insertBeforeCompass方法什么用的？

Question

NASA wordwind java SDK里 的ApplicationTemplate类中 有四个inserXXX()方法： 
public static void insertBeforeCompass(WorldWindow wwd, Layer layer) 
public static void insertBeforePlacenames(WorldWindow wwd, Layer layer) 
public static void insertAfterPlacenames(WorldWindow wwd, Layer layer) 
public static void insertBeforeLayerName(WorldWindow wwd, Layer layer, String targetName) 
谁能说说他们都起什么作用啊？还有后面的参数表示什么？？ 

Answer 1

看看这篇文章吧！http://classicning.javaeye.com/blog/99667