Gets the name of the icon used to automatically populate the button.
If the icon name has not been set with [method@SplitButton.set_icon_name] the return value will be NULL.
the icon name
1.0
See Implementation
Gets the name of the icon used to automatically populate the button.
If the icon name has not been set with [method@SplitButton.set_icon_name] the return value will be NULL.