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typesetting/quad/quadwriter/attrs.rkt

147 lines
5.5 KiB
Racket

#lang debug racket/base
(require (for-syntax racket/base racket/syntax syntax/strip-context)
racket/match
racket/sequence
racket/string)
(provide (all-defined-out))
(define (list->attrs . kvs)
(for/list ([kv (in-slice 2 kvs)])
kv))
(define (cm->in x) (/ x 2.54))
(define (in->pts x) (* 72 x))
(define (mm->cm x) (/ x 10))
(define (parse-dimension x [round? #f])
(define val
(match x
[(? number?) x]
[(? string? x)
(match (cdr (regexp-match #rx"^(-?[0-9\\.]+)([a-z]+)$" (string-downcase x)))
[(list num-string unit)
((match unit
[(regexp #rx"in(ch(es)?)?$") in->pts]
[(regexp #rx"cm$") (compose1 in->pts cm->in)]
[(regexp #rx"mm$") (compose1 in->pts cm->in mm->cm)]
[_ (raise-argument-error 'parse-dimension "dimension string" x)]) (string->number num-string))])]))
(if round? (inexact->exact (floor val)) val))
(define (copy-block-attrs source-hash dest-hash)
(define new-hash (make-hasheq))
(for ([(k v) (in-hash dest-hash)])
(hash-set! new-hash k v))
(for* ([k (in-list block-attrs)]
[v (in-value (hash-ref source-hash k #f))]
#:when v)
(hash-set! new-hash k v))
new-hash)
(define-syntax (define-attrs stx)
(syntax-case stx ()
[(_ (ATTR-NAME ...))
(with-syntax ([(ATTR-ID ...) (for/list ([attr-id (in-list (syntax->list #'(ATTR-NAME ...)))])
(format-id stx ":~a" (syntax-e attr-id)))])
#'(begin
(define ATTR-ID 'ATTR-NAME) ...))]
[(_ ID (ATTR-NAME ...))
(replace-context stx
#'(begin
(define ID (list 'ATTR-NAME ...))
(define-attrs (ATTR-NAME ...))))]))
#|
Naming guidelines
+ shorter is better
+ general to specific: border-color-left, not border-left-color or left-border-color
+ don't refer to specific output format, e.g. PDF or HTML
+ consistency with CSS style property names is OK if the concept is mostly the same, but usually it's not
+ default value for any missing attr is #false
+ measurement units are points by default
|#
(define-attrs (font-family
font-size
font-size-adjust
font-color
font-features
font-italic
font-bold
character-tracking
bg
link
href
line-height
hyphenate
list-index
no-colbr
no-pbr
page-number
doc-title))
(define-attrs block-attrs (display
;; inset values increase the layout size of the quad.
;; they are relative to the natural layout box.
inset-top
inset-bottom
inset-left
inset-right
;; border-inset values do not increase the layout size of the quad.
;; they are relative to the layout size of the quad, with inset values included.
;; this is different from CSS, where margin + padding increase the size of the layout.
;; one has to be dependent on the other, so a choice must be made.
;; I find this approach more sensible because
;; borders are a styling element, not a layout element.
;; this means that changing the inset values will change the position of the border.
;; but this is preferable to the CSS model, where moving the border changes the layout.
;; principle: minimize the number of values that affect the layout,
;; so it's easier to reason about programmatically.
border-inset-top
border-inset-bottom
border-inset-left
border-inset-right
border-width-left
border-width-right
border-width-top
border-width-bottom
border-color-left
border-color-right
border-color-top
border-color-bottom
background-color
block-clip ; whether box boundary clips its contents
space-after ; space after a block, like a paragraph
space-before
column-count
column-gap
keep-first-lines
keep-last-lines
keep-all-lines
keep-with-next
line-align
line-align-last
first-line-indent
line-wrap
page-width
page-height
page-size ; e.g., "letter"
page-orientation ; only applies to page-size dimensions
page-margin-top
page-margin-bottom
page-margin-left
page-margin-right
footer-display))