There has been a long debate over which is more aesthetically pleasing and makes the most sense, but I think the position that the address bar should be contained within the tab is the popular one these days. I think it's especially important with XY, because the start of the textbox is directly above the TreeView,
Both FireFox and Chrome have adopted the inner address bar UX. For some reason, IE hasn't, but they have some really great UX elements to keep the UI tight and compact. I think it's especially important for side-by-side views due to the distance your eyes have to travel between the folder and the address bar (esp for the view on the right side)
It makes sense for multiple reasons:
- I think of the tabpage as the container of that view - it's the region that my eyes stay within when working on that folder. It should be the outer-most container of the folder you're viewing and the address bar which represents a part of that folder goes inside it. It could be argued that even the TreeView could go in there, but I think that would take up too much screen real estate (the treeview is another discussion)
- With split screen view, it is confusing looking at the address bar for multiple reasons:
a) Address bar starts above the TreeView (or with no TreeView, it starts above pane #1 on the left).
b) While focused on the address bar it's not immediately clear which directory list you're editing. The eyes have a long distance to travel to get to the address bar from the current view. If you have a side-by-side view, it takes even longer for the right pane. It's a constant eye movement that takes way too long. - If designed well (like Microsoft did with Windows Explorer), it can save space and be used to represent the breadcrumbs and the address all in one place. That is almost duplicate functionality that's taking twice as much real-estate as needed.
a) Mouse navigation is simple by navigating the address bar like a breadcrumb list (each piece of the breadcrumb is a button)
b) Keyboard navigation is done by clicking on the address bar, but not on a specific folder, or by using a keyboard shortcut like ALT+D
There's a lot of discussions on the web about this, but most of the strongest arguments seem to favor the inner Address bar.
I've also attached a screenshot that shows two thing:
#1) Shows how the address bar can actually appear like a part of the TreeView (especially if your display is low brightness),
#2) The distance your eye must travel for the right view