Use native rounded corners and title colors.

ui/colors.palette

@@ -89,7 +89,7 @@ tooltipBg: #eef2f5; // tooltip background (like when you put mouse over the mess
 tooltipFg: #5d6c80; // tooltip text
 tooltipBorderFg: #c9d1db; // tooltip border
 
-// custom title bar for Windows and macOS
+// custom title bar
 titleShadow: #00000003; // one pixel line shadow at the bottom of custom window title
 titleBg: windowBgOver; // custom window title background when window is inactive
 titleBgActive: titleBg; // custom window title background when window is active
@@ -109,8 +109,8 @@ titleButtonCloseBgActive: titleButtonCloseBg; // custom window title close butto
 titleButtonCloseFgActive: titleButtonCloseFg; // custom window title close button icon when window is active (Windows only)
 titleButtonCloseBgActiveOver: titleButtonCloseBgOver; // custom window title close button background with mouse over when window is active (Windows only)
 titleButtonCloseFgActiveOver: titleButtonCloseFgOver; // custom window title close button icon with mouse over when window is active (Windows only)
-titleFg: #acacac; // custom window title text when window is inactive (macOS only)
-titleFgActive: #3e3c3e; // custom window title text when window is active (macOS only)
+titleFg: #acacac; // custom window title text when window is inactive (Windows 11 and macOS)
+titleFgActive: #3e3c3e; // custom window title text when window is active (Windows 11 and macOS)
 
 // tray icon
 trayCounterBg: #f23c34; // tray icon counter background

ui/platform/win/ui_window_shadow_win.cpp

@@ -8,6 +8,7 @@
 
 #include "ui/rp_widget.h"
 #include "ui/platform/win/ui_window_win.h"
+#include "base/platform/base_platform_info.h"
 #include "styles/style_widgets.h"
 
 #include <QtGui/QPainter>
@@ -42,7 +43,8 @@ base::flat_map<HWND, not_null<WindowShadow*>> ShadowByHandle;
 
 WindowShadow::WindowShadow(not_null<RpWidget*> window, QColor color)
 : _window(window)
-, _handle(GetWindowHandle(window)) {
+, _handle(GetWindowHandle(window))
+, _windows11(::Platform::IsWindows11OrGreater()) {
 	init(color);
 }
 
@@ -315,7 +317,7 @@ void WindowShadow::horCorners(int w, Gdiplus::Graphics *pgraphics0, Gdiplus::Gra
 }
 
 Gdiplus::Color WindowShadow::getColor(uchar alpha) const {
-	return Gdiplus::Color(BYTE(alpha), _r, _g, _b);
+	return Gdiplus::Color(BYTE(_windows11 ? 1 : alpha), _r, _g, _b);
 }
 
 Gdiplus::SolidBrush WindowShadow::getBrush(uchar alpha) const {

ui/platform/win/ui_window_shadow_win.h

@@ -78,6 +78,7 @@ private:
 
 	const not_null<RpWidget*> _window;
 	const HWND _handle;
+	const bool _windows11 = false;
 
 	int _x = 0;
 	int _y = 0;

ui/platform/win/ui_window_title_win.cpp

@@ -41,6 +41,10 @@ void TitleWidget::setStyle(const style::WindowTitle &st) {
 	update();
 }
 
+not_null<const style::WindowTitle*> TitleWidget::st() const {
+	return _controls.st();
+}
+
 void TitleWidget::setResizeEnabled(bool enabled) {
 	_controls.setResizeEnabled(enabled);
 }

ui/platform/win/ui_window_title_win.h

@@ -45,6 +45,7 @@ public:
 
 	void setText(const QString &text);
 	void setStyle(const style::WindowTitle &st);
+	[[nodiscard]] not_null<const style::WindowTitle*> st() const;
 	[[nodiscard]] HitTestResult hitTest(QPoint point) const;
 	void setResizeEnabled(bool enabled);
 

ui/platform/win/ui_window_win.cpp

@@ -13,6 +13,7 @@
 #include "base/integration.h"
 #include "base/debug_log.h"
 #include "styles/palette.h"
+#include "styles/style_widgets.h"
 
 #include <QtCore/QAbstractNativeEventFilter>
 #include <QtGui/QWindow>
@@ -29,7 +30,13 @@ namespace Ui {
 namespace Platform {
 namespace {
 
-bool IsCompositionEnabled() {
+constexpr auto kDWMWCP_ROUND = DWORD(2);
+constexpr auto kDWMWA_WINDOW_CORNER_PREFERENCE = DWORD(33);
+constexpr auto kDWMWA_BORDER_COLOR = DWORD(34);
+constexpr auto kDWMWA_CAPTION_COLOR = DWORD(35);
+constexpr auto kDWMWA_TEXT_COLOR = DWORD(36);
+
+[[nodiscard]] bool IsCompositionEnabled() {
 	auto result = BOOL(FALSE);
 	const auto success = (DwmIsCompositionEnabled(&result) == S_OK);
 	return success && result;
@@ -85,23 +92,6 @@ bool IsTaskbarAutoHidden(LPRECT rcMon = nullptr, PUINT pEdge = nullptr) {
 	return bAutoHidden;
 }
 
-HRESULT WinApiSetWindowTheme(
-		HWND hWnd,
-		LPCWSTR pszSubAppName,
-		LPCWSTR pszSubIdList) {
-	static const auto method = [&] {
-		using f_SetWindowTheme = HRESULT(FAR STDAPICALLTYPE*)(
-			HWND hWnd,
-			LPCWSTR pszSubAppName,
-			LPCWSTR pszSubIdList);
-		auto result = f_SetWindowTheme();
-		const auto loaded = base::Platform::SafeLoadLibrary(L"uxtheme.dll");
-		base::Platform::LoadMethod(loaded, "SetWindowTheme", result);
-		return result;
-	}();
-	return method ? method(hWnd, pszSubAppName, pszSubIdList) : HRESULT();
-}
-
 void FixAeroSnap(HWND handle) {
 	SetWindowLongPtr(
 		handle,
@@ -198,6 +188,7 @@ void WindowHelper::setTitle(const QString &title) {
 
 void WindowHelper::setTitleStyle(const style::WindowTitle &st) {
 	_title->setStyle(st);
+	updateWindowFrameColors();
 }
 
 void WindowHelper::setNativeFrame(bool enabled) {
@@ -216,6 +207,7 @@ void WindowHelper::setNativeFrame(bool enabled) {
 		initialShadowUpdate();
 	}
 	updateMargins();
+	updateWindowFrameColors();
 	fixMaximizedWindow();
 }
 
@@ -227,6 +219,15 @@ void WindowHelper::initialShadowUpdate() {
 	} else {
 		_shadow->update(Change::Moved | Change::Resized | Change::Shown);
 	}
+
+	if (::Platform::IsWindows11OrGreater()) {
+		auto preference = kDWMWCP_ROUND;
+		DwmSetWindowAttribute(
+			_handle,
+			kDWMWA_WINDOW_CORNER_PREFERENCE,
+			&preference,
+			sizeof(preference));
+	}
 }
 
 void WindowHelper::setMinimumSize(QSize size) {
@@ -270,6 +271,7 @@ void WindowHelper::init() {
 		if (_shadow) {
 			_shadow->setColor(st::windowShadowFg->c);
 		}
+		updateWindowFrameColors();
 		Ui::ForceFullRepaint(window());
 	}, window()->lifetime());
 
@@ -291,9 +293,10 @@ void WindowHelper::init() {
 	updateMargins();
 
 	if (!::Platform::IsWindows8OrGreater()) {
-		WinApiSetWindowTheme(_handle, L" ", L" ");
+		SetWindowTheme(_handle, L" ", L" ");
 		QApplication::setStyle(QStyleFactory::create("Windows"));
 	}
+	updateWindowFrameColors();
 
 	_menu = GetSystemMenu(_handle, FALSE);
 	updateSystemMenu();
@@ -326,13 +329,15 @@ bool WindowHelper::handleNativeEvent(
 		if (LOWORD(wParam) == WA_CLICKACTIVE) {
 			Ui::MarkInactivePress(window(), true);
 		}
+		const auto active = (LOWORD(wParam) != WA_INACTIVE);
 		if (_shadow) {
-			if (LOWORD(wParam) != WA_INACTIVE) {
+			if (active) {
 				_shadow->update(WindowShadow::Change::Activate);
 			} else {
 				_shadow->update(WindowShadow::Change::Deactivate);
 			}
 		}
+		updateWindowFrameColors(active);
 		window()->update();
 	} return false;
 
@@ -553,6 +558,39 @@ int WindowHelper::titleHeight() const {
 	return _title->isHidden() ? 0 : _title->height();
 }
 
+void WindowHelper::updateWindowFrameColors() {
+	updateWindowFrameColors(window()->isActiveWindow());
+}
+
+void WindowHelper::updateWindowFrameColors(bool active) {
+	if (!::Platform::IsWindows11OrGreater()) {
+		return;
+	}
+	const auto bg = active
+		? _title->st()->bgActive->c
+		: _title->st()->bg->c;
+	COLORREF bgRef = RGB(bg.red(), bg.green(), bg.blue());
+	DwmSetWindowAttribute(
+		_handle,
+		kDWMWA_BORDER_COLOR,
+		&bgRef,
+		sizeof(COLORREF));
+	DwmSetWindowAttribute(
+		_handle,
+		kDWMWA_CAPTION_COLOR,
+		&bgRef,
+		sizeof(COLORREF));
+	const auto fg = active
+		? _title->st()->fgActive->c
+		: _title->st()->fg->c;
+	COLORREF fgRef = RGB(fg.red(), fg.green(), fg.blue());
+	DwmSetWindowAttribute(
+		_handle,
+		kDWMWA_TEXT_COLOR,
+		&fgRef,
+		sizeof(COLORREF));
+}
+
 void WindowHelper::updateMargins() {
 	if (_updatingMargins) return;
 

ui/platform/win/ui_window_win.h

@@ -38,6 +38,8 @@ private:
 
 	void init();
 	void updateMargins();
+	void updateWindowFrameColors();
+	void updateWindowFrameColors(bool active);
 	void updateSystemMenu();
 	void updateSystemMenu(Qt::WindowState state);
 	void initialShadowUpdate();