gui/gui-lib/mrlib/private/graph.rkt
2014-12-02 02:33:07 -05:00

893 lines
39 KiB
Racket

#lang racket/base
(require racket/class
racket/list
racket/math
racket/gui/base
racket/match
(for-syntax racket/base)
racket/contract)
(provide graph-snip<%>
graph-snip-mixin
graph-pasteboard<%>
graph-pasteboard-mixin)
(provide add-links add-links/text-colors remove-links set-link-label)
(define-local-member-name invalidate-edge-cache)
(define graph-snip<%>
(interface ()
get-children
add-child
remove-child
get-parents
add-parent
remove-parent
has-self-loop?
set-parent-link-label
find-shortest-path))
(define-local-member-name get-parent-links)
(define self-offset 10)
;; (or-2v arg ...)
;; like `or', except each `arg' returns two values. The
;; truth value of each arg is #t if both args are #t and
;; #f otherwise
(define-syntax (or-2v stx)
(syntax-case stx ()
[(_ arg)
(syntax arg)]
[(_ arg args ...)
(syntax
(let-values ([(one two) arg])
(if (and one two)
(values one two)
(or-2v args ...))))]))
(define snipclass (make-object snip-class%))
(define default-dark-pen (send the-pen-list find-or-create-pen "blue" 1 'solid))
(define default-light-pen (send the-pen-list find-or-create-pen "light blue" 1 'solid))
(define default-dark-brush (send the-brush-list find-or-create-brush "light blue" 'solid))
(define default-light-brush (send the-brush-list find-or-create-brush "white" 'solid))
(define default-dark-text (send the-color-database find-color "blue"))
(define default-light-text (send the-color-database find-color "light blue"))
;; label is boolean or string
(define-struct link (snip dark-pen light-pen dark-brush light-brush dark-text light-text dx dy [label #:mutable]))
;; add-links : (is-a?/c graph-snip<%>) (is-a?/c graph-snip<%>) -> void
;; : (is-a?/c graph-snip<%>) (is-a?/c graph-snip<%>) pen pen brush brush -> void
(define add-links
(case-lambda
[(parent child) (add-links parent child #f #f #f #f)]
[(parent child dark-pen light-pen dark-brush light-brush)
(add-links parent child dark-pen light-pen dark-brush light-brush 0 0)]
[(parent child dark-pen light-pen dark-brush light-brush label)
(add-links parent child dark-pen light-pen dark-brush light-brush 0 0 label)]
[(parent child dark-pen light-pen dark-brush light-brush dx dy)
(add-links parent child dark-pen light-pen dark-brush light-brush dx dy #f)]
[(parent child dark-pen light-pen dark-brush light-brush dx dy label)
(add-links/text-colors parent child
dark-pen light-pen dark-brush light-brush
#f #f
dx dy
label)]))
(define (add-links/text-colors parent child
dark-pen light-pen dark-brush light-brush
dark-text light-text
dx dy
label)
(send parent add-child child)
(send child add-parent parent dark-pen light-pen dark-brush light-brush dark-text light-text dx dy label))
(define (remove-links parent child)
(send parent remove-child child)
(send child remove-parent parent))
(define (set-link-label parent child label)
(send child set-parent-link-label parent label))
(define graph-snip-mixin
(mixin ((class->interface snip%)) (graph-snip<%>)
(inherit get-admin)
(define children null)
(define/public (get-children) children)
(define/public (add-child child)
(unless (memq child children)
(set! children (cons child children))))
(define/public (remove-child child)
(when (memq child children)
(set! children (remq child children))))
(define parent-links null)
(define/public (get-parent-links) parent-links)
(define/public (get-parents) (map link-snip parent-links))
(define/public add-parent
(case-lambda
[(parent) (add-parent parent #f #f #f #f)]
[(parent dark-pen light-pen dark-brush light-brush)
(add-parent parent dark-pen light-pen dark-brush light-brush 0 0)]
[(parent dark-pen light-pen dark-brush light-brush dx dy)
(add-parent parent dark-pen light-pen dark-brush light-brush #f #f dx dy #f)]
[(parent dark-pen light-pen dark-brush light-brush dark-text light-text dx dy label)
(unless (memf (lambda (parent-link) (eq? (link-snip parent-link) parent)) parent-links)
(define admin (get-admin))
(when admin
(define ed (send admin get-editor))
(when (is-a? ed graph-pasteboard<%>)
(send ed invalidate-edge-cache)))
(set! parent-links
(cons (make-link parent
(or dark-pen default-dark-pen)
(or light-pen default-light-pen)
(or dark-brush default-dark-brush)
(or light-brush default-light-brush)
(or dark-text default-dark-text)
(or light-text default-light-text)
dx
dy
label)
parent-links)))]))
(define/public (remove-parent parent)
(when (memf (lambda (parent-link) (eq? (link-snip parent-link) parent)) parent-links)
(set! parent-links
(remove
parent
parent-links
(lambda (parent parent-link) (eq? (link-snip parent-link) parent))))))
(define/public (set-parent-link-label parent label)
(let ([parent-link
(cond [(memf (lambda (parent-link)
(eq? (link-snip parent-link) parent))
parent-links)
=> car]
[else #f])])
(when parent-link
(set-link-label! parent-link label))))
(define/public (has-self-loop?)
(memq this (get-children)))
(define/public (find-shortest-path other)
(define visited-ht (make-hasheq))
(define (first-view? n)
(hash-ref visited-ht n (lambda ()
(hash-set! visited-ht n #f)
#t)))
(let loop ((horizon (list (list this))))
(cond
[(null? horizon) #f]
[(assq other horizon) => (lambda (winner) winner)]
[else
(let inner-loop ((paths horizon)
(acc '()))
(cond
[(null? paths) (loop (apply append acc))]
[else
(let ((path (car paths)))
(inner-loop
(cdr paths)
(cons
(map (lambda (child) (cons child path)) (filter first-view? (send (car path) get-children)))
acc)))]))])))
(super-new)
(inherit set-snipclass)
(set-snipclass snipclass)))
(define graph-pasteboard<%>
(interface ()
on-mouse-over-snips
set-arrowhead-params
get-arrowhead-params
set-draw-arrow-heads?
set-flip-labels?
draw-edges))
(define-struct rect (left top right bottom))
(define graph-pasteboard-mixin
(mixin ((class->interface pasteboard%)) (graph-pasteboard<%>)
(inherit find-first-snip find-next-selected-snip)
(init-field [edge-label-font #f]
[edge-labels? #t]
[cache-arrow-drawing? #f])
(define/public (set-edge-label-font f)
(set! edge-label-font f)
(invalidate-bitmap-cache))
(define/public (get-edge-label-font) edge-label-font)
(define draw-arrow-heads? #t)
(define flip-labels? #t)
(inherit refresh get-admin)
(define (refresh*)
(let ([admin (get-admin)])
(when admin
(let ([xb (box 0)] [yb (box 0)] [wb (box 0)] [hb (box 0)])
(send admin get-view xb yb wb hb)
(send admin needs-update
(unbox xb) (unbox yb) (unbox wb) (unbox hb))))))
(define/public (set-draw-arrow-heads? x)
(set! draw-arrow-heads? x)
(refresh*))
(define/public (set-flip-labels? x)
(set! flip-labels? x)
(refresh*))
(define arrowhead-angle-width (* 1/4 pi))
(define arrowhead-short-side 8)
(define arrowhead-long-side 12)
(define/public (set-arrowhead-params angle-width long-side short-side)
(set! arrowhead-angle-width angle-width)
(set! arrowhead-short-side short-side)
(set! arrowhead-long-side long-side))
(define/public (get-arrowhead-params)
(values arrowhead-angle-width
arrowhead-long-side
arrowhead-short-side))
(inherit dc-location-to-editor-location get-canvas get-dc)
(field (currently-overs null))
(define/override (on-event evt)
(cond
[(send evt leaving?)
(change-currently-overs null (get-dc))
(super on-event evt)]
[(or (send evt entering?)
(send evt moving?))
(let ([ex (send evt get-x)]
[ey (send evt get-y)])
(let-values ([(x y) (dc-location-to-editor-location ex ey)])
(change-currently-overs (find-snips-under-mouse x y) (get-dc))))
(super on-event evt)]
[else
(super on-event evt)]))
(define/augment (on-interactive-move evt)
(invalidate-selected-snips)
(inner (void) on-interactive-move evt))
(define/augment (after-interactive-move evt)
(invalidate-selected-snips)
(inner (void) on-interactive-move evt))
(define/override (interactive-adjust-move snip x y)
(let ([dc (get-dc)])
(when dc
(invalidate-to-children/parents snip dc)))
(super interactive-adjust-move snip x y))
(define/augment (after-insert snip before x y)
(let ([dc (get-dc)])
(when dc
(invalidate-to-children/parents snip dc)))
(inner (void) after-insert snip before x y))
;; invalidate-selected-snips : -> void
;; invalidates the region around the selected
;; snips and their parents and children
(define/private (invalidate-selected-snips)
(let ([dc (get-dc)])
(when dc
(let loop ([snip (find-next-selected-snip #f)])
(when snip
(invalidate-to-children/parents snip dc)
(loop (find-next-selected-snip snip)))))))
(define/private (add-to-rect from to rect)
(let-values ([(xf yf wf hf) (get-position from)]
[(xt yt wt ht) (get-position to)])
(make-rect
(if rect
(min xf xt (rect-left rect))
(min xf xt))
(if rect
(min yf yt (rect-top rect))
(min yf yt))
(if rect
(max (+ xf wf) (+ xt wt) (rect-right rect))
(max (+ xf wf) (+ xt wt)))
(if rect
(max (+ yf hf) (+ yt ht) (rect-bottom rect))
(max (+ yf hf) (+ yt ht))))))
;; find-snips-under-mouse : num num -> (listof graph-snip<%>)
(define/private (find-snips-under-mouse x y)
(let loop ([snip (find-first-snip)])
(cond
[snip
(let-values ([(sx sy sw sh) (get-position snip)])
(if (and (<= sx x (+ sx sw))
(<= sy y (+ sy sh))
(is-a? snip graph-snip<%>))
(cons snip (loop (send snip next)))
(loop (send snip next))))]
[else null])))
;; change-currently-overs : (listof snip) -> void
(define/private (change-currently-overs new-currently-overs dc)
(unless (set-equal new-currently-overs currently-overs)
(let ([old-currently-overs currently-overs])
(set! currently-overs new-currently-overs)
(on-mouse-over-snips currently-overs)
(for-each
(lambda (old-currently-over)
(invalidate-to-children/parents old-currently-over dc))
old-currently-overs)
(for-each
(lambda (new-currently-over)
(invalidate-to-children/parents new-currently-over dc))
new-currently-overs))))
(define/public (on-mouse-over-snips snips) (void))
;; set-equal : (listof snip) (listof snip) -> boolean
;; typically lists will be small (length 1),
;; so use andmap/memq rather than hash-tables
(define/private (set-equal los1 los2)
(and (andmap (lambda (s1) (memq s1 los2)) los1)
(andmap (lambda (s2) (memq s2 los1)) los2)
#t))
;; invalidate-to-children/parents : snip dc -> void
;; invalidates the region containing this snip and
;; all of its children and parents.
(define/private (invalidate-to-children/parents snip dc)
(when (is-a? snip graph-snip<%>)
(define-values (_1 text-height _2 _3) (send dc get-text-extent "Label" #f #f 0))
(define parents-and-children (append (get-all-parents snip)
(get-all-children snip)))
(define rects (get-rectangles snip parents-and-children))
(for ([rect (in-list rects)])
(save-rectangle-to-invalidate
(- (rect-left rect) text-height)
(- (rect-top rect) text-height)
(+ (rect-right rect) text-height)
(+ (rect-bottom rect) text-height)))))
(define pending-invalidate-rectangle #f)
(define pending-invalidate-rectangle-timer #f)
(inherit invalidate-bitmap-cache)
(define/private (run-pending-invalidate-rectangle)
(define the-pending-invalidate-rectangle pending-invalidate-rectangle)
(set! pending-invalidate-rectangle #f)
(invalidate-bitmap-cache . the-pending-invalidate-rectangle))
(define/private (save-rectangle-to-invalidate l t r b)
(unless pending-invalidate-rectangle-timer
(set! pending-invalidate-rectangle-timer
(new timer% [notify-callback
(λ () (run-pending-invalidate-rectangle))])))
(add-to-pending-indvalidate-rectangle l t r b)
(send pending-invalidate-rectangle-timer start 20 #t))
(define/private (add-to-pending-indvalidate-rectangle l t r b)
(set! pending-invalidate-rectangle
(match pending-invalidate-rectangle
[(list l2 t2 r2 b2)
(list (min l l2) (min t t2) (max r r2) (max b b2))]
[#f
(list l t r b)])))
;; get-rectangles : snip (listof snip) -> rect
;; computes the rectangles that need to be invalidated for connecting
(define/private (get-rectangles main-snip c/p-snips)
(let ([main-snip-rect (snip->rect main-snip)])
(let loop ([c/p-snips c/p-snips])
(cond
[(null? c/p-snips) null]
[else
(let* ([c/p (car c/p-snips)]
[rect
(if (eq? c/p main-snip)
(let-values ([(sx sy sw sh) (get-position c/p)]
[(_1 h _2 _3) (send (get-dc) get-text-extent "yX")])
(make-rect (- sx self-offset)
sy
(+ (+ sx sw) self-offset)
(+ (+ sy sh) self-offset h)))
(or/c-rects (list main-snip-rect
(snip->rect c/p))))])
(cons rect (loop (cdr c/p-snips))))]))))
(define/private (snip->rect snip)
(let-values ([(sx sy sw sh) (get-position snip)])
(let* ([dc (get-dc)]
[h (if dc
(let-values ([(_1 h _2 _3) (send dc get-text-extent "yX")])
h)
10)])
(make-rect sx
sy
(+ sx sw)
(max (+ sy sh)
(+ sy (/ sh 2) (* 2
(sin (/ arrowhead-angle-width 2))
arrowhead-long-side) h))))))
(define/private (rect-area rect)
(* (- (rect-right rect)
(rect-left rect))
(- (rect-bottom rect)
(rect-top rect))))
(define/private (or/c-rects rects)
(cond
[(null? rects) (make-rect 0 0 0 0)]
[else
(let loop ([rects (cdr rects)]
[l (rect-left (car rects))]
[t (rect-top (car rects))]
[r (rect-right (car rects))]
[b (rect-bottom (car rects))])
(cond
[(null? rects) (make-rect l t r b)]
[else
(let ([rect (car rects)])
(loop (cdr rects)
(min l (rect-left rect))
(min t (rect-top rect))
(max r (rect-right rect))
(max b (rect-bottom rect))))]))]))
(define/override (on-paint before? dc left top right bottom dx dy draw-caret)
(when before?
(let ([old-font (send dc get-font)])
(when edge-label-font
(send dc set-font edge-label-font))
(cond
[pending-invalidate-rectangle
(add-to-pending-indvalidate-rectangle left top right bottom)]
[else
(draw-edges dc left top right bottom dx dy)])
(when edge-label-font
(send dc set-font old-font))))
(super on-paint before? dc left top right bottom dx dy draw-caret))
(define/public (draw-edges dc left top right bottom dx dy)
(cond
[cache-arrow-drawing?
(define admin (get-admin))
(when admin
(define-values (x y w h)
(let ([xb (box 0)]
[yb (box 0)]
[wb (box 0)]
[hb (box 0)])
(send admin get-max-view xb yb wb hb)
(values (unbox xb) (unbox yb) (unbox wb) (unbox hb))))
(define this-time (list x y w h))
(unless (and edges-cache (equal? this-time edges-cache-last-time))
(set! edges-cache-last-time this-time)
(set! edges-cache (make-bitmap (inexact->exact (ceiling w))
(inexact->exact (ceiling h))))
(define bdc (make-object bitmap-dc% edges-cache))
(draw-edges/compute bdc x y (+ x w) (+ y h) dx dy #f)
(send bdc set-bitmap #f))
(send dc draw-bitmap edges-cache 0 0)
(draw-edges/compute dc left top right bottom dx dy #t))]
[else
(draw-edges/compute dc left top right bottom dx dy #f)
(draw-edges/compute dc left top right bottom dx dy #t)]))
(define/augment (on-change)
(set! edges-cache #f)
(inner (void) on-change))
(define/public (invalidate-edge-cache) (set! edges-cache #f))
(define edges-cache #f)
(define edges-cache-last-time #f)
(define/private (draw-edges/compute dc left top right bottom dx dy draw-dark-lines?)
;; draw-connection : link snip boolean boolean -> void
;; sets the drawing context (pen and brush)
;; determines if the connection is between a snip and itself or two different snips
;; and calls draw-self-connection or draw-non-self-connection
(define (draw-connection from-link to dark-lines?)
(let ([from (link-snip from-link)])
(when (send from get-admin)
(let ([dx (+ dx (link-dx from-link))]
[dy (+ dy (link-dy from-link))])
(cond
[(eq? from to)
(set-pen/brush from-link dark-lines?)
(draw-self-connection dx dy (link-snip from-link) from-link dark-lines?)]
[else
(draw-non-self-connection dx dy from-link dark-lines? to)])))))
(define (get-text-length txt)
(let-values ([(text-len h d v) (send dc get-text-extent txt)])
text-len))
(define (draw-self-connection dx dy snip the-link dark-lines?)
(let*-values ([(sx sy sw sh) (get-position snip)]
[(s1x s1y) (values (+ sx sw) (+ sy (* sh 1/2)))]
[(s2x s2y) (values (+ sx sw self-offset) (+ sy (* 3/4 sh) (* 1/2 self-offset)))]
[(s3x s3y) (values (+ sx sw) (+ sy sh self-offset))]
[(b12x b12y) (values s2x s1y)]
[(b23x b23y) (values s2x s3y)]
[(s4x s4y) (values (- sx arrowhead-short-side)
(+ sy (* sh 1/2)))]
[(s5x s5y) (values (- sx arrowhead-short-side self-offset)
(+ sy (* 3/4 sh) (* 1/2 self-offset)))]
[(s6x s6y) (values (- sx arrowhead-short-side)
(+ sy sh self-offset))]
[(b45x b45y) (values s5x s4y)]
[(b56x b56y) (values s5x s6y)])
(update-arrowhead-polygon s4x s4y sx s4y point1 point2 point3 point4)
(send dc draw-spline (+ dx s1x) (+ dy s1y) (+ dx b12x) (+ dy b12y) (+ dx s2x) (+ dy s2y))
(send dc draw-spline (+ dx s2x) (+ dy s2y) (+ dx b23x) (+ dy b23y) (+ dx s3x) (+ dy s3y))
(send dc draw-line (+ dx s3x) (+ dy s3y) (+ dx s6x) (+ dy s6y))
(when (and edge-labels? (link-label the-link))
(let* ((textlen (get-text-length (link-label the-link)))
(linelen (- s6x s3x))
(offset (* 1/2 (- linelen textlen))))
(when (or #t (> sw textlen))
(send dc draw-text
(link-label the-link)
(+ dx s3x offset)
(+ dy s3y)
#f
0
0))))
(send dc draw-spline (+ dx s4x) (+ dy s4y) (+ dx b45x) (+ dy b45y) (+ dx s5x) (+ dy s5y))
(send dc draw-spline (+ dx s5x) (+ dy s5y) (+ dx b56x) (+ dy b56y) (+ dx s6x) (+ dy s6y))
(send dc draw-polygon points dx dy)))
(define (draw-non-self-connection dx dy from-link dark-lines? to)
(let ([from (link-snip from-link)])
(let*-values ([(xf yf wf hf) (get-position from)]
[(xt yt wt ht) (get-position to)]
[(lf tf rf bf) (values xf yf (+ xf wf) (+ yf hf))]
[(lt tt rt bt) (values xt yt (+ xt wt) (+ yt ht))])
(let ([x1 (+ xf (/ wf 2))]
[y1 (+ yf (/ hf 2))]
[x2 (+ xt (/ wt 2))]
[y2 (+ yt (/ ht 2))])
(set-pen/brush from-link dark-lines?)
(let-values ([(from-x from-y)
(or-2v (find-intersection x1 y1 x2 y2
lf tf rf tf)
(find-intersection x1 y1 x2 y2
lf bf rf bf)
(find-intersection x1 y1 x2 y2
lf tf lf bf)
(find-intersection x1 y1 x2 y2
rf tf rf bf))]
[(to-x to-y)
(or-2v (find-intersection x1 y1 x2 y2
lt tt rt tt)
(find-intersection x1 y1 x2 y2
lt bt rt bt)
(find-intersection x1 y1 x2 y2
lt tt lt bt)
(find-intersection x1 y1 x2 y2
rt tt rt bt))])
(when (and from-x from-y to-x to-y)
(let ((from-pt (make-rectangular from-x from-y))
(to-pt (make-rectangular to-x to-y)))
(define (arrow-point-ok? point-x point-y)
(and (in-rectangle? point-x point-y
(min lt rt lf rf) (min tt bt tf bf)
(max lt rt lf rf) (max tt bt tf bf))
(not (strict-in-rectangle? point-x point-y
(min lt rt) (min tt bt)
(max lt rt) (max tt bt)))
(not (strict-in-rectangle? point-x point-y
(min lf rf) (min tf bf)
(max lf rf) (max tf bf)))))
(cond
[(or (in-rectangle? from-x from-y lt tt rt bt)
(in-rectangle? to-x to-y lf tf rf bf))
;; the snips overlap, draw nothing
(void)]
[else
(draw-single-edge dc dx dy from to from-x from-y to-x to-y arrow-point-ok?)
(when (and edge-labels? (link-label from-link))
(let-values ([(text-len h d v) (send dc get-text-extent (link-label from-link))])
(let* ([arrow-end-x (send point3 get-x)]
[arrow-end-y (send point3 get-y)]
[arrowhead-end (make-rectangular arrow-end-x arrow-end-y)]
[vec (- arrowhead-end from-pt)]
[angle (- (angle vec))]
[flip? (and flip-labels?
(not (< (/ pi -2) angle (/ pi 2))))]
[angle (if flip? (+ angle pi) angle)]
[middle (+ from-pt
(- (* 1/2 vec)
(make-polar (/ text-len 2) (- angle))))])
(when (> (sqrt (+ (sqr (- arrow-end-x from-x))
(sqr (- arrow-end-y from-y))))
text-len)
(send dc draw-text (link-label from-link)
(+ dx (real-part middle))
(+ dy (imag-part middle))
#f
0
angle)))))]))))))))
(define (set-pen/brush from-link dark-lines?)
(send dc set-brush
(if dark-lines?
(link-dark-brush from-link)
(link-light-brush from-link)))
(send dc set-pen
(if dark-lines?
(link-dark-pen from-link)
(link-light-pen from-link)))
(send dc set-text-foreground
(if dark-lines?
(link-dark-text from-link)
(link-light-text from-link))))
(let ([old-pen (send dc get-pen)]
[old-brush (send dc get-brush)]
[old-fg (send dc get-text-foreground)]
[os (send dc get-smoothing)])
(send dc set-smoothing 'aligned)
(let ([pairs '()])
(for-each-to-redraw
left top right bottom
(lambda (from-link to)
(let ([from (link-snip from-link)])
(when (and (or (memq from currently-overs)
(memq to currently-overs))
draw-dark-lines?)
(set! pairs (cons (cons from-link to) pairs)))
(unless draw-dark-lines?
(draw-connection from-link to #f)))))
(for-each (lambda (pr)
(draw-connection (car pr) (cdr pr) #t))
pairs))
(send dc set-smoothing os)
(send dc set-pen old-pen)
(send dc set-text-foreground old-fg)
(send dc set-brush old-brush)))
(define/public (draw-single-edge dc dx dy from to from-x from-y to-x to-y arrow-point-ok?)
(send dc draw-line
(+ dx from-x) (+ dy from-y)
(+ dx to-x) (+ dy to-y))
(update-arrowhead-polygon from-x from-y to-x to-y point1 point2 point3 point4)
(when (and draw-arrow-heads?
(arrow-point-ok? (send point1 get-x) (send point1 get-y))
(arrow-point-ok? (send point2 get-x) (send point2 get-y))
(arrow-point-ok? (send point3 get-x) (send point3 get-y))
(arrow-point-ok? (send point4 get-x) (send point4 get-y)))
;; the arrowhead is not overlapping the snips, so draw it
;; (this is only an approximate test, but probably good enough)
(send dc draw-polygon points dx dy)))
;; for-each-to-redraw : number number number number (link snip -> void)
(define/private (for-each-to-redraw left top right bottom f)
;; : link snip boolean boolean -> void
;; sets the drawing context (pen and brush)
;; determines if the connection is between a snip and itself or two different snips
;; and calls draw-self-connection or draw-non-self-connection
(define (maybe-call-f from-link to)
(let ([from (link-snip from-link)])
(when (send from get-admin)
(cond
[(eq? from to)
(f from-link to)]
[else
(let*-values ([(xf yf wf hf) (get-position from)]
[(xt yt wt ht) (get-position to)]
[(lf tf rf bf) (values xf yf (+ xf wf) (+ yf hf))]
[(lt tt rt bt) (values xt yt (+ xt wt) (+ yt ht))])
(let ([x1 (+ xf (/ wf 2))]
[y1 (+ yf (/ hf 2))]
[x2 (+ xt (/ wt 2))]
[y2 (+ yt (/ ht 2))])
(unless (or (and (x1 . <= . left)
(x2 . <= . left))
(and (x1 . >= . right)
(x2 . >= . right))
(and (y1 . <= . top)
(y2 . <= . top))
(and (y1 . >= . bottom)
(y2 . >= . bottom)))
(f from-link to))))]))))
(let loop ([snip (find-first-snip)])
(when snip
(when (and (send snip get-admin)
(is-a? snip graph-snip<%>))
(for-each (lambda (parent-link) (maybe-call-f parent-link snip))
(send snip get-parent-links)))
(loop (send snip next)))))
(field
[point1 (make-object point% 0 0)]
[point2 (make-object point% 0 0)]
[point3 (make-object point% 0 0)]
[point4 (make-object point% 0 0)]
[points (list point1 point2 point3 point4)])
;; update-arrowhead-polygon : number^4 -> void
;; updates points1, 2, and 3 with the arrow head's
;; points. Use a turtle-like movement to find the points.
;; point3 is the point where the line should end.
(define/public (update-arrowhead-polygon from-x from-y to-x to-y point1 point2 point3 point4)
(define (move tx ty ta d) (values (+ tx (* d (cos ta)))
(+ ty (* d (sin ta)))
ta))
(define (turn tx ty ta a) (values tx
ty
(+ ta a)))
(define init-angle
(cond
[(and (from-x . = . to-x)
(from-y . < . to-y))
(* pi 3/2)]
[(from-x . = . to-x)
(* pi 1/2)]
[(from-x . < . to-x)
(+ pi (atan (/ (- from-y to-y) (- from-x to-x))))]
[else
(atan (/ (- from-y to-y) (- from-x to-x)))]))
(let*-values ([(t1x t1y t1a) (values to-x to-y init-angle)]
[(t2x t2y t2a) (turn t1x t1y t1a (/ arrowhead-angle-width 2))]
[(t3x t3y t3a) (move t2x t2y t2a arrowhead-long-side)]
[(t4x t4y t4a) (turn t1x t1y t1a (- (/ arrowhead-angle-width 2)))]
[(t5x t5y t5a) (move t4x t4y t4a arrowhead-long-side)]
[(t6x t6y t6a) (move t1x t1y t1a arrowhead-short-side)])
(send point1 set-x t1x)
(send point1 set-y t1y)
(send point2 set-x t3x)
(send point2 set-y t3y)
(send point3 set-x t6x)
(send point3 set-y t6y)
(send point4 set-x t5x)
(send point4 set-y t5y)))
(define/private (should-hilite? snip)
(let ([check-one-way
(lambda (way)
(let loop ([snip snip])
(or (memq snip currently-overs)
(and (is-a? snip graph-snip<%>)
(loop (car (way snip)))))))])
(or (check-one-way (lambda (snip) (send snip get-children)))
(check-one-way (lambda (snip) (send snip get-parents))))))
(inherit get-snip-location)
(field [lb (box 0)]
[tb (box 0)]
[rb (box 0)]
[bb (box 0)])
(define/private (get-position snip)
(get-snip-location snip lb tb #f)
(get-snip-location snip rb bb #t)
(values (unbox lb)
(unbox tb)
(- (unbox rb) (unbox lb))
(- (unbox bb) (unbox tb))))
(super-new)))
;; in-rectangle? : number^2 number^2 number^2 -> boolean
;; determines if (x,y) is in the rectangle described
;; by (p1x,p1y) and (p2x,p2y).
(define (in-rectangle? x y p1x p1y p2x p2y)
(and (<= (min p1x p2x) x (max p1x p2x))
(<= (min p1y p2y) y (max p1y p2y))))
;; strict-in-rectangle? : number^2 number^2 number^2 -> boolean
;; determines if (x,y) is in the rectangle described
;; by (p1x,p1y) and (p2x,p2y), but not on the border
(define (strict-in-rectangle? x y p1x p1y p2x p2y)
(and (< (min p1x p2x) x (max p1x p2x))
(< (min p1y p2y) y (max p1y p2y))))
;; find-intersection : number^8 -> (values (or/c #f number) (or/c #f number))
;; calculates the intersection between two line segments,
;; described as pairs of points. Returns #f if they do not intersect
(define (find-intersection x1 y1 x2 y2 x3 y3 x4 y4)
(let-values ([(m1 b1) (find-mb x1 y1 x2 y2)]
[(m2 b2) (find-mb x3 y3 x4 y4)])
(let-values ([(int-x int-y)
(cond
[(and m1 m2 b1 b2
(= m1 0)
(= m2 0))
(values #f #f)]
[(and m1 m2 b1 b2
(= m1 0))
(let* ([y y1]
[x (/ (- y b2) m2)])
(values x y))]
[(and m1 m2 b1 b2
(= m2 0))
(let* ([y y3]
[x (/ (- y b1) m1)])
(values x y))]
[(and m1 m2 b1 b2
(not (= m1 m2)))
(let* ([y (/ (- b2 b1) (- m1 m2))]
[x (/ (- y b1) m1)])
(values x y))]
[(and m1 b1)
(let* ([x x3]
[y (+ (* m1 x) b1)])
(values x y))]
[(and m2 b2)
(let* ([x x1]
[y (+ (* m2 x) b2)])
(values x y))]
[else
(values #f #f)])])
(if (and int-x
int-y
(<= (min x1 x2) int-x (max x1 x2))
(<= (min y1 y2) int-y (max y1 y2))
(<= (min x3 x4) int-x (max x3 x4))
(<= (min y3 y4) int-y (max y3 y4)))
(values int-x int-y)
(values #f #f)))))
;; find-mb : number number number number -> (values (or/c #f number) (or/c #f number))
;; finds the "m" and "b" constants that describe the
;; lines from (x1, y1) to (x2, y2)
(define (find-mb x1 y1 x2 y2)
(if (= x1 x2)
(values #f #f)
(let-values ([(xl yl xr yr)
(if (x1 . <= . x2)
(values x1 y1 x2 y2)
(values x2 y2 x1 y1))])
(let* ([m (/ (- yr yl) (- xr xl))]
[b (- y1 (* m x1))])
(values m b)))))
;; get-all-relatives : (snip -> (listof snip)) snip -> (listof snip)
;; returns all editor-snip relatives (of a particular sort), including
;; any regular snip relatives along the way.
(define (get-all-relatives get-relatives snip)
(let loop ([flat-relatives (get-relatives snip)]
[relatives null])
(cond
[(null? flat-relatives) relatives]
[else
(let i-loop ([dummy (car flat-relatives)]
[acc relatives])
(cond
[(is-a? dummy graph-snip<%>)
(loop (cdr flat-relatives) (cons dummy acc))]
[else
(i-loop (car (get-relatives dummy))
(cons dummy acc))]))])))
;; get-all-children : snip -> (listof snip)
(define (get-all-children snip)
(get-all-relatives (lambda (snip) (send snip get-children)) snip))
;; get-all-parents : snip -> (listof snip)
(define (get-all-parents snip)
(get-all-relatives (lambda (snip) (send snip get-parents)) snip))