Android: tablayout/viewpager fragments within fragment or activity

Question

I have a project I am working on in Android. I have one big fragment that covers the whole of the screen in my main activity. Normally I for each ui screen the user uses I would just do a replace command and swap the fragments for each screen.

In my current one I want to put a tablayout/viewpager combo with three different fragments and depending on what tab is pushed I will show a new fragment. Problem with this is that is a tablayout showing three different fragments inside another fragment. Is this even possible or recommended? and if I have to change it to a new activity. Would the navigation drawer act normally and just shut as I loaded the activity or is there going to be a problem there as well.

Thanks for your help

Answer 1

You can check below official documentation for the same or can use my demo snippet: https://developer.android.com/reference/android/support/v4/app/FragmentTabHost.html

Try to do this to handle the Tabs in main fragment:

public class MainFragment extends Fragment {
private FragmentTabHost mTabHost;

//Mandatory Constructor
public MainFragment() {
}

public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

}

public View onCreateView(LayoutInflater inflater, ViewGroup container,
        Bundle savedInstanceState) {

    View rootView = inflater.inflate(R.layout.fragment_tabs,container, false);


    mTabHost = (FragmentTabHost)rootView.findViewById(android.R.id.tabhost);
    mTabHost.setup(getActivity(), getChildFragmentManager(), R.id.realtabcontent);

    mTabHost.addTab(mTabHost.newTabSpec("fragmentb").setIndicator("Fragment B"),
            FragmentB.class, null);
    mTabHost.addTab(mTabHost.newTabSpec("fragmentc").setIndicator("Fragment C"),
            FragmentC.class, null);
    mTabHost.addTab(mTabHost.newTabSpec("fragmentd").setIndicator("Fragment D"),
            FragmentD.class, null);


    return rootView;
}

}

With this tabs layout:

<android.support.v4.app.FragmentTabHost
xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@android:id/tabhost"
android:layout_width="match_parent"
android:layout_height="match_parent">

<LinearLayout
    android:orientation="vertical"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

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

</LinearLayout>

Answer 2

Yes, TabLayout with viewPager will maintain it's different fragments in the memory.

Since, there are going to be only 3 tabs in your case it won't affect your memory performance, you can go with pagerAdapter.

You can reuse a single fragment for other tabs, but as i said since there are only 3 tabs, it won't affect your performance.

And Yes you can have tabLayout inside your main fragment, you main fragment is a part of your activity right, it will follow the same life cycle as the hosting activity except few other callbacks.