Opening a new fragment from within a ViewPager in Android Studio - android-studio

Question

I have a question about opening a new fragment from within a ViewPager.
I setup FragmentA, FragmentB and FragmentC to be fragments of a viewpager and then proceeded to setup Fragment1 and Fragment2 as fragments of another viewpager which resides in FragmentB.
So Fragment1 and Fragment2 are in a viewpager which is essentially nested in another viewpager. I'm playing around with UI styles etc and this is is similar to that found in the Flickr app.
The problem I'm having is that once I get into the fragment1 or fragment2 (the nested fragment) I want to be able to click on something and enter a full screen fragment bypassing the toolbar I set up in FragmentB.
Below is the the code I have for FragmentB with the toolbar, tablayout and viewpager.
package com.app.fragmentdemo;
import android.os.Bundle;
import androidx.fragment.app.Fragment;
import androidx.fragment.app.FragmentActivity;
import androidx.appcompat.widget.Toolbar;
import androidx.viewpager.widget.ViewPager;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import com.google.android.material.tabs.TabLayout;
public class FragmentB extends Fragment {
public FragmentB() {
// Required empty public constructor
}
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_b,container,false);
Toolbar toolbar = (Toolbar) rootView.findViewById(R.id.toolbar);
TabLayout tabLayout = (TabLayout) rootView.findViewById(R.id.tabs);
ViewPager viewPager = (ViewPager) rootView.findViewById(R.id.viewPagerFragmentB);
ViewPagerAdapter adapter = new ViewPagerAdapter(((FragmentActivity) getContext()).getSupportFragmentManager());
adapter.addFragment(new Fragment1(),"Fragment 1");
adapter.addFragment(new Fragment2(),"Fragment 2");
viewPager.setAdapter(adapter);
tabLayout.setupWithViewPager(viewPager);
// Inflate the layout for this fragment
return rootView;
}
}
Here is the code I've put together for fragment2 which contains a button I would like to take to take me to another fragment.
package com.app.fragmentdemo;
import android.os.Bundle;
import androidx.fragment.app.Fragment;
import androidx.fragment.app.FragmentActivity;
import androidx.fragment.app.FragmentManager;
import androidx.fragment.app.FragmentTransaction;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Button;
import android.widget.Toast;
public class Fragment2 extends Fragment {
public Fragment2() {
// Required empty public constructor
}
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_2,container,false);
Button button = (Button) rootView.findViewById(R.id.button);
button.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
Fragment fragment = new FragmentFull();
FragmentManager fm = ((FragmentActivity) getContext()).getSupportFragmentManager();
FragmentTransaction ft = fm.beginTransaction();
ft.add(R.id.fragmentFullContainer,fragment);
ft.commit();
Toast.makeText(getActivity(), "Button Clicked", Toast.LENGTH_SHORT).show();
}
});
// Inflate the layout for this fragment
return rootView;
}
}
Upon clicking the button the app crashes. I get the error:
No view found for id 0x7f080084 (com.app.fragmentdemo:id/fragmentFullContainer) for fragment FragmentFull
If I change the id of the fragment container to the id I assigned to the Fragment2 layout file, it works fine. However, this is still contained in the nested viewpager and doesn't allow me to enter a new layout.
I really appreciate your help.
Thanks.

Answer 1

In the following line
ft.add(R.id.fragmentFullContainer,fragment);
fragmentFullContainer should be a view in your R.layout.fragment_2
You are getting the crash because the OS cannot find fragmentFullContainer in R.layout.fragment_2
UPDATE
replace getSupportFragmentManager with getChildFragmentManager
If you want full screen , you have to manually hide Activity View elements.
Most probably, you have toolbar from activity, you can remove it like that.
((AppCompatActivity)getActivity()).getSupportActionBar().hide();