A function that will be called when the contents of the clipboard are changed or cleared. Once this has called, the user_data_or_owner argument will not be used again.
user_data_or_owner
the #GtkClipboard
the user_data argument passed to gtk_clipboard_set_with_data(), or the owner argument passed to gtk_clipboard_set_with_owner()
user_data
owner
A function that will be called when the contents of the clipboard are changed or cleared. Once this has called, the
user_data_or_ownerargument will not be used again.