MyChitChat

activity_main.xml
===================
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical">

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="horizontal">

        <EditText
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:hint="enter your msg"
            android:layout_weight="1"
            android:id="@+id/txtMsg"/>
        <Button
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_weight="3"
            android:text="send"
            android:background="#009fff"
            android:textColor="#fff"
            android:textSize="22sp"
            android:id="@+id/btnSend"/>
    </LinearLayout>
    <ListView
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:id="@+id/lstMsg"
        android:layout_weight="1"/>
    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="horizontal">
        <EditText
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:hint="enter user name"
            android:layout_weight="1"
            android:id="@+id/txtUserName"/>
        <Button
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_weight="2"
            android:text="add"
            android:background="#009fff"
            android:textColor="#fff"
            android:textSize="16sp"
            android:id="@+id/btnAddUser"
            android:layout_margin="3dp"/>
        <Button
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_weight="2"
            android:text="list"
            android:background="#009fff"
            android:textColor="#fff"
            android:textSize="16sp"
            android:id="@+id/btnUserList"
            android:layout_margin="3dp"/>
    </LinearLayout>
</LinearLayout>


MainActivity.java
=====================
package com.example.hackeru.mychitchat;

import android.content.Context;
import android.support.annotation.NonNull;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.EditText;
import android.widget.ListView;
import android.widget.Toast;

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.List;
import java.util.UUID;

public class MainActivity extends AppCompatActivity {

    ListView myMsgList;
    EditText myMsg,txtUser;
    Context context;
    List<String> msgList;
    final String REF_ID="message";

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        setPointer();
        setMessageListener();
    }


    private void setPointer() {
        this.context=this;
        msgList=new ArrayList<>();
        txtUser=findViewById(R.id.txtUserName);
        myMsg=findViewById(R.id.txtMsg);
        myMsgList=findViewById(R.id.lstMsg);
        findViewById(R.id.btnSend).setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                sendMessage();
            }
        });
        findViewById(R.id.btnAddUser).setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                addUser();
            }
        });
        findViewById(R.id.btnUserList).setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                getUserList();
            }
        });
    }

    private void getUserList() {
        //creating instance to the database
        FirebaseDatabase database=FirebaseDatabase.getInstance();
        //creating a reference to the database
        DatabaseReference userRef = database.getReference("Users");
        //adding an event listener for getting the information back
        userRef.addListenerForSingleValueEvent(new ValueEventListener() {
            @Override
            public void onDataChange(@NonNull DataSnapshot dataSnapshot) {
                //moving on entire data that we recived from the database
                String allUsers="";
                for (DataSnapshot item:dataSnapshot.getChildren())
                {
                    //get a single value, and add to our string.
                    Users reciviedUser = item.getValue(Users.class);
                    allUsers+=reciviedUser.userName+" ";
                }
                Toast.makeText(context, allUsers, Toast.LENGTH_LONG).show();
                Log.e("Immanual", "onDataChange: "+allUsers );
            }

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

            }
        });
    }

    private void addUser() {
        String userName = txtUser.getText().toString();
        txtUser.setText("");
        Users user = new Users(userName, UUID.randomUUID().toString(),"12345","HackerU");
        user.saveData();

    }

    private void sendMessage() {
        String msg = myMsg.getText().toString();
        myMsg.setText("");
        //fire base will give us singleton of his instance

        //creating an instance to the database
        FirebaseDatabase database = FirebaseDatabase.getInstance();
        //creating a referance to message object
        DatabaseReference msgRef = database.getReference(REF_ID);
        //set value to the database
        msgRef.setValue(msg);
    }

    private void setMessageListener() {
        //create an instance to the database
        FirebaseDatabase database = FirebaseDatabase.getInstance();
        //create a referance to the database
        DatabaseReference msgRef = database.getReference(REF_ID);
        //create an event listner with callback to our Reference
        msgRef.addValueEventListener(new ValueEventListener() {
            @Override
            public void onDataChange(@NonNull DataSnapshot dataSnapshot) {
                //this method is called once with the initial value and again
                //whenever data at this location is updated
                String value=dataSnapshot.getValue(String.class);
                msgList.add(0,value);
                ChatAdapter myAdapter = new ChatAdapter(context,msgList);
                myMsgList.setAdapter(myAdapter);
            }

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

            }
        });
    }

}


Users.java
================
package com.example.hackeru.mychitchat;

import android.net.Uri;
import android.util.Log;

import com.google.android.gms.tasks.OnSuccessListener;
import com.google.firebase.database.DatabaseReference;
import com.google.firebase.database.FirebaseDatabase;
import com.google.firebase.storage.FirebaseStorage;
import com.google.firebase.storage.StorageReference;
import com.google.firebase.storage.UploadTask;

import java.io.File;

public class Users {

    public String userName;
    public String userId;
    public String userPass;
    public String userLocation;
    public String userImg;

    public Users(String userName, String userId, String userPass, String userLocation) {
        this.userName = userName;
        this.userId = userId;
        this.userPass = userPass;
        this.userLocation=userLocation;
    }

    public Users(){}

    public void saveData(String uri)
    {
        if (uri==null){
            uri="";
        }
        //create connection blat
        FirebaseDatabase database = FirebaseDatabase.getInstance();
        DatabaseReference userRef = database.getReference("Users");
        Users savedUser = new Users(this.userName,this.userId,this.userPass,this.userLocation);
        savedUser.userImg=uri;
        //save the data
        userRef.child(userId).setValue(savedUser);
    }

    public void savePic(String fileLocation, String folder)
    {
        //check if bucket exists in GCS, if not create one with S3
        StorageReference storageReference = FirebaseStorage.getInstance().getReference();
        //create the file in the memory.
        Uri file = Uri.fromFile(new File(fileLocation));
        //ref to the folder (bucket)
        final StorageReference fileRef = storageReference.child(folder);
        //let's put the file in the bucket.
        fileRef.putFile(file).addOnSuccessListener(new OnSuccessListener<UploadTask.TaskSnapshot>() {
            @Override
            public void onSuccess(UploadTask.TaskSnapshot taskSnapshot) {
                fileRef.getDownloadUrl().addOnSuccessListener(new OnSuccessListener<Uri>() {
                    @Override
                    public void onSuccess(Uri uri) {
                        Uri downloadURL = uri;
                        Log.e("FireBase", "onSuccess: "+downloadURL);
                        //https://firebasestorage.googleapis.com/v0/b/mychitchat-4a003.appspot.com/o/Moti%2Fimg.jpg?alt=media&token=8d1e1061-ced8-4eeb-9acd-d77243445b27
                        saveData(uri.toString());
                    }
                });
            }
        });

    }
}


ChatAdapter.java
==================
package com.example.hackeru.mychitchat;

import android.content.Context;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.TextView;

import java.util.List;

public class ChatAdapter extends BaseAdapter {
    Context context;
    List<String> msgList;

    public ChatAdapter(Context context, List<String> msgList) {
        this.context = context;
        this.msgList = msgList;
    }

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

    @Override
    public Object getItem(int position) {
        return null;
    }

    @Override
    public long getItemId(int position) {
        return 0;
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        TextView txt = new TextView(context);
        txt.setText(msgList.get(position));
        return txt;
    }
}