#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 (picas->pts left right) (+ (* left 12) (or right 0))) (define (cm->in x _) (/ x 2.54)) (define (in->pts x _) (* 72 x)) (define (mm->cm x _) (/ x 10.0)) (define (parse-dimension x [em-resolution-attrs #false]) (match x [#false #false] [(? number? num) num] [(? string? str) (match (regexp-match #px"^(-?[0-9\\.]+)\\s*([a-z]+)([0-9\\.]*)$" (string-downcase str)) [#false str] ; a string other than a dimension string, so leave it [(list str num-string-left unit num-string-right) ((match unit [(regexp #rx"(pt|point)(s)?$") (λ (num _) num)] ; points [(regexp #rx"(p|pica)(s)?") picas->pts] ; picas [(regexp #rx"in(ch(es)?)?$") in->pts] ; inches [(regexp #rx"cms?$") (compose1 in->pts cm->in)] ; cm [(regexp #rx"mms?$") (compose1 in->pts cm->in mm->cm)] ; mm [(regexp #rx"ems?$") (if em-resolution-attrs (λ (num _) (* (hash-ref em-resolution-attrs :font-size) num)) ;; if we don't have attrs for resolving the em string, we leave it alone (λ (num _) str))] ; em [_ (raise-argument-error 'parse-dimension "dimension string" str)]) (string->number num-string-left) (string->number num-string-right))])])) (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 v) (in-hash source-hash)] #:when (memq k block-attrs)) (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-path font-size font-color font-features font-features-adjust font-italic font-bold font-underline font-tracking font-baseline-shift font-case bg link href line-height hyphenate list-index no-colbr no-pbr page-number doc-title pdf-title pdf-subject pdf-author pdf-keywords break draw width height parent anchor-from anchor-from-parent anchor-to string color stroke x y x1 ;; x & y are the top-left pos of the bounding box. y1 ;; x1 & y1 are the starting points of a line x2 y2)) (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-with-next line-align first-line-indent line-wrap image-file image-object image-alt image-height image-width page-width page-height page-size ; e.g., "letter" page-orientation ; only applies to page-size dimensions page-number-start ; 1 page-side-start ; 'right page-margin-top page-margin-bottom page-margin-left page-margin-right page-margin-gutter footer-display footer-text ;; we want this distinct from anchor-parent ;; because the two directives may overlap / contradict. ;; for instance: repeat on every page, ;; a quad that prints on the previous page on the second line. repeat draw-debug fn-ref fn-text fn-text-start)) (define (takes-dimension-string? k) (and (memq k (list :page-width :page-height :page-margin-top :page-margin-bottom :page-margin-left :page-margin-right :page-margin-gutter :column-gap :inset-top :inset-bottom :inset-left :inset-right :border-inset-top :border-inset-bottom :border-inset-left :border-inset-right :border-width-left :border-width-right :border-width-top :border-width-bottom :space-before :space-after :image-height :image-width :font-size :font-tracking :font-baseline-shift :line-height :x :y :x1 :x2 :y1 :y2 :stroke :width)) #true)) (define (has-case-sensitive-value? k) (and (memq k (list :pdf-title :pdf-subject :pdf-author :pdf-keywords :string :footer-text)) #true)) (define (takes-path? k) (and (memq k (list :image-file)) #true))