We want to introduce the concept of fixed cell lengths (normally height) in VirtualFlow. This will allow for VirtualFlow to know the length of each cell without the costly need to actually calculate it per cell. For now we will just introduce a client property that can be set on TableView/ListView/TreeView to enable a fixed cell length, but in the long term (should this research prove fruitful) we will want to introduce a property on each control (as either a Java API or a CSS property).