It's been a while since I wrote this, but I seem to remember that widows are NP-hard at least: fitting them to pages maps onto box-packing. I really implemente

It's been a while since I wrote this, but I seem to remember that widows are NP-hard at least: fitting them to pages maps onto box-packing. I really implemented this algorithm so that I could nicely "flow" images in a GUI window. I was working with Sean Parent & Jaakko Järvi on Adam/Eve. My assertion was that there were layout principles (Adam?) for UI similar to the constraint properties for the object model (Eve?). The "other" layout principle was the grid-bag (CSS's box model for grids).