UI/Qt: Set WC's max FPS to the refresh rate of the current screen

Author: https://github.com/Lubrsi
Commit: 124bdce99c
Pull-request: https://github.com/LadybirdBrowser/ladybird/pull/5606
Reviewed-by: https://github.com/Psychpsyo
Reviewed-by: https://github.com/kalenikaliaksandr

UI/Qt/BrowserWindow.cpp

@@ -82,18 +82,26 @@ BrowserWindow::BrowserWindow(Vector<URL::URL> const& initial_urls, IsPopupWindow
     // Listen for DPI changes
     m_device_pixel_ratio = devicePixelRatio();
     m_current_screen = screen();
+    m_refresh_rate = m_current_screen->refreshRate();
+
     if (QT_VERSION < QT_VERSION_CHECK(6, 6, 0) || QGuiApplication::platformName() != "wayland") {
         setAttribute(Qt::WA_NativeWindow);
         setAttribute(Qt::WA_DontCreateNativeAncestors);
         QObject::connect(m_current_screen, &QScreen::logicalDotsPerInchChanged, this, &BrowserWindow::device_pixel_ratio_changed);
+        QObject::connect(m_current_screen, &QScreen::refreshRateChanged, this, &BrowserWindow::refresh_rate_changed);
         QObject::connect(windowHandle(), &QWindow::screenChanged, this, [this](QScreen* screen) {
             if (m_device_pixel_ratio != devicePixelRatio())
                 device_pixel_ratio_changed(devicePixelRatio());
 
-            // Listen for logicalDotsPerInchChanged signals on new screen
+            if (m_refresh_rate != screen->refreshRate())
+                refresh_rate_changed(screen->refreshRate());
+
+            // Listen for logicalDotsPerInchChanged and refreshRateChanged signals on new screen
             QObject::disconnect(m_current_screen, &QScreen::logicalDotsPerInchChanged, nullptr, nullptr);
+            QObject::disconnect(m_current_screen, &QScreen::refreshRateChanged, nullptr, nullptr);
             m_current_screen = screen;
             QObject::connect(m_current_screen, &QScreen::logicalDotsPerInchChanged, this, &BrowserWindow::device_pixel_ratio_changed);
+            QObject::connect(m_current_screen, &QScreen::refreshRateChanged, this, &BrowserWindow::refresh_rate_changed);
         });
     }
 
@@ -893,6 +901,14 @@ void BrowserWindow::device_pixel_ratio_changed(qreal dpi)
     });
 }
 
+void BrowserWindow::refresh_rate_changed(qreal refresh_rate)
+{
+    m_refresh_rate = refresh_rate;
+    for_each_tab([this](auto& tab) {
+        tab.view().set_maximum_frames_per_second(m_refresh_rate);
+    });
+}
+
 void BrowserWindow::tab_title_changed(int index, QString const& title)
 {
     // NOTE: Qt uses ampersands for shortcut keys in tab titles, so we need to escape them.

UI/Qt/BrowserWindow.h

@@ -100,8 +100,11 @@ public:
 
     Tab* current_tab() const { return m_current_tab; }
 
+    double refresh_rate() const { return m_refresh_rate; }
+
 public slots:
     void device_pixel_ratio_changed(qreal dpi);
+    void refresh_rate_changed(qreal refresh_rate);
     void tab_title_changed(int index, QString const&);
     void tab_favicon_changed(int index, QIcon const& icon);
     void tab_audio_play_state_changed(int index, Web::HTML::AudioPlayState);
@@ -174,6 +177,7 @@ private:
 
     QScreen* m_current_screen;
     double m_device_pixel_ratio { 0 };
+    double m_refresh_rate { 60.0 };
 
     Web::CSS::PreferredColorScheme m_preferred_color_scheme;
     void set_preferred_color_scheme(Web::CSS::PreferredColorScheme color_scheme);

UI/Qt/Tab.cpp

@@ -56,7 +56,11 @@ Tab::Tab(BrowserWindow* window, RefPtr<WebView::WebContentClient> parent_client,
     m_layout->setSpacing(0);
     m_layout->setContentsMargins(0, 0, 0, 0);
 
-    m_view = new WebContentView(this, parent_client, page_index);
+    auto view_initial_state = WebContentViewInitialState {
+        .maximum_frames_per_second = window->refresh_rate(),
+    };
+
+    m_view = new WebContentView(this, parent_client, page_index, AK::move(view_initial_state));
     m_find_in_page = new FindInPageWidget(this, m_view);
     m_find_in_page->setVisible(false);
     m_toolbar = new QToolBar(this);

UI/Qt/WebContentView.cpp

@@ -47,7 +47,7 @@ namespace Ladybird {
 
 bool is_using_dark_system_theme(QWidget&);
 
-WebContentView::WebContentView(QWidget* window, RefPtr<WebView::WebContentClient> parent_client, size_t page_index)
+WebContentView::WebContentView(QWidget* window, RefPtr<WebView::WebContentClient> parent_client, size_t page_index, WebContentViewInitialState initial_state)
     : QWidget(window)
 {
     m_client_state.client = parent_client;
@@ -60,6 +60,7 @@ WebContentView::WebContentView(QWidget* window, RefPtr<WebView::WebContentClient
     setFocusPolicy(Qt::FocusPolicy::StrongFocus);
 
     m_device_pixel_ratio = devicePixelRatio();
+    m_maximum_frames_per_second = initial_state.maximum_frames_per_second;
 
     QObject::connect(qGuiApp, &QGuiApplication::screenRemoved, [this](QScreen*) {
         update_screen_rects();
@@ -538,6 +539,12 @@ void WebContentView::set_device_pixel_ratio(double device_pixel_ratio)
     handle_resize();
 }
 
+void WebContentView::set_maximum_frames_per_second(double maximum_frames_per_second)
+{
+    m_maximum_frames_per_second = maximum_frames_per_second;
+    client().async_set_maximum_frames_per_second(m_client_state.page_index, m_maximum_frames_per_second);
+}
+
 void WebContentView::update_viewport_size()
 {
     auto scaled_width = int(width() * m_device_pixel_ratio);

UI/Qt/WebContentView.h

@@ -43,12 +43,16 @@ namespace Ladybird {
 
 class Tab;
 
+struct WebContentViewInitialState {
+    double maximum_frames_per_second { 60.0 };
+};
+
 class WebContentView final
     : public QWidget
     , public WebView::ViewImplementation {
     Q_OBJECT
 public:
-    WebContentView(QWidget* window, RefPtr<WebView::WebContentClient> parent_client = nullptr, size_t page_index = 0);
+    WebContentView(QWidget* window, RefPtr<WebView::WebContentClient> parent_client = nullptr, size_t page_index = 0, WebContentViewInitialState initial_state = {});
     virtual ~WebContentView() override;
 
     Function<String(const URL::URL&, Web::HTML::ActivateTab)> on_tab_open_request;
@@ -76,6 +80,7 @@ public:
 
     void set_viewport_rect(Gfx::IntRect);
     void set_device_pixel_ratio(double);
+    void set_maximum_frames_per_second(double);
 
     enum class PaletteMode {
         Default,