Added requestPostMessageChannel, postMessage, isEngagementSignalsApiAvailable methods on ChromeSafariBrowser for Android, Added onMessageChannelReady, onPostMessage, onVerticalScrollEvent, onGreatestScrollPercentageIncreased, onSessionEnded events on ChromeSafariBrowser for Android

CHANGELOG.md

@@ -1,3 +1,8 @@
+## 6.0.0-beta.27
+
+- Added `requestPostMessageChannel`, `postMessage`, `isEngagementSignalsApiAvailable` methods on `ChromeSafariBrowser` for Android
+- Added `onMessageChannelReady`, `onPostMessage`, `onVerticalScrollEvent`, `onGreatestScrollPercentageIncreased`, `onSessionEnded` events on `ChromeSafariBrowser` for Android
+
 ## 6.0.0-beta.26
 
 - Throw an error if any controller is used after being disposed

android/src/main/java/com/pichillilorenzo/flutter_inappwebview/chrome_custom_tabs/ChromeCustomTabsActivity.java

@@ -9,6 +9,7 @@ import android.graphics.Color;
 import android.net.Uri;
 import android.os.Build;
 import android.os.Bundle;
+import android.os.RemoteException;
 import android.widget.RemoteViews;
 
 import androidx.annotation.CallSuper;
@@ -19,6 +20,7 @@ import androidx.browser.customtabs.CustomTabsCallback;
 import androidx.browser.customtabs.CustomTabsIntent;
 import androidx.browser.customtabs.CustomTabsService;
 import androidx.browser.customtabs.CustomTabsSession;
+import androidx.browser.customtabs.EngagementSignalsCallback;
 
 import com.pichillilorenzo.flutter_inappwebview.R;
 import com.pichillilorenzo.flutter_inappwebview.types.AndroidResource;
@@ -32,12 +34,13 @@ import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
 
+import io.flutter.Log;
 import io.flutter.plugin.common.MethodChannel;
 
 public class ChromeCustomTabsActivity extends Activity implements Disposable {
   protected static final String LOG_TAG = "CustomTabsActivity";
   public static final String METHOD_CHANNEL_NAME_PREFIX = "com.pichillilorenzo/flutter_chromesafaribrowser_";
-  
+
   public String id;
   @Nullable
   public CustomTabsIntent.Builder builder;
@@ -76,7 +79,7 @@ public class ChromeCustomTabsActivity extends Activity implements Disposable {
 
     Bundle b = getIntent().getExtras();
     if (b == null) return;
-    
+
     id = b.getString("id");
 
     String managerId = b.getString("managerId");
@@ -143,13 +146,22 @@ public class ChromeCustomTabsActivity extends Activity implements Disposable {
       }
 
       @Override
-      public void extraCallback(@NonNull String callbackName, Bundle args) {}
+      public void extraCallback(@NonNull String callbackName, Bundle args) {
+      }
 
       @Override
-      public void onMessageChannelReady(Bundle extras) {}
+      public void onMessageChannelReady(Bundle extras) {
+        if (channelDelegate != null) {
+          channelDelegate.onMessageChannelReady();
+        }
+      }
 
       @Override
-      public void onPostMessage(@NonNull String message, Bundle extras) {}
+      public void onPostMessage(@NonNull String message, Bundle extras) {
+        if (channelDelegate != null) {
+          channelDelegate.onPostMessage(message);
+        }
+      }
 
       @Override
       public void onRelationshipValidationResult(@CustomTabsService.Relation int relation,
@@ -198,8 +210,41 @@ public class ChromeCustomTabsActivity extends Activity implements Disposable {
     return customTabActivityHelper.mayLaunchUrl(uri, null, bundleOtherLikelyURLs);
   }
 
+  @CallSuper
   public void customTabsConnected() {
     customTabsSession = customTabActivityHelper.getSession();
+
+    if (customTabsSession != null) {
+      try {
+        Bundle bundle = new Bundle();
+        if (customTabsSession.isEngagementSignalsApiAvailable(bundle)) {
+          customTabsSession.setEngagementSignalsCallback(new EngagementSignalsCallback() {
+            @Override
+            public void onVerticalScrollEvent(boolean isDirectionUp, @NonNull Bundle extras) {
+              if (channelDelegate != null) {
+                channelDelegate.onVerticalScrollEvent(isDirectionUp);
+              }
+            }
+
+            @Override
+            public void onGreatestScrollPercentageIncreased(int scrollPercentage, @NonNull Bundle extras) {
+              if (channelDelegate != null) {
+                channelDelegate.onGreatestScrollPercentageIncreased(scrollPercentage);
+              }
+            }
+
+            @Override
+            public void onSessionEnded(boolean didUserInteract, @NonNull Bundle extras) {
+              if (channelDelegate != null) {
+                channelDelegate.onSessionEnded(didUserInteract);
+              }
+            }
+          }, bundle);
+        }
+      } catch (Exception ignored) {
+      }
+    }
+
     // avoid webpage reopen if isBindSuccess is false: onServiceConnected->launchUrl
     if (isBindSuccess && initialUrl != null) {
       launchUrl(initialUrl, initialHeaders, initialReferrer, initialOtherLikelyURLs);
@@ -248,7 +293,7 @@ public class ChromeCustomTabsActivity extends Activity implements Disposable {
     }
 
     for (CustomTabsMenuItem menuItem : menuItems) {
-      builder.addMenuItem(menuItem.getLabel(), 
+      builder.addMenuItem(menuItem.getLabel(),
               createPendingIntent(menuItem.getId()));
     }
 

android/src/main/java/com/pichillilorenzo/flutter_inappwebview/chrome_custom_tabs/ChromeCustomTabsChannelDelegate.java

@@ -3,9 +3,12 @@ package com.pichillilorenzo.flutter_inappwebview.chrome_custom_tabs;
 import android.app.Activity;
 import android.content.Intent;
 import android.net.Uri;
+import android.os.Bundle;
+import android.os.RemoteException;
 
 import androidx.annotation.NonNull;
 import androidx.annotation.Nullable;
+import androidx.browser.customtabs.CustomTabsService;
 
 import com.pichillilorenzo.flutter_inappwebview.types.ChannelDelegateImpl;
 import com.pichillilorenzo.flutter_inappwebview.types.CustomTabsActionButton;
@@ -84,6 +87,35 @@ public class ChromeCustomTabsChannelDelegate extends ChannelDelegateImpl {
           result.success(false);
         }
         break;
+      case "requestPostMessageChannel":
+        if (chromeCustomTabsActivity != null && chromeCustomTabsActivity.customTabsSession != null) {
+          String sourceOrigin = (String) call.argument("sourceOrigin");
+          String targetOrigin = (String) call.argument("targetOrigin");
+          result.success(chromeCustomTabsActivity.customTabsSession.requestPostMessageChannel(Uri.parse(sourceOrigin),
+                  targetOrigin != null ? Uri.parse(targetOrigin) : null, new Bundle()));
+        } else {
+          result.success(false);
+        }
+        break;
+      case "postMessage":
+        if (chromeCustomTabsActivity != null && chromeCustomTabsActivity.customTabsSession != null) {
+          String message = (String) call.argument("message");
+          result.success(chromeCustomTabsActivity.customTabsSession.postMessage(message, new Bundle()));
+        } else {
+          result.success(CustomTabsService.RESULT_FAILURE_MESSAGING_ERROR);
+        }
+        break;
+      case "isEngagementSignalsApiAvailable":
+        if (chromeCustomTabsActivity != null && chromeCustomTabsActivity.customTabsSession != null) {
+          try {
+            result.success(chromeCustomTabsActivity.customTabsSession.isEngagementSignalsApiAvailable(new Bundle()));
+          } catch (Exception e) {
+            result.success(false);
+          }
+        } else {
+          result.success(false);
+        }
+        break;
       case "close":
         if (chromeCustomTabsActivity != null) {
           chromeCustomTabsActivity.onStop();
@@ -131,7 +163,7 @@ public class ChromeCustomTabsChannelDelegate extends ChannelDelegateImpl {
     channel.invokeMethod("onCompletedInitialLoad", obj);
   }
 
-  public void onNavigationEvent(int navigationEvent) {;
+  public void onNavigationEvent(int navigationEvent) {
     MethodChannel channel = getChannel();
     if (channel == null) return;
     Map<String, Object> obj = new HashMap<>();
@@ -175,6 +207,45 @@ public class ChromeCustomTabsChannelDelegate extends ChannelDelegateImpl {
     channel.invokeMethod("onRelationshipValidationResult", obj);
   }
 
+  public void onMessageChannelReady() {
+    MethodChannel channel = getChannel();
+    if (channel == null) return;
+    Map<String, Object> obj = new HashMap<>();
+    channel.invokeMethod("onMessageChannelReady", obj);
+  }
+
+  public void onPostMessage(@NonNull String message) {
+    MethodChannel channel = getChannel();
+    if (channel == null) return;
+    Map<String, Object> obj = new HashMap<>();
+    obj.put("message", message);
+    channel.invokeMethod("onPostMessage", obj);
+  }
+
+  public void onVerticalScrollEvent(boolean isDirectionUp) {
+    MethodChannel channel = getChannel();
+    if (channel == null) return;
+    Map<String, Object> obj = new HashMap<>();
+    obj.put("isDirectionUp", isDirectionUp);
+    channel.invokeMethod("onVerticalScrollEvent", obj);
+  }
+
+  public void onGreatestScrollPercentageIncreased(int scrollPercentage) {
+    MethodChannel channel = getChannel();
+    if (channel == null) return;
+    Map<String, Object> obj = new HashMap<>();
+    obj.put("scrollPercentage", scrollPercentage);
+    channel.invokeMethod("onGreatestScrollPercentageIncreased", obj);
+  }
+
+  public void onSessionEnded(boolean didUserInteract) {
+    MethodChannel channel = getChannel();
+    if (channel == null) return;
+    Map<String, Object> obj = new HashMap<>();
+    obj.put("didUserInteract", didUserInteract);
+    channel.invokeMethod("onSessionEnded", obj);
+  }
+
   @Override
   public void dispose() {
     super.dispose();

android/src/main/java/com/pichillilorenzo/flutter_inappwebview/chrome_custom_tabs/TrustedWebActivity.java

@@ -41,14 +41,6 @@ public class TrustedWebActivity extends ChromeCustomTabsActivity {
             referrer != null ? Uri.parse(referrer) : null, CHROME_CUSTOM_TAB_REQUEST_CODE);
   }
 
-  @Override
-  public void customTabsConnected() {
-    customTabsSession = customTabActivityHelper.getSession();
-    if (initialUrl != null) {
-      launchUrl(initialUrl, initialHeaders, initialReferrer, initialOtherLikelyURLs);
-    }
-  }
-
   private void prepareCustomTabs() {
     CustomTabColorSchemeParams.Builder defaultColorSchemeBuilder = new CustomTabColorSchemeParams.Builder();
     if (customSettings.toolbarBackgroundColor != null && !customSettings.toolbarBackgroundColor.isEmpty()) {

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

@@ -93,6 +93,7 @@
             android:name="io.flutter.embedded_views_preview"
             android:value="true" />
 
-
+        <service android:name="androidx.browser.customtabs.PostMessageService"
+            android:exported="true"/>
     </application>
 </manifest>

example/android/app/src/main/res/values/strings.xml

@@ -6,6 +6,12 @@
             \"target\": {
                 \"namespace\": \"web\",
                 \"site\": \"https://flutter.dev\"}
+        },
+        {
+            \"relation\": [\"delegate_permission/common.handle_all_urls\"],
+            \"target\": {
+                \"namespace\": \"web\",
+                \"site\": \"https://inappwebview.dev\"}
         }]
     </string>
 </resources>

example/integration_test/chrome_safari_browser/custom_tabs.dart

@@ -170,5 +170,52 @@ void customTabs() {
       expect(await ChromeSafariBrowser.getMaxToolbarItems(),
           greaterThanOrEqualTo(0));
     });
+
+    skippableTest('request and send post messages', () async {
+      var chromeSafariBrowser = MyChromeSafariBrowser();
+      expect(chromeSafariBrowser.isOpened(), false);
+
+      await chromeSafariBrowser.open(
+          url: TEST_CUSTOM_TABS_POST_MESSAGE_URL,
+          settings: ChromeSafariBrowserSettings(isSingleInstance: true));
+      await expectLater(chromeSafariBrowser.opened.future, completes);
+      expect(chromeSafariBrowser.isOpened(), true);
+
+      await expectLater(
+          chromeSafariBrowser.navigationFinished.future, completes);
+      expect(
+          await chromeSafariBrowser.requestPostMessageChannel(
+              sourceOrigin: WebUri(TEST_CUSTOM_TABS_POST_MESSAGE_URL.origin)),
+          true);
+      await expectLater(
+          chromeSafariBrowser.messageChannelReady.future, completes);
+      expect(await chromeSafariBrowser.postMessage("Message from Flutter"),
+          CustomTabsPostMessageResultType.SUCCESS);
+      await expectLater(chromeSafariBrowser.postMessageReceived.future,
+          completion("Message from JavaScript"));
+
+      await expectLater(chromeSafariBrowser.firstPageLoaded.future, completes);
+      await chromeSafariBrowser.close();
+      await expectLater(chromeSafariBrowser.closed.future, completes);
+      expect(chromeSafariBrowser.isOpened(), false);
+    });
+
+    skippableTest('Engagement Signals Api', () async {
+      var chromeSafariBrowser = MyChromeSafariBrowser();
+      expect(chromeSafariBrowser.isOpened(), false);
+
+      await chromeSafariBrowser.open(
+          url: TEST_URL_1,
+          settings: ChromeSafariBrowserSettings(isSingleInstance: true));
+      await expectLater(chromeSafariBrowser.opened.future, completes);
+
+      await expectLater(
+          chromeSafariBrowser.isEngagementSignalsApiAvailable(), completes);
+
+      await expectLater(chromeSafariBrowser.firstPageLoaded.future, completes);
+      await chromeSafariBrowser.close();
+      await expectLater(chromeSafariBrowser.closed.future, completes);
+      expect(chromeSafariBrowser.isOpened(), false);
+    });
   }, skip: shouldSkip);
 }

example/integration_test/chrome_safari_browser/trusted_web_activity.dart

@@ -13,12 +13,12 @@ void trustedWebActivity() {
       expect(chromeSafariBrowser.isOpened(), false);
 
       await chromeSafariBrowser.open(
-          url: TEST_URL_1,
+          url: TEST_TWA_URL,
           settings: ChromeSafariBrowserSettings(isTrustedWebActivity: true));
       await chromeSafariBrowser.opened.future;
       expect(chromeSafariBrowser.isOpened(), true);
       expect(() async {
-        await chromeSafariBrowser.open(url: TEST_CROSS_PLATFORM_URL_1);
+        await chromeSafariBrowser.open(url: TEST_TWA_URL);
       }, throwsAssertionError);
 
       await expectLater(chromeSafariBrowser.firstPageLoaded.future, completes);
@@ -32,13 +32,13 @@ void trustedWebActivity() {
       expect(chromeSafariBrowser.isOpened(), false);
 
       await chromeSafariBrowser.open(
-          url: TEST_URL_1,
+          url: TEST_TWA_URL,
           settings: ChromeSafariBrowserSettings(
               isTrustedWebActivity: true, isSingleInstance: true));
       await chromeSafariBrowser.opened.future;
       expect(chromeSafariBrowser.isOpened(), true);
       expect(() async {
-        await chromeSafariBrowser.open(url: TEST_CROSS_PLATFORM_URL_1);
+        await chromeSafariBrowser.open(url: TEST_TWA_URL);
       }, throwsAssertionError);
 
       await expectLater(chromeSafariBrowser.firstPageLoaded.future, completes);
@@ -57,11 +57,11 @@ void trustedWebActivity() {
       expect(
           await chromeSafariBrowser.validateRelationship(
               relation: CustomTabsRelationType.USE_AS_ORIGIN,
-              origin: TEST_CROSS_PLATFORM_URL_1),
+              origin: TEST_TWA_URL),
           true);
       expect(
           await chromeSafariBrowser.relationshipValidationResult.future, true);
-      await chromeSafariBrowser.launchUrl(url: TEST_CROSS_PLATFORM_URL_1);
+      await chromeSafariBrowser.launchUrl(url: TEST_TWA_URL);
       await chromeSafariBrowser.opened.future;
       expect(chromeSafariBrowser.isOpened(), true);
       await expectLater(chromeSafariBrowser.firstPageLoaded.future, completes);

example/integration_test/constants.dart

@@ -28,3 +28,7 @@ final TEST_SERVICE_WORKER_URL = WebUri(
 final TEST_WEBVIEW_ASSET_LOADER_DOMAIN = 'my.custom.domain.com';
 final TEST_WEBVIEW_ASSET_LOADER_URL = WebUri(
     'https://$TEST_WEBVIEW_ASSET_LOADER_DOMAIN/assets/flutter_assets/test_assets/website/index.html');
+final TEST_TWA_URL =
+    WebUri('https://inappwebview.dev/test-twa-postmessage.html');
+final TEST_CUSTOM_TABS_POST_MESSAGE_URL =
+    WebUri('https://inappwebview.dev/test-twa-postmessage.html');

example/integration_test/util.dart

@@ -118,6 +118,9 @@ class MyChromeSafariBrowser extends ChromeSafariBrowser {
   final Completer<void> closed = Completer<void>();
   final Completer<CustomTabsNavigationEventType?> navigationEvent =
       Completer<CustomTabsNavigationEventType?>();
+  final Completer<void> navigationFinished = Completer<void>();
+  final Completer<void> messageChannelReady = Completer<void>();
+  final Completer<String> postMessageReceived = Completer<String>();
   final Completer<bool> relationshipValidationResult = Completer<bool>();
 
   @override
@@ -140,6 +143,24 @@ class MyChromeSafariBrowser extends ChromeSafariBrowser {
     if (!navigationEvent.isCompleted) {
       navigationEvent.complete(type);
     }
+    if (!navigationFinished.isCompleted &&
+        type == CustomTabsNavigationEventType.FINISHED) {
+      navigationFinished.complete();
+    }
+  }
+
+  @override
+  void onMessageChannelReady() async {
+    if (!messageChannelReady.isCompleted) {
+      messageChannelReady.complete();
+    }
+  }
+
+  @override
+  void onPostMessage(String message) {
+    if (!postMessageReceived.isCompleted) {
+      postMessageReceived.complete();
+    }
   }
 
   @override

example/lib/chrome_safari_browser_example.screen.dart

@@ -19,6 +19,21 @@ class MyChromeSafariBrowser extends ChromeSafariBrowser {
   void onClosed() {
     print("ChromeSafari browser closed");
   }
+
+  @override
+  void onVerticalScrollEvent(bool isDirectionUp) {
+    print("onVerticalScrollEvent $isDirectionUp");
+  }
+
+  @override
+  void onGreatestScrollPercentageIncreased(int scrollPercentage) {
+    print("onGreatestScrollPercentageIncreased $scrollPercentage");
+  }
+
+  @override
+  void onSessionEnded(bool didUserInteract) {
+    print("onSessionEnded $didUserInteract");
+  }
 }
 
 class ChromeSafariBrowserExampleScreen extends StatefulWidget {
@@ -103,6 +118,8 @@ class _ChromeSafariBrowserExampleScreenState
                         dismissButtonStyle: DismissButtonStyle.CLOSE,
                         presentationStyle:
                             ModalPresentationStyle.OVER_FULL_SCREEN));
+                await Future.delayed(Duration(seconds: 5));
+                widget.browser.close();
               },
               child: Text("Open Chrome Safari Browser")),
         ));

lib/src/chrome_safari_browser/chrome_safari_browser.dart

@@ -5,6 +5,7 @@ import 'dart:typed_data';
 import 'package:flutter/foundation.dart';
 import 'package:flutter/services.dart';
 import '../types/custom_tabs_navigation_event_type.dart';
+import '../types/custom_tabs_post_message_result_type.dart';
 import '../types/custom_tabs_relation_type.dart';
 import '../types/prewarming_token.dart';
 import '../util.dart';
@@ -153,6 +154,25 @@ class ChromeSafariBrowser extends ChannelController {
           }
         }
         break;
+      case "onMessageChannelReady":
+        onMessageChannelReady();
+        break;
+      case "onPostMessage":
+        final String message = call.arguments["message"];
+        onPostMessage(message);
+        break;
+      case "onVerticalScrollEvent":
+        final bool isDirectionUp = call.arguments["isDirectionUp"];
+        onVerticalScrollEvent(isDirectionUp);
+        break;
+      case "onGreatestScrollPercentageIncreased":
+        final int scrollPercentage = call.arguments["scrollPercentage"];
+        onGreatestScrollPercentageIncreased(scrollPercentage);
+        break;
+      case "onSessionEnded":
+        final bool didUserInteract = call.arguments["didUserInteract"];
+        onSessionEnded(didUserInteract);
+        break;
       default:
         throw UnimplementedError("Unimplemented ${call.method} method");
     }
@@ -384,6 +404,67 @@ class ChromeSafariBrowser extends ChannelController {
     });
   }
 
+  ///Sends a request to create a two way postMessage channel between the client
+  ///and the browser.
+  ///If you want to specifying the target origin to communicate with, set the [targetOrigin].
+  ///
+  ///[sourceOrigin] - A origin that the client is requesting to be
+  ///identified as during the postMessage communication.
+  ///It has to either start with http or https.
+  ///
+  ///[targetOrigin] - The target Origin to establish the postMessage communication with.
+  ///This can be the app's package name, it has to either start with http or https.
+  ///
+  ///Returns whether the implementation accepted the request.
+  ///Note that returning true here doesn't mean an origin has already been
+  ///assigned as the validation is asynchronous.
+  ///
+  ///**Supported Platforms/Implementations**:
+  ///- Android ([Official API - CustomTabsSession.requestPostMessageChannel](https://developer.android.com/reference/androidx/browser/customtabs/CustomTabsSession#requestPostMessageChannel(android.net.Uri,android.net.Uri,android.os.Bundle)))
+  Future<bool> requestPostMessageChannel(
+      {required WebUri sourceOrigin, WebUri? targetOrigin}) async {
+    Map<String, dynamic> args = <String, dynamic>{};
+    args.putIfAbsent("sourceOrigin", () => sourceOrigin.toString());
+    args.putIfAbsent("targetOrigin", () => targetOrigin.toString());
+    return await channel?.invokeMethod<bool>(
+            "requestPostMessageChannel", args) ??
+        false;
+  }
+
+  ///Sends a postMessage request using the origin communicated via [requestPostMessageChannel].
+  ///Fails when called before [onMessageChannelReady] event.
+  ///
+  ///[message] – The message that is being sent.
+  ///
+  ///Returns an integer constant about the postMessage request result.
+  ///Will return CustomTabsService.RESULT_SUCCESS if successful.
+  ///
+  ///**Supported Platforms/Implementations**:
+  ///- Android ([Official API - CustomTabsSession.postMessage](https://developer.android.com/reference/androidx/browser/customtabs/CustomTabsSession#postMessage(java.lang.String,android.os.Bundle)))
+  Future<CustomTabsPostMessageResultType> postMessage(String message) async {
+    Map<String, dynamic> args = <String, dynamic>{};
+    args.putIfAbsent("message", () => message);
+    return CustomTabsPostMessageResultType.fromNativeValue(
+            await channel?.invokeMethod<int>("postMessage", args)) ??
+        CustomTabsPostMessageResultType.FAILURE_MESSAGING_ERROR;
+  }
+
+  ///Returns whether the Engagement Signals API is available.
+  ///The availability of the Engagement Signals API may change at runtime.
+  ///If an EngagementSignalsCallback has been set, an [onSessionEnded]
+  ///signal will be sent if the API becomes unavailable later.
+  ///
+  ///Returns whether the Engagement Signals API is available.
+  ///
+  ///**Supported Platforms/Implementations**:
+  ///- Android ([Official API - CustomTabsSession.isEngagementSignalsApiAvailable](https://developer.android.com/reference/androidx/browser/customtabs/CustomTabsSession#isEngagementSignalsApiAvailable(android.os.Bundle)))
+  Future<bool> isEngagementSignalsApiAvailable() async {
+    Map<String, dynamic> args = <String, dynamic>{};
+    return await channel?.invokeMethod<bool>(
+            "isEngagementSignalsApiAvailable", args) ??
+        false;
+  }
+
   ///On Android, returns `true` if Chrome Custom Tabs is available.
   ///On iOS, returns `true` if SFSafariViewController is available.
   ///Otherwise returns `false`.
@@ -393,7 +474,8 @@ class ChromeSafariBrowser extends ChannelController {
   ///- iOS
   static Future<bool> isAvailable() async {
     Map<String, dynamic> args = <String, dynamic>{};
-    return await _sharedChannel.invokeMethod("isAvailable", args);
+    return await _sharedChannel.invokeMethod<bool>("isAvailable", args) ??
+        false;
   }
 
   ///The maximum number of allowed secondary toolbar items.
@@ -515,6 +597,57 @@ class ChromeSafariBrowser extends ChannelController {
   ///- iOS ([Official API - SFSafariViewControllerDelegate.safariViewControllerWillOpenInBrowser](https://developer.apple.com/documentation/safariservices/sfsafariviewcontrollerdelegate/3650426-safariviewcontrollerwillopeninbr))
   void onWillOpenInBrowser() {}
 
+  ///Called when the [ChromeSafariBrowser] has requested a postMessage channel through
+  ///[requestPostMessageChannel] and the channel is ready for sending and receiving messages on both ends.
+  ///
+  ///**Supported Platforms/Implementations**:
+  ///- Android ([Official API - CustomTabsCallback.onMessageChannelReady](https://developer.android.com/reference/androidx/browser/customtabs/CustomTabsCallback#onMessageChannelReady(android.os.Bundle)))
+  void onMessageChannelReady() {}
+
+  ///Called when a tab controlled by this [ChromeSafariBrowser] has sent a postMessage.
+  ///If [postMessage] is called from a single thread, then the messages will be posted in the same order.
+  ///When received on the client side, it is the client's responsibility to preserve the ordering further.
+  ///
+  ///**Supported Platforms/Implementations**:
+  ///- Android ([Official API - CustomTabsCallback.onPostMessage](https://developer.android.com/reference/androidx/browser/customtabs/CustomTabsCallback#onPostMessage(java.lang.String,android.os.Bundle)))
+  void onPostMessage(String message) {}
+
+  ///Called when a user scrolls the tab.
+  ///
+  ///[isDirectionUp] - `false` when the user scrolls farther down the page,
+  ///and `true` when the user scrolls back up toward the top of the page.
+  ///
+  ///**NOTE**: available only if [isEngagementSignalsApiAvailable] returns `true`.
+  ///
+  ///**Supported Platforms/Implementations**:
+  ///- Android ([Official API - EngagementSignalsCallback.onVerticalScrollEvent](https://developer.android.com/reference/androidx/browser/customtabs/EngagementSignalsCallback#onVerticalScrollEvent(boolean,android.os.Bundle)))
+  void onVerticalScrollEvent(bool isDirectionUp) {}
+
+  ///Called when a user has reached a greater scroll percentage on the page. The greatest scroll
+  ///percentage is reset if the user navigates to a different page. If the current page's total
+  ///height changes, this method will be called again only if the scroll progress reaches a
+  ///higher percentage based on the new and current height of the page.
+  ///
+  ///[scrollPercentage] - An integer indicating the percent of scrollable progress
+  ///the user hasmade down the current page.
+  ///
+  ///**NOTE**: available only if [isEngagementSignalsApiAvailable] returns `true`.
+  ///
+  ///**Supported Platforms/Implementations**:
+  ///- Android ([Official API - EngagementSignalsCallback.onGreatestScrollPercentageIncreased](https://developer.android.com/reference/androidx/browser/customtabs/EngagementSignalsCallback#onGreatestScrollPercentageIncreased(int,android.os.Bundle)))
+  void onGreatestScrollPercentageIncreased(int scrollPercentage) {}
+
+  ///Called when a `CustomTabsSession` is ending or when no further Engagement Signals
+  ///callbacks are expected to report whether any user action has occurred during the session.
+  ///
+  ///[didUserInteract] - Whether the user has interacted with the page in any way, e.g. scrolling.
+  ///
+  ///**NOTE**: available only if [isEngagementSignalsApiAvailable] returns `true`.
+  ///
+  ///**Supported Platforms/Implementations**:
+  ///- Android ([Official API - EngagementSignalsCallback.onSessionEnded](https://developer.android.com/reference/androidx/browser/customtabs/EngagementSignalsCallback#onSessionEnded(boolean,android.os.Bundle)))
+  void onSessionEnded(bool didUserInteract) {}
+
   ///Event fired when the [ChromeSafariBrowser] is closed.
   ///
   ///**Supported Platforms/Implementations**:

lib/src/types/custom_tabs_post_message_result_type.dart

@@ -0,0 +1,36 @@
+import 'package:flutter/foundation.dart';
+import 'package:flutter_inappwebview_internal_annotations/flutter_inappwebview_internal_annotations.dart';
+
+part 'custom_tabs_post_message_result_type.g.dart';
+
+///Custom Tabs postMessage result type.
+@ExchangeableEnum()
+class CustomTabsPostMessageResultType_ {
+  // ignore: unused_field
+  final int _value;
+
+  // ignore: unused_field
+  final int? _nativeValue = null;
+
+  const CustomTabsPostMessageResultType_._internal(this._value);
+
+  ///Indicates that the postMessage request was accepted.
+  @EnumSupportedPlatforms(platforms: [EnumAndroidPlatform(value: 0)])
+  static const SUCCESS = const CustomTabsPostMessageResultType_._internal(0);
+
+  ///Indicates that the postMessage request was not allowed due to a bad argument
+  ///or requesting at a disallowed time like when in background.
+  @EnumSupportedPlatforms(platforms: [EnumAndroidPlatform(value: -1)])
+  static const FAILURE_DISALLOWED =
+      const CustomTabsPostMessageResultType_._internal(-1);
+
+  ///Indicates that the postMessage request has failed due to a `RemoteException`.
+  @EnumSupportedPlatforms(platforms: [EnumAndroidPlatform(value: -2)])
+  static const FAILURE_REMOTE_ERROR =
+      const CustomTabsPostMessageResultType_._internal(-2);
+
+  ///Indicates that the postMessage request has failed due to an internal error on the browser message channel.
+  @EnumSupportedPlatforms(platforms: [EnumAndroidPlatform(value: -3)])
+  static const FAILURE_MESSAGING_ERROR =
+      const CustomTabsPostMessageResultType_._internal(-3);
+}

lib/src/types/custom_tabs_post_message_result_type.g.dart

@@ -0,0 +1,141 @@
+// GENERATED CODE - DO NOT MODIFY BY HAND
+
+part of 'custom_tabs_post_message_result_type.dart';
+
+// **************************************************************************
+// ExchangeableEnumGenerator
+// **************************************************************************
+
+///Custom Tabs postMessage result type.
+class CustomTabsPostMessageResultType {
+  final int _value;
+  final int? _nativeValue;
+  const CustomTabsPostMessageResultType._internal(
+      this._value, this._nativeValue);
+// ignore: unused_element
+  factory CustomTabsPostMessageResultType._internalMultiPlatform(
+          int value, Function nativeValue) =>
+      CustomTabsPostMessageResultType._internal(value, nativeValue());
+
+  ///Indicates that the postMessage request was not allowed due to a bad argument
+  ///or requesting at a disallowed time like when in background.
+  ///
+  ///**Supported Platforms/Implementations**:
+  ///- Android native WebView
+  static final FAILURE_DISALLOWED =
+      CustomTabsPostMessageResultType._internalMultiPlatform(-1, () {
+    switch (defaultTargetPlatform) {
+      case TargetPlatform.android:
+        return -1;
+      default:
+        break;
+    }
+    return null;
+  });
+
+  ///Indicates that the postMessage request has failed due to an internal error on the browser message channel.
+  ///
+  ///**Supported Platforms/Implementations**:
+  ///- Android native WebView
+  static final FAILURE_MESSAGING_ERROR =
+      CustomTabsPostMessageResultType._internalMultiPlatform(-3, () {
+    switch (defaultTargetPlatform) {
+      case TargetPlatform.android:
+        return -3;
+      default:
+        break;
+    }
+    return null;
+  });
+
+  ///Indicates that the postMessage request has failed due to a `RemoteException`.
+  ///
+  ///**Supported Platforms/Implementations**:
+  ///- Android native WebView
+  static final FAILURE_REMOTE_ERROR =
+      CustomTabsPostMessageResultType._internalMultiPlatform(-2, () {
+    switch (defaultTargetPlatform) {
+      case TargetPlatform.android:
+        return -2;
+      default:
+        break;
+    }
+    return null;
+  });
+
+  ///Indicates that the postMessage request was accepted.
+  ///
+  ///**Supported Platforms/Implementations**:
+  ///- Android native WebView
+  static final SUCCESS =
+      CustomTabsPostMessageResultType._internalMultiPlatform(0, () {
+    switch (defaultTargetPlatform) {
+      case TargetPlatform.android:
+        return 0;
+      default:
+        break;
+    }
+    return null;
+  });
+
+  ///Set of all values of [CustomTabsPostMessageResultType].
+  static final Set<CustomTabsPostMessageResultType> values = [
+    CustomTabsPostMessageResultType.FAILURE_DISALLOWED,
+    CustomTabsPostMessageResultType.FAILURE_MESSAGING_ERROR,
+    CustomTabsPostMessageResultType.FAILURE_REMOTE_ERROR,
+    CustomTabsPostMessageResultType.SUCCESS,
+  ].toSet();
+
+  ///Gets a possible [CustomTabsPostMessageResultType] instance from [int] value.
+  static CustomTabsPostMessageResultType? fromValue(int? value) {
+    if (value != null) {
+      try {
+        return CustomTabsPostMessageResultType.values
+            .firstWhere((element) => element.toValue() == value);
+      } catch (e) {
+        return null;
+      }
+    }
+    return null;
+  }
+
+  ///Gets a possible [CustomTabsPostMessageResultType] instance from a native value.
+  static CustomTabsPostMessageResultType? fromNativeValue(int? value) {
+    if (value != null) {
+      try {
+        return CustomTabsPostMessageResultType.values
+            .firstWhere((element) => element.toNativeValue() == value);
+      } catch (e) {
+        return null;
+      }
+    }
+    return null;
+  }
+
+  ///Gets [int] value.
+  int toValue() => _value;
+
+  ///Gets [int?] native value.
+  int? toNativeValue() => _nativeValue;
+
+  @override
+  int get hashCode => _value.hashCode;
+
+  @override
+  bool operator ==(value) => value == _value;
+
+  @override
+  String toString() {
+    switch (_value) {
+      case -1:
+        return 'FAILURE_DISALLOWED';
+      case -3:
+        return 'FAILURE_MESSAGING_ERROR';
+      case -2:
+        return 'FAILURE_REMOTE_ERROR';
+      case 0:
+        return 'SUCCESS';
+    }
+    return _value.toString();
+  }
+}

lib/src/types/main.dart

@@ -223,3 +223,5 @@ export 'activity_button.dart' show ActivityButton;
 export 'ui_event_attribution.dart' show UIEventAttribution;
 export 'tracing_mode.dart' show TracingMode;
 export 'tracing_category.dart' show TracingCategory;
+export 'custom_tabs_post_message_result_type.dart'
+    show CustomTabsPostMessageResultType;

pubspec.yaml

@@ -1,6 +1,6 @@
 name: flutter_inappwebview
 description: A Flutter plugin that allows you to add an inline webview, to use an headless webview, and to open an in-app browser window.
-version: 6.0.0-beta.26
+version: 6.0.0-beta.27
 homepage: https://inappwebview.dev/
 repository: https://github.com/pichillilorenzo/flutter_inappwebview
 issue_tracker: https://github.com/pichillilorenzo/flutter_inappwebview/issues