3.13  combo-field%

Superclass: text-field%

A combo-field% object is a text-field% object that also resembles a choice% object, because it has a small popup button to the right of the text field. By default, clicking the button pops up a menu, and selecting a menu item copies the item into the text field.

• (new combo-field% (label _) (choices _) (parent _) [(callback _)] [(init-value _)] [(style _)] [(font _)] [(enabled _)] [(vert-margin _)] [(horiz-margin _)] [(min-width _)] [(min-height _)] [(stretchable-width _)] [(stretchable-height _)]) -> combo-field% object
     label : string (up to 200 characters) or #f
   choices : list of strings (up to 200 characters each)
     parent : frame%, dialog%, panel%, or pane% object
     callback = (lambda (cf e) (void)) : procedure of two arguments: a combo-field% object and a control-event% object
     init-value = "" : string
     style = null : list of symbols in '(vertical-label horizontal-label deleted)
   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 = #t : boolean
     stretchable-height = #f : boolean

  If label is not #f, it is used as the combo label. Otherwise, the combo does not display its label.

  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 X, 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 combo 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 choices list specifies the initial list of items for the combo's popup menu. The append method adds a new item to the menu with a callback to install the appended item into the combo's text field. The get-menu method returns the combo's menu to allow arbitrary other operations. This menu might not be used at all if on-popup is overridden.

  The callback procedure is called when the user changes the text in the combo or presses the Enter key (and Enter is not handled by the combo's frame or dialog; see on-traverse-char in top-level-window<%> ). If the user presses Enter, the type of event passed to the callback is 'text-field-enter, otherwise it is 'text-field.

  If init-value is not "", the minimum width of the text item is made wide enough to show init-value. Otherwise, a built-in default width is selected.

  If style includes 'vertical-label, then the combo is created with a label above the control; if style does not include 'vertical-label (and optionally includes 'horizontal-label), then the label is created to the left of the combo. If style includes 'deleted, then the combo is created as hidden, and it does not affect its parent's geometry; the combo can be made active later by calling parent's add-child method. .

  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
    append
    get-menu
    on-popup

All Methods
    accept-drop-files from window<%>
    append from combo-field%
    client->screen from window<%>
    command from control<%>
    enable from window<%>
    focus from window<%>
    get-client-size from window<%>
    get-cursor from window<%>
    get-editor from text-field%
    get-font from control<%>
    get-graphical-min-size from area<%>
    get-handle from window<%>
    get-height from window<%>
    get-label from window<%>
    get-menu from combo-field%
    get-parent from area<%>
    get-plain-label from window<%>
    get-size from window<%>
    get-top-level-window from area<%>
    get-value from text-field%
    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-popup from combo-field%
    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-value from text-field%
    show from window<%>
    stretchable-height from area<%>
    stretchable-width from area<%>
    vert-margin from subarea<%>