suzanne.soy/racket
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

...

Browse Source 
svn: r14926
This commit is contained in:
John Clements 2009-05-22 18:40:33 +00:00
parent d3665169e4
commit 0666e79327
2 changed files with 45 additions and 13 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

3
collects/stepper/stepper-tool.ss
View File

@ -219,7 +219,8 @@
(set! stepper-frame
(go this
program-expander
(+ 1 (send (get-definitions-text) get-start-position))))
(+ 1 (send (get-definitions-text) get-start-position))
(+ 1 (send (get-definitions-text) get-end-position))))
(message-box
(string-constant stepper-name)
(format (string-constant stepper-language-level-message)

55
collects/stepper/view-controller.ss
View File

@ -27,7 +27,7 @@
;; the stored representation of a step
(define-struct step (text kind posns) #:transparent)
(define (go drscheme-frame program-expander selection-posn)
(define (go drscheme-frame program-expander selection-start selection-end)
;; get the language-level name:
(define language-settings (definitions-text->settings (send drscheme-frame get-definitions-text)))
@ -169,16 +169,8 @@
;; is this step on the selected expression?
(define (selected-exp-step? history-entry)
(ormap (posn-in-span selection-posn) (step-posns history-entry)))
(define ((posn-in-span selection-posn) source-posn-info)
(match source-posn-info
[#f #f]
[(struct model:posn-info (posn span))
(and posn
(<= posn selection-posn)
(< selection-posn (+ posn span)))]))
(ormap (span-overlap selection-start selection-end) (step-posns history-entry)))
;; build gui object:
@ -304,7 +296,7 @@
;; counting steps...
(define status-text
(new text%))
(define _1 (send status-text insert ""))
(define _2 (send status-text insert ""))
(define status-canvas
(new editor-canvas%
@ -398,3 +390,42 @@
s-frame)
;; UTILITY FUNCTIONS:
;; span-overlap : number number -> posn-info -> boolean
;; return true if the selection is of zero length and precedes a char of the
;; stepping expression, *or* if the selection has positive overlap with the
;; stepping expression.
(define ((span-overlap selection-start selection-end) source-posn-info)
(match source-posn-info
[#f #f]
[(struct model:posn-info (posn span))
(let ([end (+ posn span)])
(and posn
;; you can *almost* combine these two, but not quite.
(cond [(= selection-start selection-end)
(and (<= posn selection-start) (< selection-start end))]
[else
(let ([overlap-begin (max selection-start posn)]
;; nb: we don't want zero-length overlaps at the end.
;; compensate by subtracting one from the end of the
;; current expression.
[overlap-end (min selection-end end)])
;; #t if there's positive overlap:
(< overlap-begin overlap-end))])))]))
;; a few unit tests. Use them if changing span-overlap.
#;(and
;; zero-length selection cases:
(equal? ((span-overlap 13 13) (model:make-posn-info 14 4)) #f)
(equal? ((span-overlap 14 14) (model:make-posn-info 14 4)) #t)
(equal? ((span-overlap 18 18) (model:make-posn-info 14 4)) #f)
;; nonzero-length selection cases:
(equal? ((span-overlap 13 14) (model:make-posn-info 14 4)) #f)
(equal? ((span-overlap 13 15) (model:make-posn-info 14 4)) #t)
(equal? ((span-overlap 13 23) (model:make-posn-info 14 4)) #t)
(equal? ((span-overlap 16 17) (model:make-posn-info 14 4)) #t)
(equal? ((span-overlap 16 24) (model:make-posn-info 14 4)) #t)
(equal? ((span-overlap 18 21) (model:make-posn-info 14 4)) #f))