How can i keep status 'online' in android

Question

Now i'm trying to make like a instagram chat program using firebase the problem is i want to show that member login status but android life cycle is problem

Here's my code HomeActiviy when user login success, go to HomeActivty from here i determined that online or offline

This is my code that distinguish online or offline

    private void status(String status){
        reference = FirebaseDatabase.getInstance().getReference("Users").child(firebaseUser.getUid());

        HashMap<String, Object> hashMap = new HashMap<>();
        hashMap.put("status", status);

        reference.updateChildren(hashMap);

    }

    @Override
    protected void onResume() {
        super.onResume();
        status("online");
    }


    @Override
    protected void onPause() {
        super.onPause();
        status("offline");
    }

From my HomeActivity.java when push chat ImageButton goto chat Activity and they see each other online image button green or gray

And here's my problem When go to another activity from HomeActivity the status will be show offline

and second time when i put the chat button

Here's my chat Activity

package com.example.together.activities.chat;

import android.support.annotation.NonNull;
import android.support.annotation.Nullable;
import android.support.design.widget.TabLayout;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentPagerAdapter;
import android.support.v4.view.ViewPager;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.support.v7.widget.Toolbar;
import android.widget.TextView;


import com.bumptech.glide.Glide;
import com.example.together.fragment.ChatFragment;
import com.example.together.fragment.UsersFragment;
import com.example.together.model.User;
import com.example.together.R;
import com.google.firebase.auth.FirebaseAuth;
import com.google.firebase.auth.FirebaseUser;
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 java.util.ArrayList;
import java.util.HashMap;

import de.hdodenhof.circleimageview.CircleImageView;

public class ChatsActivity extends AppCompatActivity {

    CircleImageView image_profile;
    TextView username;

    FirebaseUser firebaseUser;
    DatabaseReference reference;


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

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

        image_profile = findViewById(R.id.image_profile);
        username = findViewById(R.id.username);

        firebaseUser = FirebaseAuth.getInstance().getCurrentUser();
        reference = FirebaseDatabase.getInstance().getReference("Users").child(firebaseUser.getUid());

        reference.addValueEventListener(new ValueEventListener() {
            @Override
            public void onDataChange(@NonNull DataSnapshot dataSnapshot) {
                User user = dataSnapshot.getValue(User.class);
                username.setText(user.getUsername());
                if (user.getImageurl().equals("default")){
                    image_profile.setImageResource(R.mipmap.ic_launcher);
                }else {
                    Glide.with(ChatsActivity.this).load(user.getImageurl()).into(image_profile);
                }
            }

            @Override
            public void onCancelled(@NonNull DatabaseError databaseError) {

            }
        });

        TabLayout tabLayout = findViewById(R.id.tab_layout);
        ViewPager viewPager = findViewById(R.id.view_pager);

        ViewPagerAdapter viewPagerAdapter = new ViewPagerAdapter(getSupportFragmentManager());

        viewPagerAdapter.addFragment(new ChatFragment(), "채팅");  // `new ChatFragment()` should be inside `FragmentPagerAdapter.getItem()`
        viewPagerAdapter.addFragment(new UsersFragment(), "친구찾기");  // `new UsersFragment()` should be inside `FragmentPagerAdapter.getItem()`

        viewPager.setAdapter(viewPagerAdapter);

        tabLayout.setupWithViewPager(viewPager);



    }


    class ViewPagerAdapter extends FragmentPagerAdapter {

        private ArrayList<Fragment> fragments; // this line can cause crashes
        private ArrayList<String> titles;

        ViewPagerAdapter(FragmentManager fm){
            super(fm);
            this.fragments = new ArrayList<>();
            this.titles = new ArrayList<>();
        }

        @Override
        public Fragment getItem(int position) {
            return fragments.get(position);
        }

        @Override
        public int getCount() {
            return fragments.size();
        }

        public void addFragment(Fragment fragment, String title){
            fragments.add(fragment); // this line can cause crashes
            titles.add(title);
        }


        // Ctrl + O


        @Nullable
        @Override
        public CharSequence getPageTitle(int position) {
            return titles.get(position);
        }
    }



}

Here is my error

2019-07-09 16:46:29.993 13773-13773/com.example.blogapp E/AndroidRuntime: FATAL EXCEPTION: main
    Process: com.example.blogapp, PID: 13773
    java.lang.IllegalArgumentException: You cannot start a load for a destroyed activity
        at com.bumptech.glide.manager.RequestManagerRetriever.assertNotDestroyed(RequestManagerRetriever.java:323)
        at com.bumptech.glide.manager.RequestManagerRetriever.get(RequestManagerRetriever.java:132)
        at com.bumptech.glide.Glide.with(Glide.java:741)
        at com.example.together.activities.chat.ChatsActivity$1.onDataChange(ChatsActivity.java:66)
        at com.google.firebase.database.core.ValueEventRegistration.fireEvent(com.google.firebase:firebase-database@@17.0.0:75)
        at com.google.firebase.database.core.view.DataEvent.fire(com.google.firebase:firebase-database@@17.0.0:63)
        at com.google.firebase.database.core.view.EventRaiser$1.run(com.google.firebase:firebase-database@@17.0.0:55)
        at android.os.Handler.handleCallback(Handler.java:873)
        at android.os.Handler.dispatchMessage(Handler.java:99)
        at android.os.Looper.loop(Looper.java:193)
        at android.app.ActivityThread.main(ActivityThread.java:6669)
        at java.lang.reflect.Method.invoke(Native Method)
        at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:493)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:858)

i think it's related life cycle of activity

how can i keep status ?

At which line of code are you getting that error? – Alex Mamo Jul 09 '19 at 08:07 — Alex Mamo, Jul 09 '19 at 08:07

score 1 · Answer 1 · answered Jul 09 '19 at 08:13

The problems look like your ChatsActivity is destroyed while Glide is trying to load the image. You can use getApplicationContext() to get the current Context. Try to replace,

Glide.with(ChatsActivity.this).load(user.getImageurl()).into(image_profile);

with

Glide.with(getApplicationContext()).load(user.getImageurl()).into(image_profile);

Also, you should use .onDisconnect() method given by firebase to check the presence of the user

When you establish an onDisconnect() operation, the operation lives on the Firebase Realtime Database server. The server checks security to make sure the user can perform the write event requested, and informs the your app if it is invalid. The server then monitors the connection. If at any point the connection times out, or is actively closed by the Realtime Database client, the server checks security a second time (to make sure the operation is still valid) and then invokes the event.

You can find out more from this doc

Sumit Shukla · Accepted Answer · 2019-07-09T08:31:06.810

Put this dependency in your build.gradle file:

implementation "android.arch.lifecycle:extensions:*"

Then in your Application class, use this:

public class MyApplication extends Application implements LifecycleObserver {

    @Override
    public void onCreate() {
        super.onCreate();
        ProcessLifecycleOwner.get().getLifecycle().addObserver(this);
    }

    @OnLifecycleEvent(Lifecycle.Event.ON_STOP)
    private void onAppBackgrounded() {
        Log.d("MyApp", "App in background");
    }

    @OnLifecycleEvent(Lifecycle.Event.ON_START)
    private void onAppForegrounded() {
        Log.d("MyApp", "App in foreground");
    }
}

Update your AndroidManifest.xml file:

<application
    android:name=".MyApplication"
    ....>
</application>

When your app is in background change status to offline and when app is in foreground change it's status to online.

Reference

score 0 · Answer 3 · answered Jun 12 '20 at 11:08

Whenever user is in your app, technically he is online. So in your home activity use this:

  @Override
    protected void onStart() {
        super.onStart();
        myRef.child(uid).child("isOnline").setValue(true);
        myRef.child(uid).child("isOnline").onDisconnect().setValue(false);
    }

and also i would suggest to add to override onResume():

    @Override
    protected void onResume() {
        super.onResume();
            myRef.child(uid).child("isOnline").setValue(true); //User back online

        }

Make sure to add an if statement to check if user is connected to internet or not!

How can i keep status 'online' in android

3 Answers3

Linked