plt-scheme：在畫布上捕捉鼠標點擊事件

Question

我正在編寫一個plt-scheme中的井字遊戲作爲我的AI課程項目。 gui的想法是一個帶有9個框的網格，每個框都有一個畫布，使用窗格... 當用戶點擊畫布時，會相應繪製'X'或'O'...

問題是我如何在畫布上捕捉鼠標點擊事件？ 我發現我需要使用on-event，但仍不知道如何？ 任何線索？

Answer 1

好吧，我知道了......

(define canvas-box% 
    (class canvas% 
    (define/override (on-event e) 
      (when (equal? (send e get-event-type) 'left-down) (foobar-callback))) 
    (super-new))) 

Answer 2

我得到了所有的鼠標和鍵盤命令用途的任何地方 這裏。

(define my-canvas% 

(class canvas% 
    (define/override (on-event event) 
    (and 
     (send test reader (list (number->string (send event get-x)) 
        (number->string (send event get-y)))) 
     (send test reader (list (send event get-event-type))))) 
(define/override (on-char event) 
    (define pressed (send event get-key-code)) 
    (if (char? pressed) (send test reader (list (make-string 1 pressed))) '())) 
    (super-new))) 

(define tester% 
(class object% 
    (super-new) 
    (define command '()) 

    (define/public (reader x) 
    (and (set! command x) 
     (display x)) 
    ) 
    (define/public (outer) 
    command) 
))