gui/gui-doc/scribblings/gui/snip-example.rkt
Robby Findler 23f22a8bcf extend the example snip with wxme support
and add some tests for the example
2015-12-17 10:33:36 -06:00

66 lines
1.9 KiB
Racket

#lang racket/base
(require racket/class
racket/snip
racket/format)
(provide circle-snip%
(rename-out [circle-snip-class snip-class]))
(define circle-snip%
(class snip%
(inherit set-snipclass
get-flags set-flags
get-admin)
(init-field [size 20.0])
(super-new)
(set-snipclass circle-snip-class)
(send (get-the-snip-class-list) add circle-snip-class)
(set-flags (cons 'handles-events (get-flags)))
(define/override (get-extent dc x y
[w #f]
[h #f]
[descent #f]
[space #f]
[lspace #f]
[rspace #f])
(define (maybe-set-box! b v) (when b (set-box! b v)))
(maybe-set-box! w (+ 2.0 size))
(maybe-set-box! h (+ 2.0 size))
(maybe-set-box! descent 1.0)
(maybe-set-box! space 1.0)
(maybe-set-box! lspace 1.0)
(maybe-set-box! rspace 1.0))
(define/override (draw dc x y left top right bottom dx dy draw-caret)
(send dc draw-ellipse (+ x 1.0) (+ y 1.0) size size))
(define/override (copy)
(new circle-snip% [size size]))
(define/override (write f)
(send f put size))
(define/override (on-event dc x y editorx editory e)
(when (send e button-down?)
(set! size (+ 1.0 size))
(define admin (get-admin))
(when admin
(send admin resized this #t))))))
(define circle-snip-class%
(class snip-class%
(inherit set-classname)
(super-new)
(set-classname (~s '((lib "main.rkt" "circle-snip")
(lib "wxme-circle-snip.rkt" "circle-snip"))))
(define/override (read f)
(define size-b (box 0.0))
(send f get size-b)
(new circle-snip% [size (unbox size-b)]))))
(define circle-snip-class (new circle-snip-class%))