




 
You have already seen push buttons in earlier examples. The 
:enabled
 keyword can be used to specify whether or not the button should be selectable when it is displayed. This can be useful for disabling a button in certain situations.
The following code creates a push button which cannot be selected.
(setq offbutton (make-instance 'push-button
:data "Button"
:enabled nil))
(contain offbutton)
These 
setf
 expansions enable and disable the button:
(apply-in-pane-process
offbutton #'(setf button-enabled) t offbutton)
(apply-in-pane-process
offbutton #'(setf button-enabled) nil offbutton)
All subclasses of the 
button
 class can be disabled in this way.
CAPI User Guide (Unix version) - 30 Aug 2011