Low level API

Although the recommended method to integrate your application with Custom Tabs is using the AndroidX Browser Library, a low level implementation is also available.

The complete implementation of the Support Library is available on GitHub and an be used as a start point. It also contains the AIDL files required to connect to the service, as the ones contained in the Chromium repository are not directly usable with Android Studio.

# Basics for Launching Custom Tabs using the Low Level API

// Using a VIEW intent for compatibility with any other browsers on device.
// Caller should not be setting FLAG_ACTIVITY_NEW_TASK or 
// FLAG_ACTIVITY_NEW_DOCUMENT. 
String url = ¨https://paul.kinlan.me/¨;
Intent intent = new Intent(Intent.ACTION_VIEW, Uri.parse(url)); 
//  Must have. Extra used to match the session. Its value is an IBinder passed
//  whilst creating a news session. See newSession() below. Even if the service is not 
//  used and there is no valid session id to be provided, this extra has to be present 
//  with a null value to launch a custom tab.

private static final String EXTRA_CUSTOM_TABS_SESSION = "android.support.customtabs.extra.SESSION";
Bundle extras = new Bundle;
extras.putBinder(EXTRA_CUSTOM_TABS_SESSION, 
   sessionICustomTabsCallback.asBinder() /* Set to null for no session */);
intent.putExtras(extras);

# Adding UI Customizations

UI Customizations are included by adding Extras to the ACTION_VIEW Intent. A full list of the extras keys used to customize the UI can be found on the CustomTabsIntent docs. An example on how to add a custom toolbar color follows:

// Extra that changes the background color for the address bar. colorInt is an int
// that specifies a Color.

private static final String EXTRA_CUSTOM_TABS_TOOLBAR_COLOR = "android.support.customtabs.extra.TOOLBAR_COLOR";
intent.putExtra(EXTRA_CUSTOM_TABS_TOOLBAR_COLOR, colorInt);

# Connecting to the Custom Tabs service

The Custom Tabs service can be used in the same way other Android Services are. The interface is created with AIDL and automatically creates a proxy service class for you.

Use the methods on the proxy service to warm-up, create sessions and pre-fetch

// Package name for the Chrome channel the client wants to connect to. This
// depends on the channel name.
// Stable = com.android.chrome
// Beta = com.chrome.beta
// Dev = com.chrome.dev
public static final String CUSTOM_TAB_PACKAGE_NAME = "com.chrome.dev";  // Change when in stable

// Action to add to the service intent. This action can be used as a way 
// generically pick apps that handle custom tabs for both activity and service 
// side implementations.
public static final String ACTION_CUSTOM_TABS_CONNECTION =
       "android.support.customtabs.action.CustomTabsService";
Intent serviceIntent = new Intent(ACTION_CUSTOM_TABS_CONNECTION);

serviceIntent.setPackage(CUSTOM_TAB_PACKAGE_NAME);
context.bindService(serviceIntent, mServiceConnection,
                    Context.BIND_AUTO_CREATE | Context.BIND_WAIVE_PRIORITY);