Is it correct that for a tabpanel in 3.0 all tabs are rendered immediately (also those that are not initially visible) while in 2.x they were rendered (i.e. the gwt Widget.onLoad() is called) in a lazy way ?
I stumbled on that while debugging a sample that I am porting from 2.x to 3.x and setting a breakpoint in the onLoad()
I'll think this is the way it will work, because that the way GWT behaves.
You can avoid this by using something like mvp4g. This framework supports lazy loading of views. I'll did it with GXT 2.x and try it already with GXT 3.0. Works fine! If you are view implements LazyView, the instance of the view is created immediately and the widget when the view gets visible.
Works really nice!
If you have any questions, feel free to contact me.