Add Credential Manager to Kotlin sample

Author: marinacoelho

auth/app/build.gradle.kts

@@ -49,6 +49,11 @@ dependencies {
     // [START gradle_firebase_ui_auth]
     implementation("com.firebaseui:firebase-ui-auth:8.0.2")
 
+    // Google Identity Services SDK (only required for Auth with Google)
+    implementation("androidx.credentials:credentials:1.3.0")
+    implementation("androidx.credentials:credentials-play-services-auth:1.3.0")
+    implementation("com.google.android.libraries.identity.googleid:googleid:1.1.1")
+
     // Required only if Facebook login support is required
     // Find the latest Facebook SDK releases here: https://goo.gl/Ce5L94
     implementation("com.facebook.android:facebook-android-sdk:4.42.0")

auth/app/src/main/java/com/google/firebase/quickstart/auth/kotlin/GoogleSignInActivity.kt

@@ -1,48 +1,64 @@
 package com.google.firebase.quickstart.auth.kotlin
 
-import android.app.Activity
-import android.content.Intent
 import android.os.Bundle
 import android.util.Log
-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 androidx.appcompat.app.AppCompatActivity
+import androidx.credentials.CredentialManager
+import androidx.credentials.CustomCredential
+import androidx.credentials.GetCredentialRequest
+import androidx.credentials.exceptions.GetCredentialException
+import androidx.lifecycle.lifecycleScope
+import com.google.android.libraries.identity.googleid.GetGoogleIdOption
+import com.google.android.libraries.identity.googleid.GoogleIdTokenCredential
+import com.google.android.libraries.identity.googleid.GoogleIdTokenCredential.Companion.TYPE_GOOGLE_ID_TOKEN_CREDENTIAL
 import com.google.firebase.auth.FirebaseAuth
 import com.google.firebase.auth.FirebaseUser
 import com.google.firebase.auth.GoogleAuthProvider
 import com.google.firebase.auth.auth
 import com.google.firebase.Firebase
 import com.google.firebase.quickstart.auth.R
+import kotlinx.coroutines.launch
 
 /**
  * Demonstrate Firebase Authentication using a Google ID Token.
  */
-class GoogleSignInActivity : Activity() {
+class GoogleSignInActivity : AppCompatActivity() {
 
     // [START declare_auth]
     private lateinit var auth: FirebaseAuth
     // [END declare_auth]
 
-    private lateinit var googleSignInClient: GoogleSignInClient
+    // [START declare_credential_manager]
+    private lateinit var credentialManager: CredentialManager
+    // [END declare_credential_manager]
 
     override fun onCreate(savedInstanceState: Bundle?) {
         super.onCreate(savedInstanceState)
 
-        // [START config_signin]
-        // Configure Google Sign In
-        val gso = GoogleSignInOptions.Builder(GoogleSignInOptions.DEFAULT_SIGN_IN)
-            .requestIdToken(getString(R.string.default_web_client_id))
-            .requestEmail()
-            .build()
-
-        googleSignInClient = GoogleSignIn.getClient(this, gso)
-        // [END config_signin]
-
         // [START initialize_auth]
         // Initialize Firebase Auth
         auth = Firebase.auth
         // [END initialize_auth]
+
+        // [START initialize_credential_manager]
+        // Initialize Credential Manager
+        credentialManager = CredentialManager.create(baseContext)
+        // [END initialize_credential_manager]
+
+        // [START configure_credential_manager]
+        // Create the configuration for the Credential Manager request
+        val googleIdOption = GetGoogleIdOption.Builder()
+            .setFilterByAuthorizedAccounts(true)
+            .setServerClientId(baseContext.getString(R.string.default_web_client_id))
+            .build()
+
+        // Create the Credential Manager request using the configuration created above
+        val request = GetCredentialRequest.Builder()
+            .addCredentialOption(googleIdOption)
+            .build()
+        // [END configure_credential_manager]
+
+        getCredential(request)
     }
 
     // [START on_start_check_user]
@@ -54,25 +70,33 @@ class GoogleSignInActivity : Activity() {
     }
     // [END on_start_check_user]
 
-    // [START onactivityresult]
-    override fun onActivityResult(requestCode: Int, resultCode: Int, data: Intent?) {
-        super.onActivityResult(requestCode, resultCode, data)
-
-        // Result returned from launching the Intent from GoogleSignInApi.getSignInIntent(...);
-        if (requestCode == RC_SIGN_IN) {
-            val task = GoogleSignIn.getSignedInAccountFromIntent(data)
+    // [START get_user_credential]
+    private fun getCredential(request: GetCredentialRequest) {
+        lifecycleScope.launch {
             try {
-                // Google Sign In was successful, authenticate with Firebase
-                val account = task.getResult(ApiException::class.java)!!
-                Log.d(TAG, "firebaseAuthWithGoogle:" + account.id)
-                firebaseAuthWithGoogle(account.idToken!!)
-            } catch (e: ApiException) {
-                // Google Sign In failed, update UI appropriately
-                Log.w(TAG, "Google sign in failed", e)
+                // Launch Credential Manager UI
+                val result = credentialManager.getCredential(
+                    request = request,
+                    context = baseContext
+                )
+
+                // Extract credential from the result returned by Credential Manager
+                val credential = result.credential
+
+                // Check if credential is of type Google ID
+                if (credential is CustomCredential && credential.type == TYPE_GOOGLE_ID_TOKEN_CREDENTIAL) {
+                    val googleIdTokenCredential = GoogleIdTokenCredential.createFrom(credential.data)
+                    // Sign in to Firebase with the Google ID Token
+                    firebaseAuthWithGoogle(googleIdTokenCredential.idToken)
+                } else {
+                    Log.d(TAG, "Credential is not of type Google ID!")
+                }
+            } catch (e: GetCredentialException) {
+                Log.e(TAG, "Couldn't retrieve user's credentials: ${e.localizedMessage}")
             }
         }
     }
-    // [END onactivityresult]
+    // [END get_user_credential]
 
     // [START auth_with_google]
     private fun firebaseAuthWithGoogle(idToken: String) {
@@ -93,18 +117,10 @@ class GoogleSignInActivity : Activity() {
     }
     // [END auth_with_google]
 
-    // [START signin]
-    private fun signIn() {
-        val signInIntent = googleSignInClient.signInIntent
-        startActivityForResult(signInIntent, RC_SIGN_IN)
-    }
-    // [END signin]
-
     private fun updateUI(user: FirebaseUser?) {
     }
 
     companion object {
         private const val TAG = "GoogleActivity"
-        private const val RC_SIGN_IN = 9001
     }
 }