Use brilliant workaround to show Windows 10 top border

Sine Striker

2023-12-24 46285db399f75154ad6c451e12f2cae2e59ace25

 src/core/contexts/win32windowcontext.cpp

@@ -5,6 +5,7 @@
#include <QtCore/QHash>
#include <QtCore/QScopeGuard>
#include <QtCore/QTimer>
#include <QtCore/QDateTime>
#include <QtGui/QGuiApplication>
#include <QtGui/QPainter>
#include <QtGui/QPalette>
@@ -658,6 +659,7 @@
            }

            case DrawWindows10BorderHook: {
#if QWINDOWKIT_CONFIG(ENABLE_WINDOWS_SYSTEM_BORDER)
                if (!windowId)
                    return;

@@ -668,7 +670,7 @@
                const auto hwnd = reinterpret_cast<HWND>(windowId);

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

                const bool dark = isDarkThemeActive() && isDarkWindowFrameEnabled(hwnd);
                if (m_delegate->isWindowActive(m_host)) {
@@ -688,7 +690,7 @@
                }
                painter.save();

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

                painter.setPen(pen);
@@ -697,6 +699,33 @@
                    QPoint{m_windowHandle->width(), 0}
                });
                painter.restore();
                return;
#endif
            }

            case DrawWindows10BorderHook2: {
#if QWINDOWKIT_CONFIG(ENABLE_WINDOWS_SYSTEM_BORDER)
                if (!m_windowHandle)
                    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>(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);
#endif
                return;
            }

@@ -712,7 +741,15 @@
    }

    int Win32WindowContext::borderThickness() const {
        return getWindowFrameBorderThickness(reinterpret_cast<HWND>(windowId));
        return int(getWindowFrameBorderThickness(reinterpret_cast<HWND>(windowId)));
    }

    void Win32WindowContext::resume(const QByteArray &eventType, void *message,
                                    QT_NATIVE_EVENT_RESULT_TYPE *result) {
        const auto msg = static_cast<const MSG *>(message);
        LRESULT res =
            ::CallWindowProcW(g_qtWindowProc, msg->hwnd, msg->message, msg->wParam, msg->lParam);
        *result = decltype(*result)(res);
    }

    void Win32WindowContext::winIdChanged() {
@@ -732,6 +769,11 @@

        if (!isSystemBorderEnabled()) {
            static constexpr const MARGINS margins = {1, 1, 1, 1};
            DynamicApis::instance().pDwmExtendFrameIntoClientArea(hWnd, &margins);
        } else if (isWin10OrGreater() && !isWin11OrGreater()) {
            // https://github.com/microsoft/terminal/blob/71a6f26e6ece656084e87de1a528c4a8072eeabd/src/cascadia/WindowsTerminal/NonClientIslandWindow.cpp#L940
            // Must call DWM API to extend top frame to client area
            static constexpr const MARGINS margins = {0, 0, 1, 0};
            DynamicApis::instance().pDwmExtendFrameIntoClientArea(hWnd, &margins);
        }

@@ -956,13 +998,11 @@
            }

            BOOL enable = attribute.toBool();

            if (isWin101903OrGreater()) {
                apis.pSetPreferredAppMode(enable ? PAM_AUTO : PAM_DEFAULT);
            } else {
                apis.pAllowDarkModeForApp(enable);
            }

            for (const auto attr : {
                     _DWMWA_USE_IMMERSIVE_DARK_MODE_BEFORE_20H1,
                     _DWMWA_USE_IMMERSIVE_DARK_MODE,
@@ -971,7 +1011,6 @@
            }

            apis.pFlushMenuThemes();

            return true;
        }
        return false;