Tabs and Fragments, separate back stacks

Question

I am attempting to add Tabs to an existing app to add more functionality I've been able to implement tabs and also move everything to Fragments. However, the way I have it setup at the moment doesn't preserve the stack per tab. So basically I have a main FrameActivity that handles the tabs and attaches the fragments to each tab.

During my research I found this thread: https://stackoverflow.com/a/7480080/792407

The example he gives makes a lot of sense but I can't seem to get the fragments to display. So let me explain what I'm doing to make sure I understand it correctly:

I have a main tab activity which extends FragmentActivity and handles the tabs. Layout looks like:

<?xml version="1.0" encoding="utf-8"?>
 <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
        android:orientation="vertical"
        android:layout_width="fill_parent"
        android:layout_height="fill_parent">
    <TabHost
        android:id="@android:id/tabhost"
        android:layout_width="fill_parent"
        android:layout_height="fill_parent"
        >
        <LinearLayout
            android:orientation="vertical"
            android:layout_width="fill_parent"
            android:layout_height="fill_parent"
            >
            <TabWidget
                android:id="@android:id/tabs"
                android:orientation="horizontal"
                android:layout_width="fill_parent"
                android:layout_height="wrap_content"
                android:layout_weight="0"
                />
            <FrameLayout
                android:id="@android:id/tabcontent"
                android:layout_width="0dp"
                android:layout_height="0dp"
                android:layout_weight="0"/>

            <FrameLayout
                android:id="@+android:id/realtabcontent"
                android:layout_width="fill_parent"
                android:layout_height="0dp"
                android:layout_weight="1"/>
        </LinearLayout>
    </TabHost>
</LinearLayout>

Within this activity I initialize my tabs:

mTabHost = getTabHost();        
Resources res = getResources();
Intent intent;        
TabHost.TabSpec spec; 

//search tab
intent = new Intent().setClass(this, searchFragmentStack.class);
spec = mTabHost.newTabSpec("search").setIndicator("Search",res.getDrawable(R.drawable.ic_tab_search)).setContent(intent);        
mTabHost.addTab(spec);

//home tab
intent = new Intent().setClass(this, homeFragmentStack.class);
spec = mTabHost.newTabSpec("home").setIndicator("Home",res.getDrawable(R.drawable.ic_tab_home)).setContent(intent);        
mTabHost.addTab(spec);

The stack classes I'm using look like:

public class searchFragmentStack extends ActivityInTab {
        @Override
        protected void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            navigateTo(new search());
        }
}

The ActivityInTab abstract class is the same code he used in the thread:

abstract class ActivityInTab extends FragmentActivity { // FragmentActivity is just Activity for the support library.

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.tabs_layout);
    }

    /**
     * Navigates to a new fragment, which is added in the fragment container
     * view.
     * 
     * @param newFragment
     */
    protected void navigateTo(Fragment newFragment) {
        FragmentManager manager = getSupportFragmentManager();
        FragmentTransaction ft = manager.beginTransaction();
        ft.add(R.id.content, newFragment);
        ft.addToBackStack(null);
        ft.commit();
    }

    @Override
    public void onBackPressed() {
        FragmentManager manager = getSupportFragmentManager();
        if (manager.getBackStackEntryCount() > 0) {
            // If there are back-stack entries, leave the FragmentActivity
            // implementation take care of them.
            super.onBackPressed();
        } else {
            // Otherwise, ask user if he wants to leave :)
            //showExitDialog();
        }
    }

}

and the layout for the stack is again based on his example:

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/content"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:isScrollContainer="true">
</RelativeLayout>

And that's pretty much it. All I get are black screens in the tabs which makes me think it's a layout issue or I'm just doing it wrong. Does this make sense? Is there a better way? Am I missing something? Any help will be greatly appreciated.

Answer 1

I experimented about tabs in fragment activity. So, may be it is worth to be seen

FragmentTabHost with own fragment stack for each tab

Answer 2

I've figured it out after starting a dummy project and doing everything from scratch:

The activity I was using to handle the tabs needs to be a TabActivity and implimented as if I was creating normal Tabs using Activities, except I'll be using separate FragmentActivity "stacks" to manage the content in each tab. Also, the layout I was using for the Tab activity was wrong for what I was doing, I am now using:

<?xml version="1.0" encoding="utf-8"?>
<TabHost xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@android:id/tabhost"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent">
    <LinearLayout
        android:orientation="vertical"
        android:layout_width="fill_parent"
        android:layout_height="fill_parent"
        android:padding="5dp">
        <TabWidget
            android:id="@android:id/tabs"
            android:layout_width="fill_parent"
            android:layout_height="wrap_content" />
        <FrameLayout
            android:id="@android:id/tabcontent"
            android:layout_width="fill_parent"
            android:layout_height="fill_parent"
            android:padding="5dp" />
    </LinearLayout>
</TabHost>

Those were the two major changes, I've uploaded the source for the test project in case anyone wants to reference it for their own projects:

Seperate Fragment Stacks in Tabs

EDIT

Forgot to mention that TabActivity is deprecated so one shouldn't rely on this method for future android versions. I have not figured out how to implement this using a FragmentActivity. That said, it works for my current needs and gives me time to figure out how to do it the new way.