feat(browser): apply dark mode without restart with Qt 6.7+

src/libs/browser/settings.cpp

@@ -68,18 +68,19 @@ void Settings::applySettings()
     m_webProfile->settings()->setAttribute(QWebEngineSettings::ScrollAnimatorEnabled,
                                            m_appSettings->isSmoothScrollingEnabled);
 
+    // Qt 6.7+ does not require restart to enable dark mode.
+#if QT_VERSION >= QT_VERSION_CHECK(6, 7, 0)
+    m_webProfile->settings()->setAttribute(QWebEngineSettings::ForceDarkMode,
+                                           m_appSettings->isDarkModeEnabled());
+#endif
+
     // Apply custom CSS.
     // TODO: Apply to all open pages.
     m_webProfile->scripts()->clear(); // Remove all scripts first.
 
     // Qt 5.14+ uses native Chromium dark mode.
 #if QT_VERSION < QT_VERSION_CHECK(5, 14, 0)
-    const bool enableDarkMode
-        = m_appSettings->contentAppearance == Core::Settings::ContentAppearance::Dark
-          || (m_appSettings->contentAppearance == Core::Settings::ContentAppearance::Automatic
-              && m_appSettings->colorScheme() == Core::Settings::ColorScheme::Dark);
-
-    if (enableDarkMode) {
+    if (m_appSettings->isDarkModeEnabled()) {
         setCustomStyleSheet(QStringLiteral("_zeal_darkstylesheet"), DarkModeCssUrl);
     }
 #endif

src/libs/core/settings.cpp

@@ -73,6 +73,19 @@ Settings::~Settings()
     save();
 }
 
+bool Settings::isDarkModeEnabled() const
+{
+    if (contentAppearance == ContentAppearance::Dark) {
+        return true;
+    }
+
+    if (contentAppearance == ContentAppearance::Automatic && colorScheme() == ColorScheme::Dark) {
+        return true;
+    }
+
+    return false;
+}
+
 Zeal::Core::Settings::ColorScheme Settings::colorScheme()
 {
 #if QT_VERSION >= QT_VERSION_CHECK(6, 5, 0)
@@ -115,16 +128,12 @@ void Settings::load()
 
     settings->beginGroup(GroupContent);
 
-    // Dark mode needs to be applied before Qt WebEngine is initialized.
     contentAppearance = settings->value(QStringLiteral("appearance"),
                                         QVariant::fromValue(ContentAppearance::Automatic)).value<ContentAppearance>();
 
-#if QT_VERSION >= QT_VERSION_CHECK(5, 14, 0)
-    const bool enableDarkMode
-        = contentAppearance == ContentAppearance::Dark
-          || (contentAppearance == ContentAppearance::Automatic && colorScheme() == ColorScheme::Dark);
-
-    if (enableDarkMode) {
+#if QT_VERSION >= QT_VERSION_CHECK(5, 14, 0) && QT_VERSION < QT_VERSION_CHECK(6, 7, 0)
+    // Dark mode needs to be applied before Qt WebEngine is initialized.
+    if (isDarkModeEnabled()) {
         qputenv("QTWEBENGINE_CHROMIUM_FLAGS", "--blink-settings=forceDarkModeEnabled=true,darkModeInversionAlgorithm=4");
     }
 #endif

src/libs/core/settings.h

@@ -127,6 +127,8 @@ public:
     ~Settings() override;
 
     // Helper functions.
+    bool isDarkModeEnabled() const;
+
 #if QT_VERSION >= QT_VERSION_CHECK(6, 5, 0)
     typedef Qt::ColorScheme ColorScheme;
 #else

src/libs/ui/settingsdialog.cpp

@@ -285,6 +285,11 @@ void SettingsDialog::saveSettings()
     settings->isFuzzySearchEnabled = ui->fuzzySearchCheckBox->isChecked();
 
     // Content Tab
+#if QT_VERSION >= QT_VERSION_CHECK(5, 14, 0) && QT_VERSION < QT_VERSION_CHECK(6, 7, 0)
+    // Applying dark mode requires restart.
+    ui->appearanceLabel->setText(tr("Appearance (requires restart):"));
+#endif
+
     settings->defaultFontFamily = ui->defaultFontComboBox->currentData().toString();
     settings->serifFontFamily = ui->serifFontComboBox->currentText();
     settings->sansSerifFontFamily = ui->sansSerifFontComboBox->currentText();

src/libs/ui/settingsdialog.ui

@@ -251,7 +251,7 @@
             <item>
              <widget class="QLabel" name="appearanceLabel">
               <property name="text">
-               <string>Appearance (requires restart):</string>
+               <string>Appearance:</string>
               </property>
              </widget>
             </item>