MainPageActivity

package mk.ukim.finki.djesba;

import androidx.annotation.NonNull;
import androidx.appcompat.app.AppCompatActivity;
import androidx.appcompat.widget.Toolbar;
import androidx.recyclerview.widget.LinearLayoutManager;
import androidx.recyclerview.widget.RecyclerView;
import androidx.viewpager.widget.ViewPager;

import mk.ukim.finki.djesba.Chat.ChatListAdapter;
import mk.ukim.finki.djesba.Chat.ChatObject;
import mk.ukim.finki.djesba.Fragments.IntroAdapter;
import mk.ukim.finki.djesba.Fragments.ViewPagerAdapter;
import mk.ukim.finki.djesba.User.UserObject;
import mk.ukim.finki.djesba.Utils.SendNotification;

import android.Manifest;
import android.content.Intent;
import android.os.Build;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;

import com.facebook.drawee.backends.pipeline.Fresco;
import com.google.android.material.tabs.TabLayout;
import com.google.firebase.auth.FirebaseAuth;
import com.google.firebase.database.DataSnapshot;
import com.google.firebase.database.DatabaseError;
import com.google.firebase.database.DatabaseReference;
import com.google.firebase.database.FirebaseDatabase;
import com.google.firebase.database.ValueEventListener;
import com.onesignal.OneSignal;

import java.util.ArrayList;

public class MainPageActivity extends AppCompatActivity {

    private RecyclerView mChatList;
    private RecyclerView.Adapter mChatListAdapter;
    private RecyclerView.LayoutManager mChatListLayoutManager;

    private Toolbar toolbar;
    private ViewPager viewPager;
    private ViewPagerAdapter adapter;
    private TabLayout tabLayout;

    //ViewPager introViewPager;

    ArrayList<ChatObject> chatList;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main_page);

        /*introViewPager = findViewById(R.id.introViewPage);
        IntroAdapter introAdapter = new IntroAdapter(getSupportFragmentManager());
        introViewPager.setAdapter(introAdapter);*/

        toolbar = findViewById(R.id.toolBar);
        setSupportActionBar(toolbar);
        getSupportActionBar().setTitle("DjesBa");

        viewPager = findViewById(R.id.pager);
        adapter = new ViewPagerAdapter(getSupportFragmentManager());
        viewPager.setAdapter(adapter);
        tabLayout = findViewById(R.id.tabs);
        tabLayout.setupWithViewPager(viewPager);

        OneSignal.startInit(this).init();
        OneSignal.setSubscription(true);
        OneSignal.idsAvailable(new OneSignal.IdsAvailableHandler() {
            @Override
            public void idsAvailable(String userId, String registrationId) {
                FirebaseDatabase.getInstance().getReference().child("user").child(FirebaseAuth.getInstance().getUid()).child("notificationKey").setValue(userId);
            }
        });
        OneSignal.setInFocusDisplaying(OneSignal.OSInFocusDisplayOption.Notification);

        Fresco.initialize(this);

        Button btnLogout = findViewById(R.id.btnLogout);
      //  Button btnFindUser = findViewById(R.id.btnFindUser);

        btnLogout.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                OneSignal.setSubscription(false);
                FirebaseAuth.getInstance().signOut();
                Intent intent = new Intent(getApplicationContext(),MainPageActivity.class);
                intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
                startActivity(intent);
                finish();
                return;
            }
        });
    }
}