Question

I am trying to implement a tab-style navigation system in my app (similar to the iOS UITabBarController). The functionality I am trying to create is that each tab holds it’s own stack of screens, so that if one switches tabs the user changes to a different stack and can navigate back and forth independently of the other tabs, all the while showing a single tab bar at the top or bottom of the screen.

I have seen this functionality in apps such as Dropbox, but I am not sure if its possible to have multiple stacks or the behaviour is simply clever management of a single stack.

Any thoughts would be very much appreciated.

Answer 1

No, there is only one stack of screens and RIM OS does not support multiple screen stacks.

And you should follow some rules to work with this single stack. For instance, to show previous screen, you need to pop (close) topmost one.

If you do not pop screens, but create more and more new ones, without closing old screens, then you will get OutOfMemoryException.

You will need to redesign your app, use custom Manager class instances and compose your own interface to implement the way of appearance you need.

EDIT: You can have as many in-memory lists of screen objects as you wish, or until they fit to the device memory. But RIM OS allows only one stack of visible screens.