Win32: Add workaround for DWM flicker

And some other minor tweaks.

Signed-off-by: Yuhang Zhao <2546789017@qq.com>

CMakeLists.txt

@@ -73,7 +73,7 @@ target_compile_definitions(${PROJECT_NAME} PRIVATE
     QT_NO_CAST_TO_ASCII
     QT_NO_KEYWORDS
     QT_DEPRECATED_WARNINGS
-    QT_DISABLE_DEPRECATED_BEFORE=0x060100
+    QT_DISABLE_DEPRECATED_BEFORE=0x060200
     FRAMELESSHELPER_BUILD_LIBRARY
 )
 
@@ -85,7 +85,7 @@ endif()
 
 if(WIN32)
     target_link_libraries(${PROJECT_NAME} PRIVATE
-        dwmapi
+        dwmapi winmm
     )
 endif()
 

examples/common.pri

@@ -5,12 +5,12 @@ DEFINES += \
     QT_NO_CAST_TO_ASCII \
     QT_NO_KEYWORDS \
     QT_DEPRECATED_WARNINGS \
-    QT_DISABLE_DEPRECATED_BEFORE=0x060100
+    QT_DISABLE_DEPRECATED_BEFORE=0x060200
 RESOURCES += $$PWD/images.qrc
 win32 {
     CONFIG += windeployqt
     CONFIG -= embed_manifest_exe
-    LIBS += -luser32 -lshell32 -ldwmapi
+    LIBS += -luser32 -lshell32 -ldwmapi -lwinmm
     RC_FILE = $$PWD/example.rc
     OTHER_FILES += $$PWD/example.manifest
 }

examples/quick/qml/main.qml

@@ -1,5 +1,3 @@
-
-
 /*
  * MIT License
  *
@@ -23,6 +21,7 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  * SOFTWARE.
  */
+
 import QtQuick 2.0
 import QtQuick.Window 2.0
 import QtQuick.Controls 2.0
@@ -48,13 +47,13 @@ Window {
         interval: 500
         running: true
         repeat: true
-        onTriggered: label.text = Qt.formatTime(new Date(), "hh:mm:ss")
+        onTriggered: timeLabel.text = Qt.formatTime(new Date(), "hh:mm:ss")
     }
 
     Rectangle {
         id: titleBar
         height: framelessHelper.titleBarHeight
-        color: "transparent"
+        color: "white"
         anchors {
             top: parent.top
             topMargin: window._flh_margin
@@ -106,7 +105,7 @@ Window {
     }
 
     Label {
-        id: label
+        id: timeLabel
         anchors.centerIn: parent
         font {
             pointSize: 70
@@ -115,9 +114,10 @@ Window {
     }
 
     Button {
+        id: fullScreenButton
         anchors {
             horizontalCenter: parent.horizontalCenter
-            top: label.bottom
+            top: timeLabel.bottom
             topMargin: 15
         }
         property bool _full: window.visibility === Window.FullScreen

framelesshelper_win32.cpp

@@ -245,10 +245,12 @@ bool FramelessHelperWin::nativeEventFilter(const QByteArray &eventType, void *me
         const auto clientRect = ((static_cast<BOOL>(msg->wParam) == FALSE)
                                  ? reinterpret_cast<LPRECT>(msg->lParam)
                                  : &(reinterpret_cast<LPNCCALCSIZE_PARAMS>(msg->lParam))->rgrc[0]);
+        const bool max = IsMaximized(msg->hwnd);
+        const bool full = window->windowState() == Qt::WindowFullScreen;
         // 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 (IsMaximized(msg->hwnd) && (window->windowState() != Qt::WindowFullScreen)) {
+        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 of the monitor and
@@ -267,7 +269,7 @@ bool FramelessHelperWin::nativeEventFilter(const QByteArray &eventType, void *me
         // Make sure to use MONITOR_DEFAULTTONEAREST, so that this will
         // still find the right monitor even when we're restoring from
         // minimized.
-        if (IsMaximized(msg->hwnd) || (window->windowState() == Qt::WindowFullScreen)) {
+        if (max || full) {
             APPBARDATA abd;
             SecureZeroMemory(&abd, sizeof(abd));
             abd.cbSize = sizeof(abd);
@@ -308,8 +310,6 @@ bool FramelessHelperWin::nativeEventFilter(const QByteArray &eventType, void *me
                     left = hasAutohideTaskbar(ABE_LEFT);
                     right = hasAutohideTaskbar(ABE_RIGHT);
                 } else {
-                    // The following code is copied from Mozilla Firefox,
-                    // with some modifications.
                     int edge = -1;
                     APPBARDATA _abd;
                     SecureZeroMemory(&_abd, sizeof(_abd));
@@ -361,7 +361,7 @@ bool FramelessHelperWin::nativeEventFilter(const QByteArray &eventType, void *me
                 }
             }
         }
-#if 1
+#if 0
         // Fix the flickering issue while resizing.
         // "clientRect->right += 1;" also works.
         // This small technique is known to have two draw backs:
@@ -376,6 +376,63 @@ bool FramelessHelperWin::nativeEventFilter(const QByteArray &eventType, void *me
         // is not correct. It confuses QPA's internal logic.
         clientRect->bottom += 1;
 #endif
+        // Dirty hack to workaround the DWM flicker.
+        LARGE_INTEGER freq = {};
+        if (QueryPerformanceFrequency(&freq) == FALSE) {
+            qWarning() << Utilities::getSystemErrorMessage(QStringLiteral("QueryPerformanceFrequency"));
+            break;
+        }
+        TIMECAPS tc = {};
+        if (timeGetDevCaps(&tc, sizeof(tc)) != MMSYSERR_NOERROR) {
+            qWarning() << "timeGetDevCaps() failed.";
+            break;
+        }
+        const UINT ms_granularity = tc.wPeriodMin;
+        if (timeBeginPeriod(ms_granularity) != TIMERR_NOERROR) {
+            qWarning() << "timeBeginPeriod() failed.";
+            break;
+        }
+        LARGE_INTEGER now0 = {};
+        if (QueryPerformanceCounter(&now0) == FALSE) {
+            qWarning() << Utilities::getSystemErrorMessage(QStringLiteral("QueryPerformanceCounter"));
+            break;
+        }
+        // ask DWM where the vertical blank falls
+        DWM_TIMING_INFO dti;
+        SecureZeroMemory(&dti, sizeof(dti));
+        dti.cbSize = sizeof(dti);
+        const HRESULT hr = DwmGetCompositionTimingInfo(nullptr, &dti);
+        if (FAILED(hr)) {
+            qWarning() << Utilities::getSystemErrorMessage(QStringLiteral("DwmGetCompositionTimingInfo"));
+            break;
+        }
+        LARGE_INTEGER now1 = {};
+        if (QueryPerformanceCounter(&now1) == FALSE) {
+            qWarning() << Utilities::getSystemErrorMessage(QStringLiteral("QueryPerformanceCounter"));
+            break;
+        }
+        // - DWM told us about SOME vertical blank
+        //   - past or future, possibly many frames away
+        // - convert that into the NEXT vertical blank
+        const LONGLONG period = dti.qpcRefreshPeriod;
+        const LONGLONG dt = dti.qpcVBlank - now1.QuadPart;
+        LONGLONG w = 0, m = 0;
+        if (dt >= 0) {
+            w = dt / period;
+        } else {
+            // reach back to previous period
+            // - so m represents consistent position within phase
+            w = -1 + dt / period;
+        }
+        m = dt - (period * w);
+        Q_ASSERT(m >= 0);
+        Q_ASSERT(m < period);
+        const qreal m_ms = 1000.0 * static_cast<qreal>(m) / static_cast<qreal>(freq.QuadPart);
+        Sleep(static_cast<DWORD>(qRound(m_ms)));
+        if (timeEndPeriod(ms_granularity) != TIMERR_NOERROR) {
+            qWarning() << "timeEndPeriod() failed.";
+            break;
+        }
         // We cannot return WVR_REDRAW otherwise Windows exhibits bugs where
         // client pixels and child windows are mispositioned by the width/height
         // of the upper-left nonclient area.
@@ -502,7 +559,8 @@ bool FramelessHelperWin::nativeEventFilter(const QByteArray &eventType, void *me
         const int resizeBorderThickness = Utilities::getSystemMetric(window, SystemMetric::ResizeBorderThickness, true);
         const int titleBarHeight = Utilities::getSystemMetric(window, SystemMetric::TitleBarHeight, true);
         bool isTitleBar = false;
-        if (IsMaximized(msg->hwnd) || (window->windowState() == Qt::WindowFullScreen)) {
+        const bool max = IsMaximized(msg->hwnd);
+        if (max || (window->windowState() == Qt::WindowFullScreen)) {
             isTitleBar = (localMouse.y() >= 0) && (localMouse.y() <= titleBarHeight)
                     && (localMouse.x() >= 0) && (localMouse.x() <= windowWidth)
                     && !Utilities::isHitTestVisible(window);
@@ -513,8 +571,8 @@ bool FramelessHelperWin::nativeEventFilter(const QByteArray &eventType, void *me
                     && !Utilities::isHitTestVisible(window);
         }
         const bool isTop = localMouse.y() <= resizeBorderThickness;
-        const LRESULT hitTestResult = [clientRect, msg, isTitleBar, &localMouse, resizeBorderThickness, windowWidth, isTop, window]{
+        *result = [clientRect, isTitleBar, &localMouse, resizeBorderThickness, windowWidth, isTop, window, max](){
-            if (IsMaximized(msg->hwnd)) {
+            if (max) {
                 if (isTitleBar) {
                     return HTCAPTION;
                 }
@@ -559,7 +617,6 @@ bool FramelessHelperWin::nativeEventFilter(const QByteArray &eventType, void *me
             }
             return HTCLIENT;
         }();
-        *result = hitTestResult;
         return true;
     }
     case WM_SETICON:
@@ -591,14 +648,14 @@ bool FramelessHelperWin::nativeEventFilter(const QByteArray &eventType, void *me
         *result = ret;
         return true;
     }
-    case WM_WINDOWPOSCHANGING: {
 #if (QT_VERSION < QT_VERSION_CHECK(6, 2, 2))
+    case WM_WINDOWPOSCHANGING: {
         // Tell Windows to discard the entire contents of the client area, as re-using
         // parts of the client area would lead to jitter during resize.
         const auto windowPos = reinterpret_cast<LPWINDOWPOS>(msg->lParam);
         windowPos->flags |= SWP_NOCOPYBITS;
-#endif
     } break;
+#endif
     default:
         break;
     }

framelesshelper_windows.h

@@ -77,6 +77,7 @@
 #include <QtCore/qt_windows.h>
 #include <shellapi.h>
 #include <dwmapi.h>
+#include <timeapi.h>
 
 #ifndef WM_NCUAHDRAWCAPTION
 #define WM_NCUAHDRAWCAPTION (0x00AE)

lib.pro

@@ -9,7 +9,7 @@ DEFINES += \
     QT_NO_CAST_TO_ASCII \
     QT_NO_KEYWORDS \
     QT_DEPRECATED_WARNINGS \
-    QT_DISABLE_DEPRECATED_BEFORE=0x060100 \
+    QT_DISABLE_DEPRECATED_BEFORE=0x060200 \
     FRAMELESSHELPER_BUILD_LIBRARY
 HEADERS += \
     framelesshelper_global.h \
@@ -32,6 +32,6 @@ win32 {
     SOURCES += \
         utilities_win32.cpp \
         framelesshelper_win32.cpp
-    LIBS += -luser32 -lshell32 -ldwmapi
+    LIBS += -luser32 -lshell32 -ldwmapi -lwinmm
     RC_FILE = framelesshelper.rc
 }