windows: added headless inappwebview initial implementation

flutter_inappwebview_windows/lib/src/in_app_webview/headless_in_app_webview.dart

@@ -274,7 +274,7 @@ class WindowsHeadlessInAppWebView extends PlatformHeadlessInAppWebView
 
   dynamic _controllerFromPlatform;
 
-  WindowsHeadlessInAppWebViewCreationParams get _macosParams =>
+  WindowsHeadlessInAppWebViewCreationParams get _windowsParams =>
       params as WindowsHeadlessInAppWebViewCreationParams;
 
   _init() {
@@ -284,7 +284,7 @@ class WindowsHeadlessInAppWebView extends PlatformHeadlessInAppWebView
     _controllerFromPlatform =
         params.controllerFromPlatform?.call(_webViewController!) ??
             _webViewController!;
-    _macosParams.findInteractionController?.init(id);
+    _windowsParams.findInteractionController?.init(id);
     channel =
         MethodChannel('com.pichillilorenzo/flutter_headless_inappwebview_$id');
     handler = _handleMethod;
@@ -320,8 +320,8 @@ class WindowsHeadlessInAppWebView extends PlatformHeadlessInAppWebView
             initialSettings.toMap();
 
     Map<String, dynamic> pullToRefreshSettings =
-        _macosParams.pullToRefreshController?.params.settings.toMap() ??
+        _windowsParams.pullToRefreshController?.params.settings.toMap() ??
-            _macosParams.pullToRefreshController?.params.options.toMap() ??
+            _windowsParams.pullToRefreshController?.params.options.toMap() ??
             PullToRefreshSettings(enabled: false).toMap();
 
     Map<String, dynamic> args = <String, dynamic>{};
@@ -341,8 +341,14 @@ class WindowsHeadlessInAppWebView extends PlatformHeadlessInAppWebView
               'pullToRefreshSettings': pullToRefreshSettings,
               'initialSize': params.initialSize.toMap()
             });
-    await _sharedChannel.invokeMethod('run', args);
+    try {
-    _running = true;
+      await _sharedChannel.invokeMethod('run', args);
+      _running = true;
+    } catch (e) {
+      _running = false;
+      _started = false;
+      throw e;
+    }
   }
 
   void _inferInitialSettings(InAppWebViewSettings settings) {
@@ -420,8 +426,8 @@ class WindowsHeadlessInAppWebView extends PlatformHeadlessInAppWebView
     _webViewController?.dispose();
     _webViewController = null;
     _controllerFromPlatform = null;
-    _macosParams.pullToRefreshController?.dispose();
+    _windowsParams.pullToRefreshController?.dispose();
-    _macosParams.findInteractionController?.dispose();
+    _windowsParams.findInteractionController?.dispose();
   }
 }
 

flutter_inappwebview_windows/lib/src/inappwebview_platform.dart

@@ -3,6 +3,7 @@ import 'package:flutter_inappwebview_platform_interface/flutter_inappwebview_pla
 import 'in_app_browser/in_app_browser.dart';
 import 'in_app_webview/in_app_webview.dart';
 import 'in_app_webview/in_app_webview_controller.dart';
+import 'in_app_webview/headless_in_app_webview.dart';
 
 /// Implementation of [InAppWebViewPlatform] using the WebKit API.
 class WindowsInAppWebViewPlatform extends InAppWebViewPlatform {
@@ -61,4 +62,15 @@ class WindowsInAppWebViewPlatform extends InAppWebViewPlatform {
   WindowsInAppBrowser createPlatformInAppBrowserStatic() {
     return WindowsInAppBrowser.static();
   }
+
+  /// Creates a new [WindowsHeadlessInAppWebView].
+  ///
+  /// This function should only be called by the app-facing package.
+  /// Look at using [HeadlessInAppWebView] in `flutter_inappwebview` instead.
+  @override
+  WindowsHeadlessInAppWebView createPlatformHeadlessInAppWebView(
+      PlatformHeadlessInAppWebViewCreationParams params,
+      ) {
+    return WindowsHeadlessInAppWebView(params);
+  }
 }

flutter_inappwebview_windows/windows/CMakeLists.txt

@@ -70,6 +70,8 @@ list(APPEND PLUGIN_SOURCES
   "types/user_script.h"
   "types/plugin_script.cpp"
   "types/plugin_script.h"
+  "types/size_2d.cpp"
+  "types/size_2d.h"
   "custom_platform_view/custom_platform_view.cc"
   "custom_platform_view/custom_platform_view.h"
   "custom_platform_view/texture_bridge.cc"
@@ -96,6 +98,12 @@ list(APPEND PLUGIN_SOURCES
   "in_app_webview/in_app_webview_manager.h"
   "in_app_webview/webview_channel_delegate.cpp"
   "in_app_webview/webview_channel_delegate.h"
+  "headless_in_app_webview/headless_in_app_webview.cpp"
+  "headless_in_app_webview/headless_in_app_webview.h"
+  "headless_in_app_webview/headless_in_app_webview_manager.cpp"
+  "headless_in_app_webview/headless_in_app_webview_manager.h"
+  "headless_in_app_webview/headless_webview_channel_delegate.cpp"
+  "headless_in_app_webview/headless_webview_channel_delegate.h"
   "in_app_browser/in_app_browser_settings.cpp"
   "in_app_browser/in_app_browser_settings.h"
   "in_app_browser/in_app_browser_manager.cpp"

flutter_inappwebview_windows/windows/flutter_inappwebview_windows_plugin.cpp

@@ -1,8 +1,8 @@
 #include "flutter_inappwebview_windows_plugin.h"
 
-#include <flutter/method_channel.h>
 #include <flutter/plugin_registrar_windows.h>
 
+#include "headless_in_app_webview/headless_in_app_webview_manager.h"
 #include "in_app_browser/in_app_browser_manager.h"
 #include "in_app_webview/in_app_webview_manager.h"
 
@@ -25,6 +25,7 @@ namespace flutter_inappwebview_plugin
   {
     inAppWebViewManager = std::make_unique<InAppWebViewManager>(this);
     inAppBrowserManager = std::make_unique<InAppBrowserManager>(this);
+    headlessInAppWebViewManager = std::make_unique<HeadlessInAppWebViewManager>(this);
   }
 
   FlutterInappwebviewWindowsPlugin::~FlutterInappwebviewWindowsPlugin()

flutter_inappwebview_windows/windows/flutter_inappwebview_windows_plugin.h

@@ -8,12 +8,14 @@ namespace flutter_inappwebview_plugin
 {
   class InAppWebViewManager;
   class InAppBrowserManager;
+  class HeadlessInAppWebViewManager;
 
   class FlutterInappwebviewWindowsPlugin : public flutter::Plugin {
   public:
     flutter::PluginRegistrarWindows* registrar;
     std::unique_ptr<InAppWebViewManager> inAppWebViewManager;
     std::unique_ptr<InAppBrowserManager> inAppBrowserManager;
+    std::unique_ptr<HeadlessInAppWebViewManager> headlessInAppWebViewManager;
 
     static void RegisterWithRegistrar(flutter::PluginRegistrarWindows* registrar);
 

flutter_inappwebview_windows/windows/headless_in_app_webview/headless_in_app_webview.cpp

@@ -0,0 +1,59 @@
+#include "../utils/log.h"
+#include "headless_in_app_webview.h"
+
+namespace flutter_inappwebview_plugin
+{
+  using namespace Microsoft::WRL;
+
+  HeadlessInAppWebView::HeadlessInAppWebView(const FlutterInappwebviewWindowsPlugin* plugin, const HeadlessInAppWebViewCreationParams& params, const HWND parentWindow, std::unique_ptr<InAppWebView> webView)
+    : plugin(plugin), id(params.id),
+    webView(std::move(webView)),
+    channelDelegate(std::make_unique<HeadlessWebViewChannelDelegate>(this, plugin->registrar->messenger()))
+  {
+    prepare(params);
+    ShowWindow(parentWindow, SW_HIDE);
+  }
+
+  void HeadlessInAppWebView::prepare(const HeadlessInAppWebViewCreationParams& params)
+  {
+    if (!webView) {
+      return;
+    }
+    webView->webViewController->put_IsVisible(false);
+  }
+
+  void HeadlessInAppWebView::setSize(const std::shared_ptr<Size2D> size) const
+  {
+    if (!webView) {
+      return;
+    }
+    RECT rect = {
+      0, 0, (LONG)size->width, (LONG)size->height
+    };
+    webView->webViewController->put_Bounds(rect);
+  }
+
+  std::shared_ptr<Size2D> HeadlessInAppWebView::getSize() const
+  {
+    if (!webView) {
+      return std::make_shared<Size2D>(-1.0, -1.0);
+    }
+    RECT rect;
+    webView->webViewController->get_Bounds(&rect);
+    auto width = rect.right - rect.left;
+    auto height = rect.bottom - rect.top;
+    return std::make_shared<Size2D>((double)width, (double)height);
+  }
+
+  HeadlessInAppWebView::~HeadlessInAppWebView()
+  {
+    debugLog("dealloc HeadlessInAppWebView");
+    if (webView && webView->webViewController) {
+      HWND parentWindow;
+      if (succeededOrLog(webView->webViewController->get_ParentWindow(&parentWindow))) {
+        DestroyWindow(parentWindow);
+      }
+    }
+    webView = nullptr;
+  }
+}

flutter_inappwebview_windows/windows/headless_in_app_webview/headless_in_app_webview.h

@@ -0,0 +1,35 @@
+#ifndef FLUTTER_INAPPWEBVIEW_PLUGIN_HEADLESS_IN_APP_WEBVIEW_H_
+#define FLUTTER_INAPPWEBVIEW_PLUGIN_HEADLESS_IN_APP_WEBVIEW_H_
+
+#include "../flutter_inappwebview_windows_plugin.h"
+#include "../in_app_webview/in_app_webview.h"
+#include "../types/size_2d.h"
+#include "headless_webview_channel_delegate.h"
+
+namespace flutter_inappwebview_plugin
+{
+  struct HeadlessInAppWebViewCreationParams {
+    const std::string id;
+    const std::shared_ptr<Size2D> initialSize;
+  };
+
+  class HeadlessInAppWebView
+  {
+  public:
+    static inline const wchar_t* CLASS_NAME = L"HeadlessInAppWebView";
+    static inline const std::string METHOD_CHANNEL_NAME_PREFIX = "com.pichillilorenzo/flutter_headless_inappwebview_";
+
+    const FlutterInappwebviewWindowsPlugin* plugin;
+    std::string id;
+    std::unique_ptr<InAppWebView> webView;
+    std::unique_ptr<HeadlessWebViewChannelDelegate> channelDelegate;
+
+    HeadlessInAppWebView(const FlutterInappwebviewWindowsPlugin* plugin, const HeadlessInAppWebViewCreationParams& params, const HWND parentWindow, std::unique_ptr<InAppWebView> webView);
+    ~HeadlessInAppWebView();
+
+    void prepare(const HeadlessInAppWebViewCreationParams& params);
+    void setSize(const std::shared_ptr<Size2D> size) const;
+    std::shared_ptr<Size2D> getSize() const;
+  };
+}
+#endif //FLUTTER_INAPPWEBVIEW_PLUGIN_HEADLESS_IN_APP_WEBVIEW_H_

flutter_inappwebview_windows/windows/headless_in_app_webview/headless_in_app_webview_manager.cpp

@@ -0,0 +1,136 @@
+#include <DispatcherQueue.h>
+#include <flutter/method_channel.h>
+#include <flutter/standard_method_codec.h>
+#include <shlobj.h>
+#include <windows.graphics.capture.h>
+
+#include "../in_app_webview/in_app_webview_settings.h"
+#include "../types/size_2d.h"
+#include "../types/url_request.h"
+#include "../types/user_script.h"
+#include "../utils/flutter.h"
+#include "../utils/log.h"
+#include "../utils/string.h"
+#include "../utils/vector.h"
+#include "headless_in_app_webview_manager.h"
+
+namespace flutter_inappwebview_plugin
+{
+  HeadlessInAppWebViewManager::HeadlessInAppWebViewManager(const FlutterInappwebviewWindowsPlugin* plugin)
+    : plugin(plugin),
+    ChannelDelegate(plugin->registrar->messenger(), HeadlessInAppWebViewManager::METHOD_CHANNEL_NAME)
+  {
+    windowClass_.lpszClassName = HeadlessInAppWebView::CLASS_NAME;
+    windowClass_.lpfnWndProc = &DefWindowProc;
+
+    RegisterClass(&windowClass_);
+  }
+
+  void HeadlessInAppWebViewManager::HandleMethodCall(const flutter::MethodCall<flutter::EncodableValue>& method_call,
+    std::unique_ptr<flutter::MethodResult<flutter::EncodableValue>> result)
+  {
+    auto* arguments = std::get_if<flutter::EncodableMap>(method_call.arguments());
+    auto& methodName = method_call.method_name();
+
+    if (string_equals(methodName, "run")) {
+      run(arguments, std::move(result));
+    }
+    else {
+      result->NotImplemented();
+    }
+  }
+
+  void HeadlessInAppWebViewManager::run(const flutter::EncodableMap* arguments, std::unique_ptr<flutter::MethodResult<flutter::EncodableValue>> result)
+  {
+    auto result_ = std::shared_ptr<flutter::MethodResult<flutter::EncodableValue>>(std::move(result));
+
+    auto id = get_fl_map_value<std::string>(*arguments, "id");
+    auto params = get_fl_map_value<flutter::EncodableMap>(*arguments, "params");
+
+    auto initialSize = std::make_shared<Size2D>(get_fl_map_value<flutter::EncodableMap>(params, "initialSize"));
+
+    auto settingsMap = get_fl_map_value<flutter::EncodableMap>(params, "initialSettings");
+    auto urlRequestMap = get_optional_fl_map_value<flutter::EncodableMap>(params, "initialUrlRequest");
+    auto initialFile = get_optional_fl_map_value<std::string>(params, "initialFile");
+    auto initialDataMap = get_optional_fl_map_value<flutter::EncodableMap>(params, "initialData");
+    auto initialUserScriptList = get_optional_fl_map_value<flutter::EncodableList>(params, "initialUserScripts");
+
+    RECT bounds;
+    GetClientRect(plugin->registrar->GetView()->GetNativeWindow(), &bounds);
+
+    auto initialWidth = initialSize->width >= 0 ? initialSize->width : bounds.right - bounds.left;
+    auto initialHeight = initialSize->height >= 0 ? initialSize->height : bounds.bottom - bounds.top;
+
+    auto hwnd = CreateWindowEx(0, windowClass_.lpszClassName, L"", 0, 0,
+      0, (int)initialWidth, (int)initialHeight,
+      plugin->registrar->GetView()->GetNativeWindow(),
+      nullptr,
+      windowClass_.hInstance, nullptr);
+
+    InAppWebView::createInAppWebViewEnv(hwnd, false,
+      [=](wil::com_ptr<ICoreWebView2Environment> webViewEnv,
+        wil::com_ptr<ICoreWebView2Controller> webViewController,
+        wil::com_ptr<ICoreWebView2CompositionController> webViewCompositionController)
+      {
+        if (webViewEnv && webViewController) {
+          auto initialSettings = std::make_unique<InAppWebViewSettings>(settingsMap);
+          std::optional<std::vector<std::shared_ptr<UserScript>>> initialUserScripts = initialUserScriptList.has_value() ?
+            functional_map(initialUserScriptList.value(), [](const flutter::EncodableValue& map) { return std::make_shared<UserScript>(std::get<flutter::EncodableMap>(map)); }) :
+            std::optional<std::vector<std::shared_ptr<UserScript>>>{};
+
+          InAppWebViewCreationParams params = {
+            id,
+            std::move(initialSettings),
+            initialUserScripts
+          };
+
+          auto inAppWebView = std::make_unique<InAppWebView>(plugin, params, hwnd,
+            std::move(webViewEnv), std::move(webViewController), nullptr
+          );
+
+          HeadlessInAppWebViewCreationParams headlessParams = {
+            id,
+            std::move(initialSize)
+          };
+
+          auto headlessInAppWebView = std::make_unique<HeadlessInAppWebView>(plugin,
+            headlessParams,
+            hwnd,
+            std::move(inAppWebView));
+
+          headlessInAppWebView->webView->initChannel(std::nullopt, std::nullopt);
+
+          if (headlessInAppWebView->channelDelegate) {
+            headlessInAppWebView->channelDelegate->onWebViewCreated();
+          }
+
+          std::optional<std::shared_ptr<URLRequest>> urlRequest = urlRequestMap.has_value() ? std::make_shared<URLRequest>(urlRequestMap.value()) : std::optional<std::shared_ptr<URLRequest>>{};
+          if (urlRequest.has_value()) {
+            headlessInAppWebView->webView->loadUrl(urlRequest.value());
+          }
+          else if (initialFile.has_value()) {
+            headlessInAppWebView->webView->loadFile(initialFile.value());
+          }
+          else if (initialDataMap.has_value()) {
+            headlessInAppWebView->webView->loadData(get_fl_map_value<std::string>(initialDataMap.value(), "data"));
+          }
+
+          webViews.insert({ id, std::move(headlessInAppWebView) });
+
+          result_->Success(true);
+        }
+        else {
+          result_->Error("0", "Cannot create the HeadlessInAppWebView instance!");
+        }
+      }
+    );
+  }
+
+  HeadlessInAppWebViewManager::~HeadlessInAppWebViewManager()
+  {
+    debugLog("dealloc HeadlessInAppWebViewManager");
+    webViews.clear();
+    UnregisterClass(windowClass_.lpszClassName, nullptr);
+    plugin = nullptr;
+  }
+}

flutter_inappwebview_windows/windows/headless_in_app_webview/headless_in_app_webview_manager.h

@@ -0,0 +1,36 @@
+#ifndef FLUTTER_INAPPWEBVIEW_PLUGIN_HEADLESS_IN_APP_WEBVIEW_MANAGER_H_
+#define FLUTTER_INAPPWEBVIEW_PLUGIN_HEADLESS_IN_APP_WEBVIEW_MANAGER_H_
+
+#include <flutter/method_channel.h>
+#include <map>
+#include <string>
+#include <wil/com.h>
+#include <winrt/base.h>
+
+#include "../flutter_inappwebview_windows_plugin.h"
+#include "../types/channel_delegate.h"
+#include "headless_in_app_webview.h"
+
+namespace flutter_inappwebview_plugin
+{
+  class HeadlessInAppWebViewManager : public ChannelDelegate
+  {
+  public:
+    static inline const std::string METHOD_CHANNEL_NAME = "com.pichillilorenzo/flutter_headless_inappwebview";
+
+    const FlutterInappwebviewWindowsPlugin* plugin;
+    std::map<std::string, std::unique_ptr<HeadlessInAppWebView>> webViews;
+
+    HeadlessInAppWebViewManager(const FlutterInappwebviewWindowsPlugin* plugin);
+    ~HeadlessInAppWebViewManager();
+
+    void HandleMethodCall(
+      const flutter::MethodCall<flutter::EncodableValue>& method_call,
+      std::unique_ptr<flutter::MethodResult<flutter::EncodableValue>> result);
+
+    void run(const flutter::EncodableMap* arguments, std::unique_ptr<flutter::MethodResult<flutter::EncodableValue>> result);
+  private:
+    WNDCLASS windowClass_ = {};
+  };
+}
+#endif //FLUTTER_INAPPWEBVIEW_PLUGIN_HEADLESS_IN_APP_WEBVIEW_MANAGER_H_

flutter_inappwebview_windows/windows/headless_in_app_webview/headless_webview_channel_delegate.cpp

@@ -0,0 +1,56 @@
+#include "../utils/flutter.h"
+#include "../utils/log.h"
+#include "../utils/strconv.h"
+#include "../utils/string.h"
+#include "headless_in_app_webview.h"
+#include "headless_webview_channel_delegate.h"
+
+#include "headless_in_app_webview_manager.h"
+
+namespace flutter_inappwebview_plugin
+{
+  HeadlessWebViewChannelDelegate::HeadlessWebViewChannelDelegate(HeadlessInAppWebView* webView, flutter::BinaryMessenger* messenger)
+    : webView(webView), ChannelDelegate(messenger, HeadlessInAppWebView::METHOD_CHANNEL_NAME_PREFIX + variant_to_string(webView->id))
+  {}
+
+  void HeadlessWebViewChannelDelegate::HandleMethodCall(const flutter::MethodCall<flutter::EncodableValue>& method_call,
+    std::unique_ptr<flutter::MethodResult<flutter::EncodableValue>> result)
+  {
+    if (!webView) {
+      result->Success();
+      return;
+    }
+
+    // auto& arguments = std::get<flutter::EncodableMap>(*method_call.arguments());
+    auto& methodName = method_call.method_name();
+
+    if (string_equals(methodName, "dispose")) {
+      if (webView->plugin && webView->plugin->headlessInAppWebViewManager) {
+        std::map<std::string, std::unique_ptr<HeadlessInAppWebView>>& webViews = webView->plugin->headlessInAppWebViewManager->webViews;
+        auto& id = webView->id;
+        if (map_contains(webViews, id)) {
+          webViews.erase(id);
+        }
+      }
+      result->Success();
+    }
+    else {
+      result->NotImplemented();
+    }
+  }
+
+  void HeadlessWebViewChannelDelegate::onWebViewCreated() const
+  {
+    if (!channel) {
+      return;
+    }
+
+    channel->InvokeMethod("onWebViewCreated", nullptr);
+  }
+
+  HeadlessWebViewChannelDelegate::~HeadlessWebViewChannelDelegate()
+  {
+    debugLog("dealloc HeadlessWebViewChannelDelegate");
+    webView = nullptr;
+  }
+}

flutter_inappwebview_windows/windows/headless_in_app_webview/headless_webview_channel_delegate.h

@@ -0,0 +1,27 @@
+#ifndef FLUTTER_INAPPWEBVIEW_PLUGIN_HEADLESS_WEBVIEW_CHANNEL_DELEGATE_H_
+#define FLUTTER_INAPPWEBVIEW_PLUGIN_HEADLESS_WEBVIEW_CHANNEL_DELEGATE_H_
+
+#include "../types/channel_delegate.h"
+#include <flutter/method_channel.h>
+
+namespace flutter_inappwebview_plugin
+{
+  class HeadlessInAppWebView;
+
+  class HeadlessWebViewChannelDelegate : public ChannelDelegate
+  {
+  public:
+    HeadlessInAppWebView* webView;
+
+    HeadlessWebViewChannelDelegate(HeadlessInAppWebView* webView, flutter::BinaryMessenger* messenger);
+    ~HeadlessWebViewChannelDelegate();
+
+    void HandleMethodCall(
+      const flutter::MethodCall<flutter::EncodableValue>& method_call,
+      std::unique_ptr<flutter::MethodResult<flutter::EncodableValue>> result);
+
+    void onWebViewCreated() const;
+  };
+}
+
+#endif //FLUTTER_INAPPWEBVIEW_PLUGIN_HEADLESS_WEBVIEW_CHANNEL_DELEGATE_H_

flutter_inappwebview_windows/windows/in_app_webview/in_app_webview.cpp

@@ -274,7 +274,7 @@ namespace flutter_inappwebview_plugin
             navigationActions_.insert({ navigationId, navigationAction });
           }
 
-          if (callShouldOverrideUrlLoading_ && requestMethod == nullptr) {
+          if (settings->useShouldOverrideUrlLoading && callShouldOverrideUrlLoading_ && requestMethod == nullptr) {
             // for some reason, we can't cancel and load an URL with other HTTP methods than GET,
             // so ignore the shouldOverrideUrlLoading event.
 
@@ -1187,21 +1187,20 @@ namespace flutter_inappwebview_plugin
   InAppWebView::~InAppWebView()
   {
     debugLog("dealloc InAppWebView");
-    HWND parentWindow;
+    HWND parentWindow = nullptr;
-    webViewController->get_ParentWindow(&parentWindow);
+    if (webViewCompositionController && succeededOrLog(webViewController->get_ParentWindow(&parentWindow))) {
-    if (webView) {
-      webView->Stop();
-    }
-    if (webViewController) {
-      webViewController->Close();
-    }
-    navigationActions_.clear();
-    inAppBrowser = nullptr;
-    plugin = nullptr;
-    if (webViewCompositionController) {
       // if it's an InAppWebView,
       // then destroy the Window created with it
       DestroyWindow(parentWindow);
     }
+    if (webView) {
+      failedLog(webView->Stop());
+    }
+    if (webViewController) {
+      failedLog(webViewController->Close());
+    }
+    navigationActions_.clear();
+    inAppBrowser = nullptr;
+    plugin = nullptr;
   }
 }

flutter_inappwebview_windows/windows/in_app_webview/webview_channel_delegate.cpp

@@ -22,7 +22,7 @@ namespace flutter_inappwebview_plugin
   {
     decodeResult = [](const flutter::EncodableValue* value)
       {
-        if (value->IsNull()) {
+        if (!value || value->IsNull()) {
           return NavigationActionPolicy::cancel;
         }
         auto navigationPolicy = std::get<int>(*value);

flutter_inappwebview_windows/windows/types/size_2d.cpp

@@ -0,0 +1,21 @@
+#include "size_2d.h"
+
+namespace flutter_inappwebview_plugin
+{
+    Size2D::Size2D(const double& width, const double& height)
+    : width(width), height(height)
+  {}
+
+    Size2D::Size2D(const flutter::EncodableMap& map)
+    : width(get_fl_map_value<double>(map, "width")),
+      height(get_fl_map_value<double>(map, "height"))
+  {}
+
+  flutter::EncodableMap Size2D::toEncodableMap() const
+  {
+    return flutter::EncodableMap{
+      {"width", width},
+      {"height", height}
+    };
+  }
+}

flutter_inappwebview_windows/windows/types/size_2d.h

@@ -0,0 +1,25 @@
+#ifndef FLUTTER_INAPPWEBVIEW_PLUGIN_SIZE_2D_H_
+#define FLUTTER_INAPPWEBVIEW_PLUGIN_SIZE_2D_H_
+
+#include <flutter/standard_method_codec.h>
+#include <optional>
+
+#include "../utils/flutter.h"
+
+namespace flutter_inappwebview_plugin
+{
+  class Size2D
+  {
+  public:
+    const double width;
+    const double height;
+
+    Size2D(const double& width, const double& height);
+    Size2D(const flutter::EncodableMap& map);
+    ~Size2D() = default;
+
+    flutter::EncodableMap toEncodableMap() const;
+  };
+}
+
+#endif //FLUTTER_INAPPWEBVIEW_PLUGIN_SIZE_2D_H_