Feat : Implement Google Login with Firebase

1. Implement Splash Activity.
- Set delay(1000) and then move Activity to Login Activity
2. Implement Google Login
- Receive IDToken from Google Server
- Backend server communication not implemented
- Auto Login not implemented
3. Add KTX libraries

android/HowAboutTrip/app/build.gradle.kts

@@ -1,6 +1,9 @@
+import com.android.build.gradle.internal.cxx.configure.gradleLocalProperties
+
 plugins {
     id("com.android.application")
     id("org.jetbrains.kotlin.android")
+    id("com.google.gms.google-services")
     id("kotlin-kapt")
 }
 
@@ -21,6 +24,10 @@ android {
         }
 
         testInstrumentationRunner = "androidx.test.runner.AndroidJUnitRunner"
+
+        buildConfigField("String", "GOOGLE_OAUTH_ID", getApiKey("google_oauth_id"))
+        buildConfigField("String", "GOOGLE_MAP_API_KEY", getApiKey("google_map_api_key"))
+        buildConfigField("String", "GOOGLE_SERVER_ID", getApiKey("google_server_id"))
     }
 
     buildTypes {
@@ -41,13 +48,26 @@ android {
     }
 }
 
+fun getApiKey(propertyKey: String):String = gradleLocalProperties(rootDir).getProperty(propertyKey)
+
 dependencies {
 
     implementation("androidx.core:core-ktx:1.12.0")
     implementation("androidx.appcompat:appcompat:1.6.1")
     implementation("com.google.android.material:material:1.11.0")
     implementation("androidx.constraintlayout:constraintlayout:2.1.4")
     implementation("com.airbnb.android:lottie:6.3.0")
+
+    implementation("androidx.lifecycle:lifecycle-livedata-ktx:2.6.2")
+    implementation("androidx.fragment:fragment-ktx:1.7.0-alpha07")
+    implementation("androidx.lifecycle:lifecycle-viewmodel-ktx:2.6.2")
+
+    implementation(platform("com.google.firebase:firebase-bom:32.7.0"))
+    implementation("com.google.firebase:firebase-analytics")
+    implementation("com.google.firebase:firebase-auth:22.3.0")
+    implementation("com.google.android.gms:play-services-auth:20.7.0")
+
+
     testImplementation("junit:junit:4.13.2")
     androidTestImplementation("androidx.test.ext:junit:1.1.5")
     androidTestImplementation("androidx.test.espresso:espresso-core:3.5.1")

android/HowAboutTrip/app/google-services.json

@@ -0,0 +1,47 @@
+{
+  "project_info": {
+    "project_number": "740845966307",
+    "project_id": "howabouttrip",
+    "storage_bucket": "howabouttrip.appspot.com"
+  },
+  "client": [
+    {
+      "client_info": {
+        "mobilesdk_app_id": "1:740845966307:android:71aff1bfe733b688ad46d6",
+        "android_client_info": {
+          "package_name": "com.project.how"
+        }
+      },
+      "oauth_client": [
+        {
+          "client_id": "740845966307-oulmuvm5mv595vlu9hf1a3j5n4ouvskg.apps.googleusercontent.com",
+          "client_type": 1,
+          "android_info": {
+            "package_name": "com.project.how",
+            "certificate_hash": "8f29dbe96504294182411cc8b5af35fee8e57de8"
+          }
+        },
+        {
+          "client_id": "740845966307-vhqequ0l999eglm9p87su14da4bjreid.apps.googleusercontent.com",
+          "client_type": 3
+        }
+      ],
+      "api_key": [
+        {
+          "current_key": "AIzaSyDg0_7_UQD4gNj9XmKnQZpBGREl0r9CZ_Q"
+        }
+      ],
+      "services": {
+        "appinvite_service": {
+          "other_platform_oauth_client": [
+            {
+              "client_id": "740845966307-vhqequ0l999eglm9p87su14da4bjreid.apps.googleusercontent.com",
+              "client_type": 3
+            }
+          ]
+        }
+      }
+    }
+  ],
+  "configuration_version": "1"
+}

android/HowAboutTrip/app/src/main/AndroidManifest.xml

@@ -2,6 +2,7 @@
 <manifest xmlns:android="http://schemas.android.com/apk/res/android"
     xmlns:tools="http://schemas.android.com/tools">
 
+    <uses-permission android:name="android.permission.INTERNET"/>
     <application
         android:allowBackup="true"
         android:dataExtractionRules="@xml/data_extraction_rules"
@@ -26,6 +27,9 @@
                 <category android:name="android.intent.category.LAUNCHER" />
             </intent-filter>
         </activity>
+        <activity
+            android:name=".view.activity.MainActivity"
+            android:exported="false"/>
     </application>
 
-</manifest>
+</manifest>

android/HowAboutTrip/app/src/main/java/com/project/how/model/LoginRepository.kt

@@ -0,0 +1,26 @@
+package com.project.how.model
+
+import android.util.Log
+import androidx.lifecycle.LiveData
+import androidx.lifecycle.MutableLiveData
+import com.google.firebase.auth.FirebaseAuth
+import com.google.firebase.auth.FirebaseUser
+import com.google.firebase.auth.GoogleAuthProvider
+
+class LoginRepository {
+    private val firebaseAuth = FirebaseAuth.getInstance()
+    private val _userLiveData = MutableLiveData<FirebaseUser>()
+    val userLiveData: LiveData<FirebaseUser>
+        get() = _userLiveData
+
+    fun getUser(idToken: String) {
+        val credential = GoogleAuthProvider.getCredential(idToken, null)
+        firebaseAuth.signInWithCredential(credential).addOnCompleteListener{
+            if(it.isSuccessful){
+                _userLiveData.postValue(firebaseAuth.currentUser)
+            } else{
+                Log.e("GoogleAuthRepository", "getUser is failed\n${it.exception}")
+            }
+        }
+    }
+}

android/HowAboutTrip/app/src/main/java/com/project/how/view/activity/LoginActivity.kt

@@ -1,12 +1,58 @@
 package com.project.how.view.activity
 
+import android.app.Activity
+import android.content.Intent
 import androidx.appcompat.app.AppCompatActivity
 import android.os.Bundle
+import android.util.Log
+import android.widget.Toast
+import androidx.activity.result.ActivityResult
+import androidx.activity.result.ActivityResultLauncher
+import androidx.activity.result.contract.ActivityResultContracts
+import androidx.activity.viewModels
+import androidx.databinding.DataBindingUtil
+import com.google.android.gms.auth.api.identity.BeginSignInRequest
+import com.google.android.gms.auth.api.signin.GoogleSignIn
+import com.google.android.gms.auth.api.signin.GoogleSignInClient
+import com.google.android.gms.auth.api.signin.GoogleSignInOptions
+import com.google.android.gms.common.api.ApiException
+import com.project.how.BuildConfig
 import com.project.how.R
+import com.project.how.databinding.ActivityLoginBinding
+import com.project.how.view_model.LoginViewModel
 
 class LoginActivity : AppCompatActivity() {
+    private lateinit var binding : ActivityLoginBinding
+    private val viewModel: LoginViewModel by viewModels()
+    private lateinit var activityResultLauncher : ActivityResultLauncher<Intent>
+    private lateinit var googleSignInRequest: GoogleSignInClient
+
     override fun onCreate(savedInstanceState: Bundle?) {
         super.onCreate(savedInstanceState)
-        setContentView(R.layout.activity_login)
+        binding = DataBindingUtil.setContentView(this, R.layout.activity_login)
+        binding.login = this
+        val gso = GoogleSignInOptions.Builder(GoogleSignInOptions.DEFAULT_SIGN_IN)
+            .requestIdToken(BuildConfig.GOOGLE_SERVER_ID)
+            .requestEmail()
+            .build()
+        googleSignInRequest = GoogleSignIn.getClient(this, gso)
+        activityResultLauncher = registerForActivityResult(ActivityResultContracts.StartActivityForResult()){
+            if(it.resultCode == Activity.RESULT_OK) {
+                val task = GoogleSignIn.getSignedInAccountFromIntent(it.data)
+                try {
+                    val account = task.result
+                    viewModel.getUser(account.idToken!!)
+                    Log.d("activityResultLauncher", "Login Success\nidToken : ${account.idToken}\nid : ${account.id}\nemail : ${account.email}")
+                    startActivity(Intent(this, MainActivity::class.java))
+                } catch (e: Exception){
+                    Log.e("activityResultLauncher", "Login Failed\nError : ${e.stackTrace}\n${e.message}")
+                }
+            }
+        }
+
+        binding.googleLogin.setOnClickListener {
+            activityResultLauncher.launch(googleSignInRequest.signInIntent)
+            binding.lottie.pauseAnimation()
+        }
     }
 }

android/HowAboutTrip/app/src/main/java/com/project/how/view/activity/MainActivity.kt

@@ -0,0 +1,16 @@
+package com.project.how.view.activity
+
+import androidx.appcompat.app.AppCompatActivity
+import android.os.Bundle
+import androidx.databinding.DataBindingUtil
+import com.project.how.R
+import com.project.how.databinding.ActivityMainBinding
+
+class MainActivity : AppCompatActivity() {
+    private lateinit var binding: ActivityMainBinding
+    override fun onCreate(savedInstanceState: Bundle?) {
+        super.onCreate(savedInstanceState)
+        binding= DataBindingUtil.setContentView(this, R.layout.activity_main)
+
+    }
+}

android/HowAboutTrip/app/src/main/java/com/project/how/view/activity/SplashActivity.kt

@@ -1,12 +1,25 @@
 package com.project.how.view.activity
 
+import android.content.Intent
 import androidx.appcompat.app.AppCompatActivity
 import android.os.Bundle
+import androidx.databinding.DataBindingUtil
+import androidx.lifecycle.lifecycleScope
 import com.project.how.R
+import com.project.how.databinding.ActivitySplashBinding
+import kotlinx.coroutines.delay
+import kotlinx.coroutines.launch
 
 class SplashActivity : AppCompatActivity() {
+    private lateinit var binding : ActivitySplashBinding
     override fun onCreate(savedInstanceState: Bundle?) {
         super.onCreate(savedInstanceState)
-        setContentView(R.layout.activity_splash)
+        binding = DataBindingUtil.setContentView(this, R.layout.activity_splash)
+        binding.splash = this
+
+        lifecycleScope.launch {
+            delay(1000)
+            startActivity(Intent(this@SplashActivity, LoginActivity::class.java))
+        }
     }
 }

android/HowAboutTrip/app/src/main/java/com/project/how/view_model/LoginViewModel.kt

@@ -0,0 +1,17 @@
+package com.project.how.view_model
+
+import androidx.lifecycle.LiveData
+import androidx.lifecycle.ViewModel
+import com.google.firebase.auth.FirebaseUser
+import com.project.how.model.LoginRepository
+
+class LoginViewModel : ViewModel() {
+    private var loginRepository : LoginRepository = LoginRepository()
+    private val _userLiveData = loginRepository.userLiveData
+    val userLiveData: LiveData<FirebaseUser>
+        get() = _userLiveData
+
+    fun getUser(idToken: String){
+        loginRepository.getUser(idToken)
+    }
+}

android/HowAboutTrip/app/src/main/res/layout/activity_login.xml

@@ -15,25 +15,46 @@
 
         <com.airbnb.lottie.LottieAnimationView
             android:id="@+id/lottie"
-            android:layout_width="200dp"
+            android:layout_width="250dp"
             android:layout_height="200dp"
             app:layout_constraintBottom_toBottomOf="parent"
             app:layout_constraintEnd_toEndOf="parent"
             app:layout_constraintHorizontal_bias="0.5"
             app:layout_constraintStart_toStartOf="parent"
             app:layout_constraintTop_toTopOf="parent"
-            app:layout_constraintVertical_bias="0.3"
+            app:layout_constraintVertical_bias="0.17"
             app:lottie_autoPlay="true"
             app:lottie_loop="true"
             app:lottie_rawRes="@raw/login_animation" />
 
         <TextView
+            android:id="@+id/textView"
             android:layout_width="wrap_content"
             android:layout_height="wrap_content"
+            android:fontFamily="@font/bm_hanna"
+            android:gravity="center"
+            android:text="@string/login_under_text"
+            android:textSize="16sp"
+            android:layout_marginTop="10dp"
             app:layout_constraintEnd_toEndOf="parent"
             app:layout_constraintStart_toStartOf="parent"
             app:layout_constraintTop_toBottomOf="@+id/lottie" />
 
+        <ImageButton
+            android:id="@+id/google_login"
+            android:layout_width="250dp"
+            android:layout_height="100dp"
+            android:background="@android:color/transparent"
+            android:scaleType="fitCenter"
+            android:src="@drawable/google_login"
+            app:layout_constraintBottom_toBottomOf="parent"
+            app:layout_constraintEnd_toEndOf="parent"
+            app:layout_constraintHorizontal_bias="0.5"
+            app:layout_constraintStart_toStartOf="parent"
+            app:layout_constraintTop_toBottomOf="@+id/textView"
+            app:layout_constraintVertical_bias="0.2"
+            android:contentDescription="@string/google_login_content_desciption" />
+
     </androidx.constraintlayout.widget.ConstraintLayout>
 
 </layout>

android/HowAboutTrip/app/src/main/res/layout/activity_main.xml

@@ -0,0 +1,40 @@
+<?xml version="1.0" encoding="utf-8"?>
+<layout xmlns:app="http://schemas.android.com/apk/res-auto"
+    xmlns:android="http://schemas.android.com/apk/res/android">
+
+    <data>
+        <import type="android.view.View"/>
+        <variable
+            name="main"
+            type="com.project.how.view.activity.MainActivity" />
+    </data>
+
+    <androidx.coordinatorlayout.widget.CoordinatorLayout
+        android:layout_width="match_parent"
+        android:layout_height="match_parent">
+
+        <com.google.android.material.bottomappbar.BottomAppBar
+            android:id="@+id/bottomAppBar"
+            android:layout_width="match_parent"
+            android:layout_height="wrap_content"
+            android:layout_gravity="bottom"
+            app:fabCradleMargin="5dp"
+            app:fabCradleRoundedCornerRadius="10dp">
+            <com.google.android.material.bottomnavigation.BottomNavigationView
+                android:layout_width="match_parent"
+                android:layout_height="wrap_content" />
+        </com.google.android.material.bottomappbar.BottomAppBar>
+
+        <com.google.android.material.floatingactionbutton.FloatingActionButton
+            android:id="@+id/addButton"
+            android:layout_width="wrap_content"
+            android:layout_height="wrap_content"
+            android:backgroundTint="@color/white"
+            android:clickable="true"
+            app:layout_anchor="@+id/bottomAppBar"
+            app:layout_anchorGravity="top|center" />
+
+
+    </androidx.coordinatorlayout.widget.CoordinatorLayout>
+
+</layout>