sola/qwindowkit.git

			@@ -1,234 +1,322 @@
			// Copyright (C) 2023-2024 Stdware Collections (https://www.github.com/stdware)
			// Copyright (C) 2021-2023 wangwenx190 (Yuhang Zhao)
			// SPDX-License-Identifier: Apache-2.0

			#include "win32windowcontext_p.h"

			#include <optional>

			#include <QtCore/QAbstractEventDispatcher>
			#include <QtCore/QDateTime>
			#include <QtCore/QHash>
			#include <QtCore/QAbstractNativeEventFilter>
			#include <QtCore/QCoreApplication>
			#include <QtCore/QOperatingSystemVersion>
			#include <QtCore/QScopeGuard>
			#include <QtCore/QTimer>
			#include <QtGui/QGuiApplication>
			#include <QtGui/QPainter>
			#include <QtGui/QPalette>

			#include <QtCore/private/qsystemlibrary_p.h>
			#include <QtGui/qpa/qwindowsysteminterface.h>

			#include <QtGui/private/qhighdpiscaling_p.h>
			#if QT_VERSION >= QT_VERSION_CHECK(6, 0, 0)
			# include <QtGui/private/qguiapplication_p.h>
			#endif
			#include <QtGui/qpa/qplatformwindow.h>
			#if QT_VERSION < QT_VERSION_CHECK(6, 2, 0)
			# include <QtGui/qpa/qplatformnativeinterface.h>
			#else
			# include <QtGui/qpa/qplatformwindow_p.h>
			#endif

			#include "qwkcoreglobal_p.h"
			#include <QWKCore/qwkconfig.h>

			#include <shellscalingapi.h>
			#include <dwmapi.h>
			#include "qwkglobal_p.h"
			#include "qwkwindowsextra_p.h"

			namespace QWK {

			static constexpr const auto kAutoHideTaskBarThickness = quint8{ 2 }; // The thickness of an auto-hide taskbar in pixels.

			using WndProcHash = QHash<HWND, Win32WindowContext *>; // hWnd -> context
			Q_GLOBAL_STATIC(WndProcHash, g_wndProcHash);

			static WNDPROC g_qtWindowProc = nullptr; // Original Qt window proc function

			struct DynamicApis {
			decltype(&::DwmFlush) pDwmFlush = nullptr;
			decltype(&::GetDpiForWindow) pGetDpiForWindow = nullptr;
			decltype(&::GetSystemMetricsForDpi) pGetSystemMetricsForDpi = nullptr;
			decltype(&::GetDpiForMonitor) pGetDpiForMonitor = nullptr;

			DynamicApis() {
			QSystemLibrary user32(QStringLiteral("user32.dll"));
			pGetDpiForWindow = reinterpret_cast<decltype(pGetDpiForWindow)>(user32.resolve("GetDpiForWindow"));
			pGetSystemMetricsForDpi = reinterpret_cast<decltype(pGetSystemMetricsForDpi)>(user32.resolve("GetSystemMetricsForDpi"));

			QSystemLibrary shcore(QStringLiteral("shcore.dll"));
			pGetDpiForMonitor = reinterpret_cast<decltype(pGetDpiForMonitor)>(shcore.resolve("GetDpiForMonitor"));

			QSystemLibrary dwmapi(QStringLiteral("dwmapi.dll"));
			pDwmFlush = reinterpret_cast<decltype(pDwmFlush)>(dwmapi.resolve("DwmFlush"));
			}

			~DynamicApis() = default;

			static const DynamicApis &instance() {
			static const DynamicApis inst{};
			return inst;
			}

			private:
			Q_DISABLE_COPY_MOVE(DynamicApis)
			enum IconButtonClickLevelFlag {
			IconButtonClicked = 1,
			IconButtonDoubleClicked = 2,
			IconButtonTriggersClose = 4,
			};

			static inline constexpr bool operator==(const POINT &lhs, const POINT &rhs) noexcept
			{
			return ((lhs.x == rhs.x) && (lhs.y == rhs.y));
			// The thickness of an auto-hide taskbar in pixels.
			static constexpr const quint8 kAutoHideTaskBarThickness = 2;

			QWK_USED static constexpr const struct {
			const uint32_t activeLight = MAKE_RGBA_COLOR(110, 110, 110, 255); // #6E6E6E
			const uint32_t activeDark = MAKE_RGBA_COLOR(51, 51, 51, 255); // #333333
			const uint32_t inactiveLight = MAKE_RGBA_COLOR(167, 167, 167, 255); // #A7A7A7
			const uint32_t inactiveDark = MAKE_RGBA_COLOR(61, 61, 62, 255); // #3D3D3E
			} kWindowsColorSet;

			// hWnd -> context
			using WndProcHash = QHash<HWND, Win32WindowContext *>;
			Q_GLOBAL_STATIC(WndProcHash, g_wndProcHash)

			// Original Qt window proc function
			static WNDPROC g_qtWindowProc = nullptr;

			static inline bool
			#if !QWINDOWKIT_CONFIG(ENABLE_WINDOWS_SYSTEM_BORDERS)
			constexpr
			#endif

			isSystemBorderEnabled() {
			return
			#if QWINDOWKIT_CONFIG(ENABLE_WINDOWS_SYSTEM_BORDERS)
			isWin10OrGreater()
			#else
			false
			#endif
			;
			}

			static inline constexpr bool operator!=(const POINT &lhs, const POINT &rhs) noexcept
			{
			return !operator==(lhs, rhs);
			static inline void triggerFrameChange(HWND hwnd) {
			::SetWindowPos(hwnd, nullptr, 0, 0, 0, 0,
			SWP_NOACTIVATE \| SWP_NOMOVE \| SWP_NOSIZE \| SWP_NOZORDER \| SWP_NOOWNERZORDER \|
			SWP_FRAMECHANGED);
			}

			static inline constexpr bool operator==(const SIZE &lhs, const SIZE &rhs) noexcept
			{
			return ((lhs.cx == rhs.cx) && (lhs.cy == rhs.cy));
			}
			static void setInternalWindowFrameMargins(QWindow *window, const QMargins &margins) {
			const QVariant marginsVar = QVariant::fromValue(margins);

			static inline constexpr bool operator!=(const SIZE &lhs, const SIZE &rhs) noexcept
			{
			return !operator==(lhs, rhs);
			}

			static inline constexpr bool operator>(const SIZE &lhs, const SIZE &rhs) noexcept
			{
			return ((lhs.cx * lhs.cy) > (rhs.cx * rhs.cy));
			}

			static inline constexpr bool operator>=(const SIZE &lhs, const SIZE &rhs) noexcept
			{
			return (operator>(lhs, rhs) \|\| operator==(lhs, rhs));
			}

			static inline constexpr bool operator<(const SIZE &lhs, const SIZE &rhs) noexcept
			{
			return (operator!=(lhs, rhs) && !operator>(lhs, rhs));
			}

			static inline constexpr bool operator<=(const SIZE &lhs, const SIZE &rhs) noexcept
			{
			return (operator<(lhs, rhs) \|\| operator==(lhs, rhs));
			}

			static inline constexpr bool operator==(const RECT &lhs, const RECT &rhs) noexcept
			{
			return ((lhs.left == rhs.left) && (lhs.top == rhs.top) && (lhs.right == rhs.right) && (lhs.bottom == rhs.bottom));
			}

			static inline constexpr bool operator!=(const RECT &lhs, const RECT &rhs) noexcept
			{
			return !operator==(lhs, rhs);
			}

			static inline constexpr QPoint point2qpoint(const POINT &point)
			{
			return QPoint{ int(point.x), int(point.y) };
			}

			static inline constexpr POINT qpoint2point(const QPoint &point)
			{
			return POINT{ LONG(point.x()), LONG(point.y()) };
			}

			static inline constexpr QSize size2qsize(const SIZE &size)
			{
			return QSize{ int(size.cx), int(size.cy) };
			}

			static inline constexpr SIZE qsize2size(const QSize &size)
			{
			return SIZE{ LONG(size.width()), LONG(size.height()) };
			}

			static inline constexpr QRect rect2qrect(const RECT &rect)
			{
			return QRect{ QPoint{ int(rect.left), int(rect.top) }, QSize{ int(RECT_WIDTH(rect)), int(RECT_HEIGHT(rect)) } };
			}

			static inline constexpr RECT qrect2rect(const QRect &qrect)
			{
			return RECT{ LONG(qrect.left()), LONG(qrect.top()), LONG(qrect.right()), LONG(qrect.bottom()) };
			}

			static inline /constexpr/ QString hwnd2str(const WId windowId)
			{
			// NULL handle is allowed here.
			return QLatin1String("0x") + QString::number(windowId, 16).toUpper().rightJustified(8, u'0');
			}

			static inline /constexpr/ QString hwnd2str(const HWND hwnd)
			{
			// NULL handle is allowed here.
			return hwnd2str(reinterpret_cast<WId>(hwnd));
			}

			static inline bool isWin8Point1OrGreater() {
			static const bool result = QOperatingSystemVersion::current() >= QOperatingSystemVersion::Windows8_1;
			return result;
			}

			static inline bool isWin10OrGreater() {
			static const bool result = QOperatingSystemVersion::current() >= QOperatingSystemVersion::Windows10;
			return result;
			}

			static inline quint32 getDpiForWindow(const HWND hwnd) {
			Q_ASSERT(hwnd);
			if (!hwnd) {
			return USER_DEFAULT_SCREEN_DPI;
			// TODO: Add comments
			window->setProperty("_q_windowsCustomMargins", marginsVar);
			#if QT_VERSION < QT_VERSION_CHECK(6, 0, 0)
			if (QPlatformWindow *platformWindow = window->handle()) {
			if (const auto ni = QGuiApplication::platformNativeInterface()) {
			ni->setWindowProperty(platformWindow, QStringLiteral("WindowsCustomMargins"),
			marginsVar);
			}
			}
			const DynamicApis &apis = DynamicApis::instance();
			if (apis.pGetDpiForWindow) { // Win10
			return apis.pGetDpiForWindow(hwnd);
			} else if (apis.pGetDpiForMonitor) { // Win8.1
			const HMONITOR monitor = ::MonitorFromWindow(hwnd, MONITOR_DEFAULTTONEAREST);
			UINT dpiX{ USER_DEFAULT_SCREEN_DPI };
			UINT dpiY{ USER_DEFAULT_SCREEN_DPI };
			apis.pGetDpiForMonitor(monitor, MDT_EFFECTIVE_DPI, &dpiX, &dpiY);
			return dpiX;
			} else { // Win2K
			const HDC hdc = ::GetDC(nullptr);
			const int dpiX = ::GetDeviceCaps(hdc, LOGPIXELSX);
			const int dpiY = ::GetDeviceCaps(hdc, LOGPIXELSY);
			::ReleaseDC(nullptr, hdc);
			return quint32(dpiX);
			#else
			if (const auto platformWindow =
			dynamic_cast<QNativeInterface::Private::QWindowsWindow *>(window->handle())) {
			platformWindow->setCustomMargins(margins);
			}
			#endif
			}

			static inline quint32 getResizeBorderThickness(const HWND hwnd) {
			Q_ASSERT(hwnd);
			if (!hwnd) {
			return 0;
			}
			const DynamicApis &apis = DynamicApis::instance();
			if (apis.pGetSystemMetricsForDpi) {
			const quint32 dpi = getDpiForWindow(hwnd);
			return apis.pGetSystemMetricsForDpi(SM_CXSIZEFRAME, dpi) + apis.pGetSystemMetricsForDpi(SM_CXPADDEDBORDER, dpi);
			} else {
			return ::GetSystemMetrics(SM_CXSIZEFRAME) + ::GetSystemMetrics(SM_CXPADDEDBORDER);
			}
			}

			static inline std::optional<MONITORINFOEXW> getMonitorForWindow(const HWND hwnd)
			{
			Q_ASSERT(hwnd);
			if (!hwnd) {
			return std::nullopt;
			}
			static inline MONITORINFOEXW getMonitorForWindow(HWND hwnd) {
			// Use "MONITOR_DEFAULTTONEAREST" here so that we can still get the correct
			// monitor even if the window is minimized.
			const HMONITOR monitor = ::MonitorFromWindow(hwnd, MONITOR_DEFAULTTONEAREST);
			HMONITOR monitor = ::MonitorFromWindow(hwnd, MONITOR_DEFAULTTONEAREST);
			MONITORINFOEXW monitorInfo{};
			monitorInfo.cbSize = sizeof(monitorInfo);
			::GetMonitorInfoW(monitor, &monitorInfo);
			return monitorInfo;
			};

			static inline bool isFullScreen(const HWND hwnd) {
			Q_ASSERT(hwnd);
			if (!hwnd) {
			return false;
			}
			RECT windowRect{};
			::GetWindowRect(hwnd, &windowRect);
			const std::optional<MONITORINFOEXW> mi = getMonitorForWindow(hwnd);
			// Compare to the full area of the screen, not the work area.
			return (windowRect == mi.value_or(MONITORINFOEXW{}).rcMonitor);
			}

			static inline QPoint fromNativeLocalPosition(const QWindow *window, const QPoint &point) {
			Q_ASSERT(window);
			if (!window) {
			return point;
			static inline void moveWindowToMonitor(HWND hwnd, const MONITORINFOEXW &activeMonitor) {
			RECT currentMonitorRect = getMonitorForWindow(hwnd).rcMonitor;
			RECT activeMonitorRect = activeMonitor.rcMonitor;
			// We are in the same monitor, nothing to adjust here.
			if (currentMonitorRect == activeMonitorRect) {
			return;
			}
			#if 1
			return QHighDpi::fromNativeLocalPosition(point, window);
			RECT currentWindowRect{};
			::GetWindowRect(hwnd, &currentWindowRect);
			auto newWindowX =
			activeMonitorRect.left + (currentWindowRect.left - currentMonitorRect.left);
			auto newWindowY = activeMonitorRect.top + (currentWindowRect.top - currentMonitorRect.top);
			::SetWindowPos(hwnd, nullptr, newWindowX, newWindowY, RECT_WIDTH(currentWindowRect),
			RECT_HEIGHT(currentWindowRect),
			SWP_NOACTIVATE \| SWP_NOSIZE \| SWP_NOZORDER \| SWP_NOOWNERZORDER);
			}

			static inline bool isFullScreen(HWND hwnd) {
			RECT windowRect{};
			::GetWindowRect(hwnd, &windowRect);
			// Compare to the full area of the screen, not the work area.
			return (windowRect == getMonitorForWindow(hwnd).rcMonitor);
			}

			static inline bool isMaximized(HWND hwnd) {
			return ::IsZoomed(hwnd);
			}

			static inline bool isMinimized(HWND hwnd) {
			return ::IsIconic(hwnd);
			}

			static inline bool isWindowNoState(HWND hwnd) {
			#if 0
			WINDOWPLACEMENT wp{};
			wp.length = sizeof(wp);
			::GetWindowPlacement(hwnd, &wp);
			return ((wp.showCmd == SW_NORMAL) \|\| (wp.showCmd == SW_RESTORE));
			#else
			return QPointF(QPointF(point) / window->devicePixelRatio()).toPoint();
			if (isFullScreen(hwnd)) {
			return false;
			}
			const auto style = static_cast<DWORD>(::GetWindowLongPtrW(hwnd, GWL_STYLE));
			return (!(style & (WS_MINIMIZE \| WS_MAXIMIZE)));
			#endif
			}

			static inline void bringWindowToFront(HWND hwnd) {
			HWND oldForegroundWindow = ::GetForegroundWindow();
			if (!oldForegroundWindow) {
			// The foreground window can be NULL, it's not an API error.
			return;
			}
			MONITORINFOEXW activeMonitor = getMonitorForWindow(oldForegroundWindow);
			// We need to show the window first, otherwise we won't be able to bring it to front.
			if (!::IsWindowVisible(hwnd)) {
			::ShowWindow(hwnd, SW_SHOW);
			}
			if (isMinimized(hwnd)) {
			// Restore the window if it is minimized.
			::ShowWindow(hwnd, SW_RESTORE);
			// Once we've been restored, throw us on the active monitor.
			moveWindowToMonitor(hwnd, activeMonitor);
			// When the window is restored, it will always become the foreground window.
			// So return early here, we don't need the following code to bring it to front.
			return;
			}
			// OK, our window is not minimized, so now we will try to bring it to front manually.
			// First try to send a message to the current foreground window to check whether
			// it is currently hanging or not.
			if (!::SendMessageTimeoutW(oldForegroundWindow, WM_NULL, 0, 0,
			SMTO_BLOCK \| SMTO_ABORTIFHUNG \| SMTO_NOTIMEOUTIFNOTHUNG, 1000,
			nullptr)) {
			// The foreground window hangs, can't activate current window.
			return;
			}
			DWORD windowThreadProcessId = ::GetWindowThreadProcessId(oldForegroundWindow, nullptr);
			DWORD currentThreadId = ::GetCurrentThreadId();
			// We won't be able to change a window's Z order if it's not our own window,
			// so we use this small technique to pretend the foreground window is ours.
			::AttachThreadInput(windowThreadProcessId, currentThreadId, TRUE);

			[[maybe_unused]] const auto &cleaner =
			qScopeGuard([windowThreadProcessId, currentThreadId]() {
			::AttachThreadInput(windowThreadProcessId, currentThreadId, FALSE); //
			}); // TODO: Remove it

			::BringWindowToTop(hwnd);
			// Activate the window too. This will force us to the virtual desktop this
			// window is on, if it's on another virtual desktop.
			::SetActiveWindow(hwnd);
			// Throw us on the active monitor.
			moveWindowToMonitor(hwnd, activeMonitor);
			}

			static void syncPaintEventWithDwm() {
			// No need to sync with DWM if DWM composition is disabled.
			if (!isDwmCompositionEnabled()) {
			return;
			}
			const DynamicApis &apis = DynamicApis::instance();
			// Dirty hack to workaround the resize flicker caused by DWM.
			LARGE_INTEGER freq{};
			::QueryPerformanceFrequency(&freq);
			TIMECAPS tc{};
			apis.ptimeGetDevCaps(&tc, sizeof(tc));
			const UINT ms_granularity = tc.wPeriodMin;
			apis.ptimeBeginPeriod(ms_granularity);
			LARGE_INTEGER now0{};
			::QueryPerformanceCounter(&now0);
			// ask DWM where the vertical blank falls
			DWM_TIMING_INFO dti{};
			dti.cbSize = sizeof(dti);
			apis.pDwmGetCompositionTimingInfo(nullptr, &dti);
			LARGE_INTEGER now1{};
			::QueryPerformanceCounter(&now1);
			// - DWM told us about SOME vertical blank
			// - past or future, possibly many frames away
			// - convert that into the NEXT vertical blank
			const auto period = qreal(dti.qpcRefreshPeriod);
			const auto dt = qreal(dti.qpcVBlank - now1.QuadPart);
			const qreal ratio = (dt / period);
			auto w = qreal(0);
			auto m = qreal(0);
			if ((dt > qreal(0)) \|\| qFuzzyIsNull(dt)) {
			w = ratio;
			} else {
			// reach back to previous period
			// - so m represents consistent position within phase
			w = (ratio - qreal(1));
			}
			m = (dt - (period * w));
			if ((m < qreal(0)) \|\| qFuzzyCompare(m, period) \|\| (m > period)) {
			return;
			}
			const qreal m_ms = (qreal(1000) * m / qreal(freq.QuadPart));
			::Sleep(static_cast<DWORD>(std::round(m_ms)));
			apis.ptimeEndPeriod(ms_granularity);
			}

			// Returns false if the menu is canceled
			static bool showSystemMenu_sys(HWND hWnd, const POINT &pos, const bool selectFirstEntry,
			const bool fixedSize) {
			HMENU hMenu = ::GetSystemMenu(hWnd, FALSE);
			if (!hMenu) {
			// The corresponding window doesn't have a system menu, most likely due to the
			// lack of the "WS_SYSMENU" window style. This situation should not be treated
			// as an error so just ignore it and return early.
			return true;
			}

			const bool maxOrFull = isMaximized(hWnd) \|\| isFullScreen(hWnd);
			::EnableMenuItem(hMenu, SC_CLOSE, (MF_BYCOMMAND \| MFS_ENABLED));
			::EnableMenuItem(hMenu, SC_MAXIMIZE,
			(MF_BYCOMMAND \| ((maxOrFull \|\| fixedSize) ? MFS_DISABLED : MFS_ENABLED)));
			::EnableMenuItem(hMenu, SC_RESTORE,
			(MF_BYCOMMAND \| ((maxOrFull && !fixedSize) ? MFS_ENABLED : MFS_DISABLED)));
			// The first menu item should be selected by default if the menu is brought
			// up by keyboard. I don't know how to pre-select a menu item but it seems
			// highlight can do the job. However, there's an annoying issue if we do
			// this manually: the highlighted menu item is really only highlighted,
			// not selected, so even if the mouse cursor hovers on other menu items
			// or the user navigates to other menu items through keyboard, the original
			// highlight bar will not move accordingly, the OS will generate another
			// highlight bar to indicate the current selected menu item, which will make
			// the menu look kind of weird. Currently I don't know how to fix this issue.
			::HiliteMenuItem(hWnd, hMenu, SC_RESTORE,
			(MF_BYCOMMAND \| (selectFirstEntry ? MFS_HILITE : MFS_UNHILITE)));
			::EnableMenuItem(hMenu, SC_MINIMIZE, (MF_BYCOMMAND \| MFS_ENABLED));
			::EnableMenuItem(hMenu, SC_SIZE,
			(MF_BYCOMMAND \| ((maxOrFull \|\| fixedSize) ? MFS_DISABLED : MFS_ENABLED)));
			::EnableMenuItem(hMenu, SC_MOVE, (MF_BYCOMMAND \| (maxOrFull ? MFS_DISABLED : MFS_ENABLED)));

			// The default menu item will appear in bold font. There can only be one default
			// menu item per menu at most. Set the item ID to "UINT_MAX" (or simply "-1")
			// can clear the default item for the given menu.
			UINT defaultItemId = UINT_MAX;
			if (isWin11OrGreater()) {
			if (maxOrFull) {
			defaultItemId = SC_RESTORE;
			} else {
			defaultItemId = SC_MAXIMIZE;
			}
			}
			if (defaultItemId == UINT_MAX) {
			defaultItemId = SC_CLOSE;
			}
			::SetMenuDefaultItem(hMenu, defaultItemId, FALSE);

			// Popup the system menu at the required position.
			const auto result = ::TrackPopupMenu(
			hMenu,
			(TPM_RETURNCMD \| (QGuiApplication::isRightToLeft() ? TPM_RIGHTALIGN : TPM_LEFTALIGN) \|
			TPM_RIGHTBUTTON),
			pos.x, pos.y, 0, hWnd, nullptr);

			// Unhighlight the first menu item after the popup menu is closed, otherwise it will keep
			// highlighting until we unhighlight it manually.
			::HiliteMenuItem(hWnd, hMenu, SC_RESTORE, (MF_BYCOMMAND \| MFS_UNHILITE));

			if (!result) {
			// The user canceled the menu, no need to continue.
			return false;
			}

			// Send the command that the user chooses to the corresponding window.
			::PostMessageW(hWnd, WM_SYSCOMMAND, result, 0);
			return true;
			}

			static inline Win32WindowContext::WindowPart getHitWindowPart(int hitTestResult) {
			@@ -260,81 +348,212 @@
			return Win32WindowContext::Outside;
			}

			static bool isValidWindow(WId windowId, bool checkVisible, bool checkTopLevel) {
			const auto hwnd = reinterpret_cast<HWND>(windowId);
			if (::IsWindow(hwnd) == FALSE) {
			static bool isValidWindow(HWND hWnd, bool checkVisible, bool checkTopLevel) {
			if (!::IsWindow(hWnd)) {
			return false;
			}
			const LONG_PTR styles = ::GetWindowLongPtrW(hwnd, GWL_STYLE);
			const LONG_PTR styles = ::GetWindowLongPtrW(hWnd, GWL_STYLE);
			if (styles & WS_DISABLED) {
			return false;
			}
			const LONG_PTR exStyles = ::GetWindowLongPtrW(hwnd, GWL_EXSTYLE);
			const LONG_PTR exStyles = ::GetWindowLongPtrW(hWnd, GWL_EXSTYLE);
			if (exStyles & WS_EX_TOOLWINDOW) {
			return false;
			}
			RECT rect = {0, 0, 0, 0};
			if (::GetWindowRect(hwnd, &rect) == FALSE) {
			RECT rect{};
			if (!::GetWindowRect(hWnd, &rect)) {
			return false;
			}
			if ((rect.left >= rect.right) \|\| (rect.top >= rect.bottom)) {
			return false;
			}
			if (checkVisible) {
			if (::IsWindowVisible(hwnd) == FALSE) {
			if (!::IsWindowVisible(hWnd)) {
			return false;
			}
			}
			if (checkTopLevel) {
			if (::GetAncestor(hwnd, GA_ROOT) != hwnd) {
			if (::GetAncestor(hWnd, GA_ROOT) != hWnd) {
			return false;
			}
			}
			return true;
			}

			static inline constexpr bool isNonClientMessage(const UINT message) {
			if (((message >= WM_NCCREATE) && (message <= WM_NCACTIVATE)) \|\|
			((message >= WM_NCMOUSEMOVE) && (message <= WM_NCMBUTTONDBLCLK)) \|\|
			((message >= WM_NCXBUTTONDOWN) && (message <= WM_NCXBUTTONDBLCLK))
			#if (WINVER >= _WIN32_WINNT_WIN8)
			\|\| ((message >= WM_NCPOINTERUPDATE) && (message <= WM_NCPOINTERUP))
			#endif
			\|\| ((message == WM_NCMOUSEHOVER) \|\| (message == WM_NCMOUSELEAVE))) {
			return true;
			} else {
			return false;
			}
			}

			static MSG createMessageBlock(HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam) {
			MSG msg;
			msg.hwnd = hWnd; // re-create MSG structure
			msg.message = message; // time and pt fields ignored
			msg.wParam = wParam;
			msg.lParam = lParam;

			const DWORD dwScreenPos = ::GetMessagePos();
			msg.pt.x = GET_X_LPARAM(dwScreenPos);
			msg.pt.y = GET_Y_LPARAM(dwScreenPos);
			if (!isNonClientMessage(message)) {
			::ScreenToClient(hWnd, &msg.pt);
			}
			return msg;
			}

			static inline constexpr bool isInputMessage(UINT m) {
			switch (m) {
			case WM_IME_STARTCOMPOSITION:
			case WM_IME_ENDCOMPOSITION:
			case WM_IME_COMPOSITION:
			case WM_INPUT:
			case WM_TOUCH:
			case WM_MOUSEHOVER:
			case WM_MOUSELEAVE:
			case WM_NCMOUSEHOVER:
			case WM_NCMOUSELEAVE:
			case WM_SIZING:
			case WM_MOVING:
			case WM_SYSCOMMAND:
			case WM_COMMAND:
			case WM_DWMNCRENDERINGCHANGED:
			case WM_PAINT:
			return true;
			default:
			break;
			}
			return (m >= WM_MOUSEFIRST && m <= WM_MOUSELAST) \|\|
			(m >= WM_NCMOUSEMOVE && m <= WM_NCXBUTTONDBLCLK) \|\|
			(m >= WM_KEYFIRST && m <= WM_KEYLAST);
			}

			static inline QByteArray nativeEventType() {
			return QByteArrayLiteral("windows_generic_MSG");
			}

			// Send to QAbstractEventDispatcher
			bool filterNativeEvent(MSG msg, LRESULT result) {
			auto dispatcher = QAbstractEventDispatcher::instance();
			QT_NATIVE_EVENT_RESULT_TYPE filterResult = *result;
			if (dispatcher && dispatcher->filterNativeEvent(nativeEventType(), msg, &filterResult)) {
			*result = LRESULT(filterResult);
			return true;
			}
			return false;
			}

			// Send to QWindowSystemInterface
			bool filterNativeEvent(QWindow window, MSG msg, LRESULT *result) {
			QT_NATIVE_EVENT_RESULT_TYPE filterResult = *result;
			if (QWindowSystemInterface::handleNativeEvent(window, nativeEventType(), msg,
			&filterResult)) {
			*result = LRESULT(filterResult);
			return true;
			}
			return false;
			}

			static inline bool forwardFilteredEvent(QWindow *window, HWND hWnd, UINT message, WPARAM wParam,
			LPARAM lParam, LRESULT *result) {
			MSG msg = createMessageBlock(hWnd, message, wParam, lParam);

			// https://github.com/qt/qtbase/blob/e26a87f1ecc40bc8c6aa5b889fce67410a57a702/src/plugins/platforms/windows/qwindowscontext.cpp#L1025
			// Do exact the same as what Qt Windows plugin does.

			// Run the native event filters. QTBUG-67095: Exclude input messages which are sent
			// by QEventDispatcherWin32::processEvents()
			if (!isInputMessage(msg.message) && filterNativeEvent(&msg, result))
			return true;

			auto platformWindow = window->handle();
			if (platformWindow && filterNativeEvent(platformWindow->window(), &msg, result))
			return true;

			return false;
			}

			// https://github.com/qt/qtbase/blob/e26a87f1ecc40bc8c6aa5b889fce67410a57a702/src/plugins/platforms/windows/qwindowscontext.cpp#L1556
			// In QWindowsContext::windowsProc(), the messages will be passed to all global native event
			// filters, but because we have already filtered the messages in the hook WndProc function for
			// convenience, Qt does not know we may have already process the messages and thus will call
			// convenience, Qt does not know we may have already processed the messages and thus will call
			// DefWindowProc(). Consequently, we have to add a global native filter that forwards the result
			// of the hook function, telling Qt whether we have filtered the events before. Since Qt only
			// handles Windows window messages in the main thread, it is safe to do so.
			class WindowsNativeEventFilter : public QAbstractNativeEventFilter {
			class WindowsNativeEventFilter : public AppNativeEventFilter {
			public:
			bool nativeEventFilter(const QByteArray &eventType, void *message,
			QT_NATIVE_EVENT_RESULT_TYPE *result) override {
			// It has been observed that the pointer that Qt gives us is sometimes null on some machines.
			// We need to guard against it in such scenarios.
			Q_UNUSED(eventType)

			// It has been observed that the pointer that Qt gives us is sometimes null on some
			// machines. We need to guard against it in such scenarios.
			if (!result) {
			return false;
			}
			if (lastMessageHandled) {
			*result = static_cast<QT_NATIVE_EVENT_RESULT_TYPE>(lastMessageResult);
			return true;

			auto msg = static_cast<const MSG *>(message);
			switch (msg->message) {
			case WM_NCCALCSIZE: {
			// https://github.com/qt/qtbase/blob/e26a87f1ecc40bc8c6aa5b889fce67410a57a702/src/plugins/platforms/windows/qwindowscontext.cpp#L1546
			// Qt needs to refer to the WM_NCCALCSIZE message data that hasn't been
			// processed, so we have to process it after Qt acquires the initial data.
			if (lastMessageContext) {
			LRESULT res;
			if (lastMessageContext->nonClientCalcSizeHandler(
			msg->hwnd, msg->message, msg->wParam, msg->lParam, &res)) {
			result = decltype(result)(res);
			return true;
			}
			}
			break;
			}

			// case WM_NCHITTEST: {
			// // The child window must return HTTRANSPARENT when processing
			// WM_NCHITTEST for
			// // the parent window to receive WM_NCHITTEST.
			// if (!lastMessageContext) {
			// auto rootHWnd = ::GetAncestor(msg->hwnd, GA_ROOT);
			// if (rootHWnd != msg->hwnd) {
			// if (auto ctx = g_wndProcHash->value(rootHWnd)) {
			// *result = HTTRANSPARENT;
			// return true;
			// }
			// }
			// }
			// break;
			// }
			}
			return false;
			}

			static bool lastMessageHandled;
			static LRESULT lastMessageResult;
			static WindowsNativeEventFilter *instance;
			static inline WindowsNativeEventFilter *instance = nullptr;
			static inline Win32WindowContext *lastMessageContext = nullptr;

			static inline void install() {
			if (instance) {
			return;
			}
			instance = new WindowsNativeEventFilter();
			qApp->installNativeEventFilter(instance);
			}

			static inline void uninstall() {
			qApp->removeNativeEventFilter(instance);
			if (!instance) {
			return;
			}
			delete instance;
			instance = nullptr;
			}
			};

			bool WindowsNativeEventFilter::lastMessageHandled = false;
			LRESULT WindowsNativeEventFilter::lastMessageResult = 0;
			WindowsNativeEventFilter *WindowsNativeEventFilter::instance = nullptr;

			// https://github.com/qt/qtbase/blob/e26a87f1ecc40bc8c6aa5b889fce67410a57a702/src/plugins/platforms/windows/qwindowscontext.cpp#L1025
			// We can see from the source code that Qt will filter out some messages first and then send the
			@@ -401,40 +620,37 @@
			return ::DefWindowProcW(hWnd, message, wParam, lParam);
			}

			WindowsNativeEventFilter::lastMessageContext = ctx;
			const auto &contextCleaner = qScopeGuard([]() {
			WindowsNativeEventFilter::lastMessageContext = nullptr; //
			});

			// Since Qt does the necessary processing of the WM_NCCALCSIZE message, we need to
			// forward it right away and process it in our native event filter.
			if (message == WM_NCCALCSIZE) {
			return ::CallWindowProcW(g_qtWindowProc, hWnd, message, wParam, lParam);
			}

			// Try hooked procedure and save result
			auto &handled = WindowsNativeEventFilter::lastMessageHandled;
			auto &result = WindowsNativeEventFilter::lastMessageResult;
			handled = ctx->windowProc(hWnd, message, wParam, lParam, &result);
			LRESULT result;
			if (ctx->windowProc(hWnd, message, wParam, lParam, &result)) {
			// https://github.com/stdware/qwindowkit/issues/45
			// Forward the event to user-defined native event filters, there may be some messages
			// that need to be processed by the user.
			std::ignore =
			forwardFilteredEvent(ctx->window(), hWnd, message, wParam, lParam, &result);
			return result;
			}

			// TODO: Determine whether to show system menu
			// ...

			// Since Qt does the necessary processing of the message afterward, we still need to
			// continue dispatching it.
			// Continue dispatching.
			return ::CallWindowProcW(g_qtWindowProc, hWnd, message, wParam, lParam);
			}

			Win32WindowContext::Win32WindowContext(QWindow window, WindowItemDelegate delegate)
			: AbstractWindowContext(window, delegate) {
			}

			Win32WindowContext::~Win32WindowContext() {
			// Remove window handle mapping
			if (auto hWnd = reinterpret_cast<HWND>(windowId); hWnd) {
			g_wndProcHash->remove(hWnd);

			// Remove event filter if the all windows has been destroyed
			if (g_wndProcHash->empty()) {
			WindowsNativeEventFilter::uninstall();
			}
			static inline void addManagedWindow(QWindow window, HWND hWnd, Win32WindowContext ctx) {
			if (isSystemBorderEnabled()) {
			// Inform Qt we want and have set custom margins
			setInternalWindowFrameMargins(window, QMargins(0, -int(getTitleBarHeight(hWnd)), 0, 0));
			}
			}

			bool Win32WindowContext::setup() {
			auto winId = m_windowHandle->winId();

			// Install window hook
			auto hWnd = reinterpret_cast<HWND>(winId);

			// Store original window proc
			if (!g_qtWindowProc) {
			@@ -445,17 +661,227 @@
			::SetWindowLongPtrW(hWnd, GWLP_WNDPROC, reinterpret_cast<LONG_PTR>(QWKHookedWndProc));

			// Install global native event filter
			if (!WindowsNativeEventFilter::instance) {
			WindowsNativeEventFilter::install();
			}

			// Cache window ID
			windowId = winId;
			WindowsNativeEventFilter::install();

			// Save window handle mapping
			g_wndProcHash->insert(hWnd, this);
			g_wndProcHash->insert(hWnd, ctx);
			}

			return true;
			static inline void removeManagedWindow(HWND hWnd) {
			// Remove window handle mapping
			if (!g_wndProcHash->remove(hWnd))
			return;

			// Remove event filter if the all windows has been destroyed
			if (g_wndProcHash->empty()) {
			WindowsNativeEventFilter::uninstall();
			}
			}

			Win32WindowContext::Win32WindowContext() : AbstractWindowContext() {
			}

			Win32WindowContext::~Win32WindowContext() {
			if (m_windowId) {
			removeManagedWindow(reinterpret_cast<HWND>(m_windowId));
			}
			}

			QString Win32WindowContext::key() const {
			return QStringLiteral("win32");
			}

			void Win32WindowContext::virtual_hook(int id, void *data) {
			switch (id) {
			case RaiseWindowHook: {
			if (!m_windowId)
			return;
			m_delegate->setWindowVisible(m_host, true);
			const auto hwnd = reinterpret_cast<HWND>(m_windowId);
			bringWindowToFront(hwnd);
			return;
			}

			case ShowSystemMenuHook: {
			if (!m_windowId)
			return;
			const auto &pos = static_cast<const QPoint >(data);
			auto hWnd = reinterpret_cast<HWND>(m_windowId);
			#if QT_VERSION >= QT_VERSION_CHECK(6, 0, 0)
			const QPoint nativeGlobalPos =
			QHighDpi::toNativeGlobalPosition(pos, m_windowHandle.data());
			#else
			const QPoint nativeGlobalPos = QHighDpi::toNativePixels(pos, m_windowHandle.data());
			#endif
			std::ignore = showSystemMenu_sys(hWnd, qpoint2point(nativeGlobalPos), false,
			isHostSizeFixed());
			return;
			}

			case DefaultColorsHook: {
			auto &map = static_cast<QMap<QString, QColor> >(data);
			map.clear();
			map.insert(QStringLiteral("activeLight"), kWindowsColorSet.activeLight);
			map.insert(QStringLiteral("activeDark"), kWindowsColorSet.activeDark);
			map.insert(QStringLiteral("inactiveLight"), kWindowsColorSet.inactiveLight);
			map.insert(QStringLiteral("inactiveDark"), kWindowsColorSet.inactiveDark);
			return;
			}

			#if QWINDOWKIT_CONFIG(ENABLE_WINDOWS_SYSTEM_BORDERS)
			case DrawWindows10BorderHook: {
			if (!m_windowId)
			return;

			auto args = static_cast<void **>(data);
			auto &painter = static_cast<QPainter >(args[0]);
			const auto &rect = static_cast<const QRect >(args[1]);
			const auto &region = static_cast<const QRegion >(args[2]);
			const auto hwnd = reinterpret_cast<HWND>(m_windowId);

			QPen pen;
			pen.setWidth(int(getWindowFrameBorderThickness(hwnd)) * 2);

			const bool dark = isDarkThemeActive() && isDarkWindowFrameEnabled(hwnd);
			if (m_delegate->isWindowActive(m_host)) {
			if (isWindowFrameBorderColorized()) {
			pen.setColor(getAccentColor());
			} else {
			static QColor frameBorderActiveColorLight(kWindowsColorSet.activeLight);
			static QColor frameBorderActiveColorDark(kWindowsColorSet.activeDark);
			pen.setColor(dark ? frameBorderActiveColorDark
			: frameBorderActiveColorLight);
			}
			} else {
			static QColor frameBorderInactiveColorLight(kWindowsColorSet.inactiveLight);
			static QColor frameBorderInactiveColorDark(kWindowsColorSet.inactiveDark);
			pen.setColor(dark ? frameBorderInactiveColorDark
			: frameBorderInactiveColorLight);
			}
			painter.save();

			// We need antialiasing to give us better result.
			painter.setRenderHint(QPainter::Antialiasing);

			painter.setPen(pen);
			painter.drawLine(QLine{
			QPoint{0, 0},
			QPoint{m_windowHandle->width(), 0}
			});
			painter.restore();
			return;
			}

			case DrawWindows10BorderHook2: {
			if (!m_windowId)
			return;

			// https://github.com/microsoft/terminal/blob/71a6f26e6ece656084e87de1a528c4a8072eeabd/src/cascadia/WindowsTerminal/NonClientIslandWindow.cpp#L1025
			// https://docs.microsoft.com/en-us/windows/win32/dwm/customframe#extending-the-client-frame
			// Draw a black rectangle to make Windows native top border show

			auto hWnd = reinterpret_cast<HWND>(m_windowId);
			HDC hdc = ::GetDC(hWnd);
			RECT windowRect{};
			::GetClientRect(hWnd, &windowRect);
			RECT rcTopBorder = {
			0,
			0,
			RECT_WIDTH(windowRect),
			int(getWindowFrameBorderThickness(hWnd)),
			};
			::FillRect(hdc, &rcTopBorder,
			reinterpret_cast<HBRUSH>(::GetStockObject(BLACK_BRUSH)));
			::ReleaseDC(hWnd, hdc);
			return;
			}
			#endif

			default:
			break;
			}
			AbstractWindowContext::virtual_hook(id, data);
			}

			QVariant Win32WindowContext::windowAttribute(const QString &key) const {
			if (key == QStringLiteral("window-rect")) {
			if (!m_windowId)
			return {};

			RECT frame{};
			auto hwnd = reinterpret_cast<HWND>(m_windowId);
			// According to MSDN, WS_OVERLAPPED is not allowed for AdjustWindowRect.
			auto style = static_cast<DWORD>(::GetWindowLongPtrW(hwnd, GWL_STYLE) & ~WS_OVERLAPPED);
			auto exStyle = static_cast<DWORD>(::GetWindowLongPtrW(hwnd, GWL_EXSTYLE));
			const DynamicApis &apis = DynamicApis::instance();
			if (apis.pAdjustWindowRectExForDpi) {
			apis.pAdjustWindowRectExForDpi(&frame, style, FALSE, exStyle,
			getDpiForWindow(hwnd));
			} else {
			::AdjustWindowRectEx(&frame, style, FALSE, exStyle);
			}
			return QVariant::fromValue(rect2qrect(frame));
			}

			if (key == QStringLiteral("win10-border-needed")) {
			return isSystemBorderEnabled() && !isWin11OrGreater();
			}

			if (key == QStringLiteral("windows-system-border-enabled")) {
			return isSystemBorderEnabled();
			}

			if (key == QStringLiteral("border-thickness")) {
			return m_windowId
			? int(getWindowFrameBorderThickness(reinterpret_cast<HWND>(m_windowId)))
			: 0;
			}

			if (key == QStringLiteral("title-bar-height")) {
			return m_windowId ? int(getTitleBarHeight(reinterpret_cast<HWND>(m_windowId))) : 0;
			}
			return AbstractWindowContext::windowAttribute(key);
			}

			void Win32WindowContext::winIdChanged(WId winId, WId oldWinId) {
			// Reset the context data
			mouseLeaveBlocked = false;
			lastHitTestResult = WindowPart::Outside;
			lastHitTestResultRaw = HTNOWHERE;

			// If the original window id is valid, remove all resources related
			if (oldWinId) {
			removeManagedWindow(reinterpret_cast<HWND>(oldWinId));
			}
			if (!winId) {
			return;
			}

			// Install window hook
			auto hWnd = reinterpret_cast<HWND>(winId);
			if (!isSystemBorderEnabled()) {
			static auto margins = QVariant::fromValue(QMargins(1, 1, 1, 1));

			// If we remove the system border, the window will lose its shadow. If dwm is enabled,
			// then we need to set at least 1px margins, otherwise the following operation will
			// fail with no effect.
			setWindowAttribute(QStringLiteral("extra-margins"), margins);
			}

			// We should disable WS_SYSMENU, otherwise the system button icons will be visible if mica
			// is enabled and the title bar is transparent.
			{
			auto style = ::GetWindowLongPtrW(hWnd, GWL_STYLE);
			if (isSystemBorderEnabled()) {
			::SetWindowLongPtrW(hWnd, GWL_STYLE, style & (~WS_SYSMENU));
			} else {
			::SetWindowLongPtrW(hWnd, GWL_STYLE,
			(style \| WS_THICKFRAME \| WS_CAPTION) & (~WS_SYSMENU));
			}
			}

			// Add managed window
			addManagedWindow(m_windowHandle, hWnd, this);
			}

			bool Win32WindowContext::windowProc(HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam,
			@@ -465,8 +891,8 @@
			// We should skip these messages otherwise we will get crashes.
			// NOTE: WM_QUIT won't be posted to the WindowProc function.
			switch (message) {
			case WM_CLOSE:
			case WM_DESTROY:
			case WM_CLOSE:
			case WM_NCDESTROY:
			// Undocumented messages:
			case WM_UAHDESTROYWINDOW:
			@@ -476,7 +902,7 @@
			break;
			}

			if (!isValidWindow(windowId, false, true)) {
			if (!isValidWindow(hWnd, false, true)) {
			return false;
			}

			@@ -490,21 +916,215 @@
			return true;
			}

			// Whether to show system menu
			if (systemMenuHandler(hWnd, message, wParam, lParam, result)) {
			return true;
			}

			// Forward to native event filter subscribers
			if (!m_nativeEventFilters.isEmpty()) {
			MSG msg = createMessageBlock(hWnd, message, wParam, lParam);
			QT_NATIVE_EVENT_RESULT_TYPE res = 0;
			if (nativeDispatch(nativeEventType(), &msg, &res)) {
			*result = LRESULT(res);
			return true;
			}
			}
			return false; // Not handled
			}

			static constexpr const auto kMessageTag = WPARAM(0x97CCEA99);
			bool Win32WindowContext::windowAttributeChanged(const QString &key, const QVariant &attribute,
			const QVariant &oldAttribute) {
			Q_UNUSED(oldAttribute)

			static inline constexpr bool isTaggedMessage(WPARAM wParam) {
			return (wParam == kMessageTag);
			const auto hwnd = reinterpret_cast<HWND>(m_windowId);
			const DynamicApis &apis = DynamicApis::instance();
			static constexpr const MARGINS extendedMargins = {-1, -1, -1, -1};
			const auto &restoreMargins = [this, &apis, hwnd]() {
			auto margins = qmargins2margins(
			m_windowAttributes.value(QStringLiteral("extra-margins")).value<QMargins>());
			apis.pDwmExtendFrameIntoClientArea(hwnd, &margins);
			};

			if (key == QStringLiteral("extra-margins")) {
			auto margins = qmargins2margins(attribute.value<QMargins>());
			return SUCCEEDED(apis.pDwmExtendFrameIntoClientArea(hwnd, &margins));
			}

			if (key == QStringLiteral("dark-mode")) {
			if (!isWin101809OrGreater()) {
			return false;
			}

			BOOL enable = attribute.toBool();
			if (isWin101903OrGreater()) {
			apis.pSetPreferredAppMode(enable ? PAM_AUTO : PAM_DEFAULT);
			} else {
			apis.pAllowDarkModeForApp(enable);
			}
			const auto attr = isWin1020H1OrGreater() ? _DWMWA_USE_IMMERSIVE_DARK_MODE : _DWMWA_USE_IMMERSIVE_DARK_MODE_BEFORE_20H1;
			apis.pDwmSetWindowAttribute(hwnd, attr, &enable, sizeof(enable));

			apis.pFlushMenuThemes();
			return true;
			}

			// For Win11 or later
			if (key == QStringLiteral("mica")) {
			if (!isWin11OrGreater()) {
			return false;
			}
			if (attribute.toBool()) {
			// We need to extend the window frame into the whole client area to be able
			// to see the blurred window background.
			apis.pDwmExtendFrameIntoClientArea(hwnd, &extendedMargins);
			if (isWin1122H2OrGreater()) {
			// Use official DWM API to enable Mica, available since Windows 11 22H2
			// (10.0.22621).
			const _DWM_SYSTEMBACKDROP_TYPE backdropType = _DWMSBT_MAINWINDOW;
			apis.pDwmSetWindowAttribute(hwnd, _DWMWA_SYSTEMBACKDROP_TYPE, &backdropType,
			sizeof(backdropType));
			} else {
			// Use undocumented DWM API to enable Mica, available since Windows 11
			// (10.0.22000).
			const BOOL enable = TRUE;
			apis.pDwmSetWindowAttribute(hwnd, _DWMWA_MICA_EFFECT, &enable, sizeof(enable));
			}
			} else {
			if (isWin1122H2OrGreater()) {
			const _DWM_SYSTEMBACKDROP_TYPE backdropType = _DWMSBT_AUTO;
			apis.pDwmSetWindowAttribute(hwnd, _DWMWA_SYSTEMBACKDROP_TYPE, &backdropType,
			sizeof(backdropType));
			} else {
			const BOOL enable = FALSE;
			apis.pDwmSetWindowAttribute(hwnd, _DWMWA_MICA_EFFECT, &enable, sizeof(enable));
			}
			restoreMargins();
			}
			return true;
			}

			if (key == QStringLiteral("mica-alt")) {
			if (!isWin1122H2OrGreater()) {
			return false;
			}
			if (attribute.toBool()) {
			// We need to extend the window frame into the whole client area to be able
			// to see the blurred window background.
			apis.pDwmExtendFrameIntoClientArea(hwnd, &extendedMargins);
			// Use official DWM API to enable Mica Alt, available since Windows 11 22H2
			// (10.0.22621).
			const _DWM_SYSTEMBACKDROP_TYPE backdropType = _DWMSBT_TABBEDWINDOW;
			apis.pDwmSetWindowAttribute(hwnd, _DWMWA_SYSTEMBACKDROP_TYPE, &backdropType,
			sizeof(backdropType));
			} else {
			const _DWM_SYSTEMBACKDROP_TYPE backdropType = _DWMSBT_AUTO;
			apis.pDwmSetWindowAttribute(hwnd, _DWMWA_SYSTEMBACKDROP_TYPE, &backdropType,
			sizeof(backdropType));
			restoreMargins();
			}
			return true;
			}

			if (key == QStringLiteral("acrylic-material")) {
			if (!isWin11OrGreater()) {
			return false;
			}
			if (attribute.toBool()) {
			// We need to extend the window frame into the whole client area to be able
			// to see the blurred window background.
			apis.pDwmExtendFrameIntoClientArea(hwnd, &extendedMargins);

			const _DWM_SYSTEMBACKDROP_TYPE backdropType = _DWMSBT_TRANSIENTWINDOW;
			apis.pDwmSetWindowAttribute(hwnd, _DWMWA_SYSTEMBACKDROP_TYPE, &backdropType,
			sizeof(backdropType));

			// PRIVATE API REFERENCE:
			// QColor gradientColor = {};
			// ACCENT_POLICY policy{};
			// policy.dwAccentState = ACCENT_ENABLE_ACRYLICBLURBEHIND;
			// policy.dwAccentFlags = ACCENT_ENABLE_ACRYLIC_WITH_LUMINOSITY;
			// // This API expects the #AABBGGRR format.
			// policy.dwGradientColor =
			// DWORD(qRgba(gradientColor.blue(), gradientColor.green(),
			// gradientColor.red(), gradientColor.alpha()));
			// WINDOWCOMPOSITIONATTRIBDATA wcad{};
			// wcad.Attrib = WCA_ACCENT_POLICY;
			// wcad.pvData = &policy;
			// wcad.cbData = sizeof(policy);
			// apis.pSetWindowCompositionAttribute(hwnd, &wcad);
			} else {
			const _DWM_SYSTEMBACKDROP_TYPE backdropType = _DWMSBT_AUTO;
			apis.pDwmSetWindowAttribute(hwnd, _DWMWA_SYSTEMBACKDROP_TYPE, &backdropType,
			sizeof(backdropType));

			// PRIVATE API REFERENCE:
			// ACCENT_POLICY policy{};
			// policy.dwAccentState = ACCENT_DISABLED;
			// policy.dwAccentFlags = ACCENT_NONE;
			// WINDOWCOMPOSITIONATTRIBDATA wcad{};
			// wcad.Attrib = WCA_ACCENT_POLICY;
			// wcad.pvData = &policy;
			// wcad.cbData = sizeof(policy);
			// apis.pSetWindowCompositionAttribute(hwnd, &wcad);

			restoreMargins();
			}
			return true;
			}

			if (key == QStringLiteral("dwm-blur")) {
			if (attribute.toBool()) {
			// We can't extend the window frame for this effect.
			restoreMargins();
			if (isWin8OrGreater()) {
			ACCENT_POLICY policy{};
			policy.dwAccentState = ACCENT_ENABLE_BLURBEHIND;
			policy.dwAccentFlags = ACCENT_NONE;
			WINDOWCOMPOSITIONATTRIBDATA wcad{};
			wcad.Attrib = WCA_ACCENT_POLICY;
			wcad.pvData = &policy;
			wcad.cbData = sizeof(policy);
			apis.pSetWindowCompositionAttribute(hwnd, &wcad);
			} else {
			DWM_BLURBEHIND bb{};
			bb.fEnable = TRUE;
			bb.dwFlags = DWM_BB_ENABLE;
			apis.pDwmEnableBlurBehindWindow(hwnd, &bb);
			}
			} else {
			if (isWin8OrGreater()) {
			ACCENT_POLICY policy{};
			policy.dwAccentState = ACCENT_DISABLED;
			policy.dwAccentFlags = ACCENT_NONE;
			WINDOWCOMPOSITIONATTRIBDATA wcad{};
			wcad.Attrib = WCA_ACCENT_POLICY;
			wcad.pvData = &policy;
			wcad.cbData = sizeof(policy);
			apis.pSetWindowCompositionAttribute(hwnd, &wcad);
			} else {
			DWM_BLURBEHIND bb{};
			bb.fEnable = FALSE;
			bb.dwFlags = DWM_BB_ENABLE;
			apis.pDwmEnableBlurBehindWindow(hwnd, &bb);
			}
			}
			return true;
			}
			return false;
			}

			QWK_USED static constexpr const struct {
			const WPARAM wParam = MAKEWPARAM(44500, 61897);
			const LPARAM lParam = MAKELPARAM(62662, 44982); // Not used. Reserve for future use.
			} kMessageTag;

			static inline quint64 getKeyState() {
			quint64 result = 0;
			const auto &get = [](const int virtualKey) -> bool {
			return (::GetAsyncKeyState(virtualKey) < 0);
			};
			const bool buttonSwapped = (::GetSystemMetrics(SM_SWAPBUTTON) != FALSE);
			const bool buttonSwapped = ::GetSystemMetrics(SM_SWAPBUTTON);
			if (get(VK_LBUTTON)) {
			result \|= (buttonSwapped ? MK_RBUTTON : MK_LBUTTON);
			}
			@@ -537,7 +1157,7 @@
			// wParam is always ignored in mouse leave messages, but here we
			// give them a special tag to be able to distinguish which messages
			// are sent by ourselves.
			return kMessageTag;
			return kMessageTag.wParam;
			}
			const quint64 keyState = getKeyState();
			if ((myMsg >= WM_NCXBUTTONDOWN) && (myMsg <= WM_NCXBUTTONDBLCLK)) {
			@@ -615,6 +1235,7 @@
			SEND_MESSAGE(hWnd, WM_MOUSELEAVE, wParamNew, lParamNew);
			break;
			default:
			// unreachable
			break;
			}

			@@ -637,7 +1258,7 @@
			LPARAM lParam, LRESULT *result) {
			switch (message) {
			case WM_MOUSELEAVE: {
			if (!isTaggedMessage(wParam)) {
			if (wParam != kMessageTag.wParam) {
			// Qt will call TrackMouseEvent() to get the WM_MOUSELEAVE message when it
			// receives WM_MOUSEMOVE messages, and since we are converting every
			// WM_NCMOUSEMOVE message to WM_MOUSEMOVE message and send it back to the window
			@@ -647,10 +1268,11 @@
			// actually lost the hover state. So we filter out these superfluous mouse leave
			// events here to avoid this issue.
			DWORD dwScreenPos = ::GetMessagePos();
			QPoint qtScenePos =
			fromNativeLocalPosition(m_windowHandle, QPoint(GET_X_LPARAM(dwScreenPos),
			GET_Y_LPARAM(dwScreenPos)));
			auto dummy = CoreWindowAgent::Unknown;
			POINT screenPoint{GET_X_LPARAM(dwScreenPos), GET_Y_LPARAM(dwScreenPos)};
			::ScreenToClient(hWnd, &screenPoint);
			QPoint qtScenePos = QHighDpi::fromNativeLocalPosition(point2qpoint(screenPoint),
			m_windowHandle.data());
			auto dummy = WindowAgentBase::Unknown;
			if (isInSystemButtons(qtScenePos, &dummy)) {
			// We must record whether the last WM_MOUSELEAVE was filtered, because if
			// Qt does not receive this message it will not call TrackMouseEvent()
			@@ -694,33 +1316,110 @@
			case WM_NCPOINTERUP:
			#endif
			case WM_NCMOUSEHOVER: {
			const WindowPart currentWindowPart = lastHitTestResult;
			if (message == WM_NCMOUSEMOVE) {
			if (currentWindowPart != WindowPart::ChromeButton) {
			std::ignore = m_delegate->resetQtGrabbedControl();
			if (lastHitTestResult != WindowPart::ChromeButton) {
			// https://github.com/qt/qtbase/blob/e26a87f1ecc40bc8c6aa5b889fce67410a57a702/src/widgets/kernel/qwidgetwindow.cpp#L472
			// When the mouse press event arrives, QWidgetWindow will implicitly grab
			// the top widget right under the mouse, and set `qt_button_down` to this
			// widget. At this time, no other widgets will accept the mouse event until
			// QWidgetWindow receives the mouse release event, then set `qt_button_down`
			// to null.

			// Imagine the following situation, now the main window has a pop-up menu,
			// the focus is not on the main window, if we click outside the pop-up menu,
			// the menu will close, which seems to be completely fine. But if we close
			// the menu by clicking on the title bar draggable area, then other widgets
			// won't accept the mouse message afterwards.

			// Here's the reason.
			// When the mouse is placed in the draggable area of the title bar, there
			// are two situations.

			// 1. If the focus is on the main window, and the last result of
			// WM_NCHITTEST is HTCAPTION, the mouse click event in the title bar is
			// taken over by Windows and Qt does not receive the mouse click event.

			// 2. If the main window has a pop-up menu, it is completely different. When
			// the mouse is pressed on the title bar, Windows sends the WM_LBUTTONDOWN
			// message to the window plane of the pop-up menu, the menu is closed, but
			// Qt will continue to forward the event to the QWidget under the mouse, and
			// the event will be processed by QWidgetWindow, causing the title bar
			// widget to be implicitly grabbed. After the menu is closed, Windows
			// immediately sends WM_NCHITTEST, because the mouse is in the title bar
			// draggable area, the result is HTCAPTION, so when the mouse is released,
			// Windows sends WM_NCLBUTTONUP, which is a non-client message, and it
			// will be ignored by Qt. As a consequence, QWidgetWindow can't receive a
			// mouse release message in the client area, so the grab remains, and other
			// widgets cannot receive mouse events.

			// Since we didn't watch the menu window, we cannot capture any mouse
			// press events sent by Windows, so we cannot solve this problem by
			// recording mouse events. Fortunately, we found that the main window will
			// receive a WM_NCMOUSEMOVE message immediately after the menu is closed, so
			// we just manually send a mouse release event when this message arrives and
			// set qt_button_down to null. Don't worry, when receiving WM_NCMOUSEMOVE,
			// there shouldn't be any control in the state of being grabbed.

			// In the native window, although QWidgetWindow handles the forwarded mouse
			// press event when the menu is closed, since the native title bar is not a
			// QWidget, no widget will be grabbed, and `qt_button_down` remains empty,
			// the above problems would not arise.

			m_delegate->resetQtGrabbedControl(m_host);

			// If the mouse moves from chrome buttons to other non-client areas, a
			// WM_MOUSELEAVE message should be sent.
			if (mouseLeaveBlocked) {
			emulateClientAreaMessage(hWnd, message, wParam, lParam,
			WM_NCMOUSELEAVE);
			}
			}

			// We need to make sure we get the right hit-test result when a WM_NCMOUSELEAVE
			// comes, so we reset it when we receive a WM_NCMOUSEMOVE.

			// If the mouse is entering the client area, there must be a WM_NCHITTEST
			// setting it to `Client` before the WM_NCMOUSELEAVE comes; if the mouse is
			// leaving the window, current window part remains as `Outside`.
			lastHitTestResult = WindowPart::Outside;
			}

			if (currentWindowPart == WindowPart::ChromeButton) {
			emulateClientAreaMessage(hWnd, message, wParam, lParam);
			if (lastHitTestResult == WindowPart::ChromeButton) {
			if (message == WM_NCMOUSEMOVE) {
			// ### FIXME FIXME FIXME
			// ### FIXME: Calling DefWindowProc() here is really dangerous, investigate
			// how to avoid doing this.
			// ### FIXME FIXME FIXME
			*result = ::DefWindowProcW(hWnd, WM_NCMOUSEMOVE, wParam, lParam);
			emulateClientAreaMessage(hWnd, message, wParam, lParam);
			return true;
			}

			if (lastHitTestResultRaw == HTSYSMENU) {
			switch (message) {
			case WM_NCLBUTTONDOWN:
			if (iconButtonClickLevel == 0) {
			// A message of WM_SYSCOMMAND with SC_MOUSEMENU will be sent by
			// Windows, and the current control flow will be blocked by the
			// menu while Windows will create and execute a new event loop
			// until the menu returns
			iconButtonClickTime = ::GetTickCount64();
			*result = ::DefWindowProcW(hWnd, message, wParam, lParam);
			iconButtonClickTime = 0;
			if (iconButtonClickLevel & IconButtonTriggersClose) {
			::PostMessageW(hWnd, WM_SYSCOMMAND, SC_CLOSE, 0);
			}
			if (iconButtonClickLevel & IconButtonDoubleClicked) {
			iconButtonClickLevel = 0;
			}
			// Otherwise, no need to reset `iconButtonClickLevel` if not to
			// close, if it has value, there must be another incoming
			// WM_NCLBUTTONDOWN
			} else {
			iconButtonClickLevel = 0;
			}
			break;
			case WM_NCLBUTTONDBLCLK:
			// A message of WM_SYSCOMMAND with SC_CLOSE will be sent by Windows
			*result = ::DefWindowProcW(hWnd, message, wParam, lParam);
			break;
			default:
			*result = FALSE;
			emulateClientAreaMessage(hWnd, message, wParam, lParam);
			break;
			}
			} else {
			// According to MSDN, we should return non-zero for X button messages to
			// indicate we have handled these messages (due to historical reasons), for
			@@ -729,6 +1428,7 @@
			(((message >= WM_NCXBUTTONDOWN) && (message <= WM_NCXBUTTONDBLCLK))
			? TRUE
			: FALSE);
			emulateClientAreaMessage(hWnd, message, wParam, lParam);
			}
			return true;
			}
			@@ -742,7 +1442,7 @@
			// pressing area as HTCLIENT which maybe because of our former retransmission of
			// WM_NCLBUTTONDOWN, as a result, a WM_NCMOUSELEAVE will come immediately and a
			// lot of WM_MOUSEMOVE will come if we move the mouse, we should track the mouse
			// in advance.
			// in advance. (May be redundant?)
			if (mouseLeaveBlocked) {
			mouseLeaveBlocked = false;
			requestForMouseLeaveMessage(hWnd, false);
			@@ -759,7 +1459,9 @@
			// window from client area, which means we will get previous window part as
			// HTCLIENT if the mouse leaves window from client area and enters window
			// from non-client area, but it has no bad effect.
			std::ignore = m_delegate->resetQtGrabbedControl();

			// Why do we need to call this function here?
			m_delegate->resetQtGrabbedControl(m_host);
			}
			}
			break;
			@@ -772,231 +1474,887 @@
			}

			bool Win32WindowContext::customWindowHandler(HWND hWnd, UINT message, WPARAM wParam,
			LPARAM lParam, LRESULT *result)
			{
			LPARAM lParam, LRESULT *result) {
			switch (message) {
			case WM_NCCALCSIZE: {
			// Windows是根据这个消息的返回值来设置窗口的客户区（窗口中真正显示的内容）
			// 和非客户区（标题栏、窗口边框、菜单栏和状态栏等Windows系统自行提供的部分
			// ，不过对于Qt来说，除了标题栏和窗口边框，非客户区基本也都是自绘的）的范
			// 围的，lParam里存放的就是新客户区的几何区域，默认是整个窗口的大小，正常
			// 的程序需要修改这个参数，告知系统窗口的客户区和非客户区的范围（一般来说可
			// 以完全交给Windows，让其自行处理，使用默认的客户区和非客户区），因此如果
			// 我们不修改lParam，就可以使客户区充满整个窗口，从而去掉标题栏和窗口边框
			// （因为这些东西都被客户区给盖住了。但边框阴影也会因此而丢失，不过我们会使
			// 用其他方式将其带回，请参考其他消息的处理，此处不过多提及）。但有个情况要
			// 特别注意，那就是窗口最大化后，窗口的实际尺寸会比屏幕的尺寸大一点，从而使
			// 用户看不到窗口的边界，这样用户就不能在窗口最大化后调整窗口的大小了（虽然
			// 这个做法听起来特别奇怪，但Windows确实就是这样做的），因此如果我们要自行
			// 处理窗口的非客户区，就要在窗口最大化后，将窗口边框的宽度和高度（一般是相
			// 等的）从客户区裁剪掉，否则我们窗口所显示的内容就会超出屏幕边界，显示不全。
			// 如果用户开启了任务栏自动隐藏，在窗口最大化后，还要考虑任务栏的位置。因为
			// 如果窗口最大化后，其尺寸和屏幕尺寸相等（因为任务栏隐藏了，所以窗口最大化
			// 后其实是充满了整个屏幕，变相的全屏了），Windows会认为窗口已经进入全屏的
			// 状态，从而导致自动隐藏的任务栏无法弹出。要避免这个状况，就要使窗口的尺寸
			// 小于屏幕尺寸。我下面的做法参考了火狐、Chromium和Windows Terminal
			// 如果没有开启任务栏自动隐藏，是不存在这个问题的，所以要先进行判断。
			// 一般情况下，*result设置为0（相当于DefWindowProc的返回值为0）就可以了，
			// 根据MSDN的说法，返回0意为此消息已经被程序自行处理了，让Windows跳过此消
			// 息，否则Windows会添加对此消息的默认处理，对于当前这个消息而言，就意味着
			// 标题栏和窗口边框又会回来，这当然不是我们想要的结果。根据MSDN，当wParam
			// 为FALSE时，只能返回0，但当其为TRUE时，可以返回0，也可以返回一个WVR_常
			// 量。根据Chromium的注释，当存在非客户区时，如果返回WVR_REDRAW会导致子
			// 窗口/子控件出现奇怪的bug（自绘控件错位），并且Lucas在Windows 10
			// 上成功复现，说明这个bug至今都没有解决。我查阅了大量资料，发现唯一的解决
			// 方案就是返回0。但如果不存在非客户区，且wParam为TRUE，最好返回
			// WVR_REDRAW，否则窗口在调整大小可能会产生严重的闪烁现象。
			// 虽然对大多数消息来说，返回0都代表让Windows忽略此消息，但实际上不同消息
			// 能接受的返回值是不一样的，请注意自行查阅MSDN。
			case WM_NCHITTEST: {
			// 原生Win32窗口只有顶边是在窗口内部resize的，其余三边都是在窗口
			// 外部进行resize的，其原理是，WS_THICKFRAME这个窗口样式会在窗
			// 口的左、右和底边添加三个透明的resize区域，这三个区域在正常状态
			// 下是完全不可见的，它们由DWM负责绘制和控制。这些区域的宽度等于
			// (SM_CXSIZEFRAME + SM_CXPADDEDBORDER)，高度等于
			// (SM_CYSIZEFRAME + SM_CXPADDEDBORDER)，在100%缩放时，均等
			// 于8像素。它们属于窗口区域的一部分，但不属于客户区，而是属于非客
			// 户区，因此GetWindowRect获取的区域中是包含这三个resize区域的，
			// 而GetClientRect获取的区域是不包含它们的。当把
			// DWMWA_EXTENDED_FRAME_BOUNDS作为参数调用
			// DwmGetWindowAttribute时，也能获取到一个窗口大小，这个大小介
			// 于前面两者之间，暂时不知道这个数据的意义及其作用。我们在
			// WM_NCCALCSIZE消息的处理中，已经把整个窗口都设置为客户区了，也
			// 就是说，我们的窗口已经没有非客户区了，因此那三个透明的resize区
			// 域，此刻也已经成为窗口客户区的一部分了，从而变得不透明了。所以
			// 现在的resize，看起来像是在窗口内部resize，是因为原本透明的地方
			// 现在变得不透明了，实际上，单纯从范围上来看，现在我们resize的地方，
			// 就是普通窗口的边框外部，那三个透明区域的范围。
			// 因此，如果我们把边框完全去掉（就是我们正在做的事情），resize就
			// 会看起来是在内部进行，这个问题通过常规方法非常难以解决。我测试过
			// QQ和钉钉的窗口，它们的窗口就是在外部resize，但实际上它们是通过
			// 把窗口实际的内容，嵌入到一个完全透明的但尺寸要大一圈的窗口中实现
			// 的，虽然看起来效果还不错，但对于此项目而言，代码和窗口结构过于复
			// 杂，因此我没有采用此方案。然而，对于具体的软件项目而言，其做法也
			// 不失为一个优秀的解决方案，毕竟其在大多数条件下的表现都还可以。
			//
			// 和1.x的做法不同，现在的2.x选择了保留窗口三边，去除整个窗口顶部，
			// 好处是保留了系统的原生边框，外观较好，且与系统结合紧密，而且resize
			// 的表现也有很大改善，缺点是需要自行绘制顶部边框线。原本以为只能像
			// Windows Terminal那样在WM_PAINT里搞黑魔法，但后来发现，其实只
			// 要颜色相近，我们自行绘制一根实线也几乎能以假乱真，而且这样也不会
			// 破坏Qt自己的绘制系统，能做到不依赖黑魔法就能实现像Windows Terminal
			// 那样外观和功能都比较完美的自定义边框。

			// Sent when the size and position of a window's client area must be
			// calculated. By processing this message, an application can
			// control the content of the window's client area when the size or
			// position of the window changes. If wParam is TRUE, lParam points
			// to an NCCALCSIZE_PARAMS structure that contains information an
			// application can use to calculate the new size and position of the
			// client rectangle. If wParam is FALSE, lParam points to a RECT
			// structure. On entry, the structure contains the proposed window
			// rectangle for the window. On exit, the structure should contain
			// the screen coordinates of the corresponding window client area.
			// The client area is the window's content area, the non-client area
			// is the area which is provided by the system, such as the title
			// bar, the four window borders, the frame shadow, the menu bar, the
			// status bar, the scroll bar, etc. But for Qt, it draws most of the
			// window area (client + non-client) itself. We now know that the
			// title bar and the window frame is in the non-client area and we
			// can set the scope of the client area in this message, so we can
			// remove the title bar and the window frame by let the non-client
			// area be covered by the client area (because we can't really get
			// rid of the non-client area, it will always be there, all we can
			// do is to hide it) , which means we should let the client area's
			// size the same with the whole window's size. So there is no room
			// for the non-client area and then the user won't be able to see it
			// again. But how to achieve this? Very easy, just leave lParam (the
			// re-calculated client area) untouched. But of course you can
			// modify lParam, then the non-client area will be seen and the
			// window borders and the window frame will show up. However, things
			// are quite different when you try to modify the top margin of the
			// client area. DWM will always draw the whole title bar no matter
			// what margin value you set for the top, unless you don't modify it
			// and remove the whole top area (the title bar + the one pixel
			// height window border). This can be confirmed in Windows
			// Terminal's source code, you can also try yourself to verify
			// it. So things will become quite complicated if you want to
			// preserve the four window borders.
			// A normal Win32 window can be resized outside of it. Here is the
			// reason: the WS_THICKFRAME window style will cause a window has three
			// transparent areas beside the window's left, right and bottom
			// edge. Their width or height is eight pixels if the window is not
			// scaled. In most cases, they are totally invisible. It's DWM's
			// responsibility to draw and control them. They exist to let the
			// user resize the window, visually outside of it. They are in the
			// window area, but not the client area, so they are in the
			// non-client area actually. But we have turned the whole window
			// area into client area in WM_NCCALCSIZE, so the three transparent
			// resize areas also become a part of the client area and thus they
			// become visible. When we resize the window, it looks like we are
			// resizing inside of it, however, that's because the transparent
			// resize areas are visible now, we ARE resizing outside of the
			// window actually. But I don't know how to make them become
			// transparent again without breaking the frame shadow drawn by DWM.
			// If you really want to solve it, you can try to embed your window
			// into a larger transparent window and draw the frame shadow
			// yourself. As what we have said in WM_NCCALCSIZE, you can only
			// remove the top area of the window, this will let us be able to
			// resize outside of the window and don't need much process in this
			// message, it looks like a perfect plan, however, the top border is
			// missing due to the whole top area is removed, and it's very hard
			// to bring it back because we have to use a trick in WM_PAINT
			// (learned from Windows Terminal), but no matter what we do in
			// WM_PAINT, it will always break the backing store mechanism of Qt,
			// so actually we can't do it. And it's very difficult to do such
			// things in NativeEventFilters as well. What's worse, if we really
			// do this, the four window borders will become white and they look
			// horrible in dark mode. This solution only supports Windows 10
			// because the border width on Win10 is only one pixel, however it's
			// eight pixels on Windows 7 so preserving the three window borders
			// looks terrible on old systems.
			//
			// Unlike the 1.x code, we choose to preserve the three edges of the
			// window in 2.x, and get rid of the whole top part of the window.
			// There are quite some advantages such as the appearance looks much
			// better and due to we have the original system window frame, our
			// window can behave just like a normal Win32 window even if we now
			// doesn't have a title bar at all. Most importantly, the flicker and
			// jitter during window resizing is totally gone now. The disadvantage
			// is we have to draw a top frame border ourselves. Previously I thought
			// we have to do the black magic in WM_PAINT just like what Windows
			// Terminal does, however, later I found that if we choose a proper
			// color, our homemade top border can almost have exactly the same
			// appearance with the system's one.
			[[maybe_unused]] const auto &hitTestRecorder = qScopeGuard([this, result]() {
			lastHitTestResultRaw = int(*result);
			lastHitTestResult = getHitWindowPart(lastHitTestResultRaw);
			});

			// If `wParam` is `FALSE`, `lParam` points to a `RECT` that contains
			// the proposed window rectangle for our window. During our
			// processing of the `WM_NCCALCSIZE` message, we are expected to
			// modify the `RECT` that `lParam` points to, so that its value upon
			// our return is the new client area. We must return 0 if `wParam`
			// is `FALSE`.
			// If `wParam` is `TRUE`, `lParam` points to a `NCCALCSIZE_PARAMS`
			// struct. This struct contains an array of 3 `RECT`s, the first of
			// which has the exact same meaning as the `RECT` that is pointed to
			// by `lParam` when `wParam` is `FALSE`. The remaining `RECT`s, in
			// conjunction with our return value, can
			// be used to specify portions of the source and destination window
			// rectangles that are valid and should be preserved. We opt not to
			// implement an elaborate client-area preservation technique, and
			// simply return 0, which means "preserve the entire old client area
			// and align it with the upper-left corner of our new client area".
			const auto clientRect = ((wParam == FALSE) ? reinterpret_cast<LPRECT>(lParam) : &(reinterpret_cast<LPNCCALCSIZE_PARAMS>(lParam))->rgrc[0]);
			if (isWin10OrGreater()) {
			// Store the original top margin before the default window procedure applies the default frame.
			const LONG originalTop = clientRect->top;
			// Apply the default frame because we don't want to remove the whole window frame,
			// we still need the standard window frame (the resizable frame border and the frame
			// shadow) for the left, bottom and right edges.
			// If we return 0 here directly, the whole window frame will be removed (which means
			// there will be no resizable frame border and the frame shadow will also disappear),
			// and that's also how most applications customize their title bars on Windows. It's
			// totally OK but since we want to preserve as much original frame as possible, we
			// can't use that solution.
			const LRESULT hitTestResult = ::DefWindowProcW(hWnd, WM_NCCALCSIZE, wParam, lParam);
			if ((hitTestResult != HTERROR) && (hitTestResult != HTNOWHERE)) {
			*result = hitTestResult;
			POINT nativeGlobalPos{GET_X_LPARAM(lParam), GET_Y_LPARAM(lParam)};
			POINT nativeLocalPos = nativeGlobalPos;
			::ScreenToClient(hWnd, &nativeLocalPos);

			RECT clientRect{0, 0, 0, 0};
			::GetClientRect(hWnd, &clientRect);
			auto clientWidth = RECT_WIDTH(clientRect);
			auto clientHeight = RECT_HEIGHT(clientRect);

			QPoint qtScenePos = QHighDpi::fromNativeLocalPosition(point2qpoint(nativeLocalPos),
			m_windowHandle.data());

			int frameSize = getResizeBorderThickness(hWnd);

			bool isFixedWidth = isHostWidthFixed();
			bool isFixedHeight = isHostHeightFixed();
			bool isFixedSize = isHostSizeFixed();
			bool isInLeftBorder = nativeLocalPos.x <= frameSize;
			bool isInTopBorder = nativeLocalPos.y <= frameSize;
			bool isInRightBorder = nativeLocalPos.x > clientWidth - frameSize;
			bool isInBottomBorder = nativeLocalPos.y > clientHeight - frameSize;
			bool isInTitleBar = isInTitleBarDraggableArea(qtScenePos);
			WindowAgentBase::SystemButton sysButtonType = WindowAgentBase::Unknown;
			bool isInCaptionButtons = isInSystemButtons(qtScenePos, &sysButtonType);
			bool dontOverrideCursor = false; // ### TODO

			if (isInCaptionButtons) {
			// Firstly, we set the hit test result to a default value to be able to detect
			// whether we have changed it or not afterwards.
			*result = HTNOWHERE;
			// Even if the mouse is inside the chrome button area now, we should still allow
			// the user to be able to resize the window with the top or right window border,
			// this is also the normal behavior of a native Win32 window (but only when the
			// window is not maximized/fullscreen/minimized, of course).
			if (isWindowNoState(hWnd)) {
			static constexpr const quint8 kBorderSize = 2;
			bool isTop = nativeLocalPos.y <= kBorderSize;
			bool isLeft = nativeLocalPos.x <= kBorderSize;
			bool isRight = nativeLocalPos.x > clientWidth - kBorderSize;
			if (isTop \|\| isLeft \|\| isRight) {
			if (isFixedSize \|\| dontOverrideCursor) {
			// The user doesn't want the window to be resized, so we tell
			// Windows we are in the client area so that the controls beneath
			// the mouse cursor can still be hovered or clicked.
			*result = isInTitleBar ? HTCAPTION : HTCLIENT;
			} else {
			if (isTop) {
			if (isLeft) {
			if (isFixedWidth) {
			*result = HTTOP;
			} else if (isFixedHeight) {
			*result = HTLEFT;
			} else {
			*result = HTTOPLEFT;
			}
			} else if (isRight) {
			if (isFixedWidth) {
			*result = HTTOP;
			} else if (isFixedHeight) {
			*result = HTRIGHT;
			} else {
			*result = HTTOPRIGHT;
			}
			} else {
			*result = isFixedHeight ? HTBORDER : HTTOP;
			}
			} else {
			if (isFixedWidth) {
			*result = HTBORDER;
			} else {
			*result = isLeft ? HTLEFT : HTRIGHT;
			}
			}
			}
			}
			}
			if (*result == HTNOWHERE) {
			// OK, we are now really inside one of the chrome buttons, tell Windows the
			// exact role of our button. The Snap Layout feature introduced in Windows
			// 11 won't work without this.
			switch (sysButtonType) {
			case WindowAgentBase::WindowIcon:
			*result = HTSYSMENU;
			break;
			case WindowAgentBase::Help:
			*result = HTHELP;
			break;
			case WindowAgentBase::Minimize:
			*result = HTREDUCE;
			break;
			case WindowAgentBase::Maximize:
			*result = HTZOOM;
			break;
			case WindowAgentBase::Close:
			*result = HTCLOSE;
			break;
			default:
			// unreachable
			break;
			}
			}
			if (*result == HTNOWHERE) {
			// OK, it seems we are not inside the window resize area, nor inside the
			// chrome buttons, tell Windows we are in the client area to let Qt handle
			// this event.
			*result = HTCLIENT;
			}
			return true;
			}
			// OK, we are not inside any chrome buttons, try to find out which part of the
			// window are we hitting.

			bool max = isMaximized(hWnd);
			bool full = isFullScreen(hWnd);

			if (isSystemBorderEnabled()) {
			// This will handle the left, right and bottom parts of the frame
			// because we didn't change them.
			LRESULT originalHitTestResult = ::DefWindowProcW(hWnd, WM_NCHITTEST, 0, lParam);
			if (originalHitTestResult != HTCLIENT) {
			// Even if the window is not resizable, we still can't return HTCLIENT here
			// because when we enter this code path, it means the mouse cursor is
			// outside the window, that is, the three transparent window resize area.
			// Returning HTCLIENT will confuse Windows, we can't put our controls there
			// anyway.
			*result = HTNOWHERE; // Make sure we can know we don't set any value
			// explicitly later.
			if (originalHitTestResult == HTCAPTION) {
			} else if (isFixedSize \|\| dontOverrideCursor) {
			*result = HTBORDER;
			} else if (isFixedWidth \|\| isFixedHeight) {
			if (originalHitTestResult == HTTOPLEFT) {
			if (isFixedWidth) {
			*result = HTTOP;
			} else {
			*result = HTLEFT;
			}
			} else if (originalHitTestResult == HTTOPRIGHT) {
			if (isFixedWidth) {
			*result = HTTOP;
			} else {
			*result = HTRIGHT;
			}
			} else if (originalHitTestResult == HTBOTTOMRIGHT) {
			if (isFixedWidth) {
			*result = HTBOTTOM;
			} else {
			*result = HTRIGHT;
			}
			} else if (originalHitTestResult == HTBOTTOMLEFT) {
			if (isFixedWidth) {
			*result = HTBOTTOM;
			} else {
			*result = HTLEFT;
			}
			} else if (originalHitTestResult == HTLEFT \|\|
			originalHitTestResult == HTRIGHT) {
			if (isFixedWidth) {
			*result = HTBORDER;
			}
			} else if (originalHitTestResult == HTTOP \|\|
			originalHitTestResult == HTBOTTOM) {
			if (isFixedHeight) {
			*result = HTBORDER;
			}
			}
			}
			if (*result == HTNOWHERE) {
			*result = originalHitTestResult;
			}
			return true;
			}
			// Re-apply the original top from before the size of the default frame was applied,
			// and the whole top frame (the title bar and the top border) is gone now.
			// For the top frame, we only has 2 choices: (1) remove the top frame entirely, or
			// (2) don't touch it at all. We can't preserve the top border by adjusting the top
			// margin here. If we try to modify the top margin, the original title bar will
			// always be painted by DWM regardless what margin we set, so here we can only remove
			// the top frame entirely and use some special technique to bring the top border back.
			clientRect->top = originalTop;
			}
			const bool max = IsMaximized(hWnd);
			const bool full = isFullScreen(hWnd);
			// We don't need this correction when we're fullscreen. We will
			// have the WS_POPUP size, so we don't have to worry about
			// borders, and the default frame will be fine.
			if (max && !full) {
			// When a window is maximized, its size is actually a little bit more
			// than the monitor's work area. The window is positioned and sized in
			// such a way that the resize handles are outside the monitor and
			// then the window is clipped to the monitor so that the resize handle
			// do not appear because you don't need them (because you can't resize
			// a window when it's maximized unless you restore it).
			const quint32 frameSize = getResizeBorderThickness(hWnd);
			clientRect->top += frameSize;
			if (!isWin10OrGreater()) {
			clientRect->bottom -= frameSize;
			clientRect->left += frameSize;
			clientRect->right -= frameSize;
			if (full) {
			*result = HTCLIENT;
			return true;
			}
			}
			// Attempt to detect if there's an autohide taskbar, and if
			// there is, reduce our size a bit on the side with the taskbar,
			// so the user can still mouse-over the taskbar to reveal it.
			// Make sure to use MONITOR_DEFAULTTONEAREST, so that this will
			// still find the right monitor even when we're restoring from
			// minimized.
			if (max \|\| full) {
			APPBARDATA abd;
			SecureZeroMemory(&abd, sizeof(abd));
			abd.cbSize = sizeof(abd);
			const UINT taskbarState = ::SHAppBarMessage(ABM_GETSTATE, &abd);
			// First, check if we have an auto-hide taskbar at all:
			if (taskbarState & ABS_AUTOHIDE) {
			bool top = false, bottom = false, left = false, right = false;
			// Due to ABM_GETAUTOHIDEBAREX was introduced in Windows 8.1,
			// we have to use another way to judge this if we are running
			// on Windows 7 or Windows 8.
			if (isWin8Point1OrGreater()) {
			const std::optional<MONITORINFOEXW> monitorInfo = getMonitorForWindow(hWnd);
			const RECT monitorRect = monitorInfo.value().rcMonitor;
			// This helper can be used to determine if there's an
			// auto-hide taskbar on the given edge of the monitor
			// we're currently on.
			const auto hasAutohideTaskbar = [monitorRect](const UINT edge) -> bool {
			APPBARDATA abd2{};
			abd2.cbSize = sizeof(abd2);
			abd2.uEdge = edge;
			abd2.rc = monitorRect;
			const auto hTaskbar = reinterpret_cast<HWND>(::SHAppBarMessage(ABM_GETAUTOHIDEBAREX, &abd2));
			return (hTaskbar != nullptr);
			};
			top = hasAutohideTaskbar(ABE_TOP);
			bottom = hasAutohideTaskbar(ABE_BOTTOM);
			left = hasAutohideTaskbar(ABE_LEFT);
			right = hasAutohideTaskbar(ABE_RIGHT);
			} else {
			int edge = -1;
			APPBARDATA abd2{};
			abd2.cbSize = sizeof(abd2);
			abd2.hWnd = ::FindWindowW(L"Shell_TrayWnd", nullptr);
			const HMONITOR windowMonitor = ::MonitorFromWindow(hWnd, MONITOR_DEFAULTTONEAREST);
			const HMONITOR taskbarMonitor = ::MonitorFromWindow(abd2.hWnd, MONITOR_DEFAULTTOPRIMARY);
			if (taskbarMonitor == windowMonitor) {
			::SHAppBarMessage(ABM_GETTASKBARPOS, &abd2);
			edge = abd2.uEdge;
			if (max) {
			*result = isInTitleBar ? HTCAPTION : HTCLIENT;
			return true;
			}
			// At this point, we know that the cursor is inside the client area,
			// so it has to be either the little border at the top of our custom
			// title bar or the drag bar. Apparently, it must be the drag bar or
			// the little border at the top which the user can use to move or
			// resize the window.
			if (isInTopBorder) {
			// Return HTCLIENT instead of HTBORDER here, because the mouse is
			// inside our homemade title bar now, return HTCLIENT to let our
			// title bar can still capture mouse events.
			*result = [&]() {
			if (isFixedSize \|\| isFixedHeight \|\| dontOverrideCursor \|\|
			(isFixedWidth && (isInLeftBorder \|\| isInRightBorder))) {
			if (isInTitleBar) {
			return HTCAPTION;
			} else {
			return HTCLIENT;
			}
			} else {
			return HTTOP;
			}
			top = (edge == ABE_TOP);
			bottom = (edge == ABE_BOTTOM);
			left = (edge == ABE_LEFT);
			right = (edge == ABE_RIGHT);
			}();
			return true;
			}
			if (isInTitleBar) {
			*result = HTCAPTION;
			return true;
			}
			*result = HTCLIENT;
			return true;
			} else {
			if (full) {
			*result = HTCLIENT;
			return true;
			}
			if (max \|\| isFixedSize \|\| dontOverrideCursor) {
			*result = isInTitleBar ? HTCAPTION : HTCLIENT;
			return true;
			}
			if (isFixedWidth \|\| isFixedHeight) {
			if (isInLeftBorder && isInTopBorder) {
			if (isFixedWidth) {
			*result = HTTOP;
			} else {
			*result = HTLEFT;
			}
			} else if (isInRightBorder && isInTopBorder) {
			if (isFixedWidth) {
			*result = HTTOP;
			} else {
			*result = HTRIGHT;
			}
			} else if (isInRightBorder && isInBottomBorder) {
			if (isFixedWidth) {
			*result = HTBOTTOM;
			} else {
			*result = HTRIGHT;
			}
			} else if (isInLeftBorder && isInBottomBorder) {
			if (isFixedWidth) {
			*result = HTBOTTOM;
			} else {
			*result = HTLEFT;
			}
			} else if (isInLeftBorder \|\| isInRightBorder) {
			if (isFixedWidth) {
			*result = HTCLIENT;
			} else {
			*result = isInLeftBorder ? HTLEFT : HTRIGHT;
			}
			} else if (isInTopBorder \|\| isInBottomBorder) {
			if (isFixedHeight) {
			*result = HTCLIENT;
			} else {
			*result = isInTopBorder ? HTTOP : HTBOTTOM;
			}
			} else {
			*result = HTCLIENT;
			}
			// If there's a taskbar on any side of the monitor, reduce
			// our size a little bit on that edge.
			// Note to future code archeologists:
			// This doesn't seem to work for fullscreen on the primary
			// display. However, testing a bunch of other apps with
			// fullscreen modes and an auto-hiding taskbar has
			// shown that _none_ of them reveal the taskbar from
			// fullscreen mode. This includes Edge, Firefox, Chrome,
			// Sublime Text, PowerPoint - none seemed to support this.
			// This does however work fine for maximized.
			if (top) {
			// Peculiarly, when we're fullscreen,
			clientRect->top += kAutoHideTaskBarThickness;
			} else if (bottom) {
			clientRect->bottom -= kAutoHideTaskBarThickness;
			} else if (left) {
			clientRect->left += kAutoHideTaskBarThickness;
			} else if (right) {
			clientRect->right -= kAutoHideTaskBarThickness;
			return true;
			} else {
			if (isInTopBorder) {
			if (isInLeftBorder) {
			*result = HTTOPLEFT;
			return true;
			}
			if (isInRightBorder) {
			*result = HTTOPRIGHT;
			return true;
			}
			*result = HTTOP;
			return true;
			}
			if (isInBottomBorder) {
			if (isInLeftBorder) {
			*result = HTBOTTOMLEFT;
			return true;
			}
			if (isInRightBorder) {
			*result = HTBOTTOMRIGHT;
			return true;
			}
			*result = HTBOTTOM;
			return true;
			}
			if (isInLeftBorder) {
			*result = HTLEFT;
			return true;
			}
			if (isInRightBorder) {
			*result = HTRIGHT;
			return true;
			}
			}
			if (isInTitleBar) {
			*result = HTCAPTION;
			return true;
			}
			*result = HTCLIENT;
			return true;
			}
			// ### TODO: std::ignore = Utils::syncWmPaintWithDwm(); // This should be executed at the very last.
			// By returning WVR_REDRAW we can make the window resizing look less broken.
			// But we must return 0 if wParam is FALSE, according to Microsoft Docs.
			// IMPORTANT NOTE:
			// If you are drawing something manually through D3D in your window, don't
			// try to return WVR_REDRAW here, otherwise Windows exhibits bugs where
			// client pixels and child windows are mispositioned by the width/height
			// of the upper-left non-client area. It's confirmed that this issue exists
			// from Windows 7 to Windows 10. Not tested on Windows 11 yet. Don't know
			// whether it exists on Windows XP to Windows Vista or not.
			*result = wParam == FALSE ? FALSE : WVR_REDRAW;
			return true;
			}

			case WM_WINDOWPOSCHANGING: {
			// ### FIXME: How does this problem happen and why is it solved?
			// When toggling the "Show theme color in title bar and window border" setting in
			// Windows Settings, or calling `DrawMenuBar()`, Windows sends a message of
			// WM_WINDOWPOSCHANGING with flags 0x37. If we do not process this message,
			// the client area as a whole will shift to the left, which looks very abnormal if
			// we don't repaint it. This exception disappears if we add SWP_NOCOPYBITS flag.
			// But I don't know what caused the problem, or why this would solve it.
			static constexpr const auto kBadWindowPosFlag =
			SWP_NOSIZE \| SWP_NOMOVE \| SWP_NOZORDER \| SWP_NOACTIVATE \| SWP_FRAMECHANGED;
			const auto windowPos = reinterpret_cast<LPWINDOWPOS>(lParam);
			if (windowPos->flags == kBadWindowPosFlag) {
			windowPos->flags \|= SWP_NOCOPYBITS;
			}
			break;
			}

			default:
			break;
			}

			if (!isSystemBorderEnabled()) {
			switch (message) {
			case WM_NCUAHDRAWCAPTION:
			case WM_NCUAHDRAWFRAME: {
			// These undocumented messages are sent to draw themed window
			// borders. Block them to prevent drawing borders over the client
			// area.
			*result = FALSE;
			return true;
			}
			case WM_NCPAINT: {
			// 边框阴影处于非客户区的范围，因此如果直接阻止非客户区的绘制，会导致边框阴影丢失

			if (!isDwmCompositionEnabled()) {
			// Only block WM_NCPAINT when DWM composition is disabled. If
			// it's blocked when DWM composition is enabled, the frame
			// shadow won't be drawn.
			*result = FALSE;
			return true;
			} else {
			break;
			}
			}
			case WM_NCACTIVATE: {
			if (isDwmCompositionEnabled()) {
			// DefWindowProc won't repaint the window border if lParam (normally a HRGN)
			// is -1. See the following link's "lParam" section:
			// https://docs.microsoft.com/en-us/windows/win32/winmsg/wm-ncactivate
			// Don't use "*result = 0" here, otherwise the window won't respond to the
			// window activation state change.
			*result = ::DefWindowProcW(hWnd, WM_NCACTIVATE, wParam, -1);
			} else {
			*result = TRUE;
			}
			return true;
			}
			case WM_SETICON:
			case WM_SETTEXT: {
			// Disable painting while these messages are handled to prevent them
			// from drawing a window caption over the client area.
			const auto oldStyle = static_cast<DWORD>(::GetWindowLongPtrW(hWnd, GWL_STYLE));
			// Prevent Windows from drawing the default title bar by temporarily
			// toggling the WS_VISIBLE style.
			const DWORD newStyle = (oldStyle & ~WS_VISIBLE);
			::SetWindowLongPtrW(hWnd, GWL_STYLE, static_cast<LONG_PTR>(newStyle));
			triggerFrameChange(hWnd);
			const LRESULT originalResult = ::DefWindowProcW(hWnd, message, wParam, lParam);
			::SetWindowLongPtrW(hWnd, GWL_STYLE, static_cast<LONG_PTR>(oldStyle));
			triggerFrameChange(hWnd);
			*result = originalResult;
			return true;
			}
			default:
			break;
			}
			}
			return false;
			}

			}
			bool Win32WindowContext::nonClientCalcSizeHandler(HWND hWnd, UINT message, WPARAM wParam,
			LPARAM lParam, LRESULT *result) {
			Q_UNUSED(message)
			Q_UNUSED(this)

			// Windows是根据这个消息的返回值来设置窗口的客户区（窗口中真正显示的内容）
			// 和非客户区（标题栏、窗口边框、菜单栏和状态栏等Windows系统自行提供的部分
			// ，不过对于Qt来说，除了标题栏和窗口边框，非客户区基本也都是自绘的）的范
			// 围的，lParam里存放的就是新客户区的几何区域，默认是整个窗口的大小，正常
			// 的程序需要修改这个参数，告知系统窗口的客户区和非客户区的范围（一般来说可
			// 以完全交给Windows，让其自行处理，使用默认的客户区和非客户区），因此如果
			// 我们不修改lParam，就可以使客户区充满整个窗口，从而去掉标题栏和窗口边框
			// （因为这些东西都被客户区给盖住了。但边框阴影也会因此而丢失，不过我们会使
			// 用其他方式将其带回，请参考其他消息的处理，此处不过多提及）。但有个情况要
			// 特别注意，那就是窗口最大化后，窗口的实际尺寸会比屏幕的尺寸大一点，从而使
			// 用户看不到窗口的边界，这样用户就不能在窗口最大化后调整窗口的大小了（虽然
			// 这个做法听起来特别奇怪，但Windows确实就是这样做的），因此如果我们要自行
			// 处理窗口的非客户区，就要在窗口最大化后，将窗口边框的宽度和高度（一般是相
			// 等的）从客户区裁剪掉，否则我们窗口所显示的内容就会超出屏幕边界，显示不全。
			// 如果用户开启了任务栏自动隐藏，在窗口最大化后，还要考虑任务栏的位置。因为
			// 如果窗口最大化后，其尺寸和屏幕尺寸相等（因为任务栏隐藏了，所以窗口最大化
			// 后其实是充满了整个屏幕，变相的全屏了），Windows会认为窗口已经进入全屏的
			// 状态，从而导致自动隐藏的任务栏无法弹出。要避免这个状况，就要使窗口的尺寸
			// 小于屏幕尺寸。我下面的做法参考了火狐、Chromium和Windows Terminal
			// 如果没有开启任务栏自动隐藏，是不存在这个问题的，所以要先进行判断。
			// 一般情况下，*result设置为0（相当于DefWindowProc的返回值为0）就可以了，
			// 根据MSDN的说法，返回0意为此消息已经被程序自行处理了，让Windows跳过此消
			// 息，否则Windows会添加对此消息的默认处理，对于当前这个消息而言，就意味着
			// 标题栏和窗口边框又会回来，这当然不是我们想要的结果。根据MSDN，当wParam
			// 为FALSE时，只能返回0，但当其为TRUE时，可以返回0，也可以返回一个WVR_常
			// 量。根据Chromium的注释，当存在非客户区时，如果返回WVR_REDRAW会导致子
			// 窗口/子控件出现奇怪的bug（自绘控件错位），并且Lucas在Windows 10
			// 上成功复现，说明这个bug至今都没有解决。我查阅了大量资料，发现唯一的解决
			// 方案就是返回0。但如果不存在非客户区，且wParam为TRUE，最好返回
			// WVR_REDRAW，否则窗口在调整大小可能会产生严重的闪烁现象。
			// 虽然对大多数消息来说，返回0都代表让Windows忽略此消息，但实际上不同消息
			// 能接受的返回值是不一样的，请注意自行查阅MSDN。

			// Sent when the size and position of a window's client area must be
			// calculated. By processing this message, an application can
			// control the content of the window's client area when the size or
			// position of the window changes. If wParam is TRUE, lParam points
			// to an NCCALCSIZE_PARAMS structure that contains information an
			// application can use to calculate the new size and position of the
			// client rectangle. If wParam is FALSE, lParam points to a RECT
			// structure. On entry, the structure contains the proposed window
			// rectangle for the window. On exit, the structure should contain
			// the screen coordinates of the corresponding window client area.
			// The client area is the window's content area, the non-client area
			// is the area which is provided by the system, such as the title
			// bar, the four window borders, the frame shadow, the menu bar, the
			// status bar, the scroll bar, etc. But for Qt, it draws most of the
			// window area (client + non-client) itself. We now know that the
			// title bar and the window frame is in the non-client area, and we
			// can set the scope of the client area in this message, so we can
			// remove the title bar and the window frame by let the non-client
			// area be covered by the client area (because we can't really get
			// rid of the non-client area, it will always be there, all we can
			// do is to hide it) , which means we should let the client area's
			// size the same with the whole window's size. So there is no room
			// for the non-client area and then the user won't be able to see it
			// again. But how to achieve this? Very easy, just leave lParam (the
			// re-calculated client area) untouched. But of course you can
			// modify lParam, then the non-client area will be seen and the
			// window borders and the window frame will show up. However, things
			// are quite different when you try to modify the top margin of the
			// client area. DWM will always draw the whole title bar no matter
			// what margin value you set for the top, unless you don't modify it
			// and remove the whole top area (the title bar + the one pixel
			// height window border). This can be confirmed in Windows
			// Terminal's source code, you can also try yourself to verify
			// it. So things will become quite complicated if you want to
			// preserve the four window borders.

			// If `wParam` is `FALSE`, `lParam` points to a `RECT` that contains
			// the proposed window rectangle for our window. During our
			// processing of the `WM_NCCALCSIZE` message, we are expected to
			// modify the `RECT` that `lParam` points to, so that its value upon
			// our return is the new client area. We must return 0 if `wParam`
			// is `FALSE`.
			// If `wParam` is `TRUE`, `lParam` points to a `NCCALCSIZE_PARAMS`
			// struct. This struct contains an array of 3 `RECT`s, the first of
			// which has the exact same meaning as the `RECT` that is pointed to
			// by `lParam` when `wParam` is `FALSE`. The remaining `RECT`s, in
			// conjunction with our return value, can
			// be used to specify portions of the source and destination window
			// rectangles that are valid and should be preserved. We opt not to
			// implement an elaborate client-area preservation technique, and
			// simply return 0, which means "preserve the entire old client area
			// and align it with the upper-left corner of our new client area".
			const auto clientRect = wParam ? &(reinterpret_cast<LPNCCALCSIZE_PARAMS>(lParam))->rgrc[0]
			: reinterpret_cast<LPRECT>(lParam);
			if (isSystemBorderEnabled()) {
			// Store the original top margin before the default window procedure applies the
			// default frame.
			const LONG originalTop = clientRect->top;
			// Apply the default frame because we don't want to remove the whole window
			// frame, we still need the standard window frame (the resizable frame border
			// and the frame shadow) for the left, bottom and right edges. If we return 0
			// here directly, the whole window frame will be removed (which means there will
			// be no resizable frame border and the frame shadow will also disappear), and
			// that's also how most applications customize their title bars on Windows. It's
			// totally OK but since we want to preserve as much original frame as possible,
			// we can't use that solution.
			const LRESULT originalResult = ::DefWindowProcW(hWnd, WM_NCCALCSIZE, wParam, lParam);
			if (originalResult != 0) {
			*result = originalResult;
			return true;
			}
			// Re-apply the original top from before the size of the default frame was
			// applied, and the whole top frame (the title bar and the top border) is gone
			// now. For the top frame, we only has 2 choices: (1) remove the top frame
			// entirely, or (2) don't touch it at all. We can't preserve the top border by
			// adjusting the top margin here. If we try to modify the top margin, the
			// original title bar will always be painted by DWM regardless what margin we
			// set, so here we can only remove the top frame entirely and use some special
			// technique to bring the top border back.
			clientRect->top = originalTop;
			}

			const bool max = isMaximized(hWnd);
			const bool full = isFullScreen(hWnd);
			// We don't need this correction when we're fullscreen. We will
			// have the WS_POPUP size, so we don't have to worry about
			// borders, and the default frame will be fine.
			if (max && !full) {
			// When a window is maximized, its size is actually a little bit more
			// than the monitor's work area. The window is positioned and sized in
			// such a way that the resize handles are outside the monitor and
			// then the window is clipped to the monitor so that the resize handle
			// do not appear because you don't need them (because you can't resize
			// a window when it's maximized unless you restore it).
			const quint32 frameSize = getResizeBorderThickness(hWnd);
			clientRect->top += frameSize;
			if (!isSystemBorderEnabled()) {
			clientRect->bottom -= frameSize;
			clientRect->left += frameSize;
			clientRect->right -= frameSize;
			}
			}
			// Attempt to detect if there's an autohide taskbar, and if
			// there is, reduce our size a bit on the side with the taskbar,
			// so the user can still mouse-over the taskbar to reveal it.
			// Make sure to use MONITOR_DEFAULTTONEAREST, so that this will
			// still find the right monitor even when we're restoring from
			// minimized.
			if (max \|\| full) {
			APPBARDATA abd{};
			abd.cbSize = sizeof(abd);
			const UINT taskbarState = ::SHAppBarMessage(ABM_GETSTATE, &abd);
			// First, check if we have an auto-hide taskbar at all:
			if (taskbarState & ABS_AUTOHIDE) {
			bool top = false, bottom = false, left = false, right = false;
			// Due to ABM_GETAUTOHIDEBAREX was introduced in Windows 8.1,
			// we have to use another way to judge this if we are running
			// on Windows 7 or Windows 8.
			if (isWin8Point1OrGreater()) {
			const RECT monitorRect = getMonitorForWindow(hWnd).rcMonitor;
			// This helper can be used to determine if there's an
			// auto-hide taskbar on the given edge of the monitor
			// we're currently on.
			const auto hasAutohideTaskbar = [monitorRect](const UINT edge) -> bool {
			APPBARDATA abd2{};
			abd2.cbSize = sizeof(abd2);
			abd2.uEdge = edge;
			abd2.rc = monitorRect;
			const auto hTaskbar =
			reinterpret_cast<HWND>(::SHAppBarMessage(ABM_GETAUTOHIDEBAREX, &abd2));
			return (hTaskbar != nullptr);
			};
			top = hasAutohideTaskbar(ABE_TOP);
			bottom = hasAutohideTaskbar(ABE_BOTTOM);
			left = hasAutohideTaskbar(ABE_LEFT);
			right = hasAutohideTaskbar(ABE_RIGHT);
			} else {
			int edge = -1;
			APPBARDATA abd2{};
			abd2.cbSize = sizeof(abd2);
			abd2.hWnd = ::FindWindowW(L"Shell_TrayWnd", nullptr);
			HMONITOR windowMonitor = ::MonitorFromWindow(hWnd, MONITOR_DEFAULTTONEAREST);
			HMONITOR taskbarMonitor =
			::MonitorFromWindow(abd2.hWnd, MONITOR_DEFAULTTOPRIMARY);
			if (taskbarMonitor == windowMonitor) {
			::SHAppBarMessage(ABM_GETTASKBARPOS, &abd2);
			edge = int(abd2.uEdge);
			}
			top = (edge == ABE_TOP);
			bottom = (edge == ABE_BOTTOM);
			left = (edge == ABE_LEFT);
			right = (edge == ABE_RIGHT);
			}
			// If there's a taskbar on any side of the monitor, reduce
			// our size a little bit on that edge.
			// Note to future code archeologists:
			// This doesn't seem to work for fullscreen on the primary
			// display. However, testing a bunch of other apps with
			// fullscreen modes and an auto-hiding taskbar has
			// shown that _none_ of them reveal the taskbar from
			// fullscreen mode. This includes Edge, Firefox, Chrome,
			// Sublime Text, PowerPoint - none seemed to support this.
			// This does however work fine for maximized.
			if (top) {
			// Peculiarly, when we're fullscreen,
			clientRect->top += kAutoHideTaskBarThickness;
			} else if (bottom) {
			clientRect->bottom -= kAutoHideTaskBarThickness;
			} else if (left) {
			clientRect->left += kAutoHideTaskBarThickness;
			} else if (right) {
			clientRect->right -= kAutoHideTaskBarThickness;
			}
			}
			}
			// We should call this function only before the function returns.
			syncPaintEventWithDwm();
			// By returning WVR_REDRAW we can make the window resizing look
			// less broken. But we must return 0 if wParam is FALSE, according to Microsoft
			// Docs.
			// IMPORTANT NOTE:
			// If you are drawing something manually through D3D in your window, don't
			// try to return WVR_REDRAW here, otherwise Windows exhibits bugs where
			// client pixels and child windows are mispositioned by the width/height
			// of the upper-left non-client area. It's confirmed that this issue exists
			// from Windows 7 to Windows 10. Not tested on Windows 11 yet. Don't know
			// whether it exists on Windows XP to Windows Vista or not.

			// https://github.com/chromium/chromium/blob/5d297da3cf2a642e9ace2b23fed097370bc70814/ui/views/win/hwnd_message_handler.cc#L2330
			// Do not return WVR_REDRAW otherwise child HWNDs will be mispositioned.
			*result = FALSE;
			return true;
			}

			bool Win32WindowContext::systemMenuHandler(HWND hWnd, UINT message, WPARAM wParam,
			LPARAM lParam, LRESULT *result) {
			const auto getNativePosFromMouse = [lParam]() -> POINT {
			return {GET_X_LPARAM(lParam), GET_Y_LPARAM(lParam)};
			};
			const auto getNativeGlobalPosFromKeyboard = [hWnd]() -> POINT {
			const bool maxOrFull = isMaximized(hWnd) \|\| isFullScreen(hWnd);
			const quint32 frameSize = getResizeBorderThickness(hWnd);
			const quint32 horizontalOffset =
			((maxOrFull \|\| !isSystemBorderEnabled()) ? 0 : frameSize);
			const auto verticalOffset = [hWnd, maxOrFull, frameSize]() -> quint32 {
			const quint32 titleBarHeight = getTitleBarHeight(hWnd);
			if (!isSystemBorderEnabled()) {
			return titleBarHeight;
			}
			if (isWin11OrGreater()) {
			if (maxOrFull) {
			return (titleBarHeight + frameSize);
			}
			return titleBarHeight;
			}
			if (maxOrFull) {
			return titleBarHeight;
			}
			return titleBarHeight - frameSize;
			}();
			RECT windowPos{};
			::GetWindowRect(hWnd, &windowPos);
			return {static_cast<LONG>(windowPos.left + horizontalOffset),
			static_cast<LONG>(windowPos.top + verticalOffset)};
			};
			bool shouldShowSystemMenu = false;
			bool broughtByKeyboard = false;
			POINT nativeGlobalPos{};

			switch (message) {
			case WM_RBUTTONUP: {
			const POINT nativeLocalPos = getNativePosFromMouse();
			const QPoint qtScenePos = QHighDpi::fromNativeLocalPosition(
			point2qpoint(nativeLocalPos), m_windowHandle.data());
			WindowAgentBase::SystemButton sysButtonType = WindowAgentBase::Unknown;
			if (isInTitleBarDraggableArea(qtScenePos) \|\|
			(isInSystemButtons(qtScenePos, &sysButtonType) &&
			sysButtonType == WindowAgentBase::WindowIcon)) {
			shouldShowSystemMenu = true;
			nativeGlobalPos = nativeLocalPos;
			::ClientToScreen(hWnd, &nativeGlobalPos);
			}
			break;
			}
			case WM_NCRBUTTONUP: {
			if (wParam == HTCAPTION) {
			shouldShowSystemMenu = true;
			nativeGlobalPos = getNativePosFromMouse();
			}
			break;
			}
			case WM_SYSCOMMAND: {
			const WPARAM filteredWParam = (wParam & 0xFFF0);
			switch (filteredWParam) {
			case SC_MOUSEMENU:
			shouldShowSystemMenu = true;
			nativeGlobalPos = getNativeGlobalPosFromKeyboard();
			break;
			case SC_KEYMENU:
			if (lParam == VK_SPACE) {
			shouldShowSystemMenu = true;
			broughtByKeyboard = true;
			nativeGlobalPos = getNativeGlobalPosFromKeyboard();
			}
			break;
			default:
			break;
			}
			break;
			}
			case WM_KEYDOWN:
			case WM_SYSKEYDOWN: {
			const bool altPressed = ((wParam == VK_MENU) \|\| (::GetKeyState(VK_MENU) < 0));
			const bool spacePressed = ((wParam == VK_SPACE) \|\| (::GetKeyState(VK_SPACE) < 0));
			if (altPressed && spacePressed) {
			shouldShowSystemMenu = true;
			broughtByKeyboard = true;
			nativeGlobalPos = getNativeGlobalPosFromKeyboard();
			}
			break;
			}
			default:
			break;
			}
			if (shouldShowSystemMenu) {
			static HHOOK mouseHook = nullptr;
			static std::optional<POINT> mouseClickPos;
			static bool mouseDoubleClicked = false;
			bool mouseHookedLocal = false;

			// The menu is triggered by a click on icon button
			if (iconButtonClickTime > 0) {
			POINT menuPos{0, static_cast<LONG>(getTitleBarHeight(hWnd))};
			if (const auto tb = titleBar()) {
			auto titleBarHeight = qreal(m_delegate->mapGeometryToScene(tb).height());
			titleBarHeight *= m_windowHandle->devicePixelRatio();
			menuPos.y = qRound(titleBarHeight);
			}
			::ClientToScreen(hWnd, &menuPos);
			nativeGlobalPos = menuPos;

			// Install mouse hook
			if (!mouseHook) {
			mouseHook = ::SetWindowsHookExW(
			WH_MOUSE,
			[](int nCode, WPARAM wParam, LPARAM lParam) {
			if (nCode >= 0) {
			switch (wParam) {
			case WM_LBUTTONDBLCLK:
			mouseDoubleClicked = true;
			Q_FALLTHROUGH();

			// case WM_POINTERDOWN:

			case WM_LBUTTONDOWN: {
			auto pMouseStruct =
			reinterpret_cast<MOUSEHOOKSTRUCT *>(lParam);
			if (pMouseStruct) {
			mouseClickPos = pMouseStruct->pt;
			}
			break;
			}
			default:
			break;
			}
			}
			return ::CallNextHookEx(nullptr, nCode, wParam, lParam);
			},
			nullptr, ::GetCurrentThreadId());
			mouseHookedLocal = true;
			}
			}

			bool res =
			showSystemMenu_sys(hWnd, nativeGlobalPos, broughtByKeyboard, isHostSizeFixed());

			// Uninstall mouse hook and check if it's a double-click
			if (mouseHookedLocal) {
			::UnhookWindowsHookEx(mouseHook);

			// Emulate the Windows icon button's behavior
			if (!res && mouseClickPos.has_value()) {
			POINT nativeLocalPos = mouseClickPos.value();
			::ScreenToClient(hWnd, &nativeLocalPos);
			QPoint qtScenePos = QHighDpi::fromNativeLocalPosition(
			point2qpoint(nativeLocalPos), m_windowHandle.data());
			WindowAgentBase::SystemButton sysButtonType = WindowAgentBase::Unknown;
			if (isInSystemButtons(qtScenePos, &sysButtonType) &&
			sysButtonType == WindowAgentBase::WindowIcon) {
			iconButtonClickLevel \|= IconButtonClicked;
			if (::GetTickCount64() - iconButtonClickTime <= ::GetDoubleClickTime()) {
			iconButtonClickLevel \|= IconButtonTriggersClose;
			}
			}
			}

			if (mouseDoubleClicked) {
			iconButtonClickLevel \|= IconButtonDoubleClicked;
			}

			mouseHook = nullptr;
			mouseClickPos.reset();
			mouseDoubleClicked = false;
			}

			// QPA's internal code will handle system menu events separately, and its
			// behavior is not what we would want to see because it doesn't know our
			// window doesn't have any window frame now, so return early here to avoid
			// entering Qt's own handling logic.
			*result = FALSE;
			return true;
			}
			return false;
			}

			}