| Allegro CL version 8.2 Unrevised from 8.1 to 8.2. 8.1 version |
The class of the combo-box control
Instance of the combo-box class. This control is similar to pop-up-menu except that it can be operated from the keyboard using the arrow keys.
Click the combo-box tool on the Component toolbar. Move the mouse cursor to the part of the form where you want to place the control, and click again. The control will appear with colored resizing handles.
Controls can only be resized and moved on forms during the design stage; the size and location of everything is fixed on a running form.
Resize the control by clicking the mouse cursor and dragging one of the handles to the new size-point. Release the mouse key when you are satisfied with the new size. Note: resizing the combo-box means horizontal resizing only. Changing the size of the combo-box won't mean proportional changes in the size of the characters inside the box. Change the font property if you want to change the size of the actual characters displayed.
Move the control by clicking anywhere on it except a resizing handle and dragging it to a new location on the form. Release the mouse key when you are ready to place the control.
To allow users to type directly in the box instead of pulling down and
selecting a value, set the value of the typable property. If it is
specified non-nil
, users may type a new
value directly into the edit-box of a combo-box rather than being
forced to select a value from the drop-down list.
Combo-boxes use on-change-test to compare their value to elements in their range. The initial value of the on-change-test is eql. That value is inappropriate if the values in the range are strings: equal would be more appropriate for strings (two strings with the same characters may not be eql but are equal).
The dropping property is no longer supported. (It was supposed to control whether all values of the combo-box were always displayed or not.)
Combo-box controls
cannot have a horizontal scrollbar, so the valid choices are
:vertical
and nil
for
the scrollbars
property. If a horizontal scrollbar is needed on a combo-box,
an outline
control could be used instead, using only top-level items in the range
and turning off the draw-icons property to simulate a
combo-box.
This call to make-instance returns an instance of a combo-box. Properties can be initialization keyword arguments (the keyword has the same name as the property, with a prepended colon, e.g. :left for left). Additional arguments could be provided. Their absence indicates the default value will be used.
(make-instance 'combo-box :font (make-font-ex nil "MS Sans Serif" 11 nil) :left 238 :name :combo-box-1 :range '(:one :two :three) :top 106 :value :one)
See About how to get sample code for creating controls in cgide.htm, which explains how to use the IDE to create such code.
A diagram of window and widget classes is shown in Widget and window classes in cgide.htm.
Copyright (c) 1998-2016, Franz Inc. Oakland, CA., USA. All rights reserved.
This page was not revised from the 8.1 page.
Created 2010.1.21.
| Allegro CL version 8.2 Unrevised from 8.1 to 8.2. 8.1 version |