JDefaultMap2D structure

A layered structure

A : The all set of layer will result in interactive widget map
B : The Decoration group, you can control all layer in here
C : The MapDecoration group, this one only accesible within the class,so you'll have extend the class
D : The context

5 : The top Decoration is the InformationDecoration, you can give him some text to show up if needed. He also show up the small "redrawing" message when the map is in rendering state.
4 : The user Decoration, in this one you will found the scalebar layer, the minimap and other interactive layers
3 : These are the most important Decoration, you found in them the edition/selection Decoration and others importants ones
2 : This layer is the result of the RenderingStrategy of the map, this is the layer in which all your maplayers are rendered
1 : And the background Decoration, you can replace it to change the background color or draw a grid or even a nasty image (wink)