



 
 
So far you have only seen two types of CAPI element: the interface (which is the top level CAPI element, and is present in any CAPI window) and the 
push-button
. This section shows how you can use the CAPI to create other common windowing elements you are likely to need. 
Before trying out the examples in this chapter, define the functions 
test-callback
 and 
hello
 in your Listener. The first displays the list of arguments it is given, and returns 
nil
. The second just displays a message.
(defun test-callback (data interface)
(display-message "Data ~S in interface ~S"
data interface))
(defun hello (data interface)
(declare (ignore data interface))
(display-message "Hello World"))
We will use these callbacks in future examples.
CAPI User Guide (Macintosh version) - 30 Aug 2011