Firebase Android聊天对齐错误

Question

I'm relatively new to Android Dev't. I have built a fairly good chat system but can't get the sender's message appearing on the left and the receiver appearing on the right. Tried using the set to gravity method but didn't work out. Anyone faced a similar error? Please help. Below is my code.

Chat Activity

package com.dreamlazerstudios.gtuconline;

import android.graphics.Color;
import android.os.Bundle;
import android.support.annotation.NonNull;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.text.TextUtils;
import android.util.Log;
import android.view.Gravity;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.EditText;
import android.widget.ImageButton;
import android.widget.TextView;

import com.google.firebase.auth.FirebaseAuth;
import com.google.firebase.auth.FirebaseUser;
import com.google.firebase.database.ChildEventListener;
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.ServerValue;
import com.google.firebase.database.ValueEventListener;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

public class ChatActivity extends AppCompatActivity {

private DatabaseReference rootRef, messagesRef;
private FirebaseAuth mAuth;
private FirebaseAuth.AuthStateListener mAuthListener;
private String userID;
private String mChatUser;

private ImageButton chat_add_btn, chat_send_btn;
private EditText enter_message;

List<DataSnapshot> listData;
RecyclerView recyclerView;
ChatActivity.MyAdapter adapter;

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

    recyclerView = findViewById(R.id.messages_list);
    recyclerView.setLayoutManager(new LinearLayoutManager(this));
    recyclerView.setHasFixedSize(true);

    messagesRef = FirebaseDatabase.getInstance().getReference();

    listData = new ArrayList<>();
    adapter = new ChatActivity.MyAdapter(listData);
    adapter.setHasStableIds(true);

    chat_add_btn = findViewById(R.id.chat_add_btn);
    chat_send_btn = findViewById(R.id.chat_send_btn);
    enter_message = findViewById(R.id.chat_message_view);

    mChatUser = getIntent().getStringExtra("user_id");
    String username = getIntent().getStringExtra("user_name");
    setTitle(username);

    rootRef = FirebaseDatabase.getInstance().getReference();
    mAuth = FirebaseAuth.getInstance();
    final FirebaseUser user = mAuth.getCurrentUser();
    userID = user.getUid();

    loadMessages();

    rootRef.child("Chat").child(userID).addValueEventListener(new ValueEventListener() {
        @Override
        public void onDataChange(DataSnapshot dataSnapshot) {

            if (!dataSnapshot.hasChild(mChatUser)) {
                Map chatAddMap = new HashMap();
                chatAddMap.put("seen", false);
                chatAddMap.put("timestamp", ServerValue.TIMESTAMP);

                Map chatUserMap = new HashMap();
                chatUserMap.put("Chat/" + userID + "/" + mChatUser, chatAddMap);
                chatUserMap.put("Chat/" + mChatUser + "/" + userID, chatAddMap);

                rootRef.updateChildren(chatUserMap, new DatabaseReference.CompletionListener() {
                    @Override
                    public void onComplete(DatabaseError databaseError, DatabaseReference databaseReference) {
                        if (databaseError != null) {

                            Log.d("CHAT_LOG", databaseError.getMessage().toString());

                        }
                    }
                });
            }

        }

        @Override
        public void onCancelled(DatabaseError databaseError) {

        }
    });

    chat_send_btn.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            sendMessage();
        }
    });

}

private void loadMessages() {
    messagesRef = FirebaseDatabase.getInstance().getReference().child("messages").child(userID).child(mChatUser);

    messagesRef.addChildEventListener(new ChildEventListener() {
        @Override
        public void onChildAdded(DataSnapshot dataSnapshot, String s) {
            Messages messages = dataSnapshot.getValue(Messages.class);

            listData.add(dataSnapshot);
            recyclerView.setAdapter(adapter);
        }

        @Override
        public void onChildChanged(DataSnapshot dataSnapshot, String s) {

        }

        @Override
        public void onChildRemoved(DataSnapshot dataSnapshot) {

        }

        @Override
        public void onChildMoved(DataSnapshot dataSnapshot, String s) {

        }

        @Override
        public void onCancelled(DatabaseError databaseError) {

        }
    });
}

private void sendMessage() {
    String message = enter_message.getText().toString();
    if (!TextUtils.isEmpty(message)) {

        String current_user_ref = "messages/" + userID + "/" + mChatUser;
        String chat_user_ref = "messages/" + mChatUser + "/" + userID;

        DatabaseReference user_message_push = rootRef.child("messages").child(userID).child(mChatUser).push();

        String push_id = user_message_push.getKey();

        Map messageMap = new HashMap();
        messageMap.put("message", message);
        messageMap.put("seen", false);
        messageMap.put("type", "text");
        messageMap.put("time", ServerValue.TIMESTAMP);
        messageMap.put("from", userID);

        Map messageUserMap = new HashMap();
        messageUserMap.put(current_user_ref + "/" + push_id, messageMap);
        messageUserMap.put(chat_user_ref + "/" + push_id, messageMap);

        enter_message.setText("");

        rootRef.updateChildren(messageUserMap, new DatabaseReference.CompletionListener() {
            @Override
            public void onComplete(DatabaseError databaseError, DatabaseReference databaseReference) {
                if (databaseError != null) {
                    Log.d("CHAT_LOG", databaseError.getMessage());
                }

            }
        });
    }
}

public class MyAdapter extends RecyclerView.Adapter<ChatActivity.MyAdapter.ViewHolder> {

    List<DataSnapshot> list;

    public MyAdapter(List<DataSnapshot> List) {
        this.list = List;
    }

    @Override
    public void onBindViewHolder(@NonNull final ChatActivity.MyAdapter.ViewHolder holder, final int position) {

        final DataSnapshot studentSnapshot = list.get(position);

        final Messages students = studentSnapshot.getValue(Messages.class);

        assert students != null;
        holder.messageText.setText(students.getMessage());

        String current_user_id = mAuth.getCurrentUser().getUid();
        String from_user = students.getFrom();

        if (from_user.equals(current_user_id)) {

            holder.messageText.setBackgroundResource(R.drawable.message_text_background1);
            holder.messageText.setTextColor(Color.BLACK);
            holder.messageText.setGravity(Gravity.END | Gravity.RIGHT);

        } else {

            holder.messageText.setBackgroundResource(R.drawable.message_text_background);
            holder.messageText.setTextColor(Color.WHITE);
            holder.messageText.setGravity(Gravity.START | Gravity.LEFT);

        }


    }

    @NonNull
    @Override
    public ChatActivity.MyAdapter.ViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {

        View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.message_single_layout, parent, false);

        return new ChatActivity.MyAdapter.ViewHolder(view);
    }

    public class ViewHolder extends RecyclerView.ViewHolder {

        TextView messageText;

        public ViewHolder(View itemView) {
            super(itemView);

            messageText = itemView.findViewById(R.id.user_single_message);

        }

    }

    @Override
    public int getItemCount() {
        return list.size();
    }
}


}

My xml layout

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="@color/lightgrey"
tools:context=".ChatActivity">

<android.support.v7.widget.RecyclerView
    android:id="@+id/messages_list"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:layout_above="@+id/text_layout">

</android.support.v7.widget.RecyclerView>

<LinearLayout
    android:id="@+id/text_layout"
    android:layout_width="match_parent"
    android:layout_height="50dp"
    android:orientation="horizontal"
    android:layout_alignParentBottom="true"
    android:weightSum="100">


    <ImageButton
        android:id="@+id/chat_add_btn"
        android:layout_width="0dp"
        android:layout_height="match_parent"
        android:layout_weight="20"
        android:background="@color/white"
        android:contentDescription="@string/image"
        android:src="@drawable/ic_add_black_24dp" />

    <EditText
        android:id="@+id/chat_message_view"
        android:layout_width="0dp"
        android:layout_height="match_parent"
        android:layout_gravity="center"
        android:layout_weight="60"
        android:background="@color/white"
        android:ems="10"
        android:hint="Send a message"
        android:inputType="none"
        android:paddingEnd="3dp"
        android:paddingStart="3dp"
        android:paddingTop="5dp"
        android:textSize="17sp" />

    <ImageButton
        android:id="@+id/chat_send_btn"
        android:layout_width="0dp"
        android:layout_height="match_parent"
        android:layout_weight="20"
        android:background="@color/white"
        android:contentDescription="@string/send"
        android:src="@drawable/ic_send_black_24dp" />


</LinearLayout>

</RelativeLayout>

Layout for recyclerview

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="wrap_content"
android:weightSum="1"
android:layout_height="wrap_content">

    <TextView
        android:layout_margin="15dp"
        android:id="@+id/user_single_message"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginBottom="5dp"
        android:padding="13dp"
        android:textColor="@color/white"
        android:background="@drawable/message_text_background"
        android:layout_marginStart="10dp"
        android:text="Message Text"
        android:textSize="15sp" />

</LinearLayout>

Answer 1

I had the same problem, I simply check if the current user id is the same as the message sender id and I solved changing the adapter like this:

@Override
public void onBindViewHolder(MessageHolder holder, final int position) {
     if (conversationList != null){
         if (conversationList.get(position).getMessageSenderId().equals(User.getId())) {
            holder.chatBubbleLeft.setVisibility(View.INVISIBLE);
            holder.chatBubbleRight.setVisibility(View.VISIBLE);
            holder.chatBubbleRight.setText(conversationList.get(position).getMessageText());
        } else {
            holder.chatBubbleRight.setVisibility(View.INVISIBLE);
            holder.chatBubbleLeft.setVisibility(View.VISIBLE);
            holder.chatBubbleLeft.setText(conversationList.get(position).getMessageText());
        }
    }
}

with this layout:

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:orientation="vertical">
        <TextView
            android:id="@+id/text_view_chat_bubble_left"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginTop="5dp"
            android:layout_marginEnd="25dp"
            android:background="@drawable/bubble_left"
            android:gravity="start"
            android:paddingBottom="5dp"
            android:paddingEnd="10dp"
            android:paddingStart="10dp"
            android:paddingTop="5dp"
            android:textAlignment="textStart"
            android:textAppearance="?android:attr/textAppearanceSmall"
            android:textColor="@color/black"
            android:textSize="18sp"
            android:visibility="gone" />
        <TextView
            android:id="@+id/text_view_chat_bubble_right"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_alignParentEnd="true"
            android:layout_alignParentTop="true"
            android:layout_marginTop="5dp"
            android:layout_marginStart="25dp"
            android:background="@drawable/bubble_right"
            android:gravity="start"
            android:paddingBottom="5dp"
            android:paddingEnd="10dp"
            android:paddingStart="10dp"
            android:paddingTop="5dp"
            android:textAlignment="textStart"
            android:textAppearance="?android:attr/textAppearanceSmall"
            android:textColor="@color/black"
            android:textSize="18sp"
            android:visibility="gone" />
</RelativeLayout>