From 1a1f26d9e4ab6a4fe51baa78e40c4cdf3f402bcf Mon Sep 17 00:00:00 2001
From: Sine Striker <trueful@163.com>
Date: 周四, 07 12月 2023 14:27:00 +0800
Subject: [PATCH] Add context factory

---
 src/core/contexts/win32windowcontext.cpp |  535 +++++++++++++++++++++++++++++++++++++++++++++++++++++++----
 1 files changed, 496 insertions(+), 39 deletions(-)

diff --git a/src/core/contexts/win32windowcontext.cpp b/src/core/contexts/win32windowcontext.cpp
index d88418e..538188d 100644
--- a/src/core/contexts/win32windowcontext.cpp
+++ b/src/core/contexts/win32windowcontext.cpp
@@ -1,19 +1,30 @@
 #include "win32windowcontext_p.h"
+#include "qwkcoreglobal_p.h"
 
 #include <optional>
 
 #include <QtCore/QHash>
 #include <QtCore/QAbstractNativeEventFilter>
-#include <QtCore/QCoreApplication>
 #include <QtCore/QOperatingSystemVersion>
+#include <QtCore/QScopeGuard>
+#include <QtGui/QGuiApplication>
 
 #include <QtCore/private/qsystemlibrary_p.h>
 #include <QtGui/private/qhighdpiscaling_p.h>
-
-#include "qwkcoreglobal_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 <shellscalingapi.h>
 #include <dwmapi.h>
+
+Q_DECLARE_METATYPE(QMargins)
 
 namespace QWK {
 
@@ -25,8 +36,15 @@
 
     static WNDPROC g_qtWindowProc = nullptr; // Original Qt window proc function
 
+    static struct QWK_Hook {
+        QWK_Hook() {
+            qApp->setAttribute(Qt::AA_DontCreateNativeWidgetSiblings);
+        }
+    } g_hook{};
+
     struct DynamicApis {
         decltype(&::DwmFlush) pDwmFlush = nullptr;
+        decltype(&::DwmIsCompositionEnabled) pDwmIsCompositionEnabled = nullptr;
         decltype(&::GetDpiForWindow) pGetDpiForWindow = nullptr;
         decltype(&::GetSystemMetricsForDpi) pGetSystemMetricsForDpi = nullptr;
         decltype(&::GetDpiForMonitor) pGetDpiForMonitor = nullptr;
@@ -44,6 +62,8 @@
 
             QSystemLibrary dwmapi(QStringLiteral("dwmapi.dll"));
             pDwmFlush = reinterpret_cast<decltype(pDwmFlush)>(dwmapi.resolve("DwmFlush"));
+            pDwmIsCompositionEnabled = reinterpret_cast<decltype(pDwmIsCompositionEnabled)>(
+                dwmapi.resolve("DwmIsCompositionEnabled"));
         }
 
         ~DynamicApis() = default;
@@ -137,6 +157,12 @@
         return hwnd2str(reinterpret_cast<WId>(hwnd));
     }
 
+    static inline bool isWin8OrGreater() {
+        static const bool result =
+            QOperatingSystemVersion::current() >= QOperatingSystemVersion::Windows8;
+        return result;
+    }
+
     static inline bool isWin8Point1OrGreater() {
         static const bool result =
             QOperatingSystemVersion::current() >= QOperatingSystemVersion::Windows8_1;
@@ -149,11 +175,25 @@
         return result;
     }
 
-    static inline quint32 getDpiForWindow(HWND hwnd) {
-        Q_ASSERT(hwnd);
-        if (!hwnd) {
-            return USER_DEFAULT_SCREEN_DPI;
+    static inline bool isDwmCompositionEnabled() {
+        if (isWin8OrGreater()) {
+            return true;
         }
+        const DynamicApis &apis = DynamicApis::instance();
+        if (!apis.pDwmIsCompositionEnabled) {
+            return false;
+        }
+        BOOL enabled = FALSE;
+        return SUCCEEDED(apis.pDwmIsCompositionEnabled(&enabled)) && enabled;
+    }
+
+    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 quint32 getDpiForWindow(HWND hwnd) {
         const DynamicApis &apis = DynamicApis::instance();
         if (apis.pGetDpiForWindow) {         // Win10
             return apis.pGetDpiForWindow(hwnd);
@@ -173,10 +213,6 @@
     }
 
     static inline quint32 getResizeBorderThickness(HWND hwnd) {
-        Q_ASSERT(hwnd);
-        if (!hwnd) {
-            return 0;
-        }
         const DynamicApis &apis = DynamicApis::instance();
         if (apis.pGetSystemMetricsForDpi) {
             const quint32 dpi = getDpiForWindow(hwnd);
@@ -187,11 +223,47 @@
         }
     }
 
-    static inline std::optional<MONITORINFOEXW> getMonitorForWindow(HWND hwnd) {
-        Q_ASSERT(hwnd);
-        if (!hwnd) {
-            return std::nullopt;
+    static inline quint32 getTitleBarHeight(HWND hwnd) {
+        const auto captionHeight = [hwnd]() -> int {
+            const DynamicApis &apis = DynamicApis::instance();
+            if (apis.pGetSystemMetricsForDpi) {
+                const quint32 dpi = getDpiForWindow(hwnd);
+                return apis.pGetSystemMetricsForDpi(SM_CYCAPTION, dpi);
+            } else {
+                return ::GetSystemMetrics(SM_CYCAPTION);
+            }
+        }();
+        return captionHeight + getResizeBorderThickness(hwnd);
+    }
+
+    static inline void updateInternalWindowFrameMargins(HWND hwnd, QWindow *window) {
+        const auto margins = [hwnd]() -> QMargins {
+            const int titleBarHeight = getTitleBarHeight(hwnd);
+            if (isWin10OrGreater()) {
+                return {0, -titleBarHeight, 0, 0};
+            } else {
+                const int frameSize = getResizeBorderThickness(hwnd);
+                return {-frameSize, -titleBarHeight, -frameSize, -frameSize};
+            }
+        }();
+        const QVariant marginsVar = QVariant::fromValue(margins);
+        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("_q_windowsCustomMargins"),
+                                      marginsVar);
+            }
         }
+#else
+        if (const auto platformWindow =
+                dynamic_cast<QNativeInterface::Private::QWindowsWindow *>(window->handle())) {
+            platformWindow->setCustomMargins(margins);
+        }
+#endif
+    }
+
+    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.
         HMONITOR monitor = ::MonitorFromWindow(hwnd, MONITOR_DEFAULTTONEAREST);
@@ -201,6 +273,16 @@
         return monitorInfo;
     };
 
+    static inline void moveToDesktopCenter(HWND hwnd) {
+        const auto monitorInfo = getMonitorForWindow(hwnd);
+        RECT windowRect{};
+        ::GetWindowRect(hwnd, &windowRect);
+        const auto newX = (RECT_WIDTH(monitorInfo.rcMonitor) - RECT_WIDTH(windowRect)) / 2;
+        const auto newY = (RECT_HEIGHT(monitorInfo.rcMonitor) - RECT_HEIGHT(windowRect)) / 2;
+        ::SetWindowPos(hwnd, nullptr, newX, newY, 0, 0,
+                       SWP_NOACTIVATE | SWP_NOSIZE | SWP_NOZORDER | SWP_NOOWNERZORDER);
+    }
+
     static inline bool isFullScreen(HWND hwnd) {
         Q_ASSERT(hwnd);
         if (!hwnd) {
@@ -208,9 +290,24 @@
         }
         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);
+        return (windowRect == getMonitorForWindow(hwnd).rcMonitor);
+    }
+
+    static inline bool isWindowNoState(HWND hwnd) {
+        Q_ASSERT(hwnd);
+        if (!hwnd) {
+            return false;
+        }
+#if 0
+        WINDOWPLACEMENT wp{};
+        wp.length = sizeof(wp);
+        ::GetWindowPlacement(hwnd, &wp);
+        return ((wp.showCmd == SW_NORMAL) || (wp.showCmd == SW_RESTORE));
+#else
+        const auto style = static_cast<DWORD>(::GetWindowLongPtrW(hwnd, GWL_STYLE));
+        return (!(style & (WS_MINIMIZE | WS_MAXIMIZE)));
+#endif
     }
 
     static inline QPoint fromNativeLocalPosition(const QWindow *window, const QPoint &point) {
@@ -249,13 +346,13 @@
             case HTBORDER:
                 return Win32WindowContext::FixedBorder;
             default:
-                break;
+                break; // unreachable
         }
         return Win32WindowContext::Outside;
     }
 
     static bool isValidWindow(HWND hWnd, bool checkVisible, bool checkTopLevel) {
-        if (::IsWindow(hWnd) == FALSE) {
+        if (!::IsWindow(hWnd)) {
             return false;
         }
         const LONG_PTR styles = ::GetWindowLongPtrW(hWnd, GWL_STYLE);
@@ -266,15 +363,15 @@
         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;
             }
         }
@@ -297,11 +394,14 @@
     public:
         bool nativeEventFilter(const QByteArray &eventType, void *message,
                                QT_NATIVE_EVENT_RESULT_TYPE *result) override {
+            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;
@@ -315,11 +415,11 @@
 
         static inline void install() {
             instance = new WindowsNativeEventFilter();
-            qApp->installNativeEventFilter(instance);
+            installNativeEventFilter(instance);
         }
 
         static inline void uninstall() {
-            qApp->removeNativeEventFilter(instance);
+            removeNativeEventFilter(instance);
             delete instance;
             instance = nullptr;
         }
@@ -402,13 +502,15 @@
         // TODO: Determine whether to show system menu
         // ...
 
-        // Since Qt does the necessary processing of the message afterward, we still need to
+        // Since Qt does the necessary processing of the WM_NCCALCSIZE afterward, we still need to
         // continue dispatching it.
+        if (handled && message != WM_NCCALCSIZE) {
+            return result;
+        }
         return ::CallWindowProcW(g_qtWindowProc, hWnd, message, wParam, lParam);
     }
 
-    Win32WindowContext::Win32WindowContext(QWindow *window, WindowItemDelegate *delegate)
-        : AbstractWindowContext(window, delegate) {
+    Win32WindowContext::Win32WindowContext() : AbstractWindowContext() {
     }
 
     Win32WindowContext::~Win32WindowContext() {
@@ -423,11 +525,17 @@
         }
     }
 
-    bool Win32WindowContext::setup() {
-        auto winId = m_windowHandle->winId();
+    bool Win32WindowContext::setup(QObject *host, WindowItemDelegate *delegate) {
+        if (!AbstractWindowContext::setup(host, delegate)) {
+            return false;
+        }
 
         // Install window hook
+        auto winId = m_windowHandle->winId();
         auto hWnd = reinterpret_cast<HWND>(winId);
+
+        // Inform Qt we want and have set custom margins
+        updateInternalWindowFrameMargins(hWnd, m_windowHandle);
 
         // Store original window proc
         if (!g_qtWindowProc) {
@@ -497,7 +605,7 @@
         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);
         }
@@ -640,9 +748,10 @@
                     // actually lost the hover state. So we filter out these superfluous mouse leave
                     // events here to avoid this issue.
                     DWORD dwScreenPos = ::GetMessagePos();
+                    POINT screenPoint{GET_X_LPARAM(dwScreenPos), GET_Y_LPARAM(dwScreenPos)};
+                    ::ScreenToClient(hWnd, &screenPoint);
                     QPoint qtScenePos =
-                        fromNativeLocalPosition(m_windowHandle, QPoint(GET_X_LPARAM(dwScreenPos),
-                                                                       GET_Y_LPARAM(dwScreenPos)));
+                        fromNativeLocalPosition(m_windowHandle, {screenPoint.x, screenPoint.y});
                     auto dummy = CoreWindowAgent::Unknown;
                     if (isInSystemButtons(qtScenePos, &dummy)) {
                         // We must record whether the last WM_MOUSELEAVE was filtered, because if
@@ -767,6 +876,18 @@
     bool Win32WindowContext::customWindowHandler(HWND hWnd, UINT message, WPARAM wParam,
                                                  LPARAM lParam, LRESULT *result) {
         switch (message) {
+            case WM_SHOWWINDOW: {
+                if (!centered) {
+                    // If wParam is TRUE, the window is being shown.
+                    // If lParam is zero, the message was sent because of a call to the ShowWindow
+                    // function.
+                    if (wParam && lParam == 0) {
+                        centered = true;
+                        moveToDesktopCenter(hWnd);
+                    }
+                }
+                break;
+            }
             case WM_NCCALCSIZE: {
                 // Windows鏄牴鎹繖涓秷鎭殑杩斿洖鍊兼潵璁剧疆绐楀彛鐨勫鎴峰尯锛堢獥鍙d腑鐪熸鏄剧ず鐨勫唴瀹癸級
                 // 鍜岄潪瀹㈡埛鍖猴紙鏍囬鏍忋�佺獥鍙h竟妗嗐�佽彍鍗曟爮鍜岀姸鎬佹爮绛塛indows绯荤粺鑷鎻愪緵鐨勯儴鍒�
@@ -854,8 +975,8 @@
                 // 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]);
+                    wParam ? &(reinterpret_cast<LPNCCALCSIZE_PARAMS>(lParam))->rgrc[0]
+                           : reinterpret_cast<LPRECT>(lParam);
                 if (isWin10OrGreater()) {
                     // Store the original top margin before the default window procedure applies the
                     // default frame.
@@ -921,9 +1042,7 @@
                         // 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;
+                            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.
@@ -991,13 +1110,351 @@
                 // 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;
+                *result = wParam ? WVR_REDRAW : FALSE;
                 return true;
+            }
+            case WM_NCHITTEST: {
+                // 鍘熺敓Win32绐楀彛鍙湁椤惰竟鏄湪绐楀彛鍐呴儴resize鐨勶紝鍏朵綑涓夎竟閮芥槸鍦ㄧ獥鍙�
+                // 澶栭儴杩涜resize鐨勶紝鍏跺師鐞嗘槸锛學S_THICKFRAME杩欎釜绐楀彛鏍峰紡浼氬湪绐�
+                // 鍙g殑宸︺�佸彸鍜屽簳杈规坊鍔犱笁涓�忔槑鐨剅esize鍖哄煙锛岃繖涓変釜鍖哄煙鍦ㄦ甯哥姸鎬�
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+                // (SM_CXSIZEFRAME + SM_CXPADDEDBORDER)锛岄珮搴︾瓑浜�
+                // (SM_CYSIZEFRAME + SM_CXPADDEDBORDER)锛屽湪100%缂╂斁鏃讹紝鍧囩瓑
+                // 浜�8鍍忕礌銆傚畠浠睘浜庣獥鍙e尯鍩熺殑涓�閮ㄥ垎锛屼絾涓嶅睘浜庡鎴峰尯锛岃�屾槸灞炰簬闈炲
+                // 鎴峰尯锛屽洜姝etWindowRect鑾峰彇鐨勫尯鍩熶腑鏄寘鍚繖涓変釜resize鍖哄煙鐨勶紝
+                // 鑰孏etClientRect鑾峰彇鐨勫尯鍩熸槸涓嶅寘鍚畠浠殑銆傚綋鎶�
+                // DWMWA_EXTENDED_FRAME_BOUNDS浣滀负鍙傛暟璋冪敤
+                // DwmGetWindowAttribute鏃讹紝涔熻兘鑾峰彇鍒颁竴涓獥鍙eぇ灏忥紝杩欎釜澶у皬浠�
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+                // WM_NCCALCSIZE娑堟伅鐨勫鐞嗕腑锛屽凡缁忔妸鏁翠釜绐楀彛閮借缃负瀹㈡埛鍖轰簡锛屼篃
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+                //
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+                // 鐨勮〃鐜颁篃鏈夊緢澶ф敼鍠勶紝缂虹偣鏄渶瑕佽嚜琛岀粯鍒堕《閮ㄨ竟妗嗙嚎銆傚師鏈互涓哄彧鑳藉儚
+                // Windows Terminal閭f牱鍦╓M_PAINT閲屾悶榛戦瓟娉曪紝浣嗗悗鏉ュ彂鐜帮紝鍏跺疄鍙�
+                // 瑕侀鑹茬浉杩戯紝鎴戜滑鑷缁樺埗涓�鏍瑰疄绾夸篃鍑犱箮鑳戒互鍋囦贡鐪燂紝鑰屼笖杩欐牱涔熶笉浼�
+                // 鐮村潖Qt鑷繁鐨勭粯鍒剁郴缁燂紝鑳藉仛鍒颁笉渚濊禆榛戦瓟娉曞氨鑳藉疄鐜板儚Windows Terminal
+                // 閭f牱澶栬鍜屽姛鑳介兘姣旇緝瀹岀編鐨勮嚜瀹氫箟杈规銆�
+
+                // 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]() {
+                    lastHitTestResult = getHitWindowPart(int(*result)); //
+                });
+
+                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 = fromNativeLocalPosition(
+                    m_windowHandle, QPoint(nativeLocalPos.x, nativeLocalPos.y));
+
+                bool isFixedSize = m_delegate->isHostSizeFixed(m_host);
+                bool isTitleBar = isInTitleBarDraggableArea(qtScenePos);
+                bool dontOverrideCursor = false; // ### TODO
+
+                CoreWindowAgent::SystemButton sysButtonType = CoreWindowAgent::Unknown;
+                if (!isFixedSize && isInSystemButtons(qtScenePos, &sysButtonType)) {
+                    // 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 int kBorderSize = 2;
+                        bool isTop = (nativeLocalPos.y <= kBorderSize);
+                        bool isRight = (nativeLocalPos.x >= (clientWidth - kBorderSize));
+                        if (isTop || isRight) {
+                            if (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 = (isTitleBar ? HTCAPTION : HTCLIENT);
+                            } else {
+                                if (isTop && isRight) {
+                                    *result = HTTOPRIGHT;
+                                } else if (isTop) {
+                                    *result = HTTOP;
+                                } else {
+                                    *result = 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 CoreWindowAgent::WindowIcon:
+                                *result = HTSYSMENU;
+                                break;
+                            case CoreWindowAgent::Help:
+                                *result = HTHELP;
+                                break;
+                            case CoreWindowAgent::Minimize:
+                                *result = HTREDUCE;
+                                break;
+                            case CoreWindowAgent::Maximize:
+                                *result = HTZOOM;
+                                break;
+                            case CoreWindowAgent::Close:
+                                *result = HTCLOSE;
+                                break;
+                            default:
+                                break; // unreachable
+                        }
+                    }
+                    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);
+                int frameSize = getResizeBorderThickness(hWnd);
+                bool isTop = (nativeLocalPos.y < frameSize);
+
+                if (isWin10OrGreater()) {
+                    // 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 = ((isFixedSize || dontOverrideCursor) ? HTBORDER
+                                                                       : originalHitTestResult);
+                        return true;
+                    }
+                    if (full) {
+                        *result = HTCLIENT;
+                        return true;
+                    }
+                    if (max) {
+                        *result = (isTitleBar ? 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 (isTop) {
+                        // 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 = ((isFixedSize || dontOverrideCursor)
+                                       ? (isTitleBar ? HTCAPTION : HTCLIENT)
+                                       : HTTOP);
+                        return true;
+                    }
+                    if (isTitleBar) {
+                        *result = HTCAPTION;
+                        return true;
+                    }
+                    *result = HTCLIENT;
+                    return true;
+                } else {
+                    if (full) {
+                        *result = HTCLIENT;
+                        return true;
+                    }
+                    if (max) {
+                        *result = (isTitleBar ? HTCAPTION : HTCLIENT);
+                        return true;
+                    }
+                    if (!isFixedSize) {
+                        const bool isBottom = (nativeLocalPos.y >= (clientHeight - frameSize));
+                        // Make the border a little wider to let the user easy to resize on corners.
+                        const auto scaleFactor = ((isTop || isBottom) ? qreal(2) : qreal(1));
+                        const int scaledFrameSizeX = std::round(qreal(frameSize) * scaleFactor);
+                        const bool isLeft = (nativeLocalPos.x < scaledFrameSizeX);
+                        const bool isRight = (nativeLocalPos.x >= (clientWidth - scaledFrameSizeX));
+                        if (dontOverrideCursor && (isTop || isBottom || isLeft || isRight)) {
+                            // Return HTCLIENT instead of HTBORDER here, because the mouse is
+                            // inside the window now, return HTCLIENT to let the controls
+                            // inside our window can still capture mouse events.
+                            *result = (isTitleBar ? HTCAPTION : HTCLIENT);
+                            return true;
+                        }
+                        if (isTop) {
+                            if (isLeft) {
+                                *result = HTTOPLEFT;
+                                return true;
+                            }
+                            if (isRight) {
+                                *result = HTTOPRIGHT;
+                                return true;
+                            }
+                            *result = HTTOP;
+                            return true;
+                        }
+                        if (isBottom) {
+                            if (isLeft) {
+                                *result = HTBOTTOMLEFT;
+                                return true;
+                            }
+                            if (isRight) {
+                                *result = HTBOTTOMRIGHT;
+                                return true;
+                            }
+                            *result = HTBOTTOM;
+                            return true;
+                        }
+                        if (isLeft) {
+                            *result = HTLEFT;
+                            return true;
+                        }
+                        if (isRight) {
+                            *result = HTRIGHT;
+                            return true;
+                        }
+                    }
+                    if (isTitleBar) {
+                        *result = HTCAPTION;
+                        return true;
+                    }
+                    *result = HTCLIENT;
+                    return true;
+                }
             }
             default:
                 break;
         }
+        if (!isWin10OrGreater()) {
+            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: {
+                    // 杈规闃村奖澶勪簬闈炲鎴峰尯鐨勮寖鍥达紝鍥犳濡傛灉鐩存帴闃绘闈炲鎴峰尯鐨勭粯鍒讹紝浼氬鑷磋竟妗嗛槾褰变涪澶�
+
+                    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 {
+                        if (wParam) {
+                            *result = FALSE;
+                        } 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;
     }
 
-}
\ No newline at end of file
+}

--
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