This function is the means to successfully return a value from the current dialog. Hence, it might be called from an OK button so that pressing the button would cause the dialog to return successfully, whilst the Cancel button would call the counterpart function abort-dialog.
(capi:display-dialog
(capi:make-container
(make-instance 'capi:text-input-pane
:callback-type :data
:callback 'capi:exit-dialog)
:title "Test Dialog"))
There is another example in the file
examples/capi/dialogs/simple-dialog.lisp
.