Ladybird/Qt: Listen to DPI changes and update WebContentView accordingly

Ladybird/Qt/BrowserWindow.cpp

@@ -27,6 +27,7 @@
 #include <QPlainTextEdit>
 #include <QShortcut>
 #include <QTabBar>
+#include <QWindow>
 
 namespace Ladybird {
 
@@ -55,6 +56,22 @@ BrowserWindow::BrowserWindow(Vector<URL> const& initial_urls, WebView::CookieJar
     m_tabs_container->setDocumentMode(true);
     m_tabs_container->setTabBarAutoHide(true);
 
+    // Listen for DPI changes
+    setAttribute(Qt::WA_NativeWindow);
+    setAttribute(Qt::WA_DontCreateNativeAncestors);
+    m_device_pixel_ratio = devicePixelRatio();
+    m_current_screen = screen();
+    QObject::connect(m_current_screen, &QScreen::logicalDotsPerInchChanged, this, &BrowserWindow::device_pixel_ratio_changed);
+    QObject::connect(windowHandle(), &QWindow::screenChanged, this, [this](QScreen* screen) {
+        if (m_device_pixel_ratio != screen->devicePixelRatio())
+            device_pixel_ratio_changed(screen->devicePixelRatio());
+
+        // Listen for logicalDotsPerInchChanged signals on new screen
+        QObject::disconnect(m_current_screen, &QScreen::logicalDotsPerInchChanged, nullptr, nullptr);
+        m_current_screen = screen;
+        QObject::connect(m_current_screen, &QScreen::logicalDotsPerInchChanged, this, &BrowserWindow::device_pixel_ratio_changed);
+    });
+
     auto* menu = menuBar()->addMenu("&File");
 
     auto* new_tab_action = new QAction("New &Tab", this);
@@ -562,6 +579,14 @@ int BrowserWindow::tab_index(Tab* tab)
     return m_tabs_container->indexOf(tab);
 }
 
+void BrowserWindow::device_pixel_ratio_changed(qreal dpi)
+{
+    m_device_pixel_ratio = dpi;
+    for_each_tab([this](auto& tab) {
+        tab.view().set_device_pixel_ratio(m_device_pixel_ratio);
+    });
+}
+
 void BrowserWindow::tab_title_changed(int index, QString const& title)
 {
     m_tabs_container->setTabText(index, title);

Ladybird/Qt/BrowserWindow.h

@@ -70,6 +70,7 @@ public:
     }
 
 public slots:
+    void device_pixel_ratio_changed(qreal dpi);
     void tab_title_changed(int index, QString const&);
     void tab_favicon_changed(int index, QIcon const& icon);
     Tab& new_tab(QString const&, Web::HTML::ActivateTab);
@@ -115,6 +116,9 @@ private:
         }
     }
 
+    QScreen* m_current_screen;
+    double m_device_pixel_ratio { 0 };
+
     QTabWidget* m_tabs_container { nullptr };
     Tab* m_current_tab { nullptr };
     QMenu* m_zoom_menu { nullptr };

Ladybird/Qt/InspectorWidget.cpp

@@ -12,6 +12,7 @@
 #include <QCloseEvent>
 #include <QMenu>
 #include <QVBoxLayout>
+#include <QWindow>
 
 namespace Ladybird {
 
@@ -123,6 +124,22 @@ InspectorWidget::InspectorWidget(QWidget* tab, WebContentView& content_view)
 
     setWindowTitle("Inspector");
     resize(875, 825);
+
+    // Listen for DPI changes
+    setAttribute(Qt::WA_NativeWindow);
+    setAttribute(Qt::WA_DontCreateNativeAncestors);
+    m_device_pixel_ratio = devicePixelRatio();
+    m_current_screen = screen();
+    QObject::connect(m_current_screen, &QScreen::logicalDotsPerInchChanged, this, &InspectorWidget::device_pixel_ratio_changed);
+    QObject::connect(windowHandle(), &QWindow::screenChanged, this, [this](QScreen* screen) {
+        if (m_device_pixel_ratio != screen->devicePixelRatio())
+            device_pixel_ratio_changed(screen->devicePixelRatio());
+
+        // Listen for logicalDotsPerInchChanged signals on new screen
+        QObject::disconnect(m_current_screen, &QScreen::logicalDotsPerInchChanged, nullptr, nullptr);
+        m_current_screen = screen;
+        QObject::connect(m_current_screen, &QScreen::logicalDotsPerInchChanged, this, &InspectorWidget::device_pixel_ratio_changed);
+    });
 }
 
 InspectorWidget::~InspectorWidget() = default;
@@ -147,6 +164,12 @@ void InspectorWidget::select_default_node()
     m_inspector_client->select_default_node();
 }
 
+void InspectorWidget::device_pixel_ratio_changed(qreal dpi)
+{
+    m_device_pixel_ratio = dpi;
+    m_inspector_view->set_device_pixel_ratio(m_device_pixel_ratio);
+}
+
 void InspectorWidget::closeEvent(QCloseEvent* event)
 {
     event->accept();

Ladybird/Qt/InspectorWidget.h

@@ -31,11 +31,17 @@ public:
     void select_hovered_node();
     void select_default_node();
 
+public slots:
+    void device_pixel_ratio_changed(qreal dpi);
+
 private:
     void closeEvent(QCloseEvent*) override;
 
     QPoint to_widget_position(Gfx::IntPoint) const;
 
+    QScreen* m_current_screen;
+    double m_device_pixel_ratio { 0 };
+
     WebContentView* m_inspector_view;
     OwnPtr<WebView::InspectorClient> m_inspector_client;
 

Ladybird/Qt/WebContentView.cpp

@@ -63,7 +63,6 @@ WebContentView::WebContentView(WebContentOptions const& web_content_options, Str
     setFocusPolicy(Qt::FocusPolicy::StrongFocus);
 
     m_device_pixel_ratio = devicePixelRatio();
-    m_inverse_pixel_scaling_ratio = 1.0 / m_device_pixel_ratio;
 
     verticalScrollBar()->setSingleStep(24);
     horizontalScrollBar()->setSingleStep(24);
@@ -325,8 +324,8 @@ KeyCode get_keycode_from_qt_keyboard_event(QKeyEvent const& event)
 void WebContentView::wheelEvent(QWheelEvent* event)
 {
     if (!event->modifiers().testFlag(Qt::ControlModifier)) {
-        Gfx::IntPoint position(event->position().x() / m_inverse_pixel_scaling_ratio, event->position().y() / m_inverse_pixel_scaling_ratio);
+        Gfx::IntPoint position(event->position().x() * m_device_pixel_ratio, event->position().y() * m_device_pixel_ratio);
-        Gfx::IntPoint screen_position(event->globalPosition().x() / m_inverse_pixel_scaling_ratio, event->globalPosition().y() / m_inverse_pixel_scaling_ratio);
+        Gfx::IntPoint screen_position(event->globalPosition().x() * m_device_pixel_ratio, event->globalPosition().y() * m_device_pixel_ratio);
         auto button = get_button_from_qt_event(*event);
         auto buttons = get_buttons_from_qt_event(*event);
         auto modifiers = get_modifiers_from_qt_mouse_event(*event);
@@ -351,8 +350,8 @@ void WebContentView::wheelEvent(QWheelEvent* event)
 
 void WebContentView::mouseMoveEvent(QMouseEvent* event)
 {
-    Gfx::IntPoint position(event->position().x() / m_inverse_pixel_scaling_ratio, event->position().y() / m_inverse_pixel_scaling_ratio);
+    Gfx::IntPoint position(event->position().x() * m_device_pixel_ratio, event->position().y() * m_device_pixel_ratio);
-    Gfx::IntPoint screen_position(event->globalPosition().x() / m_inverse_pixel_scaling_ratio, event->globalPosition().y() / m_inverse_pixel_scaling_ratio);
+    Gfx::IntPoint screen_position(event->globalPosition().x() * m_device_pixel_ratio, event->globalPosition().y() * m_device_pixel_ratio);
     auto buttons = get_buttons_from_qt_event(*event);
     auto modifiers = get_modifiers_from_qt_mouse_event(*event);
     client().async_mouse_move(to_content_position(position), screen_position, 0, buttons, modifiers);
@@ -360,8 +359,8 @@ void WebContentView::mouseMoveEvent(QMouseEvent* event)
 
 void WebContentView::mousePressEvent(QMouseEvent* event)
 {
-    Gfx::IntPoint position(event->position().x() / m_inverse_pixel_scaling_ratio, event->position().y() / m_inverse_pixel_scaling_ratio);
+    Gfx::IntPoint position(event->position().x() * m_device_pixel_ratio, event->position().y() * m_device_pixel_ratio);
-    Gfx::IntPoint screen_position(event->globalPosition().x() / m_inverse_pixel_scaling_ratio, event->globalPosition().y() / m_inverse_pixel_scaling_ratio);
+    Gfx::IntPoint screen_position(event->globalPosition().x() * m_device_pixel_ratio, event->globalPosition().y() * m_device_pixel_ratio);
     auto button = get_button_from_qt_event(*event);
     if (button == 0) {
         // We could not convert Qt buttons to something that Lagom can
@@ -376,8 +375,8 @@ void WebContentView::mousePressEvent(QMouseEvent* event)
 
 void WebContentView::mouseReleaseEvent(QMouseEvent* event)
 {
-    Gfx::IntPoint position(event->position().x() / m_inverse_pixel_scaling_ratio, event->position().y() / m_inverse_pixel_scaling_ratio);
+    Gfx::IntPoint position(event->position().x() * m_device_pixel_ratio, event->position().y() * m_device_pixel_ratio);
-    Gfx::IntPoint screen_position(event->globalPosition().x() / m_inverse_pixel_scaling_ratio, event->globalPosition().y() / m_inverse_pixel_scaling_ratio);
+    Gfx::IntPoint screen_position(event->globalPosition().x() * m_device_pixel_ratio, event->globalPosition().y() * m_device_pixel_ratio);
     auto button = get_button_from_qt_event(*event);
 
     if (event->button() & Qt::MouseButton::BackButton) {
@@ -401,8 +400,8 @@ void WebContentView::mouseReleaseEvent(QMouseEvent* event)
 
 void WebContentView::mouseDoubleClickEvent(QMouseEvent* event)
 {
-    Gfx::IntPoint position(event->position().x() / m_inverse_pixel_scaling_ratio, event->position().y() / m_inverse_pixel_scaling_ratio);
+    Gfx::IntPoint position(event->position().x() * m_device_pixel_ratio, event->position().y() * m_device_pixel_ratio);
-    Gfx::IntPoint screen_position(event->globalPosition().x() / m_inverse_pixel_scaling_ratio, event->globalPosition().y() / m_inverse_pixel_scaling_ratio);
+    Gfx::IntPoint screen_position(event->globalPosition().x() * m_device_pixel_ratio, event->globalPosition().y() * m_device_pixel_ratio);
     auto button = get_button_from_qt_event(*event);
     if (button == 0) {
         // We could not convert Qt buttons to something that Lagom can
@@ -478,7 +477,7 @@ void WebContentView::focusOutEvent(QFocusEvent*)
 void WebContentView::paintEvent(QPaintEvent*)
 {
     QPainter painter(viewport());
-    painter.scale(m_inverse_pixel_scaling_ratio, m_inverse_pixel_scaling_ratio);
+    painter.scale(1 / m_device_pixel_ratio, 1 / m_device_pixel_ratio);
 
     Gfx::Bitmap const* bitmap = nullptr;
     Gfx::IntSize bitmap_size;
@@ -532,10 +531,19 @@ void WebContentView::set_window_position(Gfx::IntPoint position)
     client().async_set_window_position(position);
 }
 
+void WebContentView::set_device_pixel_ratio(double device_pixel_ratio)
+{
+    m_device_pixel_ratio = device_pixel_ratio;
+    client().async_set_device_pixels_per_css_pixel(m_device_pixel_ratio * m_zoom_level);
+    update_viewport_rect();
+    handle_resize();
+    request_repaint();
+}
+
 void WebContentView::update_viewport_rect()
 {
-    auto scaled_width = int(viewport()->width() / m_inverse_pixel_scaling_ratio);
+    auto scaled_width = int(viewport()->width() * m_device_pixel_ratio);
-    auto scaled_height = int(viewport()->height() / m_inverse_pixel_scaling_ratio);
+    auto scaled_height = int(viewport()->height() * m_device_pixel_ratio);
     Gfx::IntRect rect(max(0, horizontalScrollBar()->value()), max(0, verticalScrollBar()->value()), scaled_width, scaled_height);
 
     set_viewport_rect(rect);

Ladybird/Qt/WebContentView.h

@@ -69,6 +69,7 @@ public:
     void set_viewport_rect(Gfx::IntRect);
     void set_window_size(Gfx::IntSize);
     void set_window_position(Gfx::IntPoint);
+    void set_device_pixel_ratio(double);
 
     enum class PaletteMode {
         Default,
@@ -90,7 +91,6 @@ private:
     void update_viewport_rect();
     void update_cursor(Gfx::StandardCursor cursor);
 
-    qreal m_inverse_pixel_scaling_ratio { 1.0 };
     bool m_should_show_line_box_borders { false };
 
     Gfx::IntRect m_viewport_rect;