Add hostingMode config option

Author: AshleyScirra

src/Config.cpp

@@ -12,6 +12,7 @@ ConfigJson LoadConfigJson(const std::string& path)
 	ret.startUrl = "https://github.com/WebView-CG/CanIWebView2";
 	ret.preferUnstableChannel = false;
 	ret.additionalBrowserArguments = "";
+	ret.hostingMode = "";
 
 	// If file does not exist, just use defaults
 	if (!FileExists(path))
@@ -39,5 +40,8 @@ ConfigJson LoadConfigJson(const std::string& path)
 	if (parsedJson.contains("additionalBrowserArguments"))
 		ret.additionalBrowserArguments = parsedJson["additionalBrowserArguments"].get<std::string>();
 
+	if (parsedJson.contains("hostingMode"))
+		ret.hostingMode = parsedJson["hostingMode"].get<std::string>();
+
 	return ret;
 }

src/Config.h

@@ -6,6 +6,7 @@ struct ConfigJson {
 	std::string startUrl;
 	bool preferUnstableChannel;
 	std::string additionalBrowserArguments;
+	std::string hostingMode;
 };
 
 ConfigJson LoadConfigJson(const std::string& path);

src/WebView.cpp

@@ -37,6 +37,14 @@ int CALLBACK WinMain(
 	std::string configJsonPath = FolderFromPath(GetModulePath()) + "config.json";
 	ConfigJson configJson = LoadConfigJson(configJsonPath);
 
+	// If config.json specifies the hosting mode as "window-to-visual", force this hosting mode by setting the
+	// environment variable COREWEBVIEW2_FORCED_HOSTING_MODE to COREWEBVIEW2_HOSTING_MODE_WINDOW_TO_VISUAL.
+	// See: https://learn.microsoft.com/en-us/microsoft-edge/webview2/concepts/windowed-vs-visual-hosting
+	if (configJson.hostingMode == "window-to-visual")
+	{
+		SetEnvironmentVariable(L"COREWEBVIEW2_FORCED_HOSTING_MODE", L"COREWEBVIEW2_HOSTING_MODE_WINDOW_TO_VISUAL");
+	}
+
 	/////////////////////////////////////////////////////
 	// Register window class
 	WNDCLASSEX wcex;