How to show layer when select another layer?

Question

I have an OpenaLayers/gxp application. I have base and overlay layers groups. I want to show some overlay layers when select base layer. For example when i choose BaseLayer1 i want to show OverlayLayer1 and OverlayLayer2 automaticaly. I seek something in gxp but cant find nothing interesting in class gxp.plugins.LayerTree.
So i think onlyOpenLayers can help me. Its possible to show layers when i choose another layer?

Answer 1

You should listen to the BaseLayer's visibilitychanged event, and then change the visibility of your OverLay layers