Ok, but is it possible / wanted to set the renderer (as full-class name and maybe also as method name) from the style ?
What style specifically are you referring to? A tree view's node renderer is set via the setNodeRenderer() method.
Or the renderer is called only from paint, and i have to choose the operation to do (or the renderer to call) depending on this new style property ?
Renderers are used for layout and paint operations. But you wouldn't dynamically choose a renderer at paint time - rather, the render would paint itself appropriately based on the current node state at paint time. Swing renderers work the same way.
