start footnotes

quad/qtest/demo-footnotes.rkt

@@ -0,0 +1,14 @@
+#lang quadwriter
+
+#:page-height "8in"
+#:page-width "6in"
+
+"Hello"
+
+'(q ((flow "footnote")(font-size-adjust "80%")(line-height-adjust "70%")) "A convertible value in the sense of convertible? is used in a renderer-specific way, but values convertible to 'text renders the same as the resulting string. If a renderer is not able to convert the value to a known format, the value is converted to a string using write." (q ((break "para"))))
+
+" world."
+
+'(q ((flow "footnote")(font-size-adjust "80%")(line-height-adjust "70%")) "An instance of link-element has a tag for the target of the link." (q ((break "para"))))
+
+" I love you."

quad/quadwriter/attrs.rkt

@@ -78,6 +78,7 @@ Naming guidelines
                link
                href
                line-height
+               line-height-adjust
                hyphenate
                list-index
                no-colbr

quad/quadwriter/font.rkt

@@ -75,10 +75,16 @@
 (define (parse-percentage pstr)
   (/ (string->number (string-trim pstr "%")) 100.0))
 
-(define (resolve-font-size! attrs)
-  (define this-font-size (hash-ref! attrs :font-size default-font-size))
-  (define this-font-size-adjust (parse-percentage (hash-ref! attrs :font-size-adjust "100%")))
-  ;; we bake the adjustment into the font size...
-  (hash-set! attrs :font-size (* this-font-size this-font-size-adjust))
+(define (adjuster-base attrs key adjustment-key default-value)
+  (define this-val (hash-ref! attrs key default-value))
+  (define this-val-adjust (parse-percentage (hash-ref! attrs adjustment-key "100%")))
+  ;; we bake the adjustment into the val...
+  (hash-set! attrs key (and this-val (* this-val this-val-adjust)))
   ;; and then set the adjustment back to 100% (since it's now accounted for)
-  (hash-set! attrs :font-size-adjust "100%"))
+  (hash-set! attrs adjustment-key "100%"))
+
+(define (resolve-font-size! attrs)
+  (adjuster-base attrs :font-size :font-size-adjust default-font-size))
+
+(define (resolve-line-height! attrs)
+  (adjuster-base attrs :line-height :line-height-adjust default-line-height))

quad/quadwriter/layout.rkt

@@ -670,7 +670,7 @@
                       [elems (from-parent (insert-blocks lns) 'nw)]))]
     [_ null]))
 
-(define (column-wrap qs vertical-height column-gap [column-quad q:column])
+(define (column-wrap lines fn-lines vertical-height column-gap [column-quad q:column])
   (unless (positive? vertical-height)
     (raise-argument-error 'column-wrap "positive number" vertical-height))
   
@@ -679,17 +679,27 @@
   ;; could do it after, but it would require going back inside each col quad
   ;; which seems overly interdependent, because `insert-blocks` is used to determine break locations.
   ;; `col-wrap` should emit quads that are complete.
+  (define cols (wrap lines vertical-height
+                     #:soft-break #true
+                     #:hard-break column-break-quad?
+                     #:no-break (λ (q) (quad-ref q :no-colbr)) ; cooperates with make-nobreak
+                     #:distance (λ (q dist-so-far wrap-qs)
+                                  ;; do trial block insertions
+                                  (sum-y (insert-blocks (reverse wrap-qs))))                     
+                     #:finish-wrap (col-finish-wrap column-quad)))
+  (define reversed-fn-lines (match (reverse fn-lines)
+                              [(? null?) null]
+                              [reversed-fn-lines
+                               (quad-update! (car reversed-fn-lines)
+                                             [from-parent 'sw])
+                               (for/list ([fn-line (in-list reversed-fn-lines)])
+                                 (quad-update! fn-line
+                                               [from 'nw]
+                                               [to 'sw]))]))
+  (quad-update! (car cols)
+                [elems (append (quad-elems (car cols)) reversed-fn-lines)])
   (define col-spacer (quad-copy q:column-spacer [size (pt column-gap 100)]))
-  (add-between
-   (wrap qs vertical-height
-         #:soft-break #true
-         #:hard-break column-break-quad?
-         #:no-break (λ (q) (quad-ref q :no-colbr)) ; cooperates with make-nobreak
-         #:distance (λ (q dist-so-far wrap-qs)
-                      ;; do trial block insertions
-                      (sum-y (insert-blocks (reverse wrap-qs))))                     
-         #:finish-wrap (col-finish-wrap column-quad))
-   col-spacer))
+  (add-between cols col-spacer))
 
 (define ((page-finish-wrap make-page-quad path) cols q0 q page-idx)
   (define page-quad (make-page-quad (+ (section-pages-used) page-idx)))

quad/quadwriter/render.rkt

@@ -112,6 +112,7 @@
                              complete-every-path!
                              resolve-font-path!
                              resolve-font-size!
+                             resolve-line-height!
                              parse-font-features!))])
     (proc attrs)))
 
@@ -198,6 +199,8 @@
     (hash-set! (pdf-info pdf) pdf-k (quad-ref (car qs) k "")))
   (hash-set! (pdf-info pdf) 'Creator (format "Racket ~a (Quad library)" (version))))
 
+(define (footnote-flow? q) (equal? (quad-ref q 'flow) "footnote"))
+
 (define/contract (render-pdf qx-arg pdf-path-arg
                              [base-dir-arg #false]
                              #:replace [replace-existing-file? #t]
@@ -241,13 +244,16 @@
         (define printable-height (- page-height top-margin bottom-margin))
         (define column-count (setup-column-count qs))
         (define column-gap (setup-column-gap qs))
+
+        (define-values (fn-qs main-qs) (partition footnote-flow? qs))
     
         (define line-wrap-size (/ (- printable-width (* (sub1 column-count) column-gap)) column-count))
-        (define line-qs (time-log line-wrap (apply-keeps (line-wrap qs line-wrap-size))))
+        (define line-qs (time-log line-wrap (apply-keeps (line-wrap main-qs line-wrap-size))))
+        (define fn-line-qs (time-log fn-line-wrap (apply-keeps (line-wrap fn-qs line-wrap-size))))
     
         (define col-quad-prototype (quad-copy q:column
                                               [size (pt line-wrap-size printable-height)]))
-        (define column-qs (time-log column-wrap (column-wrap line-qs printable-height column-gap col-quad-prototype)))
+        (define column-qs (time-log column-wrap (column-wrap line-qs fn-line-qs printable-height column-gap col-quad-prototype)))
 
         (define page-quad-prototype
           (λ (page-count)