MyChatsAdapter.java

public class MyChatsAdapter extends ArrayAdapter<ChatInfo> {
    private FirebaseUser currentUser = FirebaseAuth.getInstance().getCurrentUser();
    private DatabaseReference mDatabaseReference = FirebaseDatabase.getInstance().getReference();

    final private String currentUID = currentUser.getUid();

    public MyChatsAdapter(Activity context, List<ChatInfo> chatItems) {
        super(context, 0, chatItems); // 2nd par is 0 because we inflate manually
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        // Check if the existing view is being reused, otherwise inflate the view
        View listItemView = convertView;

        if (listItemView == null) {

            listItemView = LayoutInflater.from(getContext()).inflate(

                    R.layout.my_chats_item, parent, false);
        }

        final ChatInfo currentChatInfo = getItem(position);
        if (currentChatInfo != null) {
            String chatID = currentChatInfo.getChatRoomName();
            if (chatID != null) {
                final TextView lastMessageTextView = (TextView) listItemView.findViewById(R.id.last_message_text_view);
                final ImageView newMessageCircleImageView = (ImageView) listItemView.findViewById(R.id.new_message_circle_image_view);
                final TextView lastMessageTimeStampTextView = (TextView) listItemView.findViewById(R.id.last_message_stamp);
                newMessageCircleImageView.setVisibility(View.INVISIBLE);

                mDatabaseReference.child("chat_info").child(chatID).addValueEventListener(new ValueEventListener() {
                    @Override
                    public void onDataChange(DataSnapshot dataSnapshot) {

                        String last_message = dataSnapshot.child("lastMessage").getValue().toString();
                        lastMessageTextView.setText(last_message);

                        long lastMessageTimeStamp = currentChatInfo.getLastMessageTimeStamp();
                        long currentTimeStamp = System.currentTimeMillis();
                        lastMessageTimeStampTextView.setText(TimestampUtils.toDuration(currentTimeStamp - lastMessageTimeStamp));

                        if (dataSnapshot.hasChild(currentUID)) {
                            long lastUserTimeStamp = (long) dataSnapshot.child(currentUID).getValue();
//                            long lastMessageTimeStamp = (long) dataSnapshot.child("lastStamp").getValue();
                            if (lastUserTimeStamp >= lastMessageTimeStamp) {
                                newMessageCircleImageView.setVisibility(View.INVISIBLE);
                                lastMessageTextView.setTypeface(Typeface.DEFAULT);
                            } else {
                                lastMessageTextView.setTypeface(Typeface.DEFAULT_BOLD);
                                newMessageCircleImageView.setVisibility(View.VISIBLE);
                            }
                        } else {
                            lastMessageTextView.setTypeface(Typeface.DEFAULT_BOLD);
                            newMessageCircleImageView.setVisibility(View.VISIBLE);
                        }
                    }

                    @Override
                    public void onCancelled(DatabaseError databaseError) {

                    }
                });

                String chatRoomEdit = chatID.replace(currentUID, "");
                final String partnerID = chatRoomEdit.replace("_", "");


                final TextView PartnerUsernameTextView = (TextView) listItemView.findViewById(R.id.my_chat_partner);
                final ImageView userIconImageview = (ImageView) listItemView.findViewById(R.id.user_icon);

                mDatabaseReference.child("user-books").child(partnerID).child("userName").addListenerForSingleValueEvent(new ValueEventListener() {
                    @Override
                    public void onDataChange(DataSnapshot dataSnapshot) {
                        if (dataSnapshot.getValue() != null) {
                            String PartenerUserName = dataSnapshot.getValue().toString();
                            PartnerUsernameTextView.setText(PartenerUserName);

                            ColorGenerator generator = ColorGenerator.MATERIAL; // or use DEFAULT

                            int color = generator.getColor(PartenerUserName);


                            TextDrawable drawable = TextDrawable.builder()
                                    .buildRound(PartenerUserName.substring(0, 1).toUpperCase(), color);
                            userIconImageview.setImageDrawable(drawable);
                        }
                    }

                    @Override
                    public void onCancelled(DatabaseError databaseError) {

                    }
                });

                final RelativeLayout myChatLayout = (RelativeLayout) listItemView.findViewById(R.id.my_chats_linear_layout);

                myChatLayout.setOnClickListener(new View.OnClickListener() {
                    @Override
                    public void onClick(View v) {
                        Intent intent = new Intent(v.getContext(), ChatActivity.class);
                        intent.putExtra("OWNER_ID", partnerID);
                        v.getContext().startActivity(intent);
                    }
                });

            }
        }
        return listItemView;
    }

}