 			var newColumn:IAttributeColumn = vars.childListCallbacks.lastObjectAdded as IAttributeColumn;
 			if (newColumn)
 				registerLinkableChild(vars, WeaveAPI.StatisticsCache.getColumnStatistics(newColumn));
+			
+			filteredKeySet.setColumnKeySources(vars.getObjects(IAttributeColumn));
 		}
 		
 		// remembers previous unscaled width,height

		public function get bitmapData():BitmapData { return bitmap.bitmapData; }
		public const textGraphics:TextGraphics = new TextGraphics();
		public const canvas:Canvas = new Canvas();
		public var keys:Array;
		public var locals:Object; // for use inside scripts
		
		public function getSelectableAttributes():Array
		{

	import weave.api.ui.IVisToolWithSelectableAttributes;
	import weave.core.LinkableFunction;
	import weave.core.LinkableHashMap;
	import weave.data.KeySets.FilteredKeySet;
	import weave.primitives.Bounds2D;
	import weave.ui.AttributeSelectorPanel;
	import weave.ui.DraggablePanel;
	import weave.utils.GraphicsBuffer;
	import weave.utils.PlotterUtils;
	import weave.utils.TextGraphics;
