[webview_flutter_wkwebview] Add support for WKUIDelegate (flutter#4809)

Author: bparrishMines

Diff for: packages/webview_flutter/webview_flutter_wkwebview/lib/src/foundation/foundation.dart

@@ -0,0 +1,35 @@
+// 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 'dart:typed_data';
+
+import 'package:flutter/foundation.dart';
+
+/// A URL load request that is independent of protocol or URL scheme.
+///
+/// Wraps [NSUrlRequest](https://developer.apple.com/documentation/foundation/nsurlrequest?language=objc).
+@immutable
+class NSUrlRequest {
+  /// Constructs an [NSUrlRequest].
+  const NSUrlRequest({
+    required this.url,
+    this.httpMethod,
+    this.httpBody,
+    this.allHttpHeaderFields = const <String, String>{},
+  });
+
+  /// The URL being requested.
+  final String url;
+
+  /// The HTTP request method.
+  ///
+  /// The default HTTP method is “GET”.
+  final String? httpMethod;
+
+  /// Data sent as the message body of a request, as in an HTTP POST request.
+  final Uint8List? httpBody;
+
+  /// All of the HTTP header fields for a request.
+  final Map<String, String> allHttpHeaderFields;
+}

Diff for: packages/webview_flutter/webview_flutter_wkwebview/lib/src/web_kit/web_kit.dart

@@ -2,6 +2,10 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+import 'package:flutter/foundation.dart';
+
+import '../foundation/foundation.dart';
+
 /// Times at which to inject script content into a webpage.
 ///
 /// Wraps [WKUserScriptInjectionTime](https://developer.apple.com/documentation/webkit/wkuserscriptinjectiontime?language=objc).
@@ -42,12 +46,43 @@ enum WKAudiovisualMediaType {
   all,
 }
 
+/// An object that contains information about an action that causes navigation to occur.
+///
+/// Wraps [WKNavigationAction](https://developer.apple.com/documentation/webkit/wknavigationaction?language=objc).
+@immutable
+class WKNavigationAction {
+  /// Constructs a [WKNavigationAction].
+  const WKNavigationAction({required this.request, required this.targetFrame});
+
+  /// The URL request object associated with the navigation action.
+  final NSUrlRequest request;
+
+  /// The frame in which to display the new content.
+  final WKFrameInfo targetFrame;
+}
+
+/// An object that contains information about a frame on a webpage.
+///
+/// An instance of this class is a transient, data-only object; it does not
+/// uniquely identify a frame across multiple delegate method calls.
+///
+/// Wraps [WKFrameInfo](https://developer.apple.com/documentation/webkit/wkframeinfo?language=objc).
+@immutable
+class WKFrameInfo {
+  /// Construct a [WKFrameInfo].
+  const WKFrameInfo({required this.isMainFrame});
+
+  /// Indicates whether the frame is the web site's main frame or a subframe.
+  final bool isMainFrame;
+}
+
 /// A script that the web view injects into a webpage.
 ///
 /// Wraps [WKUserScript](https://developer.apple.com/documentation/webkit/wkuserscript?language=objc).
+@immutable
 class WKUserScript {
   /// Constructs a [UserScript].
-  WKUserScript(
+  const WKUserScript(
     this.source,
     this.injectionTime, {
     required this.isMainFrameOnly,
@@ -66,9 +101,10 @@ class WKUserScript {
 /// An object that encapsulates a message sent by JavaScript code from a webpage.
 ///
 /// Wraps [WKScriptMessage](https://developer.apple.com/documentation/webkit/wkscriptmessage?language=objc).
+@immutable
 class WKScriptMessage {
   /// Constructs a [WKScriptMessage].
-  WKScriptMessage({required this.name, this.body});
+  const WKScriptMessage({required this.name, this.body});
 
   /// The name of the message handler to which the message is sent.
   final String name;
@@ -88,7 +124,7 @@ class WKScriptMessageHandler {
   /// Use this method to respond to a message sent from the webpage’s
   /// JavaScript code. Use the [message] parameter to get the message contents and
   /// to determine the originating web view.
-  Future<void> setDidReceiveScriptMessage(
+  set didReceiveScriptMessage(
     void Function(
       WKUserContentController userContentController,
       WKScriptMessage message,
@@ -169,7 +205,7 @@ class WKUserContentController {
 
 /// A collection of properties that you use to initialize a web view.
 ///
-/// Wraps [WKWebViewConfiguration](https://developer.apple.com/documentation/webkit/wkwebviewconfiguration?language=objc)
+/// Wraps [WKWebViewConfiguration](https://developer.apple.com/documentation/webkit/wkwebviewconfiguration?language=objc).
 class WKWebViewConfiguration {
   /// Constructs a [WKWebViewConfiguration].
   WKWebViewConfiguration({required this.userContentController});
@@ -202,6 +238,22 @@ class WKWebViewConfiguration {
   }
 }
 
+/// The methods for presenting native user interface elements on behalf of a webpage.
+///
+/// Wraps [WKUIDelegate](https://developer.apple.com/documentation/webkit/wkuidelegate?language=objc).
+class WKUIDelegate {
+  /// Indicates a new [WebView] was requested to be created with [configuration].
+  set onCreateWebView(
+    void Function(
+      WKWebViewConfiguration configuration,
+      WKNavigationAction navigationAction,
+    )
+        onCreateeWebView,
+  ) {
+    throw UnimplementedError();
+  }
+}
+
 /// Object that displays interactive web content, such as for an in-app browser.
 ///
 /// Wraps [WKWebView](https://developer.apple.com/documentation/webkit/wkwebview?language=objc).
@@ -232,4 +284,17 @@ class WKWebView {
   /// property contains a default configuration object.
   late final WKWebViewConfiguration configuration =
       WKWebViewConfiguration._fromWebView(this);
+
+  /// Used to integrate custom user interface elements into web view interactions.
+  set uiDelegate(WKUIDelegate delegate) {
+    throw UnimplementedError();
+  }
+
+  /// Loads the web content referenced by the specified URL request object and navigates to it.
+  ///
+  /// Use this method to load a page from a local or network-based URL. For
+  /// example, you might use it to navigate to a network-based webpage.
+  Future<void> loadRequest(NSUrlRequest request) {
+    throw UnimplementedError();
+  }
 }

Diff for: packages/webview_flutter/webview_flutter_wkwebview/lib/src/web_kit_webview_widget.dart

@@ -87,6 +87,16 @@ class WebKitWebViewPlatformController extends WebViewPlatformController {
             userContentController: WKUserContentController(),
           ),
     );
+
+    webView.uiDelegate = uiDelegate;
+    uiDelegate.onCreateWebView = (
+      WKWebViewConfiguration configuration,
+      WKNavigationAction navigationAction,
+    ) {
+      if (!navigationAction.targetFrame.isMainFrame) {
+        webView.loadRequest(navigationAction.request);
+      }
+    };
   }
 
   final Map<String, WKScriptMessageHandler> _scriptMessageHandlers =
@@ -106,6 +116,10 @@ class WebKitWebViewPlatformController extends WebViewPlatformController {
   /// Represents the WebView maintained by platform code.
   late final WKWebView webView;
 
+  /// Used to integrate custom user interface elements into web view interactions.
+  @visibleForTesting
+  late final WKUIDelegate uiDelegate = webViewProxy.createUIDelgate();
+
   Future<void> _setCreationParams(
     CreationParams params, {
     required WKWebViewConfiguration configuration,
@@ -158,17 +172,15 @@ class WebKitWebViewPlatformController extends WebViewPlatformController {
         (String channelName) {
           final WKScriptMessageHandler handler =
               webViewProxy.createScriptMessageHandler()
-                ..setDidReceiveScriptMessage(
-                  (
-                    WKUserContentController userContentController,
-                    WKScriptMessage message,
-                  ) {
-                    javascriptChannelRegistry.onJavascriptChannelMessage(
-                      message.name,
-                      message.body!.toString(),
-                    );
-                  },
-                );
+                ..didReceiveScriptMessage = (
+                  WKUserContentController userContentController,
+                  WKScriptMessage message,
+                ) {
+                  javascriptChannelRegistry.onJavascriptChannelMessage(
+                    message.name,
+                    message.body!.toString(),
+                  );
+                };
           _scriptMessageHandlers[channelName] = handler;
 
           final String wrapperSource =
@@ -231,4 +243,9 @@ class WebViewWidgetProxy {
   WKScriptMessageHandler createScriptMessageHandler() {
     return WKScriptMessageHandler();
   }
+
+  /// Constructs a [WKUIDelegate].
+  WKUIDelegate createUIDelgate() {
+    return WKUIDelegate();
+  }
 }

Diff for: packages/webview_flutter/webview_flutter_wkwebview/test/src/web_kit_webview_widget_test.dart

@@ -9,6 +9,7 @@ import 'package:flutter_test/flutter_test.dart';
 import 'package:mockito/annotations.dart';
 import 'package:mockito/mockito.dart';
 import 'package:webview_flutter_platform_interface/webview_flutter_platform_interface.dart';
+import 'package:webview_flutter_wkwebview/src/foundation/foundation.dart';
 import 'package:webview_flutter_wkwebview/src/web_kit/web_kit.dart';
 import 'package:webview_flutter_wkwebview/src/web_kit_webview_widget.dart';
 
@@ -18,6 +19,7 @@ import 'web_kit_webview_widget_test.mocks.dart';
   WKScriptMessageHandler,
   WKWebView,
   WKWebViewConfiguration,
+  WKUIDelegate,
   WKUserContentController,
   JavascriptChannelRegistry,
   WebViewPlatformCallbacksHandler,
@@ -31,6 +33,7 @@ void main() {
     late MockWebViewWidgetProxy mockWebViewWidgetProxy;
     late MockWKUserContentController mockUserContentController;
     late MockWKWebViewConfiguration mockWebViewConfiguration;
+    late MockWKUIDelegate mockUIDelegate;
 
     late MockWebViewPlatformCallbacksHandler mockCallbacksHandler;
     late MockJavascriptChannelRegistry mockJavascriptChannelRegistry;
@@ -41,9 +44,11 @@ void main() {
       mockWebView = MockWKWebView();
       mockWebViewConfiguration = MockWKWebViewConfiguration();
       mockUserContentController = MockWKUserContentController();
+      mockUIDelegate = MockWKUIDelegate();
       mockWebViewWidgetProxy = MockWebViewWidgetProxy();
 
       when(mockWebViewWidgetProxy.createWebView(any)).thenReturn(mockWebView);
+      when(mockWebViewWidgetProxy.createUIDelgate()).thenReturn(mockUIDelegate);
       when(mockWebView.configuration).thenReturn(mockWebViewConfiguration);
       when(mockWebViewConfiguration.userContentController).thenReturn(
         mockUserContentController,
@@ -84,6 +89,26 @@ void main() {
       await buildWidget(tester);
     });
 
+    testWidgets('Requests to open a new window loads request in same window',
+        (WidgetTester tester) async {
+      await buildWidget(tester);
+
+      final dynamic onCreateWebView =
+          verify(mockUIDelegate.onCreateWebView = captureAny).captured.single
+              as void Function(WKWebViewConfiguration, WKNavigationAction);
+
+      const NSUrlRequest request = NSUrlRequest(url: 'https://google.com');
+      onCreateWebView(
+        mockWebViewConfiguration,
+        const WKNavigationAction(
+          request: request,
+          targetFrame: WKFrameInfo(isMainFrame: false),
+        ),
+      );
+
+      verify(mockWebView.loadRequest(request));
+    });
+
     group('$CreationParams', () {
       testWidgets('autoMediaPlaybackPolicy true', (WidgetTester tester) async {
         await buildWidget(
@@ -271,7 +296,7 @@ void main() {
             .single as MockWKScriptMessageHandler;
 
         final dynamic didReceiveScriptMessage =
-            verify(messageHandler.setDidReceiveScriptMessage(captureAny))
+            verify(messageHandler.didReceiveScriptMessage = captureAny)
                 .captured
                 .single as void Function(
           WKUserContentController userContentController,
@@ -280,7 +305,7 @@ void main() {
 
         didReceiveScriptMessage(
           mockUserContentController,
-          WKScriptMessage(name: 'hello', body: 'A message.'),
+          const WKScriptMessage(name: 'hello', body: 'A message.'),
         );
         verify(mockJavascriptChannelRegistry.onJavascriptChannelMessage(
           'hello',