Android: Multiple views, deep navigation, one Activity. What is the best way to handle?

Question

I'm looking for the the best way to reproduce, in an Android app, the behavior of the iPhone UiNavigationController within an UITabBarController .

I'm working on this Android app where I have a TabActivity and 4 tabs. I've already gone through a lot of posts regarding the use of activities and tabs and how it's not a good idea to use activities for everything, which seems fair enough. I decided to use one Activity on each tab anyway, since it makes sense in my application.

However, in one of those activities I have a deep navigation tree with more than one branch and up to 12 different views the user can go through.

The problem is: Android controls the navigation through activities inside an app, if you click the back button it will go to the previous one, but if I'm navigating through views, using one Activity, and I click back, it just finishes it. So how can I have a smooth navigation behavior between views in an Activity?

Answer 1

I had implemented this using a TabActivity with FragmentActivity as each tab. Utilizing Fragments API you can organize the code just like you would be using 12 different activities, still using only 1 for each tab in fact. Fragment's framework will handle back key press for you to show previous fragment instead of closing the entire activity.

There are some problems with such approach, for example, there's no MapFragment , but the workarounds can be found here on SOF.

You will need Android Support Package if your minimum SDK version is lower than 3.0.

Answer 2

Well I know very little about UiNavigationViewController , but I guess you want something to navigate between different Views. As you are using TabActivity , every tab should load into a separate Activity .
But since you want to branch it out, using that many Activities is not a perfect solution, neither the ActivityGroup too. The better solution, as per my opinion(I have run into similar problem once) is to have the main or root tabs loads into separate Activity, but for their branches, use the ViewFlipper, which flips the Views. So the whole Layout(Subclass of View) can be flipped.
You may run into some problem while flipping more than two Views (as what people say, though I never had any problem). So in that case you can use layout.setVisibility(View.GONE) to hide the layout and just change it with View.VISIBLE for next view.
And about the concerns of back button, you need to store the last used View or Activity into a variable, and in the override of onBackPressed() , just need to call them.

There might be better solution than this, not that I can remember, but yeah it's the easiest solution I can come up with.