🔥 🔐 FIREBASE AUTHENTICATION

FEATURES OF FIREBASE.

Firebase comes with bunch features essential for every android app starting from authentication to hosting the app.

Below are the advantages using Firebase in general:

• Super easy and quick to implement.

• No server side configuration needed. No PHP Scripts and No Database Designs.

• Realtime update without using GCM.

• Autoscaling built-in

• Can start for free (only need to start paying once we hit 50 connections)

• Robust APIs for Javascript (including several frameworks like Angular), iOS, and Android

• Built-in support for authentication services like Facebook, Google, and Twitter

• Declarative Security Rules model allows us to enforce read/write privileges and data validation throughout the tree

ENABLING FIREBASE AUTH

To checkout this on a blog use this Link for a much clearer view. 👉 Click here 😄

1. First thing you need to do is go to https://firebase.google.com/ and make an account to gain access to their console. After you gain access to the console you can start by creating your first project.

• Give your project a name of your choice.

2. Next go to your project dashboard. Find the Auth and click get started. Go to set up sign in method and choose Email & Password and enable it.

3. We need to now add Firebase to our android app so go to the project overview section and choose android.

3. Give the package name of your project (mine is com.zecolloauth.zecolloauth) in which you are going to integrate the Firebase.

4. Here the google-services.json file will be downloaded.

5. Switch to the Project view in Android Studio to see your project root directory. Move the google-services.json file you just downloaded into your Android app module app/src/main root directory.

CREATING ANDROID PROJECT

As we work here you can compare some section of your code with my Repository incase you get stuck!

Reposiory Link 👉 https://github.com/zecollokaris/FireBase-Authentication-Tutorial/tree/USE-This-Demo

1. Create a new project in Android Studio from File ⇒ New Project. When it prompts you to select the default activity, select Blank Activity and proceed.

While filling the project details, use the same package name which you gave in firebase console. In my case I am using same com.zecolloauth.zecolloauth.

2. Open AndroidManifest.xml and add the INTERNET permission as we need to make network calls and change the theme to NoActionBar

AndroidManifest.xml

<uses-permission android:name="android.permission.INTERNET" />

Now change the theme to @style/Theme.AppCompat.Light.NoActionBar

AndroidManifest.xml

    <application
        android:theme="@style/Theme.AppCompat.Light.NoActionBar">

3. Confirm that you had added the google-services.json file to your project’s app folder. This step is very important as your project won’t build without this file.

4. Now open the build.gradle located in project’s home directory and add firebase dependency.

build.gradle

    dependencies {
        classpath 'com.android.tools.build:gradle:3.1.1'
        classpath 'com.google.gms:google-services:4.2.0'
        

        // NOTE: Do not place your application dependencies here; they belong
        // in the individual module build.gradle files
    }

5. Open app/build.gradle and add firebase auth dependency. At the very bottom of the file, add apply plugin: ‘com.google.gms.google-services’

app/build.gradle

dependencies {
    implementation 'com.google.firebase:firebase-auth:9.0.2'
}
 
apply plugin: 'com.google.gms.google-services'

6. Add the below resources to **dimens.xml, colors.xml, strings.xml and string.xml **. These resources doesn’t require for firebase, but for this demo.

dimens.xml

<resources>
    <!-- Default screen margins, per the Android Design guidelines. -->
    <dimen name="activity_horizontal_margin">16dp</dimen>
    <dimen name="activity_vertical_margin">16dp</dimen>
    <dimen name="fab_margin">16dp</dimen>
    <dimen name="logo_w_h">100dp</dimen>
</resources>

colors.xml

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <color name="colorPrimary">#00bcd4</color>
    <color name="colorPrimaryDark">#0097a7</color>
    <color name="colorAccent">#f2fe71</color>

    <color name="white">#ffffff</color>
    <color name="colorRed">#EB3349</color>
    <color name="colorPink">#FF4081</color>
    <color name="colorTransparentPink">#FF9EA1</color>

    <color name="colorWhite">#FFFFFF</color>
    <color name="colorTransparentWhite">#cccccc</color>
    <color name="colorStandardBlack">#262626</color>
    <color name="colorDarkBlue">#001621</color>
    <color name="colorCyanBlue">#0B9BE2</color>
    <color name="colorMidBlue">#032B3F</color>
    <color name="colorCoinBackground">#01242b</color>
</resources>

strings.xml

<resources>
    <string name="app_name">Firebase Auth</string>
    <string name="action_sign_in_short">REGISTER</string>
    <string name="email">Email</string>
    <string name="minimum_password">Password too short, enter minimum 6 characters!</string>
    <string name="auth_failed">Authentication failed, check your email and password or sign up</string>
    <string name="change_email">Change Email</string>
    <string name="change_password">Change Password</string>
    <string name="send_password_reset_email">Send Password reset email</string>
    <string name="remove_user">Remove user</string>
    <string name="new_pass">New Password</string>
    <string name="title_activity_profile">Firebase</string>
    <string name="title_activity_login">Sign in</string>
    <string name="hint_email">Email</string>
    <string name="hint_password">Password</string>
    <string name="hint_name">Fullname</string>
    <string name="btn_login">LOGIN</string>
    <string name="btn_link_to_register">Not a member? Get registered in Firebase now!</string>
    <string name="btn_link_to_login">Already registered. Login Me!</string>
    <string name="title_activity_reset_password">ResetPasswordActivity</string>
    <string name="btn_forgot_password">Forgot your password?</string>
    <string name="btn_reset_password">RESET PASSWORD</string>
    <string name="btn_back"><![CDATA[<< Back]]></string>
    <string name="hint_new_email">New Email</string>
    <string name="btn_change">Change</string>
    <string name="btn_send">Send</string>
    <string name="btn_remove">Remove</string>
    <string name="btn_sign_out">Sign Out</string>
    <string name="lbl_forgot_password">Forgot password?</string>
    <string name="forgot_password_msg">We just need your registered Email Id to sent you password reset instructions.</string>
    <string name="settings_name">Account Settings</string>
</resources>

styles.xml

<resources>

    <!-- Base application theme. -->
    <style name="AppTheme" parent="Theme.AppCompat.Light.DarkActionBar">
        <item name="android:background">@color/white</item>
    </style>

    <!--Toolbar theme-->
    <style name="CustomToolbarStyle" parent="Theme.AppCompat.Light.NoActionBar">
        <item name="android:background">@color/white</item>
    </style>

    <!--Menu Item Theme-->
    <style name="CustomPopupStyle" parent="Theme.AppCompat.Light.NoActionBar">
        <item name="android:background">@color/white</item>
        <item name="overlapAnchor">false</item>
        <item name="android:dropDownVerticalOffset">-4dp</item>
    </style>

    <!--Input Theme-->
    <style name="CustomInputStyle" parent="Theme.AppCompat.Light.NoActionBar">
        <item name="android:background">@color/colorStandardBlack</item>
        <item name="android:theme">@color/colorDarkBlue</item>
    </style>

</resources>

7. Create a new layout file in the drawable folder app/src/main/res/drawable/ named roundbutton.xml

roundbutton.xml

<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android"
    android:shape="rectangle">
    <solid android:color="@color/colorRed"/>
    <corners android:radius="150dp"/>

</shape>

Now we have the project ready with all the dependencies added. Let’s start by adding the sign up screen.

SIGNUP WITH EMAIL & PASSWORD.

1. Create an activity named ResetPasswordActivity.java and add the following code to the layout file activity_reset_password.xml

activity_reset_password.xml

<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout 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"
    tools:context=".MainActivity">

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Everything Works Okay!"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

</android.support.constraint.ConstraintLayout>

2. Create an activity named SignupActivity.java and add the following code to the layout file activity_signup.xml

activity_signup.xml

<?xml version="1.0" encoding="utf-8"?>
<android.support.design.widget.CoordinatorLayout 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:fitsSystemWindows="true"
    tools:context=".LoginActivity">

    <LinearLayout
        android:layout_width="fill_parent"
        android:layout_height="fill_parent"
        android:background="@color/colorWhite"
        android:gravity="center"
        android:orientation="vertical"
        android:padding="@dimen/activity_horizontal_margin">


        <ImageView
            android:layout_width="@dimen/logo_w_h"
            android:layout_height="@dimen/logo_w_h"
            android:layout_gravity="center_horizontal"
            android:layout_marginBottom="30dp"
            android:src="@drawable/knight"/>

        <android.support.design.widget.TextInputLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            app:passwordToggleEnabled="true"
            android:textColorHint="@color/colorPink">

            <EditText
                android:id="@+id/email"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:layout_marginBottom="10dp"
                android:hint="@string/hint_email"
                android:drawableLeft="@drawable/email"
                android:drawablePadding="10dp"
                app:fontFamily="@font/poiretoneregular"
                android:inputType="textEmailAddress"
                android:textColor="@color/colorTransparentPink"
                android:theme="@style/CustomInputStyle"/>
        </android.support.design.widget.TextInputLayout>

        <android.support.design.widget.TextInputLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            app:passwordToggleEnabled="true"
            android:textColorHint="@color/colorPink">

            <EditText
                android:id="@+id/password"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:layout_marginBottom="10dp"
                android:drawableLeft="@drawable/key"
                android:drawablePadding="12dp"
                android:ems="20"
                android:hint="@string/hint_password"
                app:fontFamily="@font/poiretoneregular"
                android:inputType="textPassword"
                android:textColor="@color/colorTransparentPink"
                android:theme="@style/CustomInputStyle"/>
        </android.support.design.widget.TextInputLayout>

        <!-- Login Button -->

        <Button
            android:id="@+id/btn_login"
            android:layout_width="fill_parent"
            android:layout_height="wrap_content"
            android:layout_marginTop="30dp"
            app:fontFamily="@font/josefinslabbold"
            android:background="@drawable/roundbutton"
            android:text="@string/btn_login"
            android:textColor="@color/colorTransparentWhite" />

        <Button
            android:id="@+id/btn_reset_password"
            android:layout_width="fill_parent"
            android:layout_height="wrap_content"
            android:layout_marginTop="10dp"
            android:background="@null"
            android:text="@string/btn_forgot_password"
            android:textAllCaps="false"
            app:fontFamily="@font/josefinslabitalic"
            android:textColor="@color/colorPink" />

        <!-- Link to Login Screen -->

        <Button
            android:id="@+id/btn_signup"
            android:layout_width="fill_parent"
            android:layout_height="wrap_content"
            android:layout_marginTop="10dp"
            android:background="@null"
            android:text="@string/btn_link_to_register"
            android:textAllCaps="false"
            android:textColor="@color/colorPink"
            app:fontFamily="@font/josefinslabbold"
            android:textSize="15dp"/>
    </LinearLayout>

    <ProgressBar
        android:id="@+id/progressBar"
        android:layout_width="30dp"
        android:layout_height="30dp"
        android:layout_gravity="center|bottom"
        android:layout_marginBottom="20dp"
        android:visibility="gone" />
</android.support.design.widget.CoordinatorLayout>

3. Open SignupActivity.java and add the following. Firebase provides createUserWithEmailAndPassword() method to create a new user with email and password data.

SignupActivity.java

package com.zecolloauth.zecolloauth;

import android.content.Intent;
import android.os.Bundle;
import android.support.annotation.NonNull;
import android.support.v7.app.AppCompatActivity;
import android.text.TextUtils;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.ProgressBar;
import android.widget.Toast;

import com.google.android.gms.tasks.OnCompleteListener;
import com.google.android.gms.tasks.Task;
import com.google.firebase.auth.AuthResult;
import com.google.firebase.auth.FirebaseAuth;

public class SignupActivity extends AppCompatActivity {

    private EditText inputEmail, inputPassword;
    private Button btnSignIn, btnSignUp, btnResetPassword;
    private ProgressBar progressBar;
    private FirebaseAuth auth;

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

        //Get Firebase auth instance
        auth = FirebaseAuth.getInstance();

        btnSignIn = (Button) findViewById(R.id.sign_in_button);
        btnSignUp = (Button) findViewById(R.id.sign_up_button);
        inputEmail = (EditText) findViewById(R.id.email);
        inputPassword = (EditText) findViewById(R.id.password);
        progressBar = (ProgressBar) findViewById(R.id.progressBar);
        btnResetPassword = (Button) findViewById(R.id.btn_reset_password);

        btnResetPassword.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                startActivity(new Intent(SignupActivity.this, ResetPasswordActivity.class));
            }
        });

        btnSignIn.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                finish();
            }
        });

        btnSignUp.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {

                String email = inputEmail.getText().toString().trim();
                String password = inputPassword.getText().toString().trim();

                if (TextUtils.isEmpty(email)) {
                    Toast.makeText(getApplicationContext(), "Enter email address!", Toast.LENGTH_SHORT).show();
                    return;
                }

                if (TextUtils.isEmpty(password)) {
                    Toast.makeText(getApplicationContext(), "Enter password!", Toast.LENGTH_SHORT).show();
                    return;
                }

                if (password.length() < 6) {
                    Toast.makeText(getApplicationContext(), "Password too short, enter minimum 6 characters!", Toast.LENGTH_SHORT).show();
                    return;
                }

                progressBar.setVisibility(View.VISIBLE);
                //create user
                auth.createUserWithEmailAndPassword(email, password)
                        .addOnCompleteListener(SignupActivity.this, new OnCompleteListener<AuthResult>() {
                            @Override
                            public void onComplete(@NonNull Task<AuthResult> task) {
                                Toast.makeText(SignupActivity.this, "createUserWithEmail:onComplete:" + task.isSuccessful(), Toast.LENGTH_SHORT).show();
                                progressBar.setVisibility(View.GONE);
                                // If sign in fails, display a message to the user. If sign in succeeds
                                // the auth state listener will be notified and logic to handle the
                                // signed in user can be handled in the listener.
                                if (!task.isSuccessful()) {
                                    Toast.makeText(SignupActivity.this, "Authentication failed." + task.getException(),
                                            Toast.LENGTH_SHORT).show();
                                } else {
                                    startActivity(new Intent(SignupActivity.this, MainActivity.class));
                                    finish();
                                }
                            }
                        });

            }
        });
    }

    @Override
    protected void onResume() {
        super.onResume();
        progressBar.setVisibility(View.GONE);
    }
}

4. Before we run the application confirm your dependencies in app/build.gradle are as follows.

dependencies {
    implementation fileTree(dir: 'libs', include: ['*.jar'])
    implementation 'com.android.support:appcompat-v7:27.0.0'
    implementation 'com.android.support:design:27.1.0'
    implementation 'com.android.support.constraint:constraint-layout:1.1.3'
    testImplementation 'junit:junit:4.12'
    androidTestImplementation 'com.android.support.test:runner:1.0.2'
    androidTestImplementation 'com.android.support.test.espresso:espresso-core:3.0.2'
    implementation 'com.google.firebase:firebase-auth:9.0.2'
}

apply plugin: 'com.google.gms.google-services'

5. Open AndroidManifest.xml and make SignupActivity as launcher activity (temporarily) and test the sign up.

If you login to Firebase console, you can see the user created with the email id you have given the android app.

LOGIN WITH EMAIL & PASSWORD!

Now we’ll add the login screen and check the credentials we have created on sign up screen.

1. Create another activity named LoginActivity.java and add the below code to its layout file activity_login.xml.

activity_login.xml

<?xml version="1.0" encoding="utf-8"?>
<android.support.design.widget.CoordinatorLayout 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:fitsSystemWindows="true"
    tools:context=".LoginActivity">

    <LinearLayout
        android:layout_width="fill_parent"
        android:layout_height="fill_parent"
        android:background="@color/colorWhite"
        android:gravity="center"
        android:orientation="vertical"
        android:padding="@dimen/activity_horizontal_margin">


        <ImageView
            android:layout_width="@dimen/logo_w_h"
            android:layout_height="@dimen/logo_w_h"
            android:layout_gravity="center_horizontal"
            android:layout_marginBottom="30dp"
            android:src="@drawable/knight"/>

        <android.support.design.widget.TextInputLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            app:passwordToggleEnabled="true"
            android:textColorHint="@color/colorPink">

            <EditText
                android:id="@+id/email"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:layout_marginBottom="10dp"
                android:hint="@string/hint_email"
                android:drawableLeft="@drawable/email"
                android:drawablePadding="10dp"
                app:fontFamily="@font/poiretoneregular"
                android:inputType="textEmailAddress"
                android:textColor="@color/colorTransparentPink"
                android:theme="@style/CustomInputStyle"/>
        </android.support.design.widget.TextInputLayout>

        <android.support.design.widget.TextInputLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            app:passwordToggleEnabled="true"
            android:textColorHint="@color/colorPink">

            <EditText
                android:id="@+id/password"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:layout_marginBottom="10dp"
                android:drawableLeft="@drawable/key"
                android:drawablePadding="12dp"
                android:ems="20"
                android:hint="@string/hint_password"
                app:fontFamily="@font/poiretoneregular"
                android:inputType="textPassword"
                android:textColor="@color/colorTransparentPink"
                android:theme="@style/CustomInputStyle"/>
        </android.support.design.widget.TextInputLayout>

        <!-- Login Button -->

        <Button
            android:id="@+id/btn_login"
            android:layout_width="fill_parent"
            android:layout_height="wrap_content"
            android:layout_marginTop="30dp"
            app:fontFamily="@font/josefinslabbold"
            android:background="@drawable/roundbutton"
            android:text="@string/btn_login"
            android:textColor="@color/colorTransparentWhite" />

        <Button
            android:id="@+id/btn_reset_password"
            android:layout_width="fill_parent"
            android:layout_height="wrap_content"
            android:layout_marginTop="10dp"
            android:background="@null"
            android:text="@string/btn_forgot_password"
            android:textAllCaps="false"
            app:fontFamily="@font/josefinslabitalic"
            android:textColor="@color/colorPink" />

        <!-- Link to Login Screen -->

        <Button
            android:id="@+id/btn_signup"
            android:layout_width="fill_parent"
            android:layout_height="wrap_content"
            android:layout_marginTop="10dp"
            android:background="@null"
            android:text="@string/btn_link_to_register"
            android:textAllCaps="false"
            android:textColor="@color/colorPink"
            app:fontFamily="@font/josefinslabbold"
            android:textSize="15dp"/>
    </LinearLayout>

    <ProgressBar
        android:id="@+id/progressBar"
        android:layout_width="30dp"
        android:layout_height="30dp"
        android:layout_gravity="center|bottom"
        android:layout_marginBottom="20dp"
        android:visibility="gone" />
</android.support.design.widget.CoordinatorLayout>

2. Open LoginActivity.java and do the below changes. Firebase provides signInWithEmailAndPassword() method to sign in the user.

LoginActivity.java

package com.zecolloauth.zecolloauth;

import android.content.Intent;
import android.os.Bundle;
import android.support.annotation.NonNull;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.Toolbar;
import android.text.TextUtils;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.ProgressBar;
import android.widget.Toast;
 
import com.google.android.gms.tasks.OnCompleteListener;
import com.google.android.gms.tasks.Task;
import com.google.firebase.auth.AuthResult;
import com.google.firebase.auth.FirebaseAuth;
 
public class LoginActivity extends AppCompatActivity {
 
    private EditText inputEmail, inputPassword;
    private FirebaseAuth auth;
    private ProgressBar progressBar;
    private Button btnSignup, btnLogin, btnReset;
 
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
 
        //Get Firebase auth instance
        auth = FirebaseAuth.getInstance();
 
        if (auth.getCurrentUser() != null) {
            startActivity(new Intent(LoginActivity.this, MainActivity.class));
            finish();
        }
 
        // set the view now
        setContentView(R.layout.activity_login);
 
        // Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
        // setSupportActionBar(toolbar);
 
        inputEmail = (EditText) findViewById(R.id.email);
        inputPassword = (EditText) findViewById(R.id.password);
        progressBar = (ProgressBar) findViewById(R.id.progressBar);
        btnSignup = (Button) findViewById(R.id.btn_signup);
        btnLogin = (Button) findViewById(R.id.btn_login);
        btnReset = (Button) findViewById(R.id.btn_reset_password);
 
        //Get Firebase auth instance
        auth = FirebaseAuth.getInstance();
 
        btnSignup.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                startActivity(new Intent(LoginActivity.this, SignupActivity.class));
            }
        });
 
        btnReset.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                startActivity(new Intent(LoginActivity.this, ResetPasswordActivity.class));
            }
        });
 
        btnLogin.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                String email = inputEmail.getText().toString();
                final String password = inputPassword.getText().toString();
 
                if (TextUtils.isEmpty(email)) {
                    Toast.makeText(getApplicationContext(), "Enter email address!", Toast.LENGTH_SHORT).show();
                    return;
                }
 
                if (TextUtils.isEmpty(password)) {
                    Toast.makeText(getApplicationContext(), "Enter password!", Toast.LENGTH_SHORT).show();
                    return;
                }
 
                progressBar.setVisibility(View.VISIBLE);
 
                //authenticate user
                auth.signInWithEmailAndPassword(email, password)
                        .addOnCompleteListener(LoginActivity.this, new OnCompleteListener<AuthResult>() {
                            @Override
                            public void onComplete(@NonNull Task<AuthResult> task) {
                                // If sign in fails, display a message to the user. If sign in succeeds
                                // the auth state listener will be notified and logic to handle the
                                // signed in user can be handled in the listener.
                                progressBar.setVisibility(View.GONE);
                                if (!task.isSuccessful()) {
                                    // there was an error
                                    if (password.length() < 6) {
                                        inputPassword.setError(getString(R.string.minimum_password));
                                    } else {
                                        Toast.makeText(LoginActivity.this, getString(R.string.auth_failed), Toast.LENGTH_LONG).show();
                                    }
                                } else {
                                    Intent intent = new Intent(LoginActivity.this, MainActivity.class);
                                    startActivity(intent);
                                    finish();
                                }
                            }
                        });
            }
        });
    }
}

3. Open AndroidManifest.xml and make the LoginActivity.java as launcher activity to make the login screen as first screen.

• Run the project and login with the credentials which you used while signing up.

RESET PASSWORD!

We shall try sending reset password email when required. This is a very difficult task if you want to have your own email server.

1. We had already created an activity named ResetPasswordActivity.java previously. Add the code below to its layout file and class.

activity_reset_password.xml

<?xml version="1.0" encoding="utf-8"?>
<android.support.design.widget.CoordinatorLayout 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:layout_gravity="center"
    android:background="@color/colorTransparentWhite"
    android:fitsSystemWindows="true"
    tools:context=".ResetPasswordActivity">

    <LinearLayout
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:layout_marginTop="30dp"
        android:gravity="center"
        android:orientation="vertical"
        android:padding="@dimen/activity_horizontal_margin">


        <ImageView
            android:layout_width="@dimen/logo_w_h"
            android:layout_height="@dimen/logo_w_h"
            android:layout_gravity="center_horizontal"
            android:layout_marginBottom="10dp"
            android:src="@drawable/knight" />

        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_gravity="center_horizontal"
            android:padding="10dp"
            android:text="@string/lbl_forgot_password"
            android:textColor="@color/colorPink"
            app:fontFamily="@font/josefinslabbold"
            android:textSize="20dp" />

        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginBottom="10dp"
            android:gravity="center_horizontal"
            android:padding="@dimen/activity_horizontal_margin"
            android:text="@string/forgot_password_msg"
            android:textColor="@color/colorPink"
            app:fontFamily="@font/josefinslabitalic"
            android:textSize="14dp" />

        <android.support.design.widget.TextInputLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content">

            <EditText
                android:id="@+id/email"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:drawableLeft="@drawable/email"
                android:drawablePadding="10dp"
                android:layout_marginBottom="10dp"
                android:layout_marginTop="20dp"
                android:hint="@string/hint_email"
                app:fontFamily="@font/poiretoneregular"
                android:inputType="textEmailAddress"
                android:textColor="@color/colorTransparentPink"
                android:textColorHint="@android:color/white" />
        </android.support.design.widget.TextInputLayout>

        <!-- Login Button -->

        <Button
            android:id="@+id/btn_reset_password"
            android:layout_width="fill_parent"
            android:layout_height="wrap_content"
            android:layout_marginTop="30dp"
            app:fontFamily="@font/josefinslabbold"
            android:background="@drawable/roundbutton"
            android:text="@string/btn_reset_password"
            android:textColor="@color/colorTransparentWhite"  />

        <Button
            android:id="@+id/btn_back"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginTop="10dp"
            android:background="@null"
            android:text="@string/btn_back"
            android:textColor="@color/colorPink"
            app:fontFamily="@font/josefinslabbold" />

    </LinearLayout>

    <ProgressBar
        android:id="@+id/progressBar"
        android:layout_width="30dp"
        android:layout_height="30dp"
        android:layout_gravity="center|bottom"
        android:layout_marginBottom="20dp"
        android:visibility="gone" />
</android.support.design.widget.CoordinatorLayout>

2. Open ResetPasswordActivity.java add the below code. You can use sendPasswordResetEmail() method to send the password reset email.

ResetPasswordActivity.java

package com.zecolloauth.zecolloauth;

import android.os.Bundle;
import android.support.annotation.NonNull;
import android.support.v7.app.AppCompatActivity;
import android.text.TextUtils;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.ProgressBar;
import android.widget.Toast;
 
import com.google.android.gms.tasks.OnCompleteListener;
import com.google.android.gms.tasks.Task;
import com.google.firebase.auth.FirebaseAuth;
 
public class ResetPasswordActivity extends AppCompatActivity {
 
    private EditText inputEmail;
    private Button btnReset, btnBack;
    private FirebaseAuth auth;
    private ProgressBar progressBar;
 
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_reset_password);
 
        inputEmail = (EditText) findViewById(R.id.email);
        btnReset = (Button) findViewById(R.id.btn_reset_password);
        btnBack = (Button) findViewById(R.id.btn_back);
        progressBar = (ProgressBar) findViewById(R.id.progressBar);
 
        auth = FirebaseAuth.getInstance();
 
        btnBack.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                finish();
            }
        });
 
        btnReset.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
 
                String email = inputEmail.getText().toString().trim();
 
                if (TextUtils.isEmpty(email)) {
                    Toast.makeText(getApplication(), "Enter your registered email id", Toast.LENGTH_SHORT).show();
                    return;
                }
 
                progressBar.setVisibility(View.VISIBLE);
                auth.sendPasswordResetEmail(email)
                        .addOnCompleteListener(new OnCompleteListener<Void>() {
                            @Override
                            public void onComplete(@NonNull Task<Void> task) {
                                if (task.isSuccessful()) {
                                    Toast.makeText(ResetPasswordActivity.this, "We have sent you instructions to reset your password!", Toast.LENGTH_SHORT).show();
                                } else {
                                    Toast.makeText(ResetPasswordActivity.this, "Failed to send reset email!", Toast.LENGTH_SHORT).show();
                                }
 
                                progressBar.setVisibility(View.GONE);
                            }
                        });
            }
        });
    }
 
}

Here is the password reset email user will receive.

ADD TOOLBAR WITH ACCOUNT SETTINGS

1. Create a new layout file named app_bar in app/src/main/res/layout/ and change it root element to android.support.v7.widget.Toolbar

2. Add custom theme to a tool bar we shall create.

app_bar.xml

<?xml version="1.0" encoding="utf-8"?>
<android.support.v7.widget.Toolbar xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    app:theme="@style/CustomToolbarStyle"
    app:popupTheme="@style/CustomPopupStyle">
</android.support.v7.widget.Toolbar>

1. Create another activity named AccountActivity.java and add the below code to its layout file activity_account.xml.

activity_account.xml

<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout 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"
    tools:context=".AccountActivity">

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Welcome to Accounts Department!"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

</android.support.constraint.ConstraintLayout>

3. In the MainActivity class we shall create a toolbar and menu to change to a new activity.

activity_main

<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout 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"
    tools:context=".MainActivity">

    <include
        layout="@layout/app_bar"
        android:id="@+id/app_bar">
    </include>

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Hello World!"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

</android.support.constraint.ConstraintLayout>

MainActivity.java

package com.zecolloauth.zecolloauth;

import android.content.Intent;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.support.v7.widget.Toolbar;
import android.view.Menu;
import android.view.MenuInflater;
import android.view.MenuItem;

public class MainActivity extends AppCompatActivity {

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

        Toolbar toolbar = (Toolbar) findViewById(R.id.app_bar);
        setSupportActionBar(toolbar);
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        MenuInflater inflater = getMenuInflater();
        inflater.inflate(R.menu.menu, menu);
        return super.onCreateOptionsMenu(menu);
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        switch (item.getItemId())
        {
            case R.id.action_setting:
            //settings

                Intent settings = new Intent(this, AccountActivity.class);
                startActivity(settings);
                break;

            default:
            // select an option

        }
        return super.onOptionsItemSelected(item);
    }
}

4. Create another new layout file named menu.xml which will hold the menu widget with the account setting option.

menu.xml

<?xml version="1.0" encoding="utf-8"?>
<menu xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto">
<item
    android:id="@+id/action_setting"
    android:title="@string/settings_name"
    app:showAsAction= "never">
</item>
</menu>

• Run the project and you will get a menu icon which contains an Accounts Setting option.

• Once you click on the option it will launch the AccountsActivity

ACCOUNT SETTING - PUT ALL TOGETHER

1. Now we’ll keep all the above functionalities in main activity and make fully functional app. Open the layout file of Account activity activity_account.xml and add the below layout code.

activity_account.xml

<?xml version="1.0" encoding="utf-8"?>
<android.support.design.widget.CoordinatorLayout 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"
    tools:context=".AccountActivity"
    android:id="@+id/main_layout">

    <android.support.design.widget.AppBarLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        app:elevation="0dp">

        <android.support.v7.widget.Toolbar
            android:id="@+id/toolbar"
            android:layout_width="match_parent"
            android:layout_height="?attr/actionBarSize"
            android:background="@color/colorPink" />

    </android.support.design.widget.AppBarLayout>

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="vertical"
        android:paddingBottom="@dimen/activity_vertical_margin"
        android:paddingLeft="@dimen/activity_horizontal_margin"
        android:paddingRight="@dimen/activity_horizontal_margin"
        android:paddingTop="@dimen/activity_vertical_margin"
        app:layout_behavior="@string/appbar_scrolling_view_behavior">

        <EditText
            android:id="@+id/old_email"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:hint="@string/hint_email"
            android:inputType="textEmailAddress"
            android:maxLines="1"
            android:singleLine="true" />

        <EditText
            android:id="@+id/new_email"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:hint="@string/hint_new_email"
            android:inputType="textEmailAddress"
            android:maxLines="1"
            android:singleLine="true" />

        <EditText
            android:id="@+id/password"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:focusableInTouchMode="true"
            android:hint="@string/hint_password"
            android:imeOptions="actionUnspecified"
            android:inputType="textPassword"
            android:maxLines="1"
            android:singleLine="true" />

        <EditText
            android:id="@+id/newPassword"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:focusableInTouchMode="true"
            android:hint="@string/new_pass"
            android:imeOptions="actionUnspecified"
            android:inputType="textPassword"
            android:maxLines="1"
            android:singleLine="true" />

        <Button
            android:id="@+id/changeEmail"
            style="?android:textAppearanceSmall"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginTop="16dp"
            android:background="@color/colorPrimaryDark"
            android:text="@string/btn_change"
            android:textColor="@android:color/white"
            android:textStyle="bold" />

        <Button
            android:id="@+id/changePass"
            style="?android:textAppearanceSmall"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginTop="16dp"
            android:background="@color/colorPrimaryDark"
            android:text="@string/btn_change"
            android:textColor="@android:color/white"
            android:textStyle="bold" />

        <Button
            android:id="@+id/send"
            style="?android:textAppearanceSmall"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginTop="16dp"
            android:background="@color/colorPrimaryDark"
            android:text="@string/btn_send"
            android:textColor="@android:color/white"
            android:textStyle="bold" />

        <ProgressBar
            android:id="@+id/progressBar"
            android:layout_width="30dp"
            android:layout_height="30dp"
            android:visibility="gone" />

        <Button
            android:id="@+id/remove"
            style="?android:textAppearanceSmall"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginTop="16dp"
            android:background="@color/colorPrimaryDark"
            android:text="@string/btn_remove"
            android:textColor="@android:color/white"
            android:textStyle="bold" />

        <Button
            android:id="@+id/change_email_button"
            style="?android:textAppearanceSmall"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_marginTop="16dp"
            android:text="@string/change_email"
            android:textStyle="bold" />

        <Button
            android:id="@+id/change_password_button"
            style="?android:textAppearanceSmall"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_marginTop="16dp"
            android:text="@string/change_password"
            android:textStyle="bold" />

        <Button
            android:id="@+id/sending_pass_reset_button"
            style="?android:textAppearanceSmall"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_marginTop="16dp"
            android:text="@string/send_password_reset_email"
            android:textStyle="bold" />

        <Button
            android:id="@+id/remove_user_button"
            style="?android:textAppearanceSmall"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_marginTop="16dp"
            android:text="@string/remove_user"
            android:textStyle="bold" />

        <Button
            android:id="@+id/sign_out"
            style="?android:textAppearanceSmall"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_marginTop="16dp"
            android:background="@color/colorPrimary"
            android:text="@string/btn_sign_out"
            android:textColor="@android:color/white"
            android:textStyle="bold" />

    </LinearLayout>
</android.support.design.widget.CoordinatorLayout>

2. Open the AccountActivity.java and the following code. Basically here we combine all the functionalities into a single activity.

AccountActivity.java

package com.zecolloauth.zecolloauth;

import android.content.Intent;
import android.os.Bundle;
import android.support.annotation.NonNull;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.RecyclerView;
import android.support.v7.widget.Toolbar;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.ProgressBar;
import android.widget.Toast;

import com.google.android.gms.tasks.OnCompleteListener;
import com.google.android.gms.tasks.Task;
import com.google.firebase.auth.FirebaseAuth;
import com.google.firebase.auth.FirebaseUser;



public class AccountActivity extends AppCompatActivity {
    public static final   String TAG = AccountActivity.class.getSimpleName();
    private Button btnChangeEmail, btnChangePassword, btnSendResetEmail, btnRemoveUser,
            changeEmail, changePassword, sendEmail, remove, signOut;
    private EditText oldEmail, newEmail, password, newPassword;
    private ProgressBar progressBar;
    private FirebaseAuth.AuthStateListener authListener;
    private FirebaseAuth auth;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_account);
        Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
        toolbar.setTitle(getString(R.string.app_name));
        setSupportActionBar(toolbar);

        //get firebase auth instance
        auth = FirebaseAuth.getInstance();
        //get current user
        final FirebaseUser user = FirebaseAuth.getInstance().getCurrentUser();
        authListener = new FirebaseAuth.AuthStateListener() {
            @Override
            public void onAuthStateChanged(@NonNull FirebaseAuth firebaseAuth) {
                FirebaseUser user = firebaseAuth.getCurrentUser();
                if (user == null) {
                    startActivity(new Intent(AccountActivity.this, LoginActivity.class));
                    finish();
                }
            }
        };
        btnChangeEmail = (Button) findViewById(R.id.change_email_button);
        btnChangePassword = (Button) findViewById(R.id.change_password_button);
        btnSendResetEmail = (Button) findViewById(R.id.sending_pass_reset_button);
        btnRemoveUser = (Button) findViewById(R.id.remove_user_button);
        changeEmail = (Button) findViewById(R.id.changeEmail);
        changePassword = (Button) findViewById(R.id.changePass);
        sendEmail = (Button) findViewById(R.id.send);
        remove = (Button) findViewById(R.id.remove);
        signOut = (Button) findViewById(R.id.sign_out);

        oldEmail = (EditText) findViewById(R.id.old_email);
        newEmail = (EditText) findViewById(R.id.new_email);
        password = (EditText) findViewById(R.id.password);
        newPassword = (EditText) findViewById(R.id.newPassword);

        oldEmail.setVisibility(View.GONE);
        newEmail.setVisibility(View.GONE);
        password.setVisibility(View.GONE);
        newPassword.setVisibility(View.GONE);
        changeEmail.setVisibility(View.GONE);
        changePassword.setVisibility(View.GONE);
        sendEmail.setVisibility(View.GONE);
        remove.setVisibility(View.GONE);
        progressBar = (ProgressBar) findViewById(R.id.progressBar);
        if (progressBar != null) {
            progressBar.setVisibility(View.GONE);
        }
        btnChangeEmail.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                oldEmail.setVisibility(View.GONE);
                newEmail.setVisibility(View.VISIBLE);
                password.setVisibility(View.GONE);
                newPassword.setVisibility(View.GONE);
                changeEmail.setVisibility(View.VISIBLE);
                changePassword.setVisibility(View.GONE);
                sendEmail.setVisibility(View.GONE);
                remove.setVisibility(View.GONE);
            }
        });
        changeEmail.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                progressBar.setVisibility(View.VISIBLE);
                if (user != null && !newEmail.getText().toString().trim().equals("")) {
                    user.updateEmail(newEmail.getText().toString().trim())
                            .addOnCompleteListener(new OnCompleteListener<Void>() {
                                @Override
                                public void onComplete(@NonNull Task<Void> task) {
                                    if (task.isSuccessful()) {
                                        Toast.makeText(AccountActivity.this, "Email address is updated. Please sign in with new email!", Toast.LENGTH_LONG).show();
                                        signOut();
                                        progressBar.setVisibility(View.GONE);
                                    } else {
                                        Toast.makeText(AccountActivity.this, "Failed to update email!", Toast.LENGTH_LONG).show();
                                        progressBar.setVisibility(View.GONE);
                                    }
                                }
                            });
                } else if (newEmail.getText().toString().trim().equals("")) {
                    newEmail.setError("Enter email");
                    progressBar.setVisibility(View.GONE);
                }
            }
        });
        btnSendResetEmail.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                oldEmail.setVisibility(View.VISIBLE);
                newEmail.setVisibility(View.GONE);
                password.setVisibility(View.GONE);
                newPassword.setVisibility(View.GONE);
                changeEmail.setVisibility(View.GONE);
                changePassword.setVisibility(View.GONE);
                sendEmail.setVisibility(View.VISIBLE);
                remove.setVisibility(View.GONE);
            }
        });
        sendEmail.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                progressBar.setVisibility(View.VISIBLE);
                if (!oldEmail.getText().toString().trim().equals("")) {
                    auth.sendPasswordResetEmail(oldEmail.getText().toString().trim())
                            .addOnCompleteListener(new OnCompleteListener<Void>() {
                                @Override
                                public void onComplete(@NonNull Task<Void> task) {
                                    if (task.isSuccessful()) {
                                        Toast.makeText(AccountActivity.this, "Reset password. email is sent!", Toast.LENGTH_SHORT).show();
                                        progressBar.setVisibility(View.GONE);
                                    } else {
                                        Toast.makeText(AccountActivity.this, "Failed to send reset email!", Toast.LENGTH_SHORT).show();
                                        progressBar.setVisibility(View.GONE);
                                    }
                                }
                            });
                } else {
                    oldEmail.setError("Enter email");
                    progressBar.setVisibility(View.GONE);
                }
            }
        });

        btnRemoveUser.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                progressBar.setVisibility(View.VISIBLE);
                if (user != null) {
                    user.delete()
                            .addOnCompleteListener(new OnCompleteListener<Void>() {
                                @Override
                                public void onComplete(@NonNull Task<Void> task) {
                                    if (task.isSuccessful()) {
                                        Toast.makeText(AccountActivity.this, "Your profile is deleted:( Create a account now!", Toast.LENGTH_SHORT).show();
                                        startActivity(new Intent(AccountActivity.this, SignupActivity.class));
                                        finish();
                                        progressBar.setVisibility(View.GONE);
                                    } else {
                                        Toast.makeText(AccountActivity.this, "Failed to delete your account!", Toast.LENGTH_SHORT).show();
                                        progressBar.setVisibility(View.GONE);
                                    }
                                }
                            });
                }
            }
        });
        signOut.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                signOut();
            }
        });

    }

    //sign out method
    public void signOut() {
        auth.signOut();
    }

    @Override
    protected void onResume() {
        super.onResume();
        progressBar.setVisibility(View.GONE);
    }

    @Override
    public void onStart() {
        super.onStart();
        auth.addAuthStateListener(authListener);
    }

    @Override
    public void onStop() {
        super.onStop();
        if (authListener != null) {
            auth.removeAuthStateListener(authListener);
        }
    }
}

BELOW ARE OTHER QUICK CODE SNIPPETS

Checking User Session

auth = FirebaseAuth.getInstance();
        if (auth.getCurrentUser() != null) {
            // User is logged in
        }

Change Email

FirebaseUser user = FirebaseAuth.getInstance().getCurrentUser();
 
user.updateEmail(newEmail.getText().toString().trim())
            .addOnCompleteListener(new OnCompleteListener<Void>() {
        @Override
        public void onComplete(@NonNull Task<Void> task) {
            if (task.isSuccessful()) {
                Toast.makeText(MainActivity.this, "Email address is updated.", Toast.LENGTH_LONG).show();
            } else {
                Toast.makeText(MainActivity.this, "Failed to update email!", Toast.LENGTH_LONG).show();
            }
        }
    });

Deleting Account / User

FirebaseUser user = FirebaseAuth.getInstance().getCurrentUser();
if (user != null) {
        user.delete()
                .addOnCompleteListener(new OnCompleteListener<Void>() {
                    @Override
                    public void onComplete(@NonNull Task<Void> task) {
                        if (task.isSuccessful()) {
                            Toast.makeText(MainActivity.this, "Your profile is deleted:( Create a account now!", Toast.LENGTH_SHORT).show();
                        } else {
                            Toast.makeText(MainActivity.this, "Failed to delete your account!", Toast.LENGTH_SHORT).show();
                        }
                    }
                });
    }

Sign Out!

auth.signOut();
 
// this listener will be called when there is change in firebase user session
FirebaseAuth.AuthStateListener authListener = new FirebaseAuth.AuthStateListener() {
            @Override
            public void onAuthStateChanged(@NonNull FirebaseAuth firebaseAuth) {
                FirebaseUser user = firebaseAuth.getCurrentUser();
                if (user == null) {
                    // user auth state is changed - user is null
                    // launch login activity
                    startActivity(new Intent(MainActivity.this, LoginActivity.class));
                    finish();
                }
            }
        };

👏 Congratulation you have now Ingegrated Login and Register with Firebase.

Developed by

• Mobile number: (+254) 798731203

• Email Address: collo.kariss@gmail.com

• github-username: zecollokaris