IUP

;; {{{ Data types

(foreign-declare
  "#include <ffi.h>\n"
  "#include <locale.h>\n"
  "#include <im.h>\n"
  "#include <im_binfile.h>\n"
  "#include <iup.h>\n"
  "#include <iupim.h>\n"
  "typedef struct Iclass_ Iclass;\n"
  "struct Ihandle_ { char sig[4]; Iclass *iclass; /* ... */ } ;\n"
  "extern char *iupClassCallbackGetFormat(Iclass *iclass, const char *name);\n")

(define *ihandle-tag* "Ihandle")
(define ihandle? (cut tagged-pointer? <> *ihandle-tag*))

(define (ihandle->pointer nonnull?)
  (if nonnull?
    (lambda (handle)
      (ensure ihandle? handle)
      handle)
    (lambda (handle)
      (ensure (disjoin not ihandle?) handle)
      handle)))

(define (pointer->ihandle nonnull?)
  (if nonnull?
    (lambda (handle)
      (ensure pointer? handle)
      (tag-pointer handle *ihandle-tag*))
    (lambda (handle)
      (and handle (tag-pointer handle *ihandle-tag*)))))

(define (ihandle-list->pointer-vector lst)
  (let ([ptrs (make-pointer-vector (add1 (length lst)) #f)])
    (do-ec (:list handle (index i) lst)
      (begin
        (ensure ihandle? handle)
        (pointer-vector-set! ptrs i handle)))
    ptrs))

(define (istatus->integer status)
  (case status
    [(error)                 +1]
    [(opened invalid ignore) -1]
    [(default)               -2]
    [(close #f)              -3]
    [(continue)              -4]
    [else                    (if (integer? status) status 0)]))

(define (integer->istatus status)
  (case status
    [(+1) 'error]
    [( 0) #t]
    [(-1) 'ignore]
    [(-2) 'default]
    [(-3) #f]
    [(-4) 'continue]
    [else status]))

(define (iname->string default-case)
  (let ([change-case
         (case default-case
           [(upcase)   string-upcase]
           [(downcase) string-downcase]
           [else       (error 'iname->string "unsupported default case" default-case)])]
        [keyword-or-symbol->string
         (lambda (name)
           (cond [(keyword? name) (keyword->string name)]
                 [(symbol? name) (symbol->string name)]
                 [else (error 'iname->string "not a keyword or symbol" name)]))])
    (lambda (name)
      (cond
        [(or (not name) (string? name))
         name]
        [(or (symbol? name) (keyword? name))
         (change-case (string-translate (keyword-or-symbol->string name) #\- #\_))]
        [else
         (error 'iname->string "bad name" name)]))))

(define (string->iname default-case)
  (let ([specials
         (irregex
           (case default-case
             [(upcase)   "[-a-z]"]
             [(downcase) "[-A-Z]"]
             [else       (error 'string->iname "unsupported default case" default-case)]))])
    (lambda (name)
      (cond
        [(or (not name) (irregex-search specials name))
         name]
        [else
         (string->symbol (string-downcase (string-translate name #\_ #\-)))]))))

(include "iup-types.scm")

;; }}}

;; {{{ Support macros and functions

(define-syntax :children
  (syntax-rules ()
    [(:children cc child handle)
     (:do cc ([child (child-ref handle 0)]) child ((sibling child)))]))

(define-syntax optional-args
  (syntax-rules ()
    [(optional-args [name default] ...)
     (lambda (args) (let-optionals args ([name default] ...) (list name ...)))]))

(define ((make-constructor-procedure proc #!key [apply-args values]) . args)
  (let more ([keys '()] [key-args '()] [pos-args '()] [rest args])
    (cond
      [(null? rest)
       (let ([handle (apply proc (apply-args (reverse! pos-args)))])
         (do-ec (:parallel (:list key keys) (:list arg key-args))
           ((if (procedure? arg) callback-set! attribute-set!) handle key arg))
         handle)]
      [(keyword? (car rest))
       (more
         (cons (car rest) keys) (cons (cadr rest) key-args) pos-args
         (cddr rest))]
      [else
       (more
         keys key-args (cons (car rest) pos-args)
         (cdr rest))])))

;; }}}

;; {{{ System functions

(define iup-version
  (foreign-lambda c-string "IupVersion"))

(define load/led
  (letrec ([load/raw (foreign-lambda c-string "IupLoad" c-string)])
    (lambda (file)
      (and-let* ([status (load/raw file)])
        (error 'load/led status))
      (void))))

;; }}}

;; {{{ Attribute functions

(define attribute-set!
  (letrec ([set/string! (foreign-safe-lambda void "IupStoreAttribute" ihandle iname/upcase c-string)]
           [set/handle! (foreign-safe-lambda void "IupSetAttributeHandle" ihandle iname/upcase ihandle)])
    (lambda (handle name value)
      (cond
        [(or (not value) (string? value))
         (set/string! handle name value)]
        [(ihandle? value)
         (set/handle! handle name value)]
        [(boolean? value)
         (set/string! handle name (if value "YES" "NO"))]
        [else
         (set/string! handle name (->string value))]))))

(define attribute-reset!
  (foreign-safe-lambda void "IupResetAttribute" ihandle iname/upcase))

(define attribute
  (getter-with-setter
    (foreign-safe-lambda c-string "IupGetAttribute" ihandle iname/upcase)
    attribute-set!))

(define attributes
  (foreign-primitive scheme-object ([ihandle handle])
    "int n = IupGetAllAttributes(handle, NULL, 0);"
    "if (n > 0) {"
    "  char **buf = (char **) alloca(n * sizeof(char *));"
    "  if (IupGetAllAttributes(handle, buf, n) == n) {"
    "    int i, m = C_SIZEOF_LIST(n);"
    "    for (i = 0; i < n; ++i) m += C_SIZEOF_STRING(strlen(buf[i]));"
    "    C_word *mrk = C_alloc(m), lst = C_SCHEME_END_OF_LIST;"
    "    for (i = n-1; i >= 0; --i) lst = C_pair(&mrk, C_string2(&mrk, buf[i]), lst);"
    "    C_return(lst);"
    "  }"
    "}"
    "C_return(C_SCHEME_END_OF_LIST);"))

(define handle-name-set!
  (letrec ([handle-set! (foreign-lambda ihandle "IupSetHandle" iname/downcase ihandle)])
    (lambda (handle name)
      (handle-set! (or name (handle-name handle)) (and name handle)))))

(define handle-name
  (getter-with-setter
    (foreign-lambda iname/downcase "IupGetName" nonnull-ihandle)
    handle-name-set!))

(define handle-ref
  (foreign-lambda ihandle "IupGetHandle" iname/downcase))

;; }}}

;; {{{ Event functions

(define main-loop
  (letrec ([loop (foreign-safe-lambda istatus "IupMainLoop")])
    (lambda ()
      (let ([status (loop)])
        (case status
          [(#t) (void)]
          [else (error 'main-loop (format "error in IUP main loop (~s)" status))])))))

(define main-loop-step
  (letrec ([loop-step (foreign-safe-lambda istatus "IupLoopStep")]
           [loop-step/wait (foreign-safe-lambda istatus "IupLoopStepWait")])
    (lambda (poll?)
      (let ([status ((if poll? loop-step loop-step/wait))])
        (case status
          [(error) (error 'main-loop-step "error in IUP main loop")]
          [else    status])))))

(define main-loop-level
  (foreign-lambda int "IupMainLoopLevel"))

(define main-loop-exit
  (foreign-lambda void "IupExitLoop"))

(define main-loop-flush
  (foreign-safe-lambda void "IupFlush"))

(define (make-wrapper cif)
  (let-location ([proc c-pointer #f])
    (let ([closure
           ((foreign-lambda* (c-pointer "ffi_closure") ([(nonnull-c-pointer c-pointer) proc])
              "C_return(ffi_closure_alloc(sizeof(ffi_closure), proc));" )
            (location proc))])

(define (wrapper-id proc)
  (and proc (pointer->address proc)))

(define wrapper-destroy!
  (foreign-lambda void "ffi_closure_free" (nonnull-c-pointer "ffi_closure")))

(define-values (registry-ref registry-add! registry-remove! registry-clear!)
  (let ([registry (make-hash-table = number-hash)])
    (values
     (lambda (id)
       (cdr (hash-table-ref registry id)))
     (lambda (handle cif data)
       (let*-values ([(closure proc) (make-wrapper cif)]
                     [(id) (pointer->address proc)])
         (hash-table-set!
          registry id
          (cons closure data))
         (hash-table-update!/default
          registry (pointer->address handle)
          (cut cons id <>) '())
         proc))
     (lambda (handle proc)
       (cond
        [(wrapper-id proc)
         => (lambda (id)
              (hash-table-update!/default
               registry (pointer->address handle)
               (cut delete id <> =) '())
              (let ([closure (car (hash-table-ref registry id))])
                (hash-table-delete! registry id)
                (wrapper-destroy! closure)))]))
     (lambda (handle)
       (let* ([key (pointer->address handle)]
              [ids (hash-table-ref/default registry key '())])
         (hash-table-delete! registry key)
         (do-ec (:list id ids)
           (let ([closure (car (hash-table-ref registry id))])
             (hash-table-delete! registry id)
             (wrapper-destroy! closure))))))))

(define call-interface
  (let ([interfaces (make-hash-table string=? string-hash)])
    (lambda (sig)
      (or
        (hash-table-ref/default interfaces sig #f)
        (let ([cif

                (string-length sig) sig)])
          (unless cif
            (error 'callback-set! "unsupported signature"))
          (hash-table-set! interfaces sig cif)
          cif)))))

(define-external (callback_entry [(c-pointer "ffi_cif") cif] [c-pointer pret] [(c-pointer c-pointer) args] [c-pointer proc]) void
  (define frame-arg/ubyte!
    (foreign-lambda* unsigned-byte ([(c-pointer c-pointer) args] [size_t i]) "C_return(*(uint8_t *)args[i]);"))
  (define frame-arg/int!
    (foreign-lambda* int ([(c-pointer c-pointer) args] [size_t i]) "C_return(*(int *)args[i]);"))
  (define frame-arg/float!
    (foreign-lambda* float ([(c-pointer c-pointer) args] [size_t i]) "C_return(*(float *)args[i]);"))
  (define frame-arg/double!
    (foreign-lambda* double ([(c-pointer c-pointer) args] [size_t i]) "C_return(*(double *)args[i]);"))
  (define frame-arg/string!
    (foreign-lambda* c-string ([(c-pointer c-pointer) args] [size_t i]) "C_return(*(const char **)args[i]);"))
  (define frame-arg/pointer!
    (foreign-lambda* c-pointer ([(c-pointer c-pointer) args] [size_t i]) "C_return(*(void **)args[i]);"))
  (define frame-arg/handle!
    (foreign-lambda* ihandle ([(c-pointer c-pointer) args] [size_t i]) "C_return(*(Ihandle **)args[i]);"))

  (define frame-return/ubyte!
    (foreign-lambda* void ([c-pointer ret] [unsigned-byte v]) "*(uint8_t *)ret = v;"))
  ;(define frame-return/int!
  ; (foreign-lambda* void ([c-pointer ret] [int v]) "*(int *)ret = v;"))
  (define frame-return/status!
    (foreign-lambda* void ([c-pointer ret] [istatus v]) "*(int *)ret = v;"))
  (define frame-return/float!
    (foreign-lambda* void ([c-pointer ret] [float v]) "*(float *)ret = v;"))
  (define frame-return/double!
    (foreign-lambda* void ([c-pointer ret] [double v]) "*(double *)ret = v;"))
  (define frame-return/pointer!
    (foreign-lambda* void ([c-pointer ret] [c-pointer v]) "*(void **)ret = v;"))
  (define frame-return/handle!
    (foreign-lambda* void ([c-pointer ret] [ihandle v]) "*(Ihandle **)ret = v;"))

  (call-with-current-continuation
   (lambda (return)
     (let ([sig "i"] [ret? #f])
       (dynamic-wind
         void
         (lambda ()
           (let* ([data (registry-ref (wrapper-id proc))]
                  [proc (cdr data)])
             (set! sig (car data))
             (let ([args (list-ec (:string chr (index i) (string-drop sig 1))
                           (case chr
                             [(#\b)     (frame-arg/ubyte! args i)]
                             [(#\i)     (frame-arg/int! args i)]
                             [(#\f)     (frame-arg/float! args i)]
                             [(#\d)     (frame-arg/double! args i)]
                             [(#\s)     (frame-arg/string! args i)]
                             [(#\v #\C) (frame-arg/pointer! args i)]
                             [(#\h)     (frame-arg/handle! args i)]))])
               (handle-exceptions exn
                 (print-error-message exn (current-error-port) "Error: in callback")
                 (let ([ret (apply proc args)])
                   (case (string-ref sig 0)
                     [(#\b)     (frame-return/ubyte! pret ret)]
                     [(#\i)     (frame-return/status! pret ret)]
                     [(#\f)     (frame-return/float! pret ret)]
                     [(#\d)     (frame-return/double! pret ret)]
                     [(#\v #\C) (frame-return/pointer! pret ret)]
                     [(#\h)     (frame-return/handle! pret ret)])
                   (set! ret? #t))))))
         (lambda ()
           (unless ret?
             (case (string-ref sig 0)
               [(#\b)         (frame-return/ubyte! pret 0)]
               [(#\i)         (frame-return/status! pret 'continue)]
               [(#\f)         (frame-return/float! pret 0.0)]
               [(#\d)         (frame-return/double! pret 0.0)]
               [(#\v #\C #\h) (frame-return/pointer! pret #f)]))
           (return (void))))))))

(define-values (callback-set! callback)
  (letrec ([signature/raw
            (foreign-lambda* c-string ([nonnull-ihandle handle] [iname/upcase name])
              "C_return(iupClassCallbackGetFormat(handle->iclass, name));")]
           [set/pointer!
            (foreign-lambda c-pointer "IupSetCallback" nonnull-ihandle iname/upcase c-pointer)]
           [get/pointer
            (foreign-lambda c-pointer "IupGetCallback" nonnull-ihandle iname/upcase)]
           [sigils
            (irregex "([bifdsvCh]*)(?:=([bifdvCh]))?")]
           [callback-set!
            (lambda (handle name proc)
              (let* ([sig
                      (cond
                        [(irregex-match sigils (or (signature/raw handle name) ""))
                         => (lambda (groups)
                              (string-append
                                (or (irregex-match-substring groups 2) "i")
                                "h" (irregex-match-substring groups 1)))]
                        [else
                         (error 'callback-set! "callback has bad signature" handle name)])]
                     [new
                      (cond
                        [(or (not proc) (pointer? proc)) proc]
                        [else (registry-add! handle (call-interface sig) (cons sig proc))])])
                (cond
                 [(set/pointer! handle name new) =>
                  (cut registry-remove! handle <>)])))]
           [callback
            (lambda (handle name)
              (let ([proc (get/pointer handle name)])
                (cond
                  [(wrapper-id proc)
                   => (lambda (id)
                        (cdr (registry-ref id)))]
                  [else proc])))])
    (values
      callback-set!
      (getter-with-setter callback callback-set!))))

;; }}}

;; {{{ Layout functions

(define create
  (make-constructor-procedure
    (foreign-lambda nonnull-ihandle "IupCreate" iname/downcase)))

(define destroy!
  (letrec ([collect-handles
            (lambda (handle acc)
              (cons
               handle
               (fold-ec acc (:children child handle)
                 child collect-handles)))]
           [handle-destroy!
            (foreign-safe-lambda void "IupDestroy" nonnull-ihandle)])
    (lambda (handle)
      (let ([handles (collect-handles handle '())])
        (handle-destroy! handle)
        (main-loop-flush)
        (for-each registry-clear! handles)))))

(define map-peer!
  (letrec ([map-peer/raw! (foreign-safe-lambda istatus "IupMap" nonnull-ihandle)])
    (lambda (handle)
      (let ([status (map-peer/raw! handle)])
        (case status
          [(#t) (void)]
          [else (error 'map-peer! (format "failed to map peer (~s)" status) handle)])))))

(define unmap-peer!
  (foreign-safe-lambda void "IupUnmap" nonnull-ihandle))

(define class-name
  (foreign-lambda iname/downcase "IupGetClassName" nonnull-ihandle))

(define class-type
  (foreign-lambda iname/downcase "IupGetClassType" nonnull-ihandle))

(define save-attributes!
  (foreign-lambda void "IupSaveClassAttributes" nonnull-ihandle))

(define parent
  (foreign-lambda ihandle "IupGetParent" nonnull-ihandle))

(define parent-dialog
  (foreign-lambda ihandle "IupGetDialog" nonnull-ihandle))

(define sibling
  (foreign-lambda ihandle "IupGetBrother" nonnull-ihandle))

(define child-add!
  (letrec ([append! (foreign-safe-lambda ihandle "IupAppend" nonnull-ihandle nonnull-ihandle)]
           [insert! (foreign-safe-lambda ihandle "IupInsert" nonnull-ihandle nonnull-ihandle nonnull-ihandle)])
    (lambda (child container #!optional [anchor #f])
      (or (if anchor
              (insert! container anchor child)
              (append! container child))
          (error 'child-add! "failed to add child" child container anchor)))))

(define child-remove!
  (foreign-safe-lambda void "IupDetach" nonnull-ihandle))

(define child-move!
  (letrec ([move! (foreign-safe-lambda istatus "IupReparent" nonnull-ihandle nonnull-ihandle ihandle)])
    (lambda (child parent #!optional ref-child)
      (let ([status (move! child parent ref-child)])
        (case status
          [(#t) (void)]
          [else (error 'child-move! (format "failed to move child (~s)" status) child parent)])))))

(define child-ref
  (letrec ([ref/position (foreign-lambda ihandle "IupGetChild" nonnull-ihandle int)]
           [ref/name (foreign-lambda ihandle "IupGetDialogChild" nonnull-ihandle iname/upcase)])
    (lambda (container id)
      ((if (integer? id) ref/position ref/name) container id))))

(define child-pos
  (letrec ([pos/raw (foreign-lambda int "IupGetChildPos" nonnull-ihandle nonnull-ihandle)])
    (lambda (parent child)
      (let ([pos (pos/raw parent child)])
        (and (not (negative? pos)) pos)))))

(define child-count
  (foreign-lambda int "IupGetChildCount" nonnull-ihandle))

(define (children handle)
  (list-ec (:children child handle) child))

(define refresh
  (foreign-safe-lambda void "IupRefresh" nonnull-ihandle))

(define redraw
  (letrec ([update
            (foreign-safe-lambda* void ([nonnull-ihandle handle] [bool children])
              "IupUpdate(handle); if (children) IupUpdateChildren(handle);")]
           [update/sync
            (foreign-safe-lambda void "IupRedraw" nonnull-ihandle bool)])
    (lambda (handle #!key [children? #f] [sync? #f])
      ((if sync? update/sync update) handle children?))))

(define child-x/y->pos
  (letrec ([x/y->pos/raw (foreign-lambda int "IupConvertXYToPos" nonnull-ihandle int int)])
    (lambda (parent x y)
      (let ([pos (x/y->pos/raw parent x y)])
        (and (not (negative? pos)) pos)))))

;; }}}

;; {{{ Dialog functions

(define show
  (letrec ([position

    (lambda (handle #!key [x 'current] [y 'current] [modal? #f])
      (let ([status ((if modal? popup show/x/y) handle (position x) (position y))])
        (case status
          [(error) (error 'show "failed to show" handle)]
          [else    status])))))

(define hide
  (letrec ([hide/raw (foreign-safe-lambda istatus "IupHide" nonnull-ihandle)])
    (lambda (handle)
      (let ([status (hide/raw handle)])
        (case status
          [(#t) (void)]
          [else (error 'hide (format "failed to hide (~s)" status) handle)])))))

;; }}}

;; {{{ Composition functions

(define dialog
  (make-constructor-procedure
    (foreign-lambda nonnull-ihandle "IupDialog" ihandle)))

(define fill
  (make-constructor-procedure
    (foreign-lambda nonnull-ihandle "IupFill")))

(define gridbox
  (make-constructor-procedure
    (foreign-lambda* nonnull-ihandle ([ihandle-list handles]) "C_return(IupGridBoxv((Ihandle **)handles));")
    #:apply-args list))

(define hbox
  (make-constructor-procedure
    (foreign-lambda* nonnull-ihandle ([ihandle-list handles]) "C_return(IupHboxv((Ihandle **)handles));")
    #:apply-args list))

(define vbox
  (make-constructor-procedure
    (foreign-lambda* nonnull-ihandle ([ihandle-list handles]) "C_return(IupVboxv((Ihandle **)handles));")
    #:apply-args list))

(define zbox
  (make-constructor-procedure
    (foreign-lambda* nonnull-ihandle ([ihandle-list handles]) "C_return(IupZboxv((Ihandle **)handles));")
    #:apply-args list))

(define cbox
  (make-constructor-procedure
    (foreign-lambda* nonnull-ihandle ([ihandle-list handles]) "C_return(IupCboxv((Ihandle **)handles));")
    #:apply-args list))

(define sbox
  (make-constructor-procedure
    (foreign-lambda nonnull-ihandle "IupSbox" ihandle)))

(define radio
  (make-constructor-procedure
    (foreign-lambda nonnull-ihandle "IupRadio" ihandle)))

(define normalizer
  (make-constructor-procedure
    (foreign-lambda* nonnull-ihandle ([ihandle-list handles]) "C_return(IupNormalizerv((Ihandle **)handles));")
    #:apply-args list))

(define backgroundbox
  (make-constructor-procedure
    (foreign-lambda nonnull-ihandle "IupBackgroundBox" ihandle)))

(define detachbox
  (make-constructor-procedure
    (foreign-lambda nonnull-ihandle "IupDetachBox" ihandle)))

(define expandbox
  (make-constructor-procedure
    (foreign-lambda nonnull-ihandle "IupExpander" ihandle)))

(define scrollbox
  (make-constructor-procedure
    (foreign-lambda nonnull-ihandle "IupScrollBox" ihandle)))

(define split
  (make-constructor-procedure
    (foreign-lambda nonnull-ihandle "IupSplit" ihandle ihandle)))

;; }}}

;; {{{ Image resource functions

(define image/palette
  (make-constructor-procedure
    (foreign-lambda nonnull-ihandle "IupImage" int int blob)))

(define image/rgb
  (make-constructor-procedure
    (foreign-lambda nonnull-ihandle "IupImageRGB" int int blob)))

(define image/rgba
  (make-constructor-procedure
    (foreign-lambda nonnull-ihandle "IupImageRGBA" int int blob)))

(define image/file
  (letrec ([load-image (foreign-lambda ihandle "IupLoadImage" c-string)])
    (make-constructor-procedure
      (lambda (file)
        (or (load-image file) (error 'image/file (attribute #f 'iupim-lasterror)))))))

(define image/blob
  (letrec ([load-image
            (foreign-lambda* ihandle ([scheme-pointer data] [int size])
              "Ihandle *image;"
              "imBinMemoryFileName file;"
              "int oldModule = imBinFileSetCurrentModule(IM_MEMFILE);"
              "file.buffer = data;"
              "file.size = size;"
              "file.reallocate = 0;"
              "image = IupLoadImage((const char *)&file);"
              "imBinFileSetCurrentModule(oldModule);"
              "C_return(image);")])
    (make-constructor-procedure
      (lambda (data)
        (or (load-image
             data
             (cond
              [(blob? data) (blob-size data)]
              [(string? data) (string-length data)]
              [else (error 'image/blob "unknown argument type")]))
            (error 'image/blob (attribute #f 'iupim-lasterror)))))))

(define image-save
  (letrec ([save-image (foreign-lambda bool "IupSaveImage" nonnull-ihandle c-string iname/upcase)])
    (lambda (handle file format)
      (unless (save-image handle file format)
        (error 'image-save (attribute #f 'iupim-lasterror))))))

;; }}}

;; {{{ Focus functions

(define current-focus
  (letrec ([focus (foreign-safe-lambda ihandle "IupGetFocus")]
           [focus-set! (foreign-safe-lambda ihandle "IupSetFocus" ihandle)]
           [current-focus
            (case-lambda
              [()       (focus)]
              [(handle) (focus-set! handle)])])
    (getter-with-setter current-focus current-focus)))

(define focus-next
  (letrec ([focus-next/raw (foreign-safe-lambda ihandle "IupNextField" ihandle)])
    (lambda (#!optional [handle (current-focus)])
      (focus-next/raw handle))))

(define focus-previous
  (letrec ([focus-previous/raw (foreign-safe-lambda ihandle "IupPreviousField" ihandle)])
    (lambda (#!optional [handle (current-focus)])
      (focus-previous/raw handle))))

;; }}}

;; {{{ Menu functions

(define menu
  (make-constructor-procedure
    (foreign-lambda* nonnull-ihandle ([ihandle-list handles]) "C_return(IupMenuv((Ihandle **)handles));")
    #:apply-args list))

(define menu-item
  (letrec ([action-item (foreign-lambda nonnull-ihandle "IupItem" c-string iname/upcase)]
           [submenu-item (foreign-lambda nonnull-ihandle "IupSubmenu" c-string ihandle)])
    (make-constructor-procedure
     (lambda (#!optional [title #f] [action/menu #f])
       ((if (ihandle? action/menu) submenu-item action-item) title action/menu)))))

(define menu-separator
  (make-constructor-procedure
    (foreign-lambda nonnull-ihandle "IupSeparator")))

;; }}}

;; {{{ Miscellaneous resource functions

(define clipboard
  (make-constructor-procedure
    (foreign-lambda nonnull-ihandle "IupClipboard")))

(define timer
  (make-constructor-procedure
    (foreign-lambda nonnull-ihandle "IupTimer")))

(define send-url
  (letrec ([send-url/raw (foreign-lambda int "IupHelp" c-string)])
    (lambda (url)
      (and-let* ([status (send-url/raw url)]
                 [(not (= status 1))])
        (error 'send-url (format "failed to open URL (~s)" status) url))
      (void))))

;; }}}

;; {{{ The library watchdog

(define thread-watchdog
  (letrec ([open (foreign-lambda* istatus () "C_return(IupOpen(NULL, NULL));")]
           [setlocale (foreign-lambda* void () "setlocale(LC_NUMERIC, \"C\");")]
           [open-imglib (foreign-lambda void "IupImageLibOpen")]
           [close (foreign-lambda void "IupClose")]
           [chicken-yield (foreign-value "&CHICKEN_yield" c-pointer)])
    (and-let* ([(let ([status (dynamic-wind void open setlocale)])
                  (case status
                    [(#t)     #t]
                    [(ignore) #f]
                    [else     (error 'iup (format "failed to initialize library (~s)" status))]))]
               [(open-imglib)]
               [watchdog (timer)])
      (set-finalizer!
       watchdog
       (lambda (watchdog)
         (destroy! watchdog)
         (close)))
      (callback-set! watchdog 'action-cb chicken-yield)