combo-field% : class?

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 label]       [choices choices]       [parent parent]      [ [callback callback]       [init-value init-value]       [style style]       [font font]       [enabled enabled]       [vert-margin vert-margin]       [horiz-margin horiz-margin]       [min-width min-width]       [min-height min-height]       [stretchable-width stretchable-width]       [stretchable-height stretchable-height]])

→ (is-a?/c combo-field%)

label : (or/c label-string? false/c)

choices : (listof label-string?)

parent   :   (or/c (is-a?/c frame%) (is-a?/c dialog%)       (is-a?/c panel%) (is-a?/c pane%))

callback   :   ((is-a?/c combo-field%) (is-a?/c control-event%) . -> . any)       =   (lambda (c e) (void))

init-value : string = ""

style   :   (listof (one-of/c 'horizontal-label 'vertical-label                   'deleted))       =   null

font : (is-a?/c font%) = normal-control-font

enabled : any/c = #t

vert-margin : (integer-in 0 1000) = 2

horiz-margin : (integer-in 0 1000) = 2

min-width : (integer-in 0 10000) = graphical-minimum-width

min-height : (integer-in 0 10000) = graphical-minimum-height

stretchable-width : any/c = #t

stretchable-height : any/c = #f

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

If & occurs in label, it is specially parsed as for button%.

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<%>.

(send a-combo-field append l) → void?

l : label-string?

Adds a new item to the combo’s popup menu. The given label is used for the item’s name, and the item’s callback installs the label into the combo’s text field.

(send a-combo-field get-menu) → (is-a?/c popup-menu%)

Returns the popup-menu% that is used by the default on-popup method. This menu is initialized with the labels argument when the combo-field% is created, and the append method adds a new item to the menu.

(send a-combo-field on-popup event) → void?

event : (is-a?/c control-event%)

Specification: Called when the user clicks the combo’s popup button.

Default implementation: Gets a menu from get-menu, sets its minimum width to match the combo control’s width, and then pops up the menu.