gtk:message-dialog-message-area (object)

dialog -- a gtk:message-dialog widget
area -- a gtk:box widget with :vertical orientation

The accessor for the message-area slot of the gtk:message-dialog class returns the gtk:box widget with :vertical orientation corresponding to the "message area" in the message dialog. This is the box where the primary and secondary labels of the message dialog are packed.

You can add your own extra content to that box and it will appear below those labels. See the gtk:dialog-content-area function for the corresponding function in the parent gtk:dialog class. The gtk:message-dialog widget is deprecated since 4.10. Use the gtk:alert-dialog widget instead.