[webview] Add new method for cross plugin webview access (#11714)

A new way of supporting cross plugin communication is coming in Flutter 3.44 which allows for access to plugin published values through the `FlutterPluginBinding` on Android and the `FlutterPluginRegistry` on iOS. Update native WebView access to support these new methods and deprecate the old methods.

refs: flutter/flutter#121527 flutter/flutter#182753

## Pre-Review Checklist

Author: fuzzybinary

packages/webview_flutter/webview_flutter_android/CHANGELOG.md

@@ -1,3 +1,7 @@
+## 4.13.0
+
+* Adds new method for accessing a native `WebView` from a `FlutterPluginBinding`.
+
 ## 4.12.2
 
 * Bumps the androidx group across 10 directories with 1 update.

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

@@ -8,6 +8,7 @@
 import androidx.annotation.NonNull;
 import androidx.annotation.Nullable;
 import io.flutter.embedding.engine.FlutterEngine;
+import io.flutter.embedding.engine.plugins.FlutterPlugin;
 
 /**
  * App and package facing native API provided by the `webview_flutter_android` plugin.
@@ -27,18 +28,44 @@ public interface WebViewFlutterAndroidExternalApi {
    * <p>See the Dart method `AndroidWebViewController.webViewIdentifier` to get the identifier of an
    * underlying `WebView`.
    *
+   * @param binding the plugin binding provided by the Flutter engine. If the binding 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.
+   */
+  @Nullable
+  static WebView getWebView(@NonNull FlutterPlugin.FlutterPluginBinding binding, long identifier) {
+    final WebViewFlutterPlugin webViewPlugin =
+        (WebViewFlutterPlugin) binding.getPlugin(WebViewFlutterPlugin.class);
+
+    return getWebViewFromPlugin(webViewPlugin, identifier);
+  }
+
+  /**
+   * Retrieves the {@link WebView} that is associated with `identifier`.
+   *
+   * <p>See the Dart method `AndroidWebViewController.webViewIdentifier` to get the identifier of an
+   * underlying `WebView`.
+   *
+   * @deprecated Use {@link #getWebView(FlutterPlugin.FlutterPluginBinding, long)} instead.
    * @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.
    */
+  @Deprecated
   @Nullable
   static WebView getWebView(@NonNull FlutterEngine engine, long identifier) {
     final WebViewFlutterPlugin webViewPlugin =
         (WebViewFlutterPlugin) engine.getPlugins().get(WebViewFlutterPlugin.class);
 
+    return getWebViewFromPlugin(webViewPlugin, identifier);
+  }
+
+  private static WebView getWebViewFromPlugin(WebViewFlutterPlugin webViewPlugin, long identifier) {
     if (webViewPlugin != null && webViewPlugin.getInstanceManager() != null) {
       final Object instance = webViewPlugin.getInstanceManager().getInstance(identifier);
       if (instance instanceof WebView) {

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

@@ -6,6 +6,7 @@
 
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertNotNull;
+import static org.junit.Assert.assertNull;
 import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.when;
 
@@ -33,6 +34,7 @@ public class WebViewFlutterAndroidExternalApiTest {
 
   @Mock FlutterPlugin.FlutterPluginBinding mockPluginBinding;
 
+  @SuppressWarnings("deprecation")
   @Test
   public void getWebView() {
     final WebViewFlutterPlugin webViewFlutterPlugin = new WebViewFlutterPlugin();
@@ -60,4 +62,34 @@ public void getWebView() {
 
     webViewFlutterPlugin.onDetachedFromEngine(mockPluginBinding);
   }
+
+  @Test
+  public void getWebViewFromBinding() {
+    final WebViewFlutterPlugin webViewFlutterPlugin = new WebViewFlutterPlugin();
+
+    when(mockPluginBinding.getApplicationContext()).thenReturn(mockContext);
+    when(mockPluginBinding.getPlatformViewRegistry()).thenReturn(mockViewRegistry);
+    when(mockPluginBinding.getBinaryMessenger()).thenReturn(mockBinaryMessenger);
+
+    webViewFlutterPlugin.onAttachedToEngine(mockPluginBinding);
+
+    final AndroidWebkitLibraryPigeonInstanceManager instanceManager =
+        webViewFlutterPlugin.getInstanceManager();
+    assertNotNull(instanceManager);
+
+    final WebView mockWebView = mock(WebView.class);
+    instanceManager.addDartCreatedInstance(mockWebView, 0);
+
+    when(mockPluginBinding.getPlugin(WebViewFlutterPlugin.class)).thenReturn(webViewFlutterPlugin);
+
+    assertEquals(WebViewFlutterAndroidExternalApi.getWebView(mockPluginBinding, 0), mockWebView);
+
+    webViewFlutterPlugin.onDetachedFromEngine(mockPluginBinding);
+  }
+
+  @Test
+  public void getWebViewFromBindingReturnsNullForUnknownPlugin() {
+    when(mockPluginBinding.getPlugin(WebViewFlutterPlugin.class)).thenReturn(null);
+    assertNull(WebViewFlutterAndroidExternalApi.getWebView(mockPluginBinding, 0));
+  }
 }

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/packages/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: 4.12.2
+version: 4.13.0
 
 environment:
   sdk: ^3.12.0

packages/webview_flutter/webview_flutter_wkwebview/CHANGELOG.md

@@ -1,3 +1,8 @@
+## 3.26.0
+
+* Adds new method for accessing a native `WKWebView` from a `FlutterPluginRegistrar`.
+* Updates minimum supported SDK version to Flutter 3.44/Dart 3.12.
+
 ## 3.25.1
 
 * Relands update to prevent message calls when application will terminate.

packages/webview_flutter/webview_flutter_wkwebview/darwin/Tests/FWFWebViewFlutterWKWebViewExternalAPITests.swift

@@ -27,11 +27,11 @@ class FWFWebViewFlutterWKWebViewExternalAPITests: XCTestCase {
 
     WebViewFlutterPlugin.register(with: registrar)
 
-    let plugin = registry.registrar.plugin as! WebViewFlutterPlugin?
+    let plugin = registry.registrar.publishedValue as! WebViewFlutterPlugin
 
     let webView = WKWebView(frame: .zero)
     let webViewIdentifier = 0
-    plugin?.proxyApiRegistrar?.instanceManager.addDartCreatedInstance(
+    plugin.proxyApiRegistrar?.instanceManager.addDartCreatedInstance(
       webView, withIdentifier: Int64(webViewIdentifier))
 
     let result = FWFWebViewFlutterWKWebViewExternalAPI.webView(
@@ -40,26 +40,54 @@ class FWFWebViewFlutterWKWebViewExternalAPITests: XCTestCase {
   }
 
   @MainActor func testWebViewForIdentifierHandlesIncorrectRegistry() {
-    let registry = TestRegistry(publishedValue: false)
+    let registry = TestRegistry()
     // Ensure that passing an empty registry, such as the FlutterAppDelegate
     // in an app that has adopted UIScene, gracefully returns nil.
     let result = FWFWebViewFlutterWKWebViewExternalAPI.webView(
       forIdentifier: 0, withPluginRegistry: registry)
     XCTAssertEqual(result, nil)
   }
+
+  // FlutterPluginRegistrar.valuePublished(byPlugin:) is not available on macOS. This
+  // can be removed once this method becomes available.
+  // See https://github.com/flutter/flutter/issues/186911.
+  #if os(iOS)
+    @MainActor func testWebViewForIdentifierFromRegistrar() {
+      let registry = TestRegistry()
+
+      #if os(iOS)
+        let registrar = registry.registrar(forPlugin: "")!
+      #elseif os(macOS)
+        let registrar = registry.registrar(forPlugin: "")
+      #endif
+
+      WebViewFlutterPlugin.register(with: registrar)
+
+      let plugin = registry.registrar.publishedValue as! WebViewFlutterPlugin
+
+      let webView = WKWebView(frame: .zero)
+      let webViewIdentifier = 0
+      plugin.proxyApiRegistrar?.instanceManager.addDartCreatedInstance(
+        webView, withIdentifier: Int64(webViewIdentifier))
+
+      let result = FWFWebViewFlutterWKWebViewExternalAPI.webView(
+        forIdentifier: Int64(webViewIdentifier), withPluginRegistrar: registrar)
+      XCTAssertEqual(result, webView)
+    }
+
+    @MainActor func testWebViewForIdentifierHandlesIncorrectRegistrar() {
+      let registrar = TestFlutterPluginRegistrar()
+      // Ensure that passing an empty registry, such as the FlutterAppDelegate
+      // in an app that has adopted UIScene, gracefully returns nil.
+      let result = FWFWebViewFlutterWKWebViewExternalAPI.webView(
+        forIdentifier: 0, withPluginRegistrar: registrar)
+      XCTAssertEqual(result, nil)
+    }
+  #endif
 }
 
 class TestRegistry: NSObject, FlutterPluginRegistry {
   let registrar = TestFlutterPluginRegistrar()
-  let publishedValue: Bool
-
-  init(publishedValue: Bool) {
-    self.publishedValue = publishedValue
-  }
-
-  convenience override init() {
-    self.init(publishedValue: true)
-  }
 
   #if os(iOS)
     func registrar(forPlugin pluginKey: String) -> FlutterPluginRegistrar? {
@@ -76,10 +104,7 @@ class TestRegistry: NSObject, FlutterPluginRegistry {
   }
 
   func valuePublished(byPlugin pluginKey: String) -> NSObject? {
-    if publishedValue && pluginKey == "WebViewFlutterPlugin" {
-      return registrar.plugin
-    }
-    return nil
+    return registrar.publishedValue
   }
 }
 
@@ -98,7 +123,7 @@ class TestFlutterTextureRegistry: NSObject, FlutterTextureRegistry {
 }
 
 class TestFlutterPluginRegistrar: NSObject, FlutterPluginRegistrar {
-  var plugin: WebViewFlutterPlugin? = nil
+  var publishedValue: NSObject? = nil
 
   #if os(iOS)
     var viewController: UIViewController?
@@ -144,7 +169,7 @@ class TestFlutterPluginRegistrar: NSObject, FlutterPluginRegistrar {
   }
 
   func publish(_ value: NSObject) {
-    plugin = (value as! WebViewFlutterPlugin)
+    publishedValue = value
   }
 
   func addMethodCallDelegate(_ delegate: FlutterPlugin, channel: FlutterMethodChannel) {
@@ -159,7 +184,10 @@ class TestFlutterPluginRegistrar: NSObject, FlutterPluginRegistrar {
     return ""
   }
 
-  func valuePublished(byPlugin: String) -> NSObject? {
+  func valuePublished(byPlugin pluginKey: String) -> NSObject? {
+    if pluginKey == "WebViewFlutterPlugin" {
+      return publishedValue
+    }
     return nil
   }
 }

packages/webview_flutter/webview_flutter_wkwebview/darwin/webview_flutter_wkwebview/Sources/webview_flutter_wkwebview/WebViewFlutterWKWebViewExternalAPI.swift

@@ -24,6 +24,11 @@ public class FWFWebViewFlutterWKWebViewExternalAPI: NSObject {
   ///
   /// See the Dart method `WebKitWebViewController.webViewIdentifier` to get the identifier of an
   /// underlying `WKWebView`.
+  #if os(iOS)
+    // Only deprecate this method on iOS until FlutterPluginRegistrar.valuePublished(byPlugin:) is
+    // available on macOS. See https://github.com/flutter/flutter/issues/186911.
+    @available(*, deprecated, message: "Use webView(forIdentifier:withPluginRegistrar:) instead.")
+  #endif
   @objc(webViewForIdentifier:withPluginRegistry:)
   public static func webView(
     forIdentifier identifier: Int64, withPluginRegistry registry: FlutterPluginRegistry
@@ -33,7 +38,33 @@ public class FWFWebViewFlutterWKWebViewExternalAPI: NSObject {
       return nil
     }
 
-    let webView: WKWebView? = webviewPlugin.proxyApiRegistrar?.instanceManager.instance(
+    return webview(forIdentifier: identifier, withPlugin: webviewPlugin)
+  }
+
+  // This method is only available on iOS until FlutterPluginRegistrar.valuePublished(byPlugin:) is
+  // available on macOS. See https://github.com/flutter/flutter/issues/186911.
+  #if os(iOS)
+    /// Retrieves the `WKWebView` that is associated with `identifier` using a FlutterPluginRegistrar
+    ///
+    /// See the Dart method `WebKitWebViewController.webViewIdentifier` to get the identifier of an
+    /// underlying `WKWebView`.
+    @objc(webViewForIdentifier:withPluginRegistrar:)
+    public static func webView(
+      forIdentifier identifier: Int64, withPluginRegistrar registrar: FlutterPluginRegistrar
+    ) -> WKWebView? {
+      let plugin = registrar.valuePublished(byPlugin: "WebViewFlutterPlugin")
+      guard let webviewPlugin = plugin as? WebViewFlutterPlugin else {
+        return nil
+      }
+
+      return webview(forIdentifier: identifier, withPlugin: webviewPlugin)
+    }
+  #endif
+
+  private static func webview(forIdentifier identifier: Int64, withPlugin: WebViewFlutterPlugin)
+    -> WKWebView?
+  {
+    let webView: WKWebView? = withPlugin.proxyApiRegistrar?.instanceManager.instance(
       forIdentifier: identifier)
     return webView
   }

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

@@ -14,16 +14,11 @@ class WebKitSslAuthError extends PlatformSslAuthError {
   WebKitSslAuthError({
     required super.certificate,
     required super.description,
-    required SecTrust trust,
+    required this._trust,
     required this.host,
     required this.port,
-    required Future<void> Function(
-      UrlSessionAuthChallengeDisposition disposition,
-      URLCredential? credential,
-    )
-    onResponse,
-  }) : _trust = trust,
-       _onResponse = onResponse;
+    required this._onResponse,
+  });
 
   final SecTrust _trust;
 

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

@@ -1353,10 +1353,7 @@ class WebKitNavigationDelegate extends PlatformNavigationDelegate {
 
 /// WebKit implementation of [PlatformWebViewPermissionRequest].
 class WebKitWebViewPermissionRequest extends PlatformWebViewPermissionRequest {
-  const WebKitWebViewPermissionRequest._({
-    required super.types,
-    required void Function(PermissionDecision decision) onDecision,
-  }) : _onDecision = onDecision;
+  const WebKitWebViewPermissionRequest._({required super.types, required this._onDecision});
 
   final void Function(PermissionDecision) _onDecision;
 

packages/webview_flutter/webview_flutter_wkwebview/pubspec.yaml

@@ -2,11 +2,11 @@ name: webview_flutter_wkwebview
 description: A Flutter plugin that provides a WebView widget based on Apple's WKWebView control.
 repository: https://github.com/flutter/packages/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: 3.25.1
+version: 3.26.0
 
 environment:
-  sdk: ^3.10.0
-  flutter: ">=3.38.0"
+  sdk: ^3.12.0
+  flutter: ">=3.44.0"
 
 flutter:
   plugin: