I just perused the AdvancedDataGrid class in the hopes of overriding the itemOpen and itemClose handlers but I don't see anything in there that'll help me in preventing the entire thing from collapsing. It's the same thing with HierarchicalCollectionView openNode() and closeNode() methods. I don't seem to have any access to the rowHeight or contents.
Is there some kind of closed state or default rowHeight that I'm not seeing?