racket/collects/stepper/stepper-tool.ss
2005-05-27 18:56:37 +00:00

570 lines
27 KiB
Scheme

(module stepper-tool mzscheme
(require (lib "contract.ss")
(lib "tool.ss" "drscheme")
(lib "mred.ss" "mred")
(prefix frame: (lib "framework.ss" "framework"))
(lib "unitsig.ss")
(lib "class.ss")
(lib "etc.ss")
(lib "list.ss")
(prefix model: "private/model.ss")
"private/my-macros.ss"
(prefix x: "private/mred-extensions.ss")
"private/shared.ss"
"private/model-settings.ss"
(lib "pconvert.ss")
(lib "string-constant.ss" "string-constants")
(lib "async-channel.ss")
(lib "bitmap-label.ss" "mrlib"))
;; mflatt: MINOR HACK - work around temporary
;; print-convert problems
(define (stepper-print-convert v)
(or (and (procedure? v)
(object-name v))
(print-convert v)))
; hidden invariant: this list should be a sublist of the language-level dialog (i.e., same order):
(define stepper-works-for
(list (string-constant beginning-student)
(string-constant beginning-student/abbrev)
(string-constant intermediate-student)
(string-constant intermediate-student/lambda)))
(provide stepper-tool@)
(define stepper-tool@
(unit/sig drscheme:tool-exports^
(import drscheme:tool^
(xml-snip% scheme-snip%))
; tool magic here:
(define (phase1) (void))
(define (phase2) (void))
(define stepper-initial-width 500)
(define stepper-initial-height 500)
(define drscheme-eventspace (current-eventspace))
(define stepper-frame%
(class (drscheme:frame:basics-mixin (frame:frame:standard-menus-mixin frame:frame:basic%))
(init-field drscheme-frame)
;; PRINTING-PROC
(public set-printing-proc)
(define (set-printing-proc proc)
(set! printing-proc proc))
(define (printing-proc item evt)
(message-box "error?" "shouldn't be called"))
(define/private (file-menu:print a b) (printing-proc a b))
;; MENUS
(define/override (edit-menu:between-find-and-preferences edit-menu) (void))
(define/override (edit-menu:between-select-all-and-find edit-menu) (void))
(define/override (file-menu:between-save-as-and-print file-menu) (void))
;; CUSTODIANS
(define custodian #f)
(define/public (set-custodian! cust)
(set! custodian cust))
(define/augment (on-close)
(when custodian
(custodian-shutdown-all custodian))
(send drscheme-frame on-stepper-close)
(inner (void) on-close))
;; WARNING BOXES:
(define program-changed-warning-str (string-constant stepper-program-has-changed))
(define window-closed-warning-str (string-constant stepper-program-window-closed))
(define warning-message-visible-already #f)
(define/private (add-warning-message warning-str)
(let ([warning-msg (instantiate x:stepper-warning% ()
(warning-str warning-str)
(parent (get-area-container)))])
(send (get-area-container)
change-children
(if warning-message-visible-already
(lambda (l)
(list (car l)
warning-msg
(caddr l)))
(lambda (l)
(list (car l)
warning-msg
(cadr l)))))
(set! warning-message-visible-already #t)))
(inherit get-area-container)
(define program-change-already-warned? #f)
(define/public (original-program-changed)
(unless program-change-already-warned?
(set! program-change-already-warned? #t)
(add-warning-message program-changed-warning-str)))
(define/public (original-program-gone)
(add-warning-message window-closed-warning-str))
(super-instantiate ("Stepper" #f stepper-initial-width stepper-initial-height))))
;; view-controller-go: called when the stepper starts; starts the stepper's view&controller
;; drscheme-frame : the drscheme frame which is starting the stepper
;; program-expander : see "model.ss" for the contract on a program-expander
;; -> returns the new frame%
(define (view-controller-go drscheme-frame program-expander)
(define language-settings
(send (send drscheme-frame get-definitions-text) get-next-settings))
(define language
(drscheme:language-configuration:language-settings-language language-settings))
(define language-level-name
(car (last-pair (send language get-language-position))))
(define simple-settings
(drscheme:language-configuration:language-settings-settings language-settings))
;; VALUE CONVERSION CODE:
;; render-to-string : TST -> string
(define (render-to-string val)
(let ([string-port (open-output-string)])
(send language
render-value
val
simple-settings
string-port)
(get-output-string string-port)))
;; make-print-convert-hook: simple-settings -> (TST (TST -> TST) (TST -> TST) -> TST)
;; this code copied from various locations in language.ss and rep.ss
(define (make-print-convert-hook simple-settings)
(lambda (expr basic-convert sub-convert)
(cond
[(is-a? expr snip%)
(send expr copy)]
#;[((drscheme:rep:use-number-snip) expr)
(let ([number-snip-type (drscheme:language:simple-settings-fraction-style simple-settings)])
(cond
[(eq? number-snip-type 'repeating-decimal)
(drscheme:number-snip:make-repeating-decimal-snip expr #f)]
[(eq? number-snip-type 'repeating-decimal-e)
(drscheme:number-snip:make-repeating-decimal-snip expr #t)]
[(eq? number-snip-type 'mixed-fraction)
(drscheme:number-snip:make-fraction-snip expr #f)]
[(eq? number-snip-type 'mixed-fraction-e)
(drscheme:number-snip:make-fraction-snip expr #t)]
[else
(error 'which-number-snip
"expected either 'repeating-decimal, 'repeating-decimal-e, 'mixed-fraction, or 'mixed-fraction-e got : ~e"
number-snip-type)]))]
[else (basic-convert expr)])))
;; render-to-sexp : TST -> sexp
(define (render-to-sexp val)
(parameterize ([current-print-convert-hook (make-print-convert-hook simple-settings)])
(set-print-settings
language
simple-settings
(lambda ()
(simple-module-based-language-convert-value val simple-settings)))))
; channel for incoming views
(define view-channel (make-async-channel))
; the semaphore associated with the view at the end of the view-history
; note that because these are fresh semaphores for every step, posting to a semaphore
; multiple times is no problem.
(define release-for-next-step #f)
; the list of available views
(define view-history null)
; the view in the stepper window
(define view 0)
; whether the stepper is waiting for a new view to become available
; (initially true)
; possible values: #f, 'waiting-for-any-step, 'waiting-for-application
(define stepper-is-waiting? 'waiting-for-any-step)
; hand-off-and-block : (-> text%? boolean? void?)
; hand-off-and-block generates a new semaphore, hands off a thunk to drscheme's eventspace,
; and blocks on the new semaphore. The thunk adds the text% to the waiting queue, and checks
; to see if the stepper is waiting for a new step. If so, takes that new text% out of the
; queue and puts it on the list of available ones. If the stepper is waiting for a new step,
; it checks to see whether this is of the kind that the stepper wants. If so, display it.
; otherwise, release the stepped program to continue execution.
(define (hand-off-and-block step-text step-kind)
(let ([new-semaphore (make-semaphore)])
(parameterize ([current-eventspace drscheme-eventspace])
(queue-callback
(lambda ()
(async-channel-put view-channel (list step-text new-semaphore step-kind))
(when stepper-is-waiting?
(let ([try-get (async-channel-try-get view-channel)])
(unless try-get
(error 'check-for-stepper-waiting "queue is empty, even though a step was just added."))
(add-view-triple try-get)
(if (right-kind-of-step? (caddr try-get))
; got the desired step; show the user:
(begin
(set! stepper-is-waiting? #f)
(update-view/existing (- (length view-history) 1)))
; nope, keep running:
(begin
(en/dis-able-buttons)
(semaphore-post new-semaphore)))))))
(semaphore-wait new-semaphore))))
; right-kind-of-step? : (boolean? . -> . boolean?)
; is this step the kind of step that the gui is waiting for?
(define (right-kind-of-step? step-kind)
(case stepper-is-waiting?
[(waiting-for-any-step) #t]
[(waiting-for-application) (or (eq? step-kind 'user-application)
(eq? step-kind 'finished-stepping))]
[(#f) (error 'right-kind-of-step "this code should be unreachable with stepper-is-waiting? set to #f")]
[else (error 'right-kind-of-step "unknown value for stepper-is-waiting?: ~a" stepper-is-waiting?)]))
;; add-view-triple : set the release-semaphore to be the new one, add the view to the list.
(define (add-view-triple view-triple)
(set! release-for-next-step (cadr view-triple))
(set! view-history (append view-history (list (list (car view-triple) (caddr view-triple))))))
;; find-later-application-step : search through the history, starting at 'n', for an application step.
(define (find-later-application-step n)
(let ([history-length (length view-history)])
(let loop ([step (+ n 1)])
(cond [(>= step history-length) #f]
[(application-step? (list-ref view-history step)) step]
[else (loop (+ step 1))]))))
;; is this an application step?
(define (application-step? history-entry)
(case (cadr history-entry)
[(user-application finished stepping) #t]
[else #f]))
; build gui object:
;; home : the action of the 'home' button
(define (home)
(when stepper-is-waiting?
(set! stepper-is-waiting? #f))
(update-view/existing 0))
;; next : the action of the 'next' button
(define (next)
(let ([new-view (+ view 1)])
(if (< new-view (length view-history))
(update-view/existing new-view)
(begin
(semaphore-post release-for-next-step) ; each step has its own semaphore, so releasing one twice is no problem.
(when stepper-is-waiting?
(error 'try-to-get-view "try-to-get-view should not be reachable when already waiting for new step"))
(let ([try-get (async-channel-try-get view-channel)])
(if try-get
(begin
(add-view-triple try-get)
(update-view/existing new-view))
(begin
(set! stepper-is-waiting? 'waiting-for-any-step)
(en/dis-able-buttons))))))))
;; next-application : the action of the 'next-application' button
;; NB: while this function looks a lot like (next), the abstractions of the two that I came up with
;; were hard to read. So I left them separate -- JBC
(define (next-application)
(let ([next-application-step (find-later-application-step view)])
(if next-application-step
(update-view/existing next-application-step)
(begin
(semaphore-post release-for-next-step) ; each step has its own semaphore, so releasing one twice is no problem.
(when stepper-is-waiting?
(error 'try-to-get-view "try-to-get-view should not be reachable when already waiting for new step"))
(let ([try-get (async-channel-try-get view-channel)])
(if try-get
(begin
(add-view-triple try-get)
(if (application-step? (list-ref view-history (+ view 1)))
(update-view/existing (+ view 1))
(begin
(set! stepper-is-waiting? 'waiting-for-application)
(en/dis-able-buttons))))
(begin
(set! stepper-is-waiting? 'waiting-for-application)
(en/dis-able-buttons))))))))
;; previous : the action of the 'previous' button
(define (previous)
(when stepper-is-waiting?
(set! stepper-is-waiting? #f))
(when (= view 0)
(error 'previous-application "previous-step button should not be enabled in view zero."))
(update-view/existing (- view 1)))
;; previous-application : the action of the 'previous-application' button
(define (previous-application)
(when stepper-is-waiting?
(set! stepper-is-waiting? #f))
(when (= view 0)
(error 'previous-application "previous-application button should not be enabled in view zero."))
(let loop ([new-view (- view 1)])
(cond [(= new-view 0)
(update-view/existing new-view)]
[(application-step? (list-ref view-history new-view))
(update-view/existing new-view)]
[else
(loop (- new-view 1))])))
;; GUI ELEMENTS:
(define s-frame (make-object stepper-frame% drscheme-frame))
(define button-panel (make-object horizontal-panel% (send s-frame get-area-container)))
(define home-button (make-object button% (string-constant stepper-home) button-panel
(lambda (_1 _2) (home))))
(define previous-application-button (make-object button% (string-constant stepper-previous-application) button-panel
(lambda (dc-1 dc-2) (previous-application))))
(define previous-button (make-object button% (string-constant stepper-previous) button-panel
(lambda (_1 _2) (previous))))
(define next-button (make-object button% (string-constant stepper-next) button-panel
(lambda (_1 _2) (next))))
(define next-application-button (make-object button% (string-constant stepper-next-application) button-panel
(lambda (dc-1 dc-2) (next-application))))
(define canvas (make-object x:stepper-canvas% (send s-frame get-area-container)))
;; update-view/existing : set an existing step as the one shown in the frame
(define (update-view/existing new-view)
(set! view new-view)
(let ([e (car (list-ref view-history view))])
(send e begin-edit-sequence)
(send canvas set-editor e)
(send e reset-width canvas)
(send e set-position (send e last-position))
(send e end-edit-sequence))
(en/dis-able-buttons))
;; en/dis-able-buttons : set enable & disable the stepper buttons, based on view-controller state
(define (en/dis-able-buttons)
(let* ([can-go-back? (> view 0)])
(send previous-button enable can-go-back?)
(send previous-application-button enable can-go-back?)
(send home-button enable can-go-back?)
(send next-button enable (not (and (>= view (- (length view-history) 1)) stepper-is-waiting?)))
(send next-application-button enable (or (find-later-application-step view) (not stepper-is-waiting?)))))
(define (print-current-view item evt)
(send (send canvas get-editor) print))
; receive-result takes a result from the model and renders it on-screen. Runs on the user thread.
; : (step-result -> void)
(define (receive-result result)
(let ([step-text
(cond [(before-after-result? result)
(instantiate x:stepper-text% ()
[finished-exprs (before-after-result-finished-exprs result)]
[exps (before-after-result-exp result)]
[post-exps (before-after-result-post-exp result)]
[error-msg #f]
[after-exprs (before-after-result-after-exprs result)])]
[(before-error-result? result)
(instantiate x:stepper-text% ()
[finished-exprs (before-error-result-finished-exprs result)]
[exps (before-error-result-exp result)]
[post-exps null]
[error-msg (before-error-result-err-msg result)]
[after-exprs (before-error-result-after-exprs result)])]
[(error-result? result)
(instantiate x:stepper-text% ()
[finished-exprs (error-result-finished-exprs result)]
[exps null]
[post-exps null]
[error-msg (error-result-err-msg result)]
[after-exprs null])]
[(finished-result? result)
(instantiate x:stepper-text% ()
[finished-exprs (finished-result-finished-exprs result)]
[exps null]
[post-exps null]
[error-msg #f]
[after-exprs null])]
[(finished-stepping? result)
x:finished-text])]
[step-kind (or (and (before-after-result? result)
(before-after-result-kind result))
(and (finished-stepping? result)
'finished-stepping))])
(hand-off-and-block step-text step-kind)))
; need to capture the custodian as the thread starts up:
(define (program-expander-prime init iter)
(program-expander (lambda args
(send s-frame set-custodian! (current-custodian))
(apply init args))
iter))
;; CONFIGURE GUI ELEMENTS
(send s-frame set-printing-proc print-current-view)
(send button-panel stretchable-width #f)
(send button-panel stretchable-height #f)
(send canvas stretchable-height #t)
(en/dis-able-buttons)
(send (send s-frame edit-menu:get-undo-item) enable #f)
(send (send s-frame edit-menu:get-redo-item) enable #f)
; START THE MODEL
(model:go program-expander-prime receive-result (get-render-settings render-to-string render-to-sexp #t)
(not (string=? language-level-name (string-constant intermediate-student/lambda))))
(send s-frame show #t)
s-frame)
;; stepper-bitmap : the image used for the stepper button
(define stepper-bitmap
(bitmap-label-maker
(string-constant stepper-button-label)
(build-path (collection-path "icons") "foot.png")))
;; stepper-unit-frame<%> : the interface that the extended drscheme frame fulfils
(define stepper-unit-frame<%>
(interface ()
get-stepper-frame
on-stepper-close))
;; stepper-unit-frame-mixin : the mixin that is applied to the drscheme frame to interact with a possible stepper window
(define (stepper-unit-frame-mixin super%)
(class* super% (stepper-unit-frame<%>)
(inherit get-button-panel get-interactions-text get-definitions-text)
(define stepper-frame #f)
(define/public (on-stepper-close)
(set! stepper-frame #f))
(define/public (get-stepper-frame) stepper-frame)
(super-instantiate ())
;; program-expander : produces expanded expressions from the definitions window one at a time and calls 'iter' on each one
(define (program-expander init iter)
(let* ([lang-settings
(send (get-definitions-text) get-next-settings)]
[lang (drscheme:language-configuration:language-settings-language lang-settings)]
[settings (drscheme:language-configuration:language-settings-settings lang-settings)])
(drscheme:eval:expand-program
(drscheme:language:make-text/pos (get-definitions-text)
0
(send (get-definitions-text)
last-position))
lang-settings
#f
(lambda ()
(init)
(error-value->string-handler
(lambda (val len)
(let ([sp (open-output-string)])
(send lang render-value val settings sp)
(let ([str (get-output-string sp)])
(if ((string-length str) . <= . len)
str
(string-append (substring str 0 (max 0 (- len 3))) "...")))))))
void ; kill
iter)))
;; STEPPER BUTTON
(define/public (get-stepper-button) stepper-button)
(define stepper-button
(make-object button%
(stepper-bitmap this)
(get-button-panel)
(lambda (button evt)
(if stepper-frame
(send stepper-frame show #t)
(let* ([settings (send (get-definitions-text) get-next-settings)]
[language (drscheme:language-configuration:language-settings-language settings)]
[language-level (car (last-pair (send language get-language-position)))])
(if (member language-level stepper-works-for)
(set! stepper-frame (view-controller-go this program-expander))
(message-box (string-constant stepper-name)
(format (string-constant stepper-language-level-message)
language-level
(car stepper-works-for)
(car (reverse stepper-works-for))))))))))
(define/augment (enable-evaluation)
(send stepper-button enable #t)
(inner (void) enable-evaluation))
(define/augment (disable-evaluation)
(send stepper-button enable #f)
(inner (void) disable-evaluation))
(define/augment (on-close)
(when stepper-frame
(send stepper-frame original-program-gone))
(inner (void) on-close))
; add the stepper button to the button panel:
(send (get-button-panel) change-children
(lx (cons stepper-button (remq stepper-button _))))))
;; stepper-definitions-text-mixin : a mixin for the definitions text that alerts thet stepper when the definitions
;; text is altered or destroyed
(define (stepper-definitions-text-mixin %)
(class %
(inherit get-top-level-window)
(define/private (notify-stepper-frame-of-change)
(let ([win (get-top-level-window)])
(when (is-a? win stepper-unit-frame<%>) ;; should only be #f when win is #f.
(let ([stepper-window (send win get-stepper-frame)])
(when stepper-window
(send stepper-window original-program-changed))))))
(define/augment (on-insert x y)
(notify-stepper-frame-of-change)
(inner (void) on-insert x y))
(define/augment (on-delete x y)
(notify-stepper-frame-of-change)
(inner (void) on-delete x y))
(super-instantiate ())))
;; COPIED FROM drscheme/private/language.ss
;; simple-module-based-language-convert-value : TST settings -> TST
(define (simple-module-based-language-convert-value value simple-settings)
(case (drscheme:language:simple-settings-printing-style simple-settings)
[(write) value]
[(constructor)
(parameterize ([constructor-style-printing #t]
[show-sharing (drscheme:language:simple-settings-show-sharing simple-settings)])
(stepper-print-convert value))]
[(quasiquote)
(parameterize ([constructor-style-printing #f]
[show-sharing (drscheme:language:simple-settings-show-sharing simple-settings)])
(stepper-print-convert value))]))
;; set-print-settings ; settings ( -> TST) -> TST
(define (set-print-settings language simple-settings thunk)
(unless (method-in-interface? 'set-printing-parameters (object-interface language))
(error 'stepper-tool "language object does not contain set-printing-parameters method"))
(send language set-printing-parameters simple-settings thunk))
;; apply the mixins dynamically to the drscheme unit frame and definitions text:
(drscheme:get/extend:extend-unit-frame stepper-unit-frame-mixin)
(drscheme:get/extend:extend-definitions-text stepper-definitions-text-mixin))))