[webview_flutter] Implementation of the app facing WebViewController …

…for v4 (#6280)

packages/webview_flutter/webview_flutter/lib/src/v4/src/webview_controller.dart

@@ -0,0 +1,260 @@
+// 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:math';
+
+// TODO(a14n): remove this import once Flutter 3.1 or later reaches stable (including flutter/flutter#104231)
+// ignore: unnecessary_import
+import 'dart:typed_data';
+
+import 'package:flutter/material.dart';
+import 'package:webview_flutter_platform_interface/v4/webview_flutter_platform_interface.dart';
+
+/// Controls a WebView provided by the host platform.
+///
+/// Pass this to a [WebViewWidget] to display the WebView.
+class WebViewController {
+  /// Constructs a [WebViewController].
+  WebViewController()
+      : this.fromPlatformCreationParams(
+          const PlatformWebViewControllerCreationParams(),
+        );
+
+  /// Constructs a [WebViewController] from creation params for a specific
+  /// platform.
+  WebViewController.fromPlatformCreationParams(
+    PlatformWebViewControllerCreationParams params,
+  ) : this.fromPlatform(PlatformWebViewController(params));
+
+  /// Constructs a [WebViewController] from a specific platform implementation.
+  WebViewController.fromPlatform(this.platform);
+
+  /// Implementation of [PlatformWebViewController] for the current platform.
+  final PlatformWebViewController platform;
+
+  /// Loads the file located on the specified [absoluteFilePath].
+  ///
+  /// The [absoluteFilePath] parameter should contain the absolute path to the
+  /// file as it is stored on the device. For example:
+  /// `/Users/username/Documents/www/index.html`.
+  ///
+  /// Throws a `PlatformException` if the [absoluteFilePath] does not exist.
+  Future<void> loadFile(String absoluteFilePath) {
+    return platform.loadFile(absoluteFilePath);
+  }
+
+  /// Loads the Flutter asset specified in the pubspec.yaml file.
+  ///
+  /// Throws a `PlatformException` if [key] is not part of the specified assets
+  /// in the pubspec.yaml file.
+  Future<void> loadFlutterAsset(String key) {
+    assert(key.isNotEmpty);
+    return platform.loadFlutterAsset(key);
+  }
+
+  /// Loads the supplied HTML string.
+  ///
+  /// The [baseUrl] parameter is used when resolving relative URLs within the
+  /// HTML string.
+  Future<void> loadHtmlString(String html, {String? baseUrl}) {
+    assert(html.isNotEmpty);
+    return platform.loadHtmlString(html, baseUrl: baseUrl);
+  }
+
+  /// Makes a specific HTTP request ands loads the response in the webview.
+  ///
+  /// [method] must be one of the supported HTTP methods in [LoadRequestMethod].
+  ///
+  /// If [headers] is not empty, its key-value pairs will be added as the
+  /// headers for the request.
+  ///
+  /// If [body] is not null, it will be added as the body for the request.
+  ///
+  /// Throws an ArgumentError if [uri] has an empty scheme.
+  Future<void> loadRequest(
+    Uri uri, {
+    LoadRequestMethod method = LoadRequestMethod.get,
+    Map<String, String> headers = const <String, String>{},
+    Uint8List? body,
+  }) {
+    if (uri.scheme.isEmpty) {
+      throw ArgumentError('Missing scheme in uri: $uri');
+    }
+    return platform.loadRequest(LoadRequestParams(
+      uri: uri,
+      method: method,
+      headers: headers,
+      body: body,
+    ));
+  }
+
+  /// Returns the current URL that the WebView is displaying.
+  ///
+  /// If no URL was ever loaded, returns `null`.
+  Future<String?> currentUrl() {
+    return platform.currentUrl();
+  }
+
+  /// Checks whether there's a back history item.
+  Future<bool> canGoBack() {
+    return platform.canGoBack();
+  }
+
+  /// Checks whether there's a forward history item.
+  Future<bool> canGoForward() {
+    return platform.canGoForward();
+  }
+
+  /// Goes back in the history of this WebView.
+  ///
+  /// If there is no back history item this is a no-op.
+  Future<void> goBack() {
+    return platform.goBack();
+  }
+
+  /// Goes forward in the history of this WebView.
+  ///
+  /// If there is no forward history item this is a no-op.
+  Future<void> goForward() {
+    return platform.goForward();
+  }
+
+  /// Reloads the current URL.
+  Future<void> reload() {
+    return platform.reload();
+  }
+
+  /// Clears all caches used by the WebView.
+  ///
+  /// The following caches are cleared:
+  ///	1. Browser HTTP Cache.
+  ///	2. [Cache API](https://developers.google.com/web/fundamentals/instant-and-offline/web-storage/cache-api)
+  ///    caches. Service workers tend to use this cache.
+  ///	3. Application cache.
+  Future<void> clearCache() {
+    return platform.clearCache();
+  }
+
+  /// Clears the local storage used by the WebView.
+  Future<void> clearLocalStorage() {
+    return platform.clearLocalStorage();
+  }
+
+  /// Runs the given JavaScript in the context of the current page.
+  ///
+  /// The Future completes with an error if a JavaScript error occurred.
+  Future<void> runJavaScript(String javaScript) {
+    return platform.runJavaScript(javaScript);
+  }
+
+  /// Runs the given JavaScript in the context of the current page, and returns
+  /// the result.
+  ///
+  /// The Future completes with an error if a JavaScript error occurred, or if
+  /// the type the given expression evaluates to is unsupported. Unsupported
+  /// values include certain non-primitive types on iOS, as well as `undefined`
+  /// or `null` on iOS 14+.
+  Future<Object> runJavaScriptReturningResult(String javaScript) {
+    return platform.runJavaScriptReturningResult(javaScript);
+  }
+
+  /// Adds a new JavaScript channel to the set of enabled channels.
+  ///
+  /// The JavaScript code can then call `postMessage` on that object to send a
+  /// message that will be passed to [onMessageReceived].
+  ///
+  /// For example, after adding the following JavaScript channel:
+  ///
+  /// ```dart
+  /// final WebViewController controller = WebViewController();
+  /// controller.addJavaScriptChannel(
+  ///   name: 'Print',
+  ///   onMessageReceived: (JavascriptMessage message) {
+  ///     print(message.message);
+  ///   },
+  /// );
+  /// ```
+  ///
+  /// JavaScript code can call:
+  ///
+  /// ```javascript
+  /// Print.postMessage('Hello');
+  /// ```
+  ///
+  /// to asynchronously invoke the message handler which will print the message
+  /// to standard output.
+  ///
+  /// Adding a new JavaScript channel only takes affect after the next page is
+  /// loaded.
+  ///
+  /// A channel [name] cannot be the same for multiple channels.
+  Future<void> addJavaScriptChannel(
+    String name, {
+    required void Function(JavaScriptMessage) onMessageReceived,
+  }) {
+    assert(name.isNotEmpty);
+    return platform.addJavaScriptChannel(JavaScriptChannelParams(
+      name: name,
+      onMessageReceived: onMessageReceived,
+    ));
+  }
+
+  /// Removes the JavaScript channel with the matching name from the set of
+  /// enabled channels.
+  ///
+  /// This disables the channel with the matching name if it was previously
+  /// enabled through the [addJavaScriptChannel].
+  Future<void> removeJavaScriptChannel(String javaScriptChannelName) {
+    return platform.removeJavaScriptChannel(javaScriptChannelName);
+  }
+
+  /// The title of the currently loaded page.
+  Future<String?> getTitle() {
+    return platform.getTitle();
+  }
+
+  /// Sets the scrolled position of this view.
+  ///
+  /// The parameters `x` and `y` specify the position to scroll to in WebView
+  /// pixels.
+  Future<void> scrollTo(int x, int y) {
+    return platform.scrollTo(x, y);
+  }
+
+  /// Moves the scrolled position of this view.
+  ///
+  /// The parameters `x` and `y` specify the amount of WebView pixels to scroll
+  /// by.
+  Future<void> scrollBy(int x, int y) {
+    return platform.scrollBy(x, y);
+  }
+
+  /// Returns the current scroll position of this view.
+  ///
+  /// Scroll position is measured from the top left.
+  Future<Offset> getScrollPosition() async {
+    final Point<int> position = await platform.getScrollPosition();
+    return Offset(position.x.toDouble(), position.y.toDouble());
+  }
+
+  /// Whether to support zooming using the on-screen zoom controls and gestures.
+  Future<void> enableZoom(bool enabled) {
+    return platform.enableZoom(enabled);
+  }
+
+  /// Sets the current background color of this view.
+  Future<void> setBackgroundColor(Color color) {
+    return platform.setBackgroundColor(color);
+  }
+
+  /// Sets the JavaScript execution mode to be used by the WebView.
+  Future<void> setJavaScriptMode(JavaScriptMode javaScriptMode) {
+    return platform.setJavaScriptMode(javaScriptMode);
+  }
+
+  /// Sets the value used for the HTTP `User-Agent:` request header.
+  Future<void> setUserAgent(String? userAgent) {
+    return platform.setUserAgent(userAgent);
+  }
+}

packages/webview_flutter/webview_flutter/lib/src/v4/src/webview_cookie_manager.dart

@@ -8,21 +8,19 @@ import 'package:webview_flutter_platform_interface/v4/webview_flutter_platform_i
 class WebViewCookieManager {
   /// Constructs a [WebViewCookieManager].
   WebViewCookieManager()
-      : this.fromPlatform(
-          platform: PlatformWebViewCookieManager(
-            const PlatformWebViewCookieManagerCreationParams(),
-          ),
+      : this.fromPlatformCreationParams(
+          const PlatformWebViewCookieManagerCreationParams(),
         );
 
   /// Constructs a [WebViewCookieManager] from creation params for a specific
   /// platform.
   WebViewCookieManager.fromPlatformCreationParams(
     PlatformWebViewCookieManagerCreationParams params,
-  ) : this.fromPlatform(platform: PlatformWebViewCookieManager(params));
+  ) : this.fromPlatform(PlatformWebViewCookieManager(params));
 
   /// Constructs a [WebViewCookieManager] from a specific platform
   /// implementation.
-  WebViewCookieManager.fromPlatform({required this.platform});
+  WebViewCookieManager.fromPlatform(this.platform);
 
   /// Implementation of [PlatformWebViewCookieManager] for the current platform.
   final PlatformWebViewCookieManager platform;

packages/webview_flutter/webview_flutter/lib/src/v4/webview_flutter.dart

@@ -5,6 +5,7 @@
 library webview_flutter;
 
 export 'package:webview_flutter_platform_interface/v4/webview_flutter_platform_interface.dart'
-    show WebViewCookie;
+    show JavaScriptMessage, LoadRequestMethod, WebViewCookie;
 
+export 'src/webview_controller.dart';
 export 'src/webview_cookie_manager.dart';