Optimize Custom Tabs (Beta)

The web view APIs for ads makes app signals available to the tags in your CustomTabSession, helping to improve monetization for the web publishers that provided the content and to protect advertisers from spam.

How it works

Communication with the Google Mobile Ads SDK only happens in response to ad events triggered by any of the following:

• AdSense code
• Google Publisher Tag
• IMA for HTML5

The Google Mobile Ads SDK facilitates communication by opening a postMessage channel with the CustomTabsSession provided by the Android framework.

Warning: Don't call CustomTabsSession.requestPostMessageChannel() from your CustomTabsSession instance as this has unintended side effects. Use CustomTabsSession.postMessage() to send postMessages and CustomTabsCallback.onPostMessage() to listen for these events.

Prerequisites

• Google Mobile Ads SDK 23.0.0 or higher.
• An existing Chrome Custom Tabs implementation in your mobile app. See Warm-up and pre-fetch: using the Custom Tabs Service.
• Associate your mobile app to a website with Digital Asset Links.

• Add the following <meta-data> tag in your AndroidManifest.xml file to bypass the check for the APPLICATION_ID. If you miss this step and don't provide the <meta-data> tag, the Google Mobile Ads SDK throws an IllegalStateException on app start.

  <!-- Bypass APPLICATION_ID check for web view APIs for ads -->
   <meta-data
       android:name="com.google.android.gms.ads.INTEGRATION_MANAGER"
       android:value="webview"/>
  

Implementation

Within your Chrome Custom Tabs implementation, modify the code in the onCustomTabsServiceConnected() callback. Replace newSession() with MobileAds.registerCustomTabsSession(). This establishes a connection with the postMessage channel to enrich the ad tags with SDK signals. A Digital Asset Link is needed to connect the postMessage channel. Optionally, you can set the CustomTabsCallback parameter to listen for Chrome Custom Tab events.

You should still be able to send messages from the CustomTabsSession received from the Google Mobile Ads SDK but the port could change when the SDK requests a new channel that overrides the existing one.

The following code snippet shows how to register a CustomTabsSession using the Google Mobile Ads SDK:

Java

import com.google.android.gms.ads.MobileAds;

class MainActivity extends ComponentActivity {
  // Replace this URL with an associated website.
  private static final String ORIGIN = "https://www.google.com";
  private CustomTabsClient customTabsClient;
  private CustomTabsSession customTabsSession;

  @Override
  protected void onCreate(@Nullable Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    // Get the default browser package name, this will be null if
    // the default browser does not provide a CustomTabsService.
    String packageName = CustomTabsClient.getPackageName(getApplicationContext(), null);
    if (packageName == null) {
      // Do nothing as service connection is not supported.
      return;
    }

    CustomTabsClient.bindCustomTabsService(
        getApplicationContext(),
        packageName,
        new CustomTabsServiceConnection() {
          @Override
          public void onCustomTabsServiceConnected(@NonNull ComponentName name,
              @NonNull CustomTabsClient client) {
            customTabsClient = client;

            // Warm up the browser process.
            customTabsClient.warmup(0);
            // Create a new browser session using the Google Mobile Ads SDK.
            customTabsSession = MobileAds.registerCustomTabsSession(
                MainActivity.this.getApplicationContext(),
                client,
                // Checks the "Digital Asset Link" to connect the postMessage channel.
                ORIGIN,
                // Optional parameter to receive the delegated callbacks.
                customTabsCallback);

            // Create a new browser session if the Google Mobile Ads SDK is
            // unable to create one.
            if (customTabsSession == null) {
              customTabsSession = client.newSession(customTabsCallback);
            }

            // Pass the custom tabs session into the intent.
            CustomTabsIntent intent = new CustomTabsIntent.Builder(customTabsSession).build();
            intent.launchUrl(MainActivity.this, Uri.parse("YOUR_URL"));
          }

          @Override
          public void onServiceDisconnected(ComponentName componentName) {
            // Remove the custom tabs client and custom tabs session.
            customTabsClient = null;
            customTabsSession = null;
          }
        }

    );
  }

  // Listen for events from the CustomTabsSession delegated by the Google Mobile Ads SDK.
  private final CustomTabsCallback customTabsCallback = new CustomTabsCallback() {
    @Override
    public void onNavigationEvent(int navigationEvent, @Nullable Bundle extras) {
      // Called when a navigation event happens.
      super.onNavigationEvent(navigationEvent, extras);
    }

    @Override
    public void onMessageChannelReady(@Nullable Bundle extras) {
      // Called when the channel is ready for sending and receiving messages on both
      // ends. This will frequently happen, such as each time the SDK requests a
      // new channel.
      super.onMessageChannelReady(extras);
    }

    @Override
    public void onPostMessage(@NonNull String message, @Nullable Bundle extras) {
      // Called when a tab controlled by this CustomTabsSession has sent a postMessage.
      super.onPostMessage(message, extras);
    }

    @Override
    public void onRelationshipValidationResult(int relation, @NonNull Uri requestedOrigin,
        boolean result, @Nullable Bundle extras) {
      // Called when a relationship validation result is available.
      super.onRelationshipValidationResult(relation, requestedOrigin, result, extras);
    }

    @Override
    public void onActivityResized(int height, int width, @NonNull Bundle extras) {
      // Called when the tab is resized.
      super.onActivityResized(height, width, extras);
    }

    @Override
    public void extraCallback(@NonNull String callbackName, @Nullable Bundle args) {
      super.extraCallback(callbackName, args);
    }

    @Nullable
    @Override
    public Bundle extraCallbackWithResult(@NonNull String callbackName, @Nullable Bundle args) {
      return super.extraCallbackWithResult(callbackName, args);
    }
  };
}

Kotlin

import com.google.android.gms.ads.MobileAds

class MainActivity : ComponentActivity() {
  private var customTabsClient: CustomTabsClient? = null
  private var customTabsSession: CustomTabsSession? = null

  override fun onCreate(savedInstanceState: Bundle?) {
    super.onCreate(savedInstanceState)
    setContentView(R.layout.activity_main)

    // Get the default browser package name, this will be null if
    // the default browser does not provide a CustomTabsService.
    val packageName = CustomTabsClient.getPackageName(applicationContext, null);
    if (packageName == null) {
      // Do nothing as service connection is not supported.
      return
    }

    CustomTabsClient.bindCustomTabsService(
      applicationContext,
      packageName,
      object : CustomTabsServiceConnection() {
        override fun onCustomTabsServiceConnected(
          name: ComponentName, client: CustomTabsClient,
          ) {
            customTabsClient = client

            // Warm up the browser process.
            customTabsClient?.warmup(0L)
            // Create a new browser session using the Google Mobile Ads SDK.
            customTabsSession = MobileAds.registerCustomTabsSession(
              [e-mail],
              client,
              // Checks the "Digital Asset Link" to connect the postMessage channel.
              ORIGIN,
              // Optional parameter to receive the delegated callbacks.
              customTabsCallback
            )

            // Create a new browser session if the Google Mobile Ads SDK is
            // unable to create one.
            if (customTabsSession == null) {
              customTabsSession = client.newSession(customTabsCallback)
            }

            // Pass the custom tabs session into the intent.
            val customTabsIntent = CustomTabsIntent.Builder(customTabsSession).build()
            customTabsIntent.launchUrl(this@MainActivity,
                                      Uri.parse("YOUR_URL"))
          }

          override fun onServiceDisconnected(componentName: ComponentName) {
            // Remove the custom tabs client and custom tabs session.
            customTabsClient = null
            customTabsSession = null
          }
      })
  }

  // Listen for events from the CustomTabsSession delegated by the Google Mobile Ads SDK.
  private val customTabsCallback: CustomTabsCallback = object : CustomTabsCallback() {
    @Synchronized
    override fun onNavigationEvent(navigationEvent: Int, extras: Bundle?) {
      // Called when a navigation event happens.
    }

    @Synchronized
    override fun onMessageChannelReady(extras: Bundle?) {
      // Called when the channel is ready for sending and receiving messages on both
      // ends. This will frequently happen, such as each time the SDK requests a
      // new channel.
    }

    @Synchronized
    override fun onPostMessage(message: String, extras: Bundle?) {
      // Called when a tab controlled by this CustomTabsSession has sent a postMessage.
    }

    override fun onRelationshipValidationResult(
      relation: Int, requestedOrigin: Uri, result: Boolean, extras: Bundle?
    ) {
      // Called when a relationship validation result is available.
    }

    override fun onActivityResized(height: Int, width: Int, extras: Bundle) {
      // Called when the tab is resized.
    }

    override fun extraCallback(callbackName: String, args: Bundle?) {

    }

    override fun extraCallbackWithResult(callbackName: String, args: Bundle?): Bundle? {
      return null
    }
  }

  companion object {
    // Replace this URL with an associated website.
    const val ORIGIN = "https://www.google.com"
  }
}