qt_web_browser: Focus on the first link element

Focusing on the first link element fixes element navigation upon loading the web applet in games such as Super Mario Odyssey

src/yuzu/applets/qt_web_browser.cpp

@@ -107,6 +107,7 @@ void QtNXWebEngineView::LoadLocalWebPage(const std::string& main_url,
     is_local = true;
 
     LoadExtractedFonts();
+    FocusFirstLinkElement();
     SetUserAgent(UserAgent::WebApplet);
     SetFinished(false);
     SetExitReason(Service::AM::Applets::WebExitReason::EndButtonPressed);
@@ -121,6 +122,7 @@ void QtNXWebEngineView::LoadExternalWebPage(const std::string& main_url,
                                             const std::string& additional_args) {
     is_local = false;
 
+    FocusFirstLinkElement();
     SetUserAgent(UserAgent::WebApplet);
     SetFinished(false);
     SetExitReason(Service::AM::Applets::WebExitReason::EndButtonPressed);
@@ -364,6 +366,17 @@ void QtNXWebEngineView::LoadExtractedFonts() {
         Qt::QueuedConnection);
 }
 
+void QtNXWebEngineView::FocusFirstLinkElement() {
+    QWebEngineScript focus_link_element;
+
+    focus_link_element.setName(QStringLiteral("focus_link_element.js"));
+    focus_link_element.setSourceCode(QString::fromStdString(FOCUS_LINK_ELEMENT_SCRIPT));
+    focus_link_element.setWorldId(QWebEngineScript::MainWorld);
+    focus_link_element.setInjectionPoint(QWebEngineScript::Deferred);
+    focus_link_element.setRunsOnSubFrames(true);
+    default_profile->scripts()->insert(focus_link_element);
+}
+
 #endif
 
 QtWebBrowser::QtWebBrowser(GMainWindow& main_window) {

src/yuzu/applets/qt_web_browser.h

@@ -161,6 +161,9 @@ private:
     /// Loads the extracted fonts using JavaScript.
     void LoadExtractedFonts();
 
+    /// Brings focus to the first available link element.
+    void FocusFirstLinkElement();
+
     InputCommon::InputSubsystem* input_subsystem;
 
     std::unique_ptr<UrlRequestInterceptor> url_interceptor;

src/yuzu/applets/qt_web_browser_scripts.h

@@ -73,6 +73,12 @@ constexpr char LOAD_NX_FONT[] = R"(
 })();
 )";
 
+constexpr char FOCUS_LINK_ELEMENT_SCRIPT[] = R"(
+if (document.getElementsByTagName("a").length > 0) {
+    document.getElementsByTagName("a")[0].focus();
+}
+)";
+
 constexpr char GAMEPAD_SCRIPT[] = R"(
 window.addEventListener("gamepadconnected", function(e) {
     console.log("Gamepad connected at index %d: %s. %d buttons, %d axes.",