#lang s-exp rosette

(require "../applications/geothings.rkt")

(require "reactive.rkt")

(define (put-first item things)

(let* ([things-list (unbox things)]

[others (filter (lambda (x) (not (eq? item x))) things-list)])

(set-box! things (cons item others))))

(define selection-example%

(class reactive-thing%

(inherit button-going-down? mouse-position image previous)

(super-new)

(define c1 (make-circle this (circle (point 150 150) 50 (color "blue"))))

(define c2 (make-circle this (circle (point 200 150) 50 (color "red"))))

(define c3 (make-circle this (circle (point 250 150) 50 (color "green"))))

(define my-image (box (list c1 c2 c3)))

(define actual-target null)

(define actual-offset null)

(send this set-image! my-image)

(define (potential-targets)

; (printf "computing potential targets\n")

(filter (lambda (c) (contains-point c (mouse-position)))

(send this wally-evaluate (unbox my-image))))

(when (button-going-down?)

(let ([tgs (potential-targets)])

; (printf "tgs = ~a mousepos ~a \n" tgs (mouse-position))

(cond [(pair? tgs)

(set! actual-target (car tgs))

(set! actual-offset (point-minus (mouse-position) (circle-center actual-target)))

(put-first actual-target my-image)]))

(send this solve)

)))

(define s (new selection-example%))

(make-viewer s #:title "Selection example")