I am working on a user interface design for an application on Android. Currently, I am struggling to choose a suitable form of navigation as it is my first time creating such a design.
The design is supposed to be for tablets, so for most lists, I use split view to view the list and item detail on the same screen.
The app is a digital library. It focuses on historical documents and each document has a list of its digitized pages. There are many lists in the app - list of documents, where user can perform search, list of favourites, list of collections and list of virtual documents (custom user-made documents). Moreover the list of favourites, collections and list of virtual documents should be split into two lists.
The current state of my navigation is that I have four tabs (documents, favourites, collections and virtual documents), so users can easily switch between them. The main problem is with splitting the lists. I could use another set of tabs to switch between for example my collections and already existing ones, but that does not seem to be the greatest idea.
So I thought maybe I could use the side navigation drawer for this application, or mix the navigation drawer with tabs. I am not sure how to design the navigation so it would be easy to use.
Consider the content to be displayed in the app; you're displaying lists. This means that when thinking about navigation, the most natural way to start is by 'listing' your list choices.
Your heirarchy is fine, and the tabs are a good starting point in this case. A good convention when designing for tablets is a vertical bar design, like google uses for Gmail etc. This way your entire navigational hierarchy is visible and easy to navigate through.