19.6.4 Other miscellaneous functions

Graph panes require a function which is used to plot information, called the children function. The value of the ROOTS attribute of a graph is passed as an argument to the children function in order to start the plot. The example interface uses the following simple children function. You already defined this if you have followed the example, but add it also in ib-callbacks.lisp :

(defun children-function (x)
  (when (< x 8)
    (list (* x 2) (1+ (* x 2)))))

Note: The ROOTS attribute of a graph pane has a default value of (1) . This is generated automatically by the Interface Builder.

Finally, the function test-ib-example is used to create an instance of the example interface.

(defun test-ib-example ()
  (capi:display (make-instance 'ib-example 
                               :best-height 300
                               :best-width 200)))

Common LispWorks User Guide (Unix version) - 21 Feb 2008