I need a vertical layout, which would fill browser's viewport top to bottom, with on overflow (scrollbars). I need to layout widgets on the top, and on the bottom, and have one widget in the center which would stretch to fill the remaining space.

There seems to be DockLayoutPanel for this purpose, the problem with it is that it forces me to specify widget sizes, and I don't know the sizes of the top/bottom widgets before the browser does it's layouting job, which is tricky (buggy) to track. I cannot find the right moment when to measure my widgets, and I don't want to do this kind of layouting code anyway.