Fairly straightforward and very common in many analysis tools.
Perhaps click (middle or right mouse button), drag, and release to highlight the section which will the be zoomed to fit the horizontal space; with the nice animation you already have of course :).
The reasoning for this should be obvious though. If I take a 10 second trace where I only expect, say 0.1s of actual data, I should be able to just select what I want to see and for it to zoom in all the way. Additionally, sometimes I just want it to fit my window.