Marble has recently gained support for the KML ListStyle::background element. This task is about extending support to include the ItemIcon and its subtags state and href.

https://developers.google.com/kml/documentation/kmlreference?hl=de#liststyle

The Network link isnt supported in Marble yet but as part of this task everything that can be provided without actual support should be provided. The icons that are referenced inside the KML spec are available here:

http://byte.kde.org/~tackat/closed-folder.png.zip

Check the ListStyle example as a test case.