]{
+Returns the author metadata field, specifying the author of a
+ document.
+}
+
+@defmethod[(get-subject) (or/c string? #f)]{
+Returns the subject metadata field, specifying the subject of a
+ document.
+}
+
+@defmethod[(get-keywords) (or/c string? #f)]{
+Returns the keywords metadata field, specifying the keywords
+ associated with a document.
+}
+
+@defmethod[(get-creator) (or/c string? #f)]{
+Returns the creator metadata field, specifying the software that
+ created the document. By default, the creator is set to a string
+ specifying draw-lib and the current racket version.
+}
+
+@defmethod[(get-create-date) (or/c string? #f)]{
+Returns the creation date metadata field, specifying the date and time
+ a document was created, in ISO 8601 format.
+}
+
+@defmethod[(get-mod-date) (or/c string? #f)]{
+Returns the modification date metadata field, specifying the date and
+ time a document was modified, in ISO 8601 format.
+}
+
+@defmethod[(set-title [title (or/c string? #f)]) void?]{
+Sets the title metadata field. See @method[ps-setup% get-title].
+}
+
+@defmethod[(set-author [author (or/c string? #f)]) void?]{
+Sets the author metadata field. See @method[ps-setup% get-author].
+}
+
+@defmethod[(set-subject [subject (or/c string? #f)]) void?]{
+Sets the subject metadata field. See @method[ps-setup% get-subject].
+}
+
+@defmethod[(set-keywords [keywords (or/c string? #f)]) void?]{
+Sets the keywords metadata field. See @method[ps-setup% get-keywords].
+}
+
+@defmethod[(set-creator [creator (or/c string? #f)]) void?]{
+Sets the creator metadata field. See @method[ps-setup% get-creator].
+}
+
+@defmethod[(set-create-date [create-date (or/c string? #f)]) void?]{
+Sets the creation date metadata field. See
+ @method[ps-setup% get-create-date]. The provided date must be in
+ ISO 8601 format.
+}
+
+@defmethod[(set-mod-date [mod-date (or/c string? #f)]) void?]{
+Sets the modification date metadata field. See
+ @method[ps-setup% get-mod-date]. The provided date must be in
+ ISO 8601 format.
 }}

draw-lib/racket/draw/private/post-script-dc.rkt

@@ -15,6 +15,19 @@
 (provide post-script-dc%
          pdf-dc%)
 
+(define (pdf-set-all-md! s pss)
+  (define-syntax-rule (pdf-set-md! s pss key get-prop)
+    (let ([val (send pss get-prop)])
+      (when val
+        (cairo_pdf_surface_set_metadata s key val))))
+  (pdf-set-md! s pss 'CAIRO_PDF_METADATA_TITLE get-title)
+  (pdf-set-md! s pss 'CAIRO_PDF_METADATA_AUTHOR get-author)
+  (pdf-set-md! s pss 'CAIRO_PDF_METADATA_SUBJECT get-subject)
+  (pdf-set-md! s pss 'CAIRO_PDF_METADATA_KEYWORDS get-keywords)
+  (pdf-set-md! s pss 'CAIRO_PDF_METADATA_CREATOR get-creator)
+  (pdf-set-md! s pss 'CAIRO_PDF_METADATA_CREATE_DATE get-create-date)
+  (pdf-set-md! s pss 'CAIRO_PDF_METADATA_MOD_DATE get-mod-date))
+
 (define (make-dc-backend pdf?)
   (class default-dc-backend%
     (init [interactive #t]
@@ -89,12 +102,12 @@
                                           (values w h))]
                                [(writer proc) (make-port-writer file)])
                     (values
-                     ((if pdf?
-                          cairo_pdf_surface_create_for_stream 
-                          cairo_ps_surface_create_for_stream)
-                      proc
-                      w
-                      h)
+                     (let ([s ((if pdf?
+                                 cairo_pdf_surface_create_for_stream
+                                 cairo_ps_surface_create_for_stream)
+                               proc w h)])
+                       (when pdf? (pdf-set-all-md! s pss))
+                       s)
                      file
                      (not (output-port? fn))
                      writer

draw-lib/racket/draw/private/ps-setup.rkt

@@ -1,5 +1,6 @@
 #lang racket/base
 (require racket/class
+         (only-in racket/contract/base or/c)
          "syntax.rkt")
 
 (provide ps-setup%
@@ -26,6 +27,9 @@
   (and (string? s)
        (assoc s paper-sizes)))
 
+(define default-creator-string
+  (string-append "draw-lib (racket " (version) " https://racket-lang.org)"))
+
 (define ps-setup%
   (class object%
     (properties
@@ -35,7 +39,14 @@
      [[(symbol-in preview file printer) mode] 'file]
      [[(symbol-in portrait landscape) orientation] 'portrait]
      [[paper-name-string? paper-name] "Letter 8 1/2 x 11 in"]
-     [[string? preview-command] "gv"])
+     [[string? preview-command] "gv"]
+     [[(or/c string? #f) title] #f]
+     [[(or/c string? #f) author] #f]
+     [[(or/c string? #f) subject] #f]
+     [[(or/c string? #f) keywords] #f]
+     [[(or/c string? #f) creator] default-creator-string]
+     [[(or/c string? #f) create-date] #f]
+     [[(or/c string? #f) mod-date] #f])
 
     (define editor-margin-x 20.0)
     (define editor-margin-y 20.0)

draw-lib/racket/draw/unsafe/cairo.rkt

@@ -26,6 +26,14 @@
 (define _cairo_pattern_t (_cpointer 'cairo_pattern_t))
 (define _cairo_font_options_t (_cpointer/null 'cairo_font_options_t))
 (define _CGContextRef (_cpointer 'CGContextRef))
+(define _cairo_pdf_metadata_t
+  (_enum '(CAIRO_PDF_METADATA_TITLE
+           CAIRO_PDF_METADATA_AUTHOR
+           CAIRO_PDF_METADATA_SUBJECT
+           CAIRO_PDF_METADATA_KEYWORDS
+           CAIRO_PDF_METADATA_CREATOR
+           CAIRO_PDF_METADATA_CREATE_DATE
+           CAIRO_PDF_METADATA_MOD_DATE)))
 
 (define-cstruct _cairo_matrix_t ([xx _double*]
                                  [yx _double*]
@@ -349,6 +357,8 @@
 (define-cairo cairo_pdf_surface_create_for_stream 
   _stream-surface-proc
   #:wrap stream-surface-allocator)
+(define-cairo cairo_pdf_surface_set_metadata
+  (_fun _cairo_surface_t _cairo_pdf_metadata_t _string/utf-8 -> _void))
 (define-cairo cairo_svg_surface_create_for_stream 
   _stream-surface-proc
   #:wrap stream-surface-allocator)