iPhone calendar navigation controller

to further my learning, I’m trying to replicate the default iPhone Calendar navigation implementation. What I see in portrait is a semi standard nav bar where selecting a month in the year view pushes the month view and selecting a day of the month pushes the day view.

However, change to landscape we have a segmented control instead of a title, and the title is in the left bar button position. My question is two fold.

First, how should I think about accomplishing the layout changes with the title/segmented control and left bar button when the orientation changes?

Second, what’s happening behind the scene in landscape mode with the segmented control? For instance, if the “Day”, segmented is the current view, what’s happens when a different segment is selected? If “Month” is selected, is the month view pushed on top of the day view? Or, is the day view popped before the week view is pushed? Furthermore, switch back to portrait and it appears that the current view has been pushed on top of the previous view.

I guess I’m having a hard time wrapping my head around what’s going on with toggling around the segmented control and making various selections and what not.

Portrait

Landscape

Source: Ios