I'm having trouble laying out my AdvancedDataGrid. I would like to have a tree with a depth of 1 (a root node only contains leaf nodes). The rootnode is just the expand/collapse icon, followed by a name. The leaf nodes have several columns, the first few of which are very narrow.
Basically, I want the root nodes to ignore the column structure of the leaf nodes. Something like a "colspan" in HTML. I'm using HierarchicalData, because I found the grouping method to be way too slow for my needs.
