3.8  check-box%

Implements: control<%>

A check box is a labeled box which is either checked or unchecked.

Whenever a check box is clicked by the user, the check box's value is toggled and its callback procedure is invoked. A callback procedure is provided as an initialization argument when each check box is created.

• (new check-box% (label _) (parent _) [(callback _)] [(style _)] [(value _)] [(font _)] [(enabled _)] [(vert-margin _)] [(horiz-margin _)] [(min-width _)] [(min-height _)] [(stretchable-width _)] [(stretchable-height _)]) -> check-box% object
     label : string (up to 200 characters) or bitmap% object
     parent : frame%, dialog%, panel%, or pane% object
     callback = (lambda (c e) (void)) : procedure of two arguments: a check-box% object and a control-event% object
     style = null : list of symbols in '(deleted)
   value = #f : boolean
     font = normal-control-font : font% object
     enabled = #t : boolean
     vert-margin = 2 : exact integer in [0, 1000]
     horiz-margin = 2 : exact integer in [0, 1000]
     min-width = 0 : exact integer in [0, 10000]
     min-height = 0 : exact integer in [0, 10000]
     stretchable-width = #f : boolean
     stretchable-height = #f : boolean

  Creates a check box with a string or bitmap label. If label is a bitmap, then the bitmap must be valid (see ok? in bitmap%) and not installed in a bitmap-dc% object; otherwise, an exn:fail:contract exception is raised. If the bitmap has a mask (see get-loaded-mask in bitmap%) that is the same size as the bitmap, then the mask is used for the label; furthermore, in contrast to the limitations of draw-bitmap in dc<%>, non-monochrome label masks work consistently on all platforms.

  If an ampersand (``&'') occurs in label (when label is a string), it is specially parsed; under Windows and X, the character following an ampersand is underlined in the displayed control to indicate a keyboard mnemonic. (Under Mac OS X, mnemonic underlines are not shown.) The underlined mnemonic character must be a letter or a digit. The user can effectively click the check box by typing the mnemonic when the control's top-level-window contains the keyboard focus. The user must also hold down the Meta or Alt key if the keyboard focus is currently in a control that handles normal alphanumeric input. The ampersand itself is removed from label before it is displayed for the control; a double-ampersand in label is converted to a single ampersand (with no mnemonic underlining). Under Mac OS X, a parenthesized mnemonic character is removed (along with any surrounding space) before the label is displayed, since a parenthesized mnemonic is often used for non-Roman languages. Finally, any text after a tab character is removed on all platforms. Mnemonic keyboard events are handled by on-traverse-char (but not under Mac OS X).

  The callback procedure is called (with the event type 'check-box) whenever the user clicks the check box.

  If style includes 'deleted, then the check box is created as hidden, and it does not affect its parent's geometry; the check box can be made active later by calling parent's add-child method.

  If value is true, it is passed to set-value so that the box is initially checked.

  The font argument determines the font for the control. For information about the enabled argument, see window<%>. For information about the horiz-margin and vert-margin arguments, see subarea<%>. For information about the min-width, min-height, stretchable-width, and stretchable-height arguments, see area<%>.

  
  

Methods
    get-value
    set-label
    set-value

All Methods
    accept-drop-files from window<%>
    client->screen from window<%>
    command from control<%>
    enable from window<%>
    focus from window<%>
    get-client-size from window<%>
    get-cursor from window<%>
    get-font from control<%>
    get-graphical-min-size from area<%>
    get-handle from window<%>
    get-height from window<%>
    get-label from window<%>
    get-parent from area<%>
    get-plain-label from window<%>
    get-size from window<%>
    get-top-level-window from area<%>
    get-value from check-box%
    get-width from window<%>
    get-x from window<%>
    get-y from window<%>
    has-focus? from window<%>
    horiz-margin from subarea<%>
    is-enabled? from window<%>
    is-shown? from window<%>
    min-height from area<%>
    min-width from area<%>
    on-drop-file from window<%>
    on-focus from window<%>
    on-move from window<%>
    on-size from window<%>
    on-subwindow-char from window<%>
    on-subwindow-event from window<%>
    on-superwindow-enable from window<%>
    on-superwindow-show from window<%>
    popup-menu from window<%>
    refresh from window<%>
    screen->client from window<%>
    set-cursor from window<%>
    set-label from check-box%
        overrides set-label from window<%>
    set-value from check-box%
    show from window<%>
    stretchable-height from area<%>
    stretchable-width from area<%>
    vert-margin from subarea<%>