[webview_flutter_android][webview_flutter_wkwebview] Adds support to retrieve native WebView

packages/webview_flutter/webview_flutter_android/CHANGELOG.md

@@ -1,3 +1,7 @@
+## 3.3.0
+
+* Adds support to access native `WebView`.
+
 ## 3.2.4
 
 * Renames Pigeon output files.

packages/webview_flutter/webview_flutter_android/android/src/main/java/io/flutter/plugins/webviewflutter/WebViewFlutterPlugin.java

@@ -7,8 +7,11 @@
 import android.content.Context;
 import android.os.Handler;
 import android.view.View;
+import android.webkit.WebView;
 import androidx.annotation.NonNull;
 import androidx.annotation.Nullable;
+import androidx.annotation.VisibleForTesting;
+import io.flutter.embedding.engine.FlutterEngine;
 import io.flutter.embedding.engine.plugins.FlutterPlugin;
 import io.flutter.embedding.engine.plugins.activity.ActivityAware;
 import io.flutter.embedding.engine.plugins.activity.ActivityPluginBinding;
@@ -33,12 +36,43 @@
  * <p>Call {@link #registerWith} to use the stable {@code io.flutter.plugin.common} package instead.
  */
 public class WebViewFlutterPlugin implements FlutterPlugin, ActivityAware {
-  private InstanceManager instanceManager;
+  @Nullable private InstanceManager instanceManager;
 
   private FlutterPluginBinding pluginBinding;
   private WebViewHostApiImpl webViewHostApi;
   private JavaScriptChannelHostApiImpl javaScriptChannelHostApi;
 
+  /**
+   * Retrieves the {@link WebView} that is associated with `identifer`.
+   *
+   * <p>See the Dart method `AndroidWebViewController.webViewIdentifier` to get the identifier of an
+   * underlying `WebView`.
+   *
+   * @param engine the execution environment the {@link WebViewFlutterPlugin} should belong to. If
+   *     the engine doesn't contain an attached instance of {@link WebViewFlutterPlugin}, this
+   *     method returns null.
+   * @param identifier the associated identifier of the `WebView`.
+   * @return the `WebView` associated with `identifier` or null if a `WebView` instance associated
+   *     with `identifier` could not be found.
+   */
+  @SuppressWarnings("unused")
+  @Nullable
+  public static WebView getWebView(FlutterEngine engine, long identifier) {
+    final WebViewFlutterPlugin webViewPlugin =
+        (WebViewFlutterPlugin) engine.getPlugins().get(WebViewFlutterPlugin.class);
+
+    if (webViewPlugin == null || webViewPlugin.instanceManager == null) {
+      return null;
+    }
+
+    final Object instance = webViewPlugin.instanceManager.getInstance(identifier);
+    if (instance instanceof WebView) {
+      return (WebView) instance;
+    }
+
+    return null;
+  }
+
   /**
    * Add an instance of this to {@link io.flutter.embedding.engine.plugins.PluginRegistry} to
    * register it.
@@ -148,7 +182,10 @@ public void onAttachedToEngine(@NonNull FlutterPluginBinding binding) {
 
   @Override
   public void onDetachedFromEngine(@NonNull FlutterPluginBinding binding) {
-    instanceManager.close();
+    if (instanceManager != null) {
+      instanceManager.close();
+      instanceManager = null;
+    }
   }
 
   @Override
@@ -179,6 +216,7 @@ private void updateContext(Context context) {
 
   /** Maintains instances used to communicate with the corresponding objects in Dart. */
   @Nullable
+  @VisibleForTesting
   public InstanceManager getInstanceManager() {
     return instanceManager;
   }

packages/webview_flutter/webview_flutter_android/android/src/test/java/io/flutter/plugins/webviewflutter/WebViewFlutterPluginTest.java

@@ -4,11 +4,16 @@
 
 package io.flutter.plugins.webviewflutter;
 
+import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertNotNull;
+import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.when;
 
 import android.content.Context;
+import android.webkit.WebView;
+import io.flutter.embedding.engine.FlutterEngine;
 import io.flutter.embedding.engine.plugins.FlutterPlugin;
+import io.flutter.embedding.engine.plugins.PluginRegistry;
 import io.flutter.plugin.common.BinaryMessenger;
 import io.flutter.plugin.platform.PlatformViewRegistry;
 import org.junit.Rule;
@@ -29,7 +34,7 @@ public class WebViewFlutterPluginTest {
   @Mock FlutterPlugin.FlutterPluginBinding mockPluginBinding;
 
   @Test
-  public void getInstanceManagerAfterOnAttachedToEngine() {
+  public void getWebView() {
     final WebViewFlutterPlugin webViewFlutterPlugin = new WebViewFlutterPlugin();
 
     when(mockPluginBinding.getApplicationContext()).thenReturn(mockContext);
@@ -38,7 +43,19 @@ public void getInstanceManagerAfterOnAttachedToEngine() {
 
     webViewFlutterPlugin.onAttachedToEngine(mockPluginBinding);
 
-    assertNotNull(webViewFlutterPlugin.getInstanceManager());
+    final InstanceManager instanceManager = webViewFlutterPlugin.getInstanceManager();
+    assertNotNull(instanceManager);
+
+    final WebView mockWebView = mock(WebView.class);
+    instanceManager.addDartCreatedInstance(mockWebView, 0);
+
+    final PluginRegistry mockPluginRegistry = mock(PluginRegistry.class);
+    when(mockPluginRegistry.get(WebViewFlutterPlugin.class)).thenReturn(webViewFlutterPlugin);
+
+    final FlutterEngine mockFlutterEngine = mock(FlutterEngine.class);
+    when(mockFlutterEngine.getPlugins()).thenReturn(mockPluginRegistry);
+
+    assertEquals(WebViewFlutterPlugin.getWebView(mockFlutterEngine, 0), mockWebView);
 
     webViewFlutterPlugin.onDetachedFromEngine(mockPluginBinding);
   }

packages/webview_flutter/webview_flutter_android/lib/src/android_webview_controller.dart

@@ -144,6 +144,16 @@ class AndroidWebViewController extends PlatformWebViewController {
     return webViewProxy.setWebContentsDebuggingEnabled(enabled);
   }
 
+  /// Identifier used to retrieve the underlying native `WKWebView`.
+  ///
+  /// This is typically used by other plugins to retrieve the native `WebView`
+  /// from an `InstanceManager`.
+  ///
+  /// See Java method `WebViewFlutterPlugin.getWebView`.
+  int get webViewIdentifier =>
+      // ignore: invalid_use_of_visible_for_testing_member
+      android_webview.WebView.api.instanceManager.getIdentifier(_webView)!;
+
   @override
   Future<void> loadFile(
     String absoluteFilePath,

packages/webview_flutter/webview_flutter_android/pubspec.yaml

@@ -2,7 +2,7 @@ name: webview_flutter_android
 description: A Flutter plugin that provides a WebView widget on Android.
 repository: https://github.com/flutter/plugins/tree/main/packages/webview_flutter/webview_flutter_android
 issue_tracker: https://github.com/flutter/flutter/issues?q=is%3Aissue+is%3Aopen+label%3A%22p%3A+webview%22
-version: 3.2.4
+version: 3.3.0
 
 environment:
   sdk: ">=2.17.0 <3.0.0"

packages/webview_flutter/webview_flutter_android/test/android_webview_controller_test.dart

@@ -14,6 +14,7 @@ import 'package:mockito/mockito.dart';
 import 'package:webview_flutter_android/src/android_proxy.dart';
 import 'package:webview_flutter_android/src/android_webview.dart'
     as android_webview;
+import 'package:webview_flutter_android/src/android_webview_api_impls.dart';
 import 'package:webview_flutter_android/src/instance_manager.dart';
 import 'package:webview_flutter_android/src/platform_views_service_proxy.dart';
 import 'package:webview_flutter_android/webview_flutter_android.dart';
@@ -884,6 +885,29 @@ void main() {
     verify(mockSettings.setMediaPlaybackRequiresUserGesture(true)).called(1);
   });
 
+  test('webViewIdentifier', () {
+    final MockWebView mockWebView = MockWebView();
+    final InstanceManager instanceManager = InstanceManager(
+      onWeakReferenceRemoved: (_) {},
+    );
+    instanceManager.addHostCreatedInstance(mockWebView, 0);
+
+    android_webview.WebView.api = WebViewHostApiImpl(
+      instanceManager: instanceManager,
+    );
+
+    final AndroidWebViewController controller = createControllerWithMocks(
+      mockWebView: mockWebView,
+    );
+
+    expect(
+      controller.webViewIdentifier,
+      0,
+    );
+
+    android_webview.WebView.api = WebViewHostApiImpl();
+  });
+
   group('AndroidWebViewWidget', () {
     testWidgets('Builds Android view using supplied parameters',
         (WidgetTester tester) async {

packages/webview_flutter/webview_flutter_wkwebview/CHANGELOG.md

@@ -1,3 +1,7 @@
+## 3.1.0
+
+* Adds support to access native `WKWebView`.
+
 ## 3.0.5
 
 * Renames Pigeon output files.

packages/webview_flutter/webview_flutter_wkwebview/example/ios/RunnerTests/FLTWebViewFlutterPluginTests.m

@@ -0,0 +1,27 @@
+// Copyright 2013 The Flutter Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#import <OCMock/OCMock.h>
+#import <XCTest/XCTest.h>
+
+@import webview_flutter_wkwebview;
+
+@interface FLTWebViewFlutterPluginTests : XCTestCase
+@end
+
+@implementation FLTWebViewFlutterPluginTests
+- (void)testWebViewForIdentifier {
+  WKWebView *webView = [[WKWebView alloc] init];
+  FWFInstanceManager *instanceManager = [[FWFInstanceManager alloc] init];
+  [instanceManager addDartCreatedInstance:webView withIdentifier:0];
+
+  id<FlutterPluginRegistry> mockPluginRegistry = OCMProtocolMock(@protocol(FlutterPluginRegistry));
+  OCMStub([mockPluginRegistry valuePublishedByPlugin:@"FLTWebViewFlutterPlugin"])
+      .andReturn(instanceManager);
+
+  XCTAssertEqualObjects([FLTWebViewFlutterPlugin webViewForIdentifier:0
+                                                   withPluginRegistry:mockPluginRegistry],
+                        webView);
+}
+@end

packages/webview_flutter/webview_flutter_wkwebview/ios/Classes/FLTWebViewFlutterPlugin.h

@@ -3,6 +3,26 @@
 // found in the LICENSE file.
 
 #import <Flutter/Flutter.h>
+#import <WebKit/WebKit.h>
+
+NS_ASSUME_NONNULL_BEGIN
 
 @interface FLTWebViewFlutterPlugin : NSObject <FlutterPlugin>
+/**
+Retrieves the `WKWebView` that is associated with `identifer`.
+
+See the Dart method `WebKitWebViewController.webViewIdentifier` to get the identifier of an
+underlying `WKWebView`.
+
+@param identifier The associated identifier of the `WebView`.
+@param registry The plugin registry the `FLTWebViewFlutterPlugin` should belong to. If
+       the registry doesn't contain an attached instance of `FLTWebViewFlutterPlugin`,
+       this method returns nil.
+@return The `WKWebView` associated with `identifier` or nil if a `WKWebView` instance associated
+with `identifier` could not be found.
+*/
++ (nullable WKWebView *)webViewForIdentifier:(long)identifier
+                          withPluginRegistry:(id<FlutterPluginRegistry>)registry;
 @end
+
+NS_ASSUME_NONNULL_END

packages/webview_flutter/webview_flutter_wkwebview/ios/Classes/FLTWebViewFlutterPlugin.m

@@ -108,6 +108,19 @@ + (void)registerWithRegistrar:(NSObject<FlutterPluginRegistrar> *)registrar {
   [registrar publish:instanceManager];
 }
 
++ (nullable WKWebView *)webViewForIdentifier:(long)identifier
+                          withPluginRegistry:(id<FlutterPluginRegistry>)registry {
+  FWFInstanceManager *instanceManager =
+      (FWFInstanceManager *)[registry valuePublishedByPlugin:@"FLTWebViewFlutterPlugin"];
+
+  NSObject *instance = [instanceManager instanceForIdentifier:identifier];
+  if ([instance isKindOfClass:[WKWebView class]]) {
+    return (WKWebView *)instance;
+  }
+
+  return nil;
+}
+
 - (void)detachFromEngineForRegistrar:(NSObject<FlutterPluginRegistrar> *)registrar {
   [registrar publish:[NSNull null]];
 }

packages/webview_flutter/webview_flutter_wkwebview/lib/src/webkit_webview_controller.dart

@@ -164,6 +164,16 @@ class WebKitWebViewController extends PlatformWebViewController {
   WebKitWebViewControllerCreationParams get _webKitParams =>
       params as WebKitWebViewControllerCreationParams;
 
+  /// Identifier used to retrieve the underlying native `WKWebView`.
+  ///
+  /// This is typically used by other plugins to retrieve the native `WKWebView`
+  /// from an `FWFInstanceManager`.
+  ///
+  /// See Objective-C method
+  /// `FLTWebViewFlutterPlugin:webViewForIdentifier:withPluginRegistry`.
+  int get webViewIdentifier =>
+      _webKitParams._instanceManager.getIdentifier(_webView)!;
+
   @override
   Future<void> loadFile(String absoluteFilePath) {
     return _webView.loadFileUrl(

packages/webview_flutter/webview_flutter_wkwebview/pubspec.yaml

@@ -2,7 +2,7 @@ name: webview_flutter_wkwebview
 description: A Flutter plugin that provides a WebView widget based on Apple's WKWebView control.
 repository: https://github.com/flutter/plugins/tree/main/packages/webview_flutter/webview_flutter_wkwebview
 issue_tracker: https://github.com/flutter/flutter/issues?q=is%3Aissue+is%3Aopen+label%3A%22p%3A+webview%22
-version: 3.0.5
+version: 3.1.0
 
 environment:
   sdk: ">=2.17.0 <3.0.0"

packages/webview_flutter/webview_flutter_wkwebview/test/webkit_webview_controller_test.dart

@@ -81,6 +81,7 @@ void main() {
             return nonNullMockWebView;
           },
         ),
+        instanceManager: instanceManager,
       );
 
       final WebKitWebViewController controller = WebKitWebViewController(
@@ -935,6 +936,25 @@ void main() {
 
       expect(callbackProgress, 0);
     });
+
+    test('webViewIdentifier', () {
+      final InstanceManager instanceManager = InstanceManager(
+        onWeakReferenceRemoved: (_) {},
+      );
+      final MockWKWebView mockWebView = MockWKWebView();
+      when(mockWebView.copy()).thenReturn(MockWKWebView());
+      instanceManager.addHostCreatedInstance(mockWebView, 0);
+
+      final WebKitWebViewController controller = createControllerWithMocks(
+        createMockWebView: (_, {dynamic observeValue}) => mockWebView,
+        instanceManager: instanceManager,
+      );
+
+      expect(
+        controller.webViewIdentifier,
+        instanceManager.getIdentifier(mockWebView),
+      );
+    });
   });
 
   group('WebKitJavaScriptChannelParams', () {