FragmentBackHandle

Hi friends

Today we are learn most challenging task approximately max developer face this problem so i am resolve this problem i hope this post help you. 

 Are you ready to learn about how to handle fragment back stack....

Step 1-> Create a new sample project in android studio

Step 2->Create multiple fragments

Step 3->And now you go to  MainActivity.java this class is most powerful so please concentrate.

public class MainActivity extends AppCompatActivity implements OnItemClicks{

    public Stack<String> mFragmentStack;

    @Override

    protected void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

        setContentView(R.layout.activity_main);

        mFragmentStack = new Stack<String>();

        FragmentManager fragmentManager = 

       getSupportFragmentManager();

        FragmentTransaction transaction = 

       fragmentManager.beginTransaction();

        Fragment fragment = new FragmentFirst();

        String tag = fragment.toString();

        mFragmentStack.add(tag);

        transaction.add(R.id.containers, fragment, tag);

        transaction.addToBackStack(tag);

        transaction.commit();

   }



    @Override

    public void itemClick(String input)

    {

        if (input.equalsIgnoreCase("first"))

        {

            Fragment newFragment = new SecondFragment();

            beginTransction(newFragment);

        }else if (input.equalsIgnoreCase("second"))

        {

           Fragment newFragment = new ThirdFragment();

            beginTransction(newFragment);

        }

        else if (input.equalsIgnoreCase("third"))

        {

            Fragment fragment = new FourthFragment();

            beginTransction(fragment);

        }else if (input.equalsIgnoreCase("fourth"))

        {     Fragment fragment = new FifthFragment();

            beginTransction(fragment);

        }else if (input.equalsIgnoreCase("fifth"))

        {

            Fragment fragment = new SixFragment();

            beginTransction(fragment);

        }

    }



    private void beginTransction(Fragment fragment)

    {

        Bundle args = new Bundle();

        String tag = fragment.toString();

        fragment.setArguments(args);

        FragmentTransaction transaction = 

         getSupportFragmentManager().beginTransaction();

        transaction.setCustomAnimations(R.anim.fragment_animation_fade_in, R.anim.fragment_animation_fade_out);




        // I find what the current fragment from the stack is, take it and hide it

        // using transaction.hide(currentFragment);

        Fragment currentFragment = 

        getSupportFragmentManager().findFragmentByTag(mFragmentStack.peek());

        transaction.hide(currentFragment);

        transaction.add(R.id.containers, fragment,fragment.toString());

        // This is important, we must addToBackStack so we can pull it out later.

        transaction.addToBackStack(tag);

        // Instead of using replace we use add. Why? If we use replace, then the previous

        // fragment will always have to be re-created. What if you don't want to do that. In

        // my case, I didn't want it to be re-created all the time because I had a position

        // set and by re-creating it, I would have lost the position or had to use static flag.

        mFragmentStack.add(tag);

        transaction.commit();

    }



    @Override

    public void onBackPressed(){

        // from the stack we can get the latest fragment

        Fragment fragment = getSupportFragmentManager().findFragmentByTag(mFragmentStack.peek());

        // If its an instance of Fragment1 I don't want to finish my activity, so I launch a Toast instead.

        if (fragment instanceof FragmentFirst){

            Toast.makeText(getApplicationContext(), "YOU ARE AT THE TOP FRAGMENT", Toast.LENGTH_SHORT).show();

        }

        else{

            // Remove the framg

            removeFragment();

            super.onBackPressed();

        }

    }

    private void removeFragment(){

        // remove the current fragment from the stack.

        mFragmentStack.pop();

        FragmentTransaction transaction = getSupportFragmentManager().beginTransaction();

        // get fragment that is to be shown (in our case fragment1).

        Fragment fragment = getSupportFragmentManager().findFragmentByTag(mFragmentStack.peek());

        // This time I set an animation with no fade in, so the user doesn't wait for the animation in back press

        transaction.setCustomAnimations(R.anim.zoom_in, R.anim.zoom_out);

        // We must use the show() method.

        transaction.show(fragment);

        transaction.commit();

    }

}
Step 4-> Now you create a listener interface

public interface OnItemClicks {

    public void itemClick(String tag);

}

if you want full code source code click this link

https://github.com/SamsetDev/FragmentbackStackHandle

If this sample helps you please like this page