3.37  radio-box%

Implements: control<%>

A radio-box% control allows the user to select one of number of mutually exclusive items. The items are displayed as a vertical column or horizontal row of labelled radio buttons. Unlike a list-control<%>, the set of items in a radio-box% cannot be changed dynamically.

Whenever the user changes the selected radio button, the radio box's callback procedure is invoked. A callback procedure is provided as an initialization argument when each radio box is created.

• (instantiate radio-box% () (label _) (choices _) (parent _) (callback _) [(style _)] [(enabled _)] [(vert-margin _)] [(horiz-margin _)] [(min-width _)] [(min-height _)] [(stretchable-width _)] [(stretchable-height _)]) -> radio-box% object
     label : string (up to 200 characters) or #f
   choices : list of strings (up to 200 characters each) or bitmap% objects
     parent : frame%, dialog%, panel%, or pane% object
     callback : procedure of two arguments: a radio-box% object and a control-event% object
     style = '(vertical) : list of symbols in '(horizontal vertical)
   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 radio button set with string or bitmap labels. The choices list specifies the radio button labels; the list of choices must be homogenous, either all strings or all bitmaps.

  If an ampersand (``&'') occurs in label, 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, mnemonic underlines are not shown.) The underlined mnemonic character must be a letter or a digit. The user can move the keyboard focus to the radio 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). Mnemonic keyboard events are handled by on-traverse-char (but not under Mac OS).

  Each string in choices can also contain an ampersand, which creates a mnemonic for clicking the corresponding radio button. As for label, a double ampersand is converted to a single ampersand.

  If choices is a list of bitmaps, then the bitmaps must be valid (see ok? in bitmap%) and not installed in a bitmap-dc% object; otherwise, an exn:application:mismatch exception is raised.

  If label is a string, it is used as the label for the radio box. Otherwise, the radio box does not display its label.

  The callback procedure is called (with the event type 'radio-box) when the user changes the radio button selection.

  The style argument must include either 'vertical for a collection of radio buttons vertically arranged, or 'horizontal for a horizontal arrangement.

  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
    enable
    get-item-label
    get-item-plain-label
    get-number
    get-selection
    is-enabled?
    set-selection

All Methods
    accept-drop-files from window<%>
    client->screen from window<%>
    command from control<%>
    enable from radio-box%
        overrides enable from window<%>
    focus from window<%>
    get-client-size from window<%>
    get-cursor from window<%>
    get-graphical-min-size from area<%>
    get-height from window<%>
    get-item-label from radio-box%
    get-item-plain-label from radio-box%
    get-label from window<%>
    get-number from radio-box%
    get-parent from area<%>
    get-plain-label from window<%>
    get-selection from radio-box%
    get-size from window<%>
    get-top-level-window from area<%>
    get-width from window<%>
    get-x from window<%>
    get-y from window<%>
    has-focus? from window<%>
    horiz-margin from subarea<%>
    is-enabled? from radio-box%
        overrides 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 window<%>
    set-selection from radio-box%
    show from window<%>
    stretchable-height from area<%>
    stretchable-width from area<%>
    vert-margin from subarea<%>