port some more code (for os < win10)

Yuhang Zhao

2023-12-05 9b1599d82e86d2d0463b60fe6fa61f94be50f983

 src/core/contexts/win32windowcontext.cpp

@@ -28,6 +28,7 @@

    struct DynamicApis {
        decltype(&::DwmFlush) pDwmFlush = nullptr;
        decltype(&::DwmIsCompositionEnabled) pDwmIsCompositionEnabled = nullptr;
        decltype(&::GetDpiForWindow) pGetDpiForWindow = nullptr;
        decltype(&::GetSystemMetricsForDpi) pGetSystemMetricsForDpi = nullptr;
        decltype(&::GetDpiForMonitor) pGetDpiForMonitor = nullptr;
@@ -45,6 +46,7 @@

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

        ~DynamicApis() = default;
@@ -138,6 +140,12 @@
        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;
@@ -148,6 +156,26 @@
        static const bool result =
            QOperatingSystemVersion::current() >= QOperatingSystemVersion::Windows10;
        return result;
    }

    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) {
        Q_ASSERT(hwnd);
        if (!hwnd) {
            return;
        }
        ::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) {
@@ -266,7 +294,7 @@
            case HTBORDER:
                return Win32WindowContext::FixedBorder;
            default:
                break;
                break; // unreachable
        }
        return Win32WindowContext::Outside;
    }
@@ -1087,7 +1115,7 @@
                // 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 ourself. Previously I thought
                // 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
@@ -1165,6 +1193,8 @@
                                break;
                            case CoreWindowAgent::Unknown:
                                break;
                            default:
                                break; // unreachable
                        }
                    }
                    if (*result == HTNOWHERE) {
@@ -1291,6 +1321,66 @@
            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: {
                    // 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 {
                        if (wParam == FALSE) {
                            *result = TRUE;
                        } else {
                            *result = FALSE;
                        }
                    }
                    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;
    }