AuthTab project example

androidbrowserhelper/build.gradle

@@ -20,6 +20,7 @@ apply plugin: 'maven-publish'
 def VERSION = "2.5.0";
 
 android {
+    namespace "com.google.androidbrowserhelper"
     compileSdkVersion 31
 
     defaultConfig {

build.gradle

@@ -20,16 +20,22 @@ buildscript {
     repositories {
         google()
         jcenter()
+        maven {
+            url = uri("https://androidx.dev/snapshots/builds/12502757/artifacts/repository")
+        }
     }
     dependencies {
-        classpath 'com.android.tools.build:gradle:4.1.1'
+        classpath 'com.android.tools.build:gradle:8.7.2'
     }
 }
 
 allprojects {
     repositories {
         google()
         jcenter()
+        maven {
+            url = uri("https://androidx.dev/snapshots/builds/12502757/artifacts/repository")
+        }
     }
 }
 

demos/custom-tabs-authview/.gitignore

@@ -0,0 +1 @@
+/build

demos/custom-tabs-authview/build.gradle

@@ -0,0 +1,51 @@
+/*
+ *    Copyright 2024 Google LLC
+ *
+ *    Licensed under the Apache License, Version 2.0 (the "License");
+ *    you may not use this file except in compliance with the License.
+ *    You may obtain a copy of the License at
+ *
+ *    https://www.apache.org/licenses/LICENSE-2.0
+ *
+ *    Unless required by applicable law or agreed to in writing, software
+ *    distributed under the License is distributed on an "AS IS" BASIS,
+ *    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *    See the License for the specific language governing permissions and
+ *    limitations under the License.
+ */
+
+apply plugin: 'com.android.application'
+
+android {
+    namespace 'com.google.androidbrowserhelper.demos.customtabsauthview'
+    compileSdkVersion 35
+    defaultConfig {
+        applicationId "com.google.androidbrowserhelper.demos.customtabsauthview"
+        minSdkVersion 26
+        targetSdkVersion 35
+        versionCode 1
+        versionName "1.0"
+    }
+
+    buildTypes {
+        release {
+            minifyEnabled false
+        }
+    }
+
+    compileOptions {
+        sourceCompatibility JavaVersion.VERSION_17
+        targetCompatibility JavaVersion.VERSION_17
+    }
+}
+
+dependencies {
+    implementation project(path: ':androidbrowserhelper')
+    implementation fileTree(dir: "libs", include: ["*.jar"])
+    implementation 'androidx.appcompat:appcompat:1.7.0'
+    implementation 'androidx.activity:activity:1.9.3'
+    implementation 'androidx.browser:browser:1.9.0-SNAPSHOT'
+    implementation 'com.google.android.material:material:1.12.0'
+    implementation 'androidx.annotation:annotation:1.9.1'
+    implementation 'androidx.constraintlayout:constraintlayout:2.2.0'
+}

demos/custom-tabs-authview/src/main/AndroidManifest.xml

@@ -0,0 +1,35 @@
+<?xml version="1.0" encoding="utf-8"?>
+<manifest xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:tools="http://schemas.android.com/tools"
+    package="com.google.androidbrowserhelper.demos.customtabsauthview">
+    <uses-permission android:name="android.permission.INTERNET" />
+
+    <application
+        android:allowBackup="true"
+        android:dataExtractionRules="@xml/data_extraction_rules"
+        android:fullBackupContent="@xml/backup_rules"
+        android:icon="@mipmap/ic_launcher"
+        android:label="@string/app_name"
+        android:roundIcon="@mipmap/ic_launcher_round"
+        android:supportsRtl="true"
+        android:theme="@style/Theme.AuthTab"
+        tools:targetApi="31">
+        <activity
+            android:name=".MainActivity"
+            android:exported="true">
+            <intent-filter>
+                <action android:name="android.intent.action.MAIN" />
+                <category android:name="android.intent.category.LAUNCHER" />
+            </intent-filter>
+
+            <!-- An intent-filter for fallback to Chrome Custom Tabs -->
+            <intent-filter android:autoVerify="true">
+                <action android:name="android.intent.action.VIEW" />
+                <category android:name="android.intent.category.DEFAULT" />
+                <category android:name="android.intent.category.BROWSABLE" />
+                <data android:scheme="auth" />
+                <data android:host="callback" />
+            </intent-filter>
+        </activity>
+    </application>
+</manifest>

demos/custom-tabs-authview/src/main/java/com/google/androidbrowserhelper/demos/customtabsauthview/AuthManager.java

@@ -0,0 +1,99 @@
+package com.google.androidbrowserhelper.demos.customtabsauthview;
+
+import android.content.Context;
+import android.content.Intent;
+import android.content.SharedPreferences;
+import android.net.Uri;
+import android.os.Handler;
+import android.os.Looper;
+import android.util.Log;
+
+import androidx.activity.result.ActivityResultLauncher;
+import androidx.annotation.NonNull;
+import androidx.browser.auth.AuthTabIntent;
+import androidx.annotation.OptIn;
+import androidx.browser.auth.ExperimentalAuthTab;
+
+import java.io.IOException;
+import java.util.UUID;
+
+@OptIn(markerClass = ExperimentalAuthTab.class)
+public class AuthManager {
+    private static final String TAG = "OAuthManager";
+
+    private final String mClientId;
+    private final String mClientSecret;
+    private final String mAuthorizationEndpoint;
+    private final String mRedirectScheme;
+
+    public interface OAuthCallback {
+        void auth(String accessToken, String scope, String tokenType);
+    }
+
+    public AuthManager(String clientId, String clientSecret, String authorizationEndpoint,
+                       String redirectScheme) {
+        mClientId = clientId;
+        mClientSecret = clientSecret;
+        mAuthorizationEndpoint = authorizationEndpoint;
+        mRedirectScheme = redirectScheme;
+    }
+
+    public void authorize(Context context, ActivityResultLauncher<Intent> launcher, String scope) {
+        // Generate a random state.
+        String state = UUID.randomUUID().toString();
+
+        // Save the state so we can verify later.
+        SharedPreferences preferences =
+                context.getSharedPreferences("OAUTH_STORAGE", Context.MODE_PRIVATE);
+        preferences.edit()
+                .putString("OAUTH_STATE", state)
+                .apply();
+
+        // Create an authorization URI to the OAuth Endpoint.
+        Uri uri = Uri.parse(mAuthorizationEndpoint)
+                .buildUpon()
+                .appendQueryParameter("response_type", "code")
+                .appendQueryParameter("client_id", mClientId)
+                .appendQueryParameter("scope", scope)
+                .appendQueryParameter("state", state)
+                .build();
+
+        // Open the Authorization URI in a Chrome Custom Auth Tab.
+        AuthTabIntent authTabIntent = new AuthTabIntent.Builder().build();
+        authTabIntent.launch(launcher, uri, mRedirectScheme);
+    }
+
+    public void continueAuthFlow(@NonNull Context context, Uri uri, @NonNull OAuthCallback callback) {
+        String code = uri.getQueryParameter("code");
+        SharedPreferences preferences =
+                context.getSharedPreferences("OAUTH_STORAGE", Context.MODE_PRIVATE);
+        String state = preferences.getString("OAUTH_STATE", "");
+        Uri tokenUri = Uri.parse("https://github.com/login/oauth/access_token")
+                .buildUpon()
+                .appendQueryParameter("client_id", mClientId)
+                .appendQueryParameter("client_secret", mClientSecret)
+                .appendQueryParameter("code", code)
+                .appendQueryParameter("state", state)
+                .build();
+
+        // Run the network request off the UI thread.
+        new Thread(() -> {
+            try {
+                String response = Utils.fetch(tokenUri);
+                // The response is a query-string. We concatenate with a valid domain to be
+                // able to easily parse and extract values.
+                Uri responseUri = Uri.parse("http://example.com?" + response);
+                String accessToken = responseUri.getQueryParameter("access_token");
+                String tokenType = responseUri.getQueryParameter("token_type");
+                String scope = responseUri.getQueryParameter("scope");
+
+                // Invoke the callback in the main thread.
+                new Handler(Looper.getMainLooper()).post(
+                        () -> callback.auth(accessToken, scope, tokenType));
+
+            } catch (IOException e) {
+                Log.e(TAG, "Error requesting access token: " + e.getMessage());
+            }
+        }).start();
+    }
+}

demos/custom-tabs-authview/src/main/java/com/google/androidbrowserhelper/demos/customtabsauthview/GithubApi.java

@@ -0,0 +1,43 @@
+package com.google.androidbrowserhelper.demos.customtabsauthview;
+
+import android.net.Uri;
+import android.os.Handler;
+import android.os.Looper;
+import android.util.Log;
+
+import org.json.JSONException;
+import org.json.JSONObject;
+
+import java.io.IOException;
+import java.util.Collections;
+import java.util.Map;
+
+public class GithubApi {
+    private static final String TAG = "GithubAPI";
+    private static final String API_ENDPOINT = "https://api.github.com/user";
+    private static final String AUTH_HEADER_KEY = "Authorization";
+
+    public interface UserCallback {
+        void onUserData(String username);
+    }
+
+    public static void requestGithubUsername(String token, UserCallback callback) {
+        new Thread(() -> {
+            try {
+                Uri uri = Uri.parse(API_ENDPOINT);
+                Map<String, String> headers =
+                        Collections.singletonMap(AUTH_HEADER_KEY, "token " + token);
+                String response = Utils.fetch(uri, headers);
+                JSONObject user = new JSONObject(response);
+                String username = user.getString("name");
+
+                // Invoke the callback in the main thread.
+                new Handler(Looper.getMainLooper()).post(() -> {
+                    callback.onUserData(username);
+                });
+            } catch (IOException | JSONException ex) {
+                Log.e(TAG, "Error fetching GitHub user: " + ex.getMessage());
+            }
+        }).start();
+    }
+}

demos/custom-tabs-authview/src/main/java/com/google/androidbrowserhelper/demos/customtabsauthview/MainActivity.java

@@ -0,0 +1,101 @@
+/*
+ *    Copyright 2024 Google LLC
+ *
+ *    Licensed under the Apache License, Version 2.0 (the "License");
+ *    you may not use this file except in compliance with the License.
+ *    You may obtain a copy of the License at
+ *
+ *    https://www.apache.org/licenses/LICENSE-2.0
+ *
+ *    Unless required by applicable law or agreed to in writing, software
+ *    distributed under the License is distributed on an "AS IS" BASIS,
+ *    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *    See the License for the specific language governing permissions and
+ *    limitations under the License.
+ */
+
+package com.google.androidbrowserhelper.demos.customtabsauthview;
+
+import android.content.Intent;
+import android.net.Uri;
+import android.os.Bundle;
+import android.view.View;
+import android.widget.Button;
+import android.widget.ProgressBar;
+import android.widget.TextView;
+
+import androidx.activity.result.ActivityResultLauncher;
+import androidx.annotation.OptIn;
+import androidx.appcompat.app.AppCompatActivity;
+import androidx.browser.auth.AuthTabIntent;
+import androidx.browser.auth.ExperimentalAuthTab;
+
+@OptIn(markerClass = ExperimentalAuthTab.class)
+public class MainActivity extends AppCompatActivity {
+    private static final String TAG = "MainActivity";
+
+    private static final String AUTHORIZATION_ENDPOINT = "https://github.com/login/oauth/authorize";
+    private static final String CLIENT_ID = "<github-client-id>";
+    private static final String CLIENT_SECRET = "<github-client-secret>";
+    private static final String REDIRECT_SCHEME = "auth";
+
+    private static final AuthManager O_AUTH_MANAGER =
+            new AuthManager(CLIENT_ID, CLIENT_SECRET, AUTHORIZATION_ENDPOINT, REDIRECT_SCHEME);
+
+    private final ActivityResultLauncher<Intent> mLauncher =
+            AuthTabIntent.registerActivityResultLauncher(this, this::handleAuthResult);
+
+    private Button mLoginButton;
+    private TextView mUserText;
+    private ProgressBar mProgressBar;
+    private boolean mLoggedIn;
+
+    @Override
+    protected void onCreate(Bundle savedInstanceState) {
+        super.onCreate(savedInstanceState);
+        setContentView(R.layout.activity_main);
+
+        mLoginButton = findViewById(R.id.login_button);
+        mUserText = findViewById(R.id.user_text);
+        mProgressBar = findViewById(R.id.progress_bar);
+
+        Intent intent = getIntent();
+        if (intent != null) {
+            Uri data = intent.getData();
+            if (data != null && data.getHost() != null
+                    && data.getHost().startsWith("callback")) {
+                mProgressBar.setVisibility(View.VISIBLE);
+                mLoginButton.setEnabled(false);
+                completeAuth(data);
+            }
+        }
+    }
+
+    public void login(View v) {
+        if (mLoggedIn) {
+            mLoginButton.setText(R.string.login);
+            mUserText.setText(R.string.logged_out);
+            mLoggedIn = false;
+        } else {
+            O_AUTH_MANAGER.authorize(this, mLauncher, "user");
+        }
+    }
+
+    private void handleAuthResult(AuthTabIntent.AuthResult result) {
+        if (result.resultCode == AuthTabIntent.RESULT_OK) {
+            completeAuth(result.resultUri);
+        }
+    }
+
+    private void completeAuth(Uri uri) {
+        O_AUTH_MANAGER.continueAuthFlow(this, uri, (accessToken, scope, tokenType) -> {
+            GithubApi.requestGithubUsername(accessToken, (username -> {
+                mLoginButton.setText(R.string.logout);
+                mLoginButton.setEnabled(true);
+                mProgressBar.setVisibility(View.INVISIBLE);
+                mUserText.setText(getString(R.string.logged_in, username));
+                mLoggedIn = true;
+            }));
+        });
+    }
+}