A Disappearing Act

Yesterday, I discussed the way the Ribbon scales to different window sizes. 
I've also
mentioned that you can collapse the Ribbon by double-clicking the selected
tab or by pressing Ctrl+F1.  One piece of the design I haven't yet written about
but you might
have noticed if you watched yesterday's movie is what happens to Office windows
below about 250 pixels wide.

It's an idea we kind of stole
from
OneNote: when you size the window below a certain threshold, the whole
Ribbon disappears, leaving you with just your document.  If you've used
OneNote, you know that once you resize down below a certain threshold, most of
the frame and commands disappear, leaving you with a clean little box to take
notes in.  We've taken the idea now and expanded it to all new UI apps.

The logic goes like this.  Below a certain minimum size, no amount of
downward scaling makes the UI truly usable.  (This is the case for previous
versions of Office as well.)  So, a good assumption seems to be that you're
not actually trying to use the commands anymore at that size, but instead you
want the content of the document in a skinny window.  Maybe you want to
have it up alongside another document that you're editing.  Maybe you're
doing copy and paste from one document to another.  Or drag and drop. 
But it's unlikely that you're trying to insert a caption or debug formulas in a
window that narrow.

When you size the window back over the threshold, the Ribbon reappears, ready to
follow your orders.

If you want to see what it looks like in action, check out the
movie I posted
yesterday (1.6 MB, Windows Media Format).

It's a small touch, but I think it adds a bit of polish to a scenario in which
the UI has the potential to put its worst foot forward.