How to switch between fragments without actually overlapping the previous fragments

Question

I am new to Android Developing and I am trying to create an app based on the BottomNavgiationView. One of the bottom navigation Items have an editText so when I switch to another fragment the previous fragment where I wrote something gets overlapped due to replacing.

This is my OnNavigationItemSelectedListener

private void enableNavigation(){
    bottomNav.setOnNavigationItemSelectedListener(new BottomNavigationView.OnNavigationItemSelectedListener() {
        @Override
        public boolean onNavigationItemSelected(@NonNull MenuItem item) {
            switch(item.getItemId()){
                case R.id.btnHome:
                    HomeFragment homeFragment = new HomeFragment();
                    android.support.v4.app.FragmentManager manager = getSupportFragmentManager();
                    manager.beginTransaction().replace(R.id.container, homeFragment).commit();
                    return true;
                case R.id.btnChats:
                    ChatsFragment chatsFragment = new ChatsFragment();
                    android.support.v4.app.FragmentManager manager1 = getSupportFragmentManager();
                    manager1.beginTransaction().replace(R.id.container, chatsFragment).commit();
                    return true;
                case R.id.btnPost:
                    PostsFragment postsFragment = new PostsFragment();
                    android.support.v4.app.FragmentManager manager2 = getSupportFragmentManager();
                    manager2.beginTransaction().replace(R.id.container, postsFragment).commit();
                    return true;
                case R.id.btnFavourites:;
                    FavouritesFragment favouritesFragment = new FavouritesFragment();
                    android.support.v4.app.FragmentManager manager3 = getSupportFragmentManager();
                    manager3.beginTransaction().replace(R.id.container, favouritesFragment).commit();
                    return true;
                case R.id.btnProfile:
                    ProfileFragment profileFragment = new ProfileFragment();
                    android.support.v4.app.FragmentManager manager4 = getSupportFragmentManager();
                    manager4.beginTransaction().replace(R.id.container, profileFragment).commit();
                    return true;
            }
            return false;
        }
    });

Anyone having any solution please let me Know..

Answer 1

I assume you meant instance. Each time you switch fragment, you make a new instance and open that. So to stop doing that, you have to keep the first instance built and give that to the fragment manager when you want to switch to it.

For example, let's use your ChatFragment.

Instead of inside the switch statement, you put your ChatsFragment chatsfragmentdeclaration to the top of the Activity, so it's an instance-wide variable. Inside your switch statement, instead of building a new instance every time, you go

case R.id.btnChats:
  if(chatsFragment == null) chatsFragment = new ChatsFragment();
  android.support.v4.app.FragmentManager manager1 = getSupportFragmentManager();
  manager1.beginTransaction().replace(R.id.container, chatsFragment).commit();
  return true;

Now you only rebuild your fragment once, when it is first called. From then on, the old instance is reused.