Android Viewpager Wait Fragment Finish Load. After several attempt on how to wait all the fragment in view pager is loaded, i came out a solution where i create interface class to communicate between activity and the fragment.

OnFragmentFinishLoad.java

public interface OnFragmentFinishLoad {
    public void onFinish(String tag,boolean state);
}
 

PizzaActivity.java

public class PizzaActivity extends BaseActivity implements OnFragmentFinishLoad {

   @BindView(R.id.cover_rl)
   protected RelativeLayout cover_rl;

   int countLoad = 0;

   @Override
  public void onCreate(Bundle savedInstanceState) {
      super.onCreate(savedInstanceState);
      setContentView(R.layout.activity_carte_tab_layout);
      cover_rl.setVisibility(View.VISIBLE);

      setupViewPager(viewPager);
      mTabLayout.setupWithViewPager(viewPager);
      setupTabLayout(mTabLayout);

      .......
      .......
   }

   @Override
  public void onFinish(String tag, boolean state) {
      if (state)
         countLoad++;
      
      //cat.size() is the number of fragment in view pager.
      //each time fragment trigger this function, there will return true and countLoad will increase
      //if number of true == cat.size() the loading will disappear
  
      if (countLoad == cat.size() - 1) {
         cover_rl.setVisibility(View.GONE);
      }
   }
}

PizzaFragment.java

public class PizzaFragment extends BaseFragment {

   @Override
 
   public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
      return inflater.inflate(R.layout.default_fragment, container, false);
   }

   @Override
 
   public void onViewCreated(View view, Bundle savedInstanceState) {
       super.onViewCreated(view, savedInstanceState);

       ...
       ...

       
       //run task
       new AsyncDataTaskPizza().execute();
   }

   private class AsyncDataTaskPizza extends AsyncTask < Void, Void, Void > {
      @Override
 
      protected void onPreExecute() {
         super.onPreExecute();
      }

      @Override
      protected Void doInBackground(Void... params) {
           //HTTP Call or else
      }

      @Override
 
      protected void onPostExecute(List < PizzaDetail > result) {

          // call this function after finish load everything
          ((OnFragmentFinishLoad) getActivity()).onFinish(null, true);

      }
   }

}