I've got a cute editor in a ModalPopupExtender and when one uses the ToFullPage button it gets the right size of the current window. The only problem is that it's rendering start-point isn't at the upper left corner of the window as it should be, but instead the upper left corner of the popup.

And if said popup is centered on the screen, well, the FullScreen mode won't cover all of the visible area, only part of it and extend further outside of the visible area.

We've solved it by using another editor, a duplicate so to speak, which we instead use on editor number ones ToFullPage command. But it's not a very pretty solution.

Is there another way of solving this?
I'm happy to provide more details if that's needed.