With due respect, this does not address the requirement for the interface itself to remain fixed relative to the device, no matter how the device is oriented. For example, when the viewport is taller than it is wide, I place the toolbars horizontally at the top and bottom, and I want them to always stay there from then on. But without a fixed interface orientation, I have to move those same toolbars vertically to the sides just to maintain the same physical layout when the device is rotated to landscape, creating a visual jump in the process. Just to be clear, in the end I am relaying out the entire interface only to recreate the layout I would have had if the interface had remained fixed relative to the device in the first place.