[Bf-codereview] Drag to close areas (issue 6269044)

[jorge at lunarworkshop.com]

Okay I see it now. This is similar to what I mentioned before, and I
think it has the same root cause. It's a limitation that existed in
Blender since before this patch. T-shaped splits may not be collapsed.
In this case, the outliner or the 3D view must first be collapsed before
the header can be collapsed. Since in the default screen there are two
areas in each column (3d/timeline, outliner/properties) these must be
collapsed before the outliner can be collapsed. In other words, it's not
possible to collapse two areas at once.

Since this is an existing limitation from before this patch, I have two
options:

* I can add to this patch the ability to collapse multiple areas at
once.
* I can fix the display-related problems and not address the underlying
issues. If I do this then the user won't be able to move an area past
the header height if there's a T-shape.

Which do you recommend?

http://codereview.appspot.com/6269044/