UsersActivity.java

package com.bertho.chat;

import android.app.ProgressDialog;
import android.content.Context;
import android.content.Intent;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.support.v7.widget.Toolbar;
import android.view.View;
import android.widget.TextView;

import com.firebase.ui.database.FirebaseRecyclerAdapter;
import com.google.firebase.database.DatabaseReference;
import com.google.firebase.database.FirebaseDatabase;
import com.squareup.picasso.Callback;
import com.squareup.picasso.NetworkPolicy;
import com.squareup.picasso.Picasso;

import de.hdodenhof.circleimageview.CircleImageView;

public class UsersActivity extends AppCompatActivity {

    private Toolbar mToolbar;
    private RecyclerView mUsersList;
    private DatabaseReference mUsersDatabase;
    private ProgressDialog mDialog;
    private CircleImageView mDisplayImage;

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

        mDialog = new ProgressDialog(this);

        mToolbar = (Toolbar) findViewById(R.id.toolbar);
        setSupportActionBar(mToolbar);
        getSupportActionBar().setTitle("User List");
        getSupportActionBar().setDisplayHomeAsUpEnabled(true);

        mDisplayImage = (CircleImageView) findViewById(R.id.user_single_image);

        mUsersDatabase = FirebaseDatabase.getInstance().getReference().child("Users");
        mUsersDatabase.keepSynced( true );

        mUsersList = (RecyclerView) findViewById(R.id.users_list);
        mUsersList.setHasFixedSize(true);
        mUsersList.setLayoutManager(new LinearLayoutManager(this));

    }

    @Override
    protected void onStart() {
        super.onStart();

        showLoading("Get All User Data...");

        FirebaseRecyclerAdapter<Users, UsersViewHolder> firebaseRecyclerAdapter = new FirebaseRecyclerAdapter<Users, UsersViewHolder>(
                Users.class,
                R.layout.users_single_layout,
                UsersViewHolder.class,
                mUsersDatabase
        ) {
            @Override
            protected void populateViewHolder(UsersViewHolder usersViewHolder, Users users, int position) {
                usersViewHolder.setDisplayName(users.getName());
                usersViewHolder.setStatus(users.getStatus());
                usersViewHolder.setThumbImage(users.getThumb_image(), getApplicationContext());

                final String user_id = getRef(position).getKey();

                usersViewHolder.mView.setOnClickListener(new View.OnClickListener() {
                    @Override
                    public void onClick(View view) {

                        Intent profile_intent = new Intent(UsersActivity.this, ProfileActivity.class);
                        profile_intent.putExtra("user_id", user_id);
                        startActivity(profile_intent);

                    }
                });
                mDialog.dismiss();
            }
        };

        mUsersList.setAdapter(firebaseRecyclerAdapter);
    }

    public static class UsersViewHolder extends RecyclerView.ViewHolder {

        View mView;

        public UsersViewHolder(View itemView) {
            super(itemView);
            mView = itemView;
        }

        public void setDisplayName(String name) {
            TextView userNameView = (TextView) mView.findViewById(R.id.user_single_name);
            userNameView.setText(name);
        }

        public void setStatus(String status) {
            TextView statusView = (TextView) mView.findViewById(R.id.user_single_status);
            statusView.setText(status);
        }

        public void setThumbImage(final String thumb_image, final Context ctx) {
            final CircleImageView userImageView = (CircleImageView) mView.findViewById(R.id.user_single_image);

            /*Picasso.with(ctx)
                    .load(thumb_image)
                    .placeholder(R.drawable.no_profile)
                    .into( userImageView);*/

            Picasso.with(ctx)
                    .load(thumb_image)
                    .networkPolicy( NetworkPolicy.OFFLINE )
                    .placeholder(R.drawable.no_profile)
                    .into( userImageView, new Callback() {
                        @Override
                        public void onSuccess() {

                        }

                        @Override
                        public void onError() {
                            Picasso.with(ctx)
                                    .load(thumb_image)
                                    .placeholder(R.drawable.no_profile)
                                    .into(userImageView);
                        }
                    } );
        }
    }

    private void showLoading(String s) {
        mDialog.setTitle("Please wait a moment");
        mDialog.setMessage(s);
        mDialog.setCanceledOnTouchOutside(false);
        mDialog.show();
    }
}