racket/collects/htdp/world.ss
2005-12-01 22:01:51 +00:00

256 lines
7.9 KiB
Scheme

#| TODO
I need
color? ;; Symbol -> Boolean
|#
;; Thu Dec 1 17:03:03 EST 2005: fixed place-image; all coordinates okay now
(module world mzscheme
(require ; (lib "unitsig.ss")
(lib "etc.ss")
(lib "class.ss")
(lib "mred.ss" "mred")
(lib "error.ss" "htdp")
(lib "image.ss" "htdp")
(prefix beg: (lib "htdp-beginner.ss" "lang"))
(lib "prim.ss" "lang"))
;; --- provide ---------------------------------------------------------------
(provide (all-from (lib "image.ss" "htdp")))
(provide ;; forall(World):
big-bang ;; Number Number Number World -> true
end-of-time ;; -> World
nw:rectangle ;; Number Number Mode Color -> Image
place-image ;; Image Number Number Scence -> Scene
empty-scene ;; Number Number -> Scene
run-movie ;; (Listof Image) -> true
)
(provide
update produce ;; (update <exp> produce <exp>)
)
(provide-higher-order-primitive
on-tick-event (tock) ;; (World -> World) -> true
)
(provide-higher-order-primitive ;; (KeyEvent World -> World) -> true
on-key-event
(tock)
)
;; ---------------------------------------------------------------------------
;; Symbol Any String -> Void
(define (check-pos tag c rank)
(check-arg tag (and (number? c) (integer? c) (>= c 0)) "positive integer" rank c))
;; Symbol Any String [String] -> Void
(define (check-image tag i rank . other-message)
(if (and (pair? other-message) (string? (car other-message)))
(check-arg tag (beg:image? i) (car other-message) rank i)
(check-arg tag (beg:image? i) "image" rank i)))
;; Symbol Any String -> Void
(define (check-color tag width rank)
(check-arg tag (symbol? width) "color symbol" rank width))
(define (check-mode tag s rank)
(check-arg tag (or (eq? s 'solid) (eq? s 'outline)) "'solid or 'outline" rank s))
(define (nw:rectangle width height mode color)
(check-pos 'rectangle width "first")
(check-pos 'rectangle height "second")
(check-mode 'rectangle mode "third")
(check-color 'rectangle color "fourth")
(move-pinhole (rectangle width height mode color) (/ width -2) (/ height -2)))
(define (place-image image x y scene)
(check-image 'place-image image "first")
(check-arg 'place-image (and (number? x) (real? x)) 'number "second" x)
(check-arg 'place-image (and (number? y) (real? x)) 'number "third" y)
(check-image 'place-image scene "fourth" "scene")
(let ()
(define sw (image-width scene))
(define sh (image-height scene))
(define ns (overlay/xy scene x y image))
(define nw (image-width ns))
(define nh (image-height ns))
(if (and (= sw nw) (= sh nh))
ns
(shrink ns 0 0 sw sh))))
(define (empty-scene width height)
(check-pos 'empty-scene width "first")
(check-pos 'empty-scene height "second")
(move-pinhole
(rectangle width height 'outline 'black)
(/ width -2) (/ height -2))
)
;; display all images in list in the canvas
(define (run-movie movie)
(check-arg 'run-movie (list? movie) "list (of images)" "first" movie)
(for-each (lambda (cand) (check-image 'run-movie cand "first" "list of images"))
movie)
(let run-movie ([movie movie])
(cond [(null? movie) #t]
[(pair? movie)
(update (car movie) produce #t)
(sleep/yield .05)
(run-movie (cdr movie))])))
;; ---------------------------------------------------------------------------
;; The One and Only Visible World
(define the-frame #f)
(define txt (new text%))
;; World (type parameter)
(define the-world0 (cons 1 1))
[define the-world the-world0]
(define (check-world tag)
(when (eq? the-world0 the-world) (error tag SEQUENCE-ERROR)))
;; Number > 0
[define the-delta 1000]
;; Number Number Number World -> true
;; create the visible world (canvas)
(define (big-bang w h delta world)
(check-pos 'big-bang w "first")
(check-pos 'big-bang h "second")
(check-arg 'big-bang
(and (number? delta) (<= 0 delta 1000))
"number [of seconds] between 0 and 1000"
"first"
delta)
(when the-frame (error 'big-bang "big-bang already called once"))
(set! the-delta delta)
(set! the-world world)
(set! the-frame
(new (class frame%
(super-new)
(define/augment (on-close)
;; shut down the timer when the window is destroyed
(send the-time stop)
(inner (void) on-close)))
(label "DrScheme")))
(send
(new (class editor-canvas%
(super-new)
(define/override (on-char e)
(on-char-proc (send e get-key-code))))
(parent the-frame)
(editor txt)
(style '(no-hscroll no-vscroll))
;; this 20 stuff is a hack, for now
(min-width (+ w 20))
(min-height (+ h 20)))
focus)
(send txt hide-caret #t)
(send the-frame show #t)
#t)
;; --- time events
[define the-time (new timer% [notify-callback (lambda () (timer-callback))])]
;; (World -> World)
[define timer-callback void]
;; (World -> World) -> true
;; set the click handler
[define (on-tick-event f)
(check-proc 'on-tick-event f 1 "on-tick-event" "one argument")
(check-world 'on-tick-event)
(if (eq? timer-callback void)
(set! timer-callback
(lambda ()
(with-handlers ([exn:break? break-handler]
[exn? exn-handler])
(set! the-world (f the-world)))))
(error 'on-tick "the timing action has been set already"))
(send the-time start
(let* ([w (ceiling (* 1000 the-delta))])
(if (exact? w) w (inexact->exact w))))
#t]
;; --- key events
;; KeyEvent = (union Symbol Char)
;; KeyEvent -> Void
[define on-char-proc void]
;; (KeyEvent World -> World) -> true
;; effect: set on-char-proc so that it deals with keyboard events
[define (on-key-event f)
(check-proc 'on-key-event f 2 "on-key-event" "two arguments")
(check-world 'on-key-event)
(let ([esp (current-eventspace)])
(if (eq? on-char-proc void)
(begin
(set! on-char-proc
(lambda (e)
(parameterize ([current-eventspace esp])
(queue-callback
(lambda ()
(with-handlers ([exn:break? break-handler]
[exn? exn-handler])
(set! the-world (f e the-world))))
#t))))
#t)
(error 'on-event "the event action has been set already")))]
[define (end-of-time)
(printf "end of time~n")
(stop-it)
the-world]
;; --- library
[define (exn-handler e)
(send the-time stop)
(set! on-char-proc void)
(set! timer-callback void)
(raise e)]
[define (break-handler . _)
(printf "animation stopped")
(stop-it)
the-world]
;; -> Void
(define (stop-it)
(send the-time stop)
(set! on-char-proc void)
(set! timer-callback void))
;; --- putting images into the canvas
(define-syntax (produce stx)
(raise-syntax-error 'produce "produce must be inside a use of update" stx))
(define-syntax (update s)
(syntax-case s (produce)
[(_ pict produce exp) (syntax (begin (update-frame pict) exp))]
[(_ pict pict2 ... produce exp)
(raise-syntax-error 'update "you can place only one picture in the canvas" s)]
[(_ stmt produce)
(raise-syntax-error 'update "produce must be followed by an expression" s)]
[(_ stmt produce exp exp2 ...)
(raise-syntax-error 'update "produce must be followed by exactly one expression" s)]
[_
(raise-syntax-error 'update "use as (update <image> produce <expression>)")]))
(define (update-frame pict)
(unless the-frame (error 'update SEQUENCE-ERROR))
(check-result 'update (lambda (x) (beg:image? x)) "image" pict)
(send txt begin-edit-sequence)
(send txt lock #f)
(send txt delete 0 (send txt last-position) #f)
(send txt insert (send pict copy) 0 0 #f)
(send txt lock #t)
(send txt end-edit-sequence))
(define SEQUENCE-ERROR "evaluate (big-bang Number Number Number World) first")
)