FEAT(client): Automatically sync theme with OS color scheme

This update introduces an automatic theme switch that changes based on the OS color scheme at startup and during runtime. This feature is implemented for Qt 6.2 and includes compatibility for Qt 6.5 once Mumble upgrades. -fix

Implements mumble-voip#6515

src/mumble/MainWindow.cpp

@@ -127,9 +127,7 @@ MainWindow::MainWindow(QWidget *p)
 	else
 		SvgIcon::addSvgPixmapsToIcon(qiIcon, QLatin1String("skin:mumble.svg"));
 #else
-	{
-		SvgIcon::addSvgPixmapsToIcon(qiIcon, QLatin1String("skin:mumble.svg"));
-	}
+	{ SvgIcon::addSvgPixmapsToIcon(qiIcon, QLatin1String("skin:mumble.svg")); }
 
 	// Set application icon except on MacOSX, where the window-icon
 	// shown in the title-bar usually serves as a draggable version of the
@@ -211,8 +209,7 @@ MainWindow::MainWindow(QWidget *p)
 
 	QAccessible::installFactory(AccessibleSlider::semanticSliderFactory);
 
-	// Theme application
-	applyTheme(); // Apply the light or dark theme during initialization
+	applyTheme();
 }
 
 void MainWindow::applyTheme() {
@@ -225,6 +222,7 @@ void MainWindow::applyTheme() {
 		if (configuredStyle->name == "Auto") {
 #if QT_VERSION >= QT_VERSION_CHECK(6, 5, 0)
 			auto colorScheme = QGuiApplication::styleHints()->colorScheme();
+
 			if (colorScheme == Qt::ColorScheme::Dark) {
 				setStyleSheet(loadStyleSheet(darkThemePath)); // Apply dark theme
 			} else {
@@ -284,7 +282,6 @@ QString MainWindow::loadStyleSheet(const QString &path) {
 	return QString(); // Return empty if the file cannot be loaded
 }
 
-
 void MainWindow::createActions() {
 	gsPushTalk = new GlobalShortcut(this, GlobalShortcutType::PushToTalk, tr("Push-to-Talk", "Global Shortcut"));
 	gsPushTalk->setObjectName(QLatin1String("PushToTalk"));
@@ -841,7 +838,6 @@ void MainWindow::changeEvent(QEvent *e) {
 		QTimer::singleShot(0, this, SLOT(hide()));
 	}
 #endif
-
 	if (e->type() == QEvent::ThemeChange) {
 		applyTheme();
 	}

src/mumble/MainWindow.h

@@ -220,7 +220,6 @@ class MainWindow : public QMainWindow, public Ui::MainWindow {
 	ContextMenuTarget getContextMenuTargets();
 
 	void autocompleteUsername();
-
 	void applyTheme();
 	bool detectSystemTheme();
 	QString loadStyleSheet(const QString &path);