gtk:message-dialog-new-with-markup (parent flags type buttons message &rest args)

parent -- a transient gtk:window parent, or nil for none
flags -- a gtk:dialog-flags value for the flags to use
type -- a gtk:message-type value for the type of message
buttons -- a gtk:buttons-type value for the buttons to use
message -- a Lisp format string, or nil
args -- arguments for message

The new gtk:message-dialog widget.

Creates a new message dialog, which is a simple dialog with some text which is marked up with the Pango text markup language. When the user clicks a button a "response" signal is emitted with response IDs from the gtk:response-type enumeration. See the gtk:dialog documentation for more details.

Special XML characters in the message arguments passed to this function will automatically be escaped as necessary. Usually this is what you want, but if you have an existing Pango markup string that you want to use literally as the label, then you need to use the gtk:message-dialog-set-markup function instead, since you cannot pass the markup string either as the format, it might contain '%' characters, or as a string argument.

(defun create-message-dialog-new-with-markup (parent filename)
  (let ((dialog (gtk:message-dialog-new-with-markup
                                        parent
                                        '(:modal :destroy-with-parent)
                                        :error
                                        :close
                                        "<b>Error loading file ~s</b>"
                                        filename)))
    (g:signal-connect dialog "response"
                      (lambda (dialog response)
                        (declare (ignore response))
                        (gtk:window-destroy dialog)))
    (gtk:window-present dialog)))    

The gtk:message-dialog widget is deprecated since 4.10. Use the gtk:alert-dialog widget instead.