Optimize Windows 10 border handling

Sine Striker

2023-12-25 29901fc2a97eedd3c914f807d1819c9ea7e69973

 src/core/contexts/win32windowcontext.cpp

@@ -729,27 +729,49 @@
                return;
            }

                //            case AbstractWindowContext::DrawWindows10BackgroundHook: {
                // #if QWINDOWKIT_CONFIG(ENABLE_WINDOWS_SYSTEM_BORDER)
                //                if (!m_windowHandle)
                //                    return;
                //
                //                auto hWnd = reinterpret_cast<HWND>(windowId);
                //                HDC hdc = ::GetDC(hWnd);
                //                RECT windowRect{};
                //                ::GetClientRect(hWnd, &windowRect);
                //                RECT rcRest = {
                //                    0,
                //                    int(getWindowFrameBorderThickness(hWnd)),
                //                    RECT_WIDTH(windowRect),
                //                    RECT_HEIGHT(windowRect),
                //                };
                //                HBRUSH blueBrush = ::CreateSolidBrush(RGB(0, 0, 255));
                //
                //                // To hide the original title bar, we have to paint on top of it
                //                with
                //                // the alpha component set to 255. This is a hack to do it with
                //                GDI.
                //                // See NonClientIslandWindow::_UpdateFrameMargins for more
                //                information. HDC opaqueDc; BP_PAINTPARAMS params =
                //                {sizeof(params), BPPF_NOCLIP | BPPF_ERASE}; auto buf =
                //                BeginBufferedPaint(hdc, &rcRest, BPBF_TOPDOWNDIB, &params,
                //                &opaqueDc); if (!buf || !opaqueDc) {
                //                    return;
                //                }
                //
                //                ::FillRect(opaqueDc, &rcRest, blueBrush);
                //                ::BufferedPaintSetAlpha(buf, nullptr, 255);
                //                ::EndBufferedPaint(buf, TRUE);
                //
                //                ::DeleteObject(blueBrush);
                //                ::ReleaseDC(hWnd, hdc);
                // #endif
                //                return;
                //            }

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

    bool Win32WindowContext::needBorderPainter() const {
        Q_UNUSED(this)
        return isSystemBorderEnabled() && !isWin11OrGreater();
    }

    int Win32WindowContext::borderThickness() const {
        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() {
@@ -768,13 +790,7 @@
        auto hWnd = reinterpret_cast<HWND>(winId);

        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);
            setWindowAttribute("extra-margins", true);
        }

        {
@@ -839,7 +855,7 @@
            msg.wParam = wParam;
            msg.lParam = lParam;
            QT_NATIVE_EVENT_RESULT_TYPE res = 0;
            if (dispatch(QByteArrayLiteral("windows_generic_MSG"), &msg, &res)) {
            if (nativeDispatch(QByteArrayLiteral("windows_generic_MSG"), &msg, &res)) {
                *result = LRESULT(res);
                return true;
            }
@@ -851,9 +867,43 @@
                                                    const QVariant &oldAttribute) {
        const auto hwnd = reinterpret_cast<HWND>(m_windowHandle->winId());
        const DynamicApis &apis = DynamicApis::instance();
        static constexpr const MARGINS extendMargins = {-1, -1, -1, -1};
        static const auto defaultMargins =
            isSystemBorderEnabled() ? MARGINS{0, 0, 0, 0} : MARGINS{1, 1, 1, 1};
        static constexpr const MARGINS defaultEmptyMargins = {0, 0, 0, 0};
        static constexpr const MARGINS defaultExtraMargins = {1, 1, 1, 1};
        static constexpr const MARGINS extendedMargins = {-1, -1, -1, -1};
        if (key == QStringLiteral("extra-margins")) {
            if (isWin11OrGreater())
                return false;
            hasExtraMargins = attribute.toBool();
            DynamicApis::instance().pDwmExtendFrameIntoClientArea(
                hwnd, hasExtraMargins ? &defaultExtraMargins : &defaultEmptyMargins);
            return true;
        }

        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);
            }
            for (const auto attr : {
                     _DWMWA_USE_IMMERSIVE_DARK_MODE_BEFORE_20H1,
                     _DWMWA_USE_IMMERSIVE_DARK_MODE,
                 }) {
                apis.pDwmSetWindowAttribute(hwnd, attr, &enable, sizeof(enable));
            }

            apis.pFlushMenuThemes();
            return true;
        }

        // For Win11 or later
        static const auto &defaultMargins =
            isSystemBorderEnabled() ? defaultExtraMargins : defaultEmptyMargins;
        if (key == QStringLiteral("mica")) {
            if (!isWin11OrGreater()) {
                return false;
@@ -861,7 +911,7 @@
            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, &extendMargins);
                apis.pDwmExtendFrameIntoClientArea(hwnd, &extendedMargins);
                if (isWin1122H2OrGreater()) {
                    // Use official DWM API to enable Mica, available since Windows 11 22H2
                    // (10.0.22621).
@@ -886,14 +936,16 @@
                apis.pDwmExtendFrameIntoClientArea(hwnd, &defaultMargins);
            }
            return true;
        } else if (key == QStringLiteral("mica-alt")) {
        }

        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, &extendMargins);
                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;
@@ -906,14 +958,16 @@
                apis.pDwmExtendFrameIntoClientArea(hwnd, &defaultMargins);
            }
            return true;
        } else if (key == QStringLiteral("acrylic-material")) {
        }

        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, &extendMargins);
                apis.pDwmExtendFrameIntoClientArea(hwnd, &extendedMargins);

                const _DWM_SYSTEMBACKDROP_TYPE backdropType = _DWMSBT_TRANSIENTWINDOW;
                apis.pDwmSetWindowAttribute(hwnd, _DWMWA_SYSTEMBACKDROP_TYPE, &backdropType,
@@ -951,13 +1005,15 @@
                apis.pDwmExtendFrameIntoClientArea(hwnd, &defaultMargins);
            }
            return true;
        } else if (key == QStringLiteral("dwm-blur")) {
        }

        if (key == QStringLiteral("dwm-blur")) {
            // TODO: Optimize
            // Currently not available!!!
            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, &extendMargins);
                apis.pDwmExtendFrameIntoClientArea(hwnd, &extendedMargins);
                if (isWin8OrGreater()) {
                    ACCENT_POLICY policy{};
                    policy.dwAccentState = ACCENT_ENABLE_BLURBEHIND;
@@ -991,26 +1047,6 @@
                }
                apis.pDwmExtendFrameIntoClientArea(hwnd, &defaultMargins);
            }
            return true;
        } else 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);
            }
            for (const auto attr : {
                     _DWMWA_USE_IMMERSIVE_DARK_MODE_BEFORE_20H1,
                     _DWMWA_USE_IMMERSIVE_DARK_MODE,
                 }) {
                apis.pDwmSetWindowAttribute(hwnd, attr, &enable, sizeof(enable));
            }

            apis.pFlushMenuThemes();
            return true;
        }
        return false;
@@ -2046,4 +2082,13 @@
        return false;
    }

    bool Win32WindowContext::needBorderPainter() const {
        Q_UNUSED(this)
        return isSystemBorderEnabled() && !isWin11OrGreater();
    }

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

}