Allow disabling window title shadow on Windows.

ui/platform/win/ui_window_title_win.cpp

@@ -104,9 +104,20 @@ void TitleWidget::setText(const QString &text) {
 
 void TitleWidget::setStyle(const style::WindowTitle &st) {
 	_controls.setStyle(st);
+	if (!st.shadow) {
+		_shadow.destroy();
+	} else if (!_shadow) {
+		_shadow.create(this, st::titleShadow);
+		updateShadowGeometry();
+	}
 	refreshGeometryWithWidth(window()->width());
 }
 
+void TitleWidget::updateShadowGeometry() {
+	const auto thickness = st::lineWidth;
+	_shadow->setGeometry(0, height() - thickness, width(), thickness);
+}
+
 void TitleWidget::refreshGeometryWithWidth(int width) {
 	const auto add = additionalPadding();
 	setGeometry(0, 0, width, _controls.st()->height + add);
@@ -136,8 +147,9 @@ void TitleWidget::paintEvent(QPaintEvent *e) {
 }
 
 void TitleWidget::resizeEvent(QResizeEvent *e) {
-	const auto thickness = st::lineWidth;
-	_shadow->setGeometry(0, height() - thickness, width(), thickness);
+	if (_shadow) {
+		updateShadowGeometry();
+	}
 }
 
 HitTestResult TitleWidget::hitTest(

ui/platform/win/ui_window_title_win.h

@@ -61,6 +61,7 @@ private:
 	[[nodiscard]] bool additionalPaddingRequired() const;
 	void refreshGeometryWithWidth(int width);
 	void setAdditionalPadding(int padding);
+	void updateShadowGeometry();
 
 	std::unique_ptr<PaddingHelper> _paddingHelper;
 	TitleControls _controls;

ui/widgets/widgets.style

@@ -558,6 +558,7 @@ WindowTitle {
 	bgActive: color;
 	fg: color;
 	fgActive: color;
+	shadow: bool;
 	style: TextStyle;
 	minimize: IconButton;
 	minimizeIconActive: icon;
@@ -1428,6 +1429,7 @@ defaultWindowTitle: WindowTitle {
 	style: TextStyle(defaultTextStyle) {
 		font: font(semibold 12px);
 	}
+	shadow: true;
 	minimize: IconButton(windowTitleButton) {
 		icon: icon {
 			{ windowTitleButtonSize, titleButtonBg },