Windows: use MSG timestamps for input events

Input events have a timestamp. When dispatching an event through QPA, a
platform plugin can either provide it, or QPA will use an internal
QElapsedTimer to provide a timestamp.

Windows input messages do come with a timestamp already, so we can use
that instead of the QPA.

The two methods are not equivalent.

For instance: for various reasons, Qt does not honor Windows' "double
clicked" message, but uses the delta between two mouse events to
establish if the second click is actually a double click.

Now suppose that the user double clicks on a widget. On the first click,
the application does something that freezes it for a bit (e.g. some
heavy repainting or whatever). Does the second click register as a
double click or not?

* If we're using Qt's own timer, the answer is NO; the event is pulled
  from the WM queue after the freeze, given a timestamp far away from
  the last click, and so it will be deemed another single click
* If we use the OS' timestamps, then the second click will be seen as
  "close" to the first click, and correctly registered as second click.

This reasoning can be extended to many other QPA events, but looks like
the APIs for some are missing (e.g. enter events), so I'm not tackling
them here.

This commit reverts ade96ff6446d4b0977d4e5f03b96b77ff8223b8b.

Task-number: QTBUG-109833
Task-number: QTBUG-122226
Change-Id: I5f3fba029b44c618ef622bacdc4bcc3928e04867
Reviewed-by: Oliver Wolff <oliver.wolff@qt.io>
Reviewed-by: Shawn Rutledge <shawn.rutledge@qt.io>
Reviewed-by: Tor Arne Vestbø <tor.arne.vestbo@qt.io>
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>
Reviewed-by: Yuhang Zhao <yuhangzhao@deepin.org>

4 files changed, 32 insertions, 29 deletions

diff --git a/src/plugins/platforms/windows/qwindowscontext.cpp b/src/plugins/platforms/windows/qwindowscontext.cpp
index c363b85cb3..c85c44d949 100644
--- a/src/plugins/platforms/windows/qwindowscontext.cpp
+++ b/src/plugins/platforms/windows/qwindowscontext.cpp
@@ -1006,9 +1006,10 @@ bool QWindowsContext::windowsProc(HWND hwnd, UINT message,
 
     MSG msg;
     msg.hwnd = hwnd;         // re-create MSG structure
-    msg.message = message;   // time and pt fields ignored
+    msg.message = message;
     msg.wParam = wParam;
     msg.lParam = lParam;
+    msg.time = GetMessageTime();
     msg.pt.x = msg.pt.y = 0;
     if (et != QtWindows::CursorEvent && (et & (QtWindows::MouseEventFlag | QtWindows::NonClientEventFlag))) {
         msg.pt.x = GET_X_LPARAM(lParam);
diff --git a/src/plugins/platforms/windows/qwindowskeymapper.cpp b/src/plugins/platforms/windows/qwindowskeymapper.cpp
index af1230d240..ba76cda40b 100644
--- a/src/plugins/platforms/windows/qwindowskeymapper.cpp
+++ b/src/plugins/platforms/windows/qwindowskeymapper.cpp
@@ -801,7 +801,7 @@ static void showSystemMenu(QWindow* w)
         qWindowsWndProc(topLevelHwnd, WM_SYSCOMMAND, WPARAM(ret), 0);
 }
 
-static inline void sendExtendedPressRelease(QWindow *w, int k,
+static inline void sendExtendedPressRelease(QWindow *w, unsigned long timestamp, int k,
                                             Qt::KeyboardModifiers mods,
                                             quint32 nativeScanCode,
                                             quint32 nativeVirtualKey,
@@ -810,8 +810,8 @@ static inline void sendExtendedPressRelease(QWindow *w, int k,
                                             bool autorep = false,
                                             ushort count = 1)
 {
-    QWindowSystemInterface::handleExtendedKeyEvent(w, QEvent::KeyPress, k, mods, nativeScanCode, nativeVirtualKey, nativeModifiers, text, autorep, count);
-    QWindowSystemInterface::handleExtendedKeyEvent(w, QEvent::KeyRelease, k, mods, nativeScanCode, nativeVirtualKey, nativeModifiers, text, autorep, count);
+    QWindowSystemInterface::handleExtendedKeyEvent(w, timestamp, QEvent::KeyPress, k, mods, nativeScanCode, nativeVirtualKey, nativeModifiers, text, autorep, count);
+    QWindowSystemInterface::handleExtendedKeyEvent(w, timestamp, QEvent::KeyRelease, k, mods, nativeScanCode, nativeVirtualKey, nativeModifiers, text, autorep, count);
 }
 
 /*!
@@ -878,7 +878,7 @@ bool QWindowsKeyMapper::translateMultimediaKeyEventInternal(QWindow *window, con
 
     const int qtKey = int(CmdTbl[cmd]);
     if (!skipPressRelease)
-        sendExtendedPressRelease(receiver, qtKey, Qt::KeyboardModifier(state), 0, 0, 0);
+        sendExtendedPressRelease(receiver, msg.time, qtKey, Qt::KeyboardModifier(state), 0, 0, 0);
     // QTBUG-43343: Make sure to return false if Qt does not handle the key, otherwise,
     // the keys are not passed to the active media player.
 # if QT_CONFIG(shortcut)
@@ -958,7 +958,7 @@ bool QWindowsKeyMapper::translateKeyEventInternal(QWindow *window, MSG msg,
     // A multi-character key or a Input method character
     // not found by our look-ahead
     if (msgType == WM_CHAR || msgType == WM_IME_CHAR) {
-        sendExtendedPressRelease(receiver, 0, Qt::KeyboardModifier(state), scancode, 0, nModifiers, messageKeyText(msg), false);
+        sendExtendedPressRelease(receiver, msg.time, 0, Qt::KeyboardModifier(state), scancode, 0, nModifiers, messageKeyText(msg), false);
         return true;
     }
 
@@ -993,14 +993,14 @@ bool QWindowsKeyMapper::translateKeyEventInternal(QWindow *window, MSG msg,
                 if (dirStatus == VK_LSHIFT
                         && ((msg.wParam == VK_SHIFT && GetKeyState(VK_LCONTROL))
                             || (msg.wParam == VK_CONTROL && GetKeyState(VK_LSHIFT)))) {
-                    sendExtendedPressRelease(receiver, Qt::Key_Direction_L, {},
+                    sendExtendedPressRelease(receiver, msg.time, Qt::Key_Direction_L, {},
                                              scancode, vk_key, nModifiers, QString(), false);
                     result = true;
                     dirStatus = 0;
                 } else if (dirStatus == VK_RSHIFT
                            && ( (msg.wParam == VK_SHIFT && GetKeyState(VK_RCONTROL))
                                 || (msg.wParam == VK_CONTROL && GetKeyState(VK_RSHIFT)))) {
-                    sendExtendedPressRelease(receiver, Qt::Key_Direction_R, {},
+                    sendExtendedPressRelease(receiver, msg.time, Qt::Key_Direction_R, {},
                                              scancode, vk_key, nModifiers, QString(), false);
                     result = true;
                     dirStatus = 0;
@@ -1213,9 +1213,9 @@ bool QWindowsKeyMapper::translateKeyEventInternal(QWindow *window, MSG msg,
         // so, we have an auto-repeating key
         if (rec) {
             if (code < Qt::Key_Shift || code > Qt::Key_ScrollLock) {
-                QWindowSystemInterface::handleExtendedKeyEvent(receiver, QEvent::KeyRelease, code,
+                QWindowSystemInterface::handleExtendedKeyEvent(receiver, msg.time, QEvent::KeyRelease, code,
                                                                Qt::KeyboardModifier(state), scancode, quint32(msg.wParam), nModifiers, rec->text, true);
-                QWindowSystemInterface::handleExtendedKeyEvent(receiver, QEvent::KeyPress, code,
+                QWindowSystemInterface::handleExtendedKeyEvent(receiver, msg.time, QEvent::KeyPress, code,
                                                                Qt::KeyboardModifier(state), scancode, quint32(msg.wParam), nModifiers, rec->text, true);
                 result = true;
             }
@@ -1241,7 +1241,7 @@ bool QWindowsKeyMapper::translateKeyEventInternal(QWindow *window, MSG msg,
             if (msg.wParam == VK_PACKET)
                 code = asciiToKeycode(char(uch.cell()), state);
 
-            QWindowSystemInterface::handleExtendedKeyEvent(receiver, QEvent::KeyPress, code,
+            QWindowSystemInterface::handleExtendedKeyEvent(receiver, msg.time, QEvent::KeyPress, code,
                                                            modifiers, scancode, quint32(msg.wParam), nModifiers, text, false);
             result =true;
             bool store = true;
@@ -1283,10 +1283,10 @@ bool QWindowsKeyMapper::translateKeyEventInternal(QWindow *window, MSG msg,
             if ((msg.lParam & 0x40000000) == 0 &&
                     Qt::KeyboardModifier(state) == Qt::NoModifier &&
                     ((code == Qt::Key_F18) || (code == Qt::Key_F19) || (code == Qt::Key_F20))) {
-                QWindowSystemInterface::handleExtendedKeyEvent(receiver, QEvent::KeyPress, code,
+                QWindowSystemInterface::handleExtendedKeyEvent(receiver, msg.time, QEvent::KeyPress, code,
                                                                Qt::MetaModifier, scancode,
                                                                quint32(msg.wParam), MetaLeft);
-                QWindowSystemInterface::handleExtendedKeyEvent(receiver, QEvent::KeyRelease, code,
+                QWindowSystemInterface::handleExtendedKeyEvent(receiver, msg.time, QEvent::KeyRelease, code,
                                                                Qt::NoModifier, scancode,
                                                                quint32(msg.wParam), 0);
                 result = true;
@@ -1298,7 +1298,7 @@ bool QWindowsKeyMapper::translateKeyEventInternal(QWindow *window, MSG msg,
             // Map SHIFT + Tab to SHIFT + BackTab, QShortcutMap knows about this translation
             if (code == Qt::Key_Tab && (state & Qt::ShiftModifier) == Qt::ShiftModifier)
                 code = Qt::Key_Backtab;
-            QWindowSystemInterface::handleExtendedKeyEvent(receiver, QEvent::KeyRelease, code,
+            QWindowSystemInterface::handleExtendedKeyEvent(receiver, msg.time, QEvent::KeyRelease, code,
                                                            Qt::KeyboardModifier(state), scancode, quint32(msg.wParam),
                                                            nModifiers,
                                                            (rec ? rec->text : QString()), false);
diff --git a/src/plugins/platforms/windows/qwindowsmousehandler.cpp b/src/plugins/platforms/windows/qwindowsmousehandler.cpp
index 7833741e37..9af9fba408 100644
--- a/src/plugins/platforms/windows/qwindowsmousehandler.cpp
+++ b/src/plugins/platforms/windows/qwindowsmousehandler.cpp
@@ -289,14 +289,14 @@ bool QWindowsMouseHandler::translateMouseEvent(QWindow *window, HWND hwnd,
             && (m_lastEventButton & buttons) == 0) {
             auto releaseType = mouseEvent.type == QEvent::NonClientAreaMouseMove ?
                 QEvent::NonClientAreaMouseButtonRelease : QEvent::MouseButtonRelease;
-            QWindowSystemInterface::handleMouseEvent(window, device, clientPosition, globalPosition, buttons, m_lastEventButton,
+            QWindowSystemInterface::handleMouseEvent(window, msg.time, device, clientPosition, globalPosition, buttons, m_lastEventButton,
                                                      releaseType, keyModifiers, source);
     }
     m_lastEventType = mouseEvent.type;
     m_lastEventButton = mouseEvent.button;
 
     if (mouseEvent.type >= QEvent::NonClientAreaMouseMove && mouseEvent.type <= QEvent::NonClientAreaMouseButtonDblClick) {
-        QWindowSystemInterface::handleMouseEvent(window, device, clientPosition,
+        QWindowSystemInterface::handleMouseEvent(window, msg.time, device, clientPosition,
                                                            globalPosition, buttons,
                                                            mouseEvent.button, mouseEvent.type,
                                                            keyModifiers, source);
@@ -446,7 +446,7 @@ bool QWindowsMouseHandler::translateMouseEvent(QWindow *window, HWND hwnd,
     }
 
     if (!discardEvent && mouseEvent.type != QEvent::None) {
-        QWindowSystemInterface::handleMouseEvent(window, device, clientPosition, globalPosition, buttons,
+        QWindowSystemInterface::handleMouseEvent(window, msg.time, device, clientPosition, globalPosition, buttons,
                                                  mouseEvent.button, mouseEvent.type,
                                                  keyModifiers, source);
     }
@@ -470,7 +470,7 @@ static bool isValidWheelReceiver(QWindow *candidate)
     return false;
 }
 
-static void redirectWheelEvent(QWindow *window, const QPoint &globalPos, int delta,
+static void redirectWheelEvent(QWindow *window, unsigned long timestamp, const QPoint &globalPos, int delta,
                                Qt::Orientation orientation, Qt::KeyboardModifiers mods)
 {
     // Redirect wheel event to one of the following, in order of preference:
@@ -491,6 +491,7 @@ static void redirectWheelEvent(QWindow *window, const QPoint &globalPos, int del
     if (handleEvent) {
         const QPoint point = (orientation == Qt::Vertical) ? QPoint(0, delta) : QPoint(delta, 0);
         QWindowSystemInterface::handleWheelEvent(receiver,
+                                                 timestamp,
                                                  QWindowsGeometryHint::mapFromGlobal(receiver, globalPos),
                                                  globalPos, QPoint(), point, mods);
     }
@@ -519,7 +520,7 @@ bool QWindowsMouseHandler::translateMouseWheelEvent(QWindow *window, HWND,
         delta = -delta;
 
     const QPoint globalPos(GET_X_LPARAM(msg.lParam), GET_Y_LPARAM(msg.lParam));
-    redirectWheelEvent(window, globalPos, delta, orientation, mods);
+    redirectWheelEvent(window, msg.time, globalPos, delta, orientation, mods);
 
     return true;
 }
@@ -550,7 +551,7 @@ bool QWindowsMouseHandler::translateScrollEvent(QWindow *window, HWND,
         return false;
     }
 
-    redirectWheelEvent(window, QCursor::pos(), delta, Qt::Horizontal, Qt::NoModifier);
+    redirectWheelEvent(window, msg.time, QCursor::pos(), delta, Qt::Horizontal, Qt::NoModifier);
 
     return true;
 }
@@ -632,6 +633,7 @@ bool QWindowsMouseHandler::translateTouchEvent(QWindow *window, HWND,
 
     const auto *keyMapper = QWindowsContext::instance()->keyMapper();
     QWindowSystemInterface::handleTouchEvent(window,
+                                             msg.time,
                                              m_touchDevice.data(),
                                              touchPoints,
                                              keyMapper->queryKeyboardModifiers());
diff --git a/src/plugins/platforms/windows/qwindowspointerhandler.cpp b/src/plugins/platforms/windows/qwindowspointerhandler.cpp
index 9f1f25db8c..71c7217671 100644
--- a/src/plugins/platforms/windows/qwindowspointerhandler.cpp
+++ b/src/plugins/platforms/windows/qwindowspointerhandler.cpp
@@ -429,7 +429,7 @@ bool QWindowsPointerHandler::translateTouchEvent(QWindow *window, HWND hwnd,
 
     if (msg.message == WM_POINTERCAPTURECHANGED) {
         const auto *keyMapper = QWindowsContext::instance()->keyMapper();
-        QWindowSystemInterface::handleTouchCancelEvent(window, m_touchDevice.data(),
+        QWindowSystemInterface::handleTouchCancelEvent(window, msg.time, m_touchDevice.data(),
                                                        keyMapper->queryKeyboardModifiers());
         m_lastTouchPoints.clear();
         return true;
@@ -541,7 +541,7 @@ bool QWindowsPointerHandler::translateTouchEvent(QWindow *window, HWND hwnd,
         m_touchInputIDToTouchPointID.clear();
 
     const auto *keyMapper = QWindowsContext::instance()->keyMapper();
-    QWindowSystemInterface::handleTouchEvent(window, m_touchDevice.data(), touchPoints,
+    QWindowSystemInterface::handleTouchEvent(window, msg.time, m_touchDevice.data(), touchPoints,
                                              keyMapper->queryKeyboardModifiers());
     return false; // Allow mouse messages to be generated.
 }
@@ -639,7 +639,7 @@ bool QWindowsPointerHandler::translatePenEvent(QWindow *window, HWND hwnd, QtWin
 
     switch (msg.message) {
     case WM_POINTERENTER: {
-        QWindowSystemInterface::handleTabletEnterLeaveProximityEvent(window, device.data(), true);
+        QWindowSystemInterface::handleTabletEnterLeaveProximityEvent(window, msg.time, device.data(), true);
         m_windowUnderPointer = window;
         // The local coordinates may fall outside the window.
         // Wait until the next update to send the enter event.
@@ -652,7 +652,7 @@ bool QWindowsPointerHandler::translatePenEvent(QWindow *window, HWND hwnd, QtWin
             m_windowUnderPointer = nullptr;
             m_currentWindow = nullptr;
         }
-        QWindowSystemInterface::handleTabletEnterLeaveProximityEvent(window, device.data(), false);
+        QWindowSystemInterface::handleTabletEnterLeaveProximityEvent(window, msg.time, device.data(), false);
         break;
     case WM_POINTERDOWN:
     case WM_POINTERUP:
@@ -678,7 +678,7 @@ bool QWindowsPointerHandler::translatePenEvent(QWindow *window, HWND hwnd, QtWin
         const auto *keyMapper = QWindowsContext::instance()->keyMapper();
         const Qt::KeyboardModifiers keyModifiers = keyMapper->queryKeyboardModifiers();
 
-        QWindowSystemInterface::handleTabletEvent(target, device.data(),
+        QWindowSystemInterface::handleTabletEvent(target, msg.time, device.data(),
                                                   localPos, hiResGlobalPos, mouseButtons,
                                                   pressure, xTilt, yTilt, tangentialPressure,
                                                   rotation, z, keyModifiers);
@@ -729,7 +729,7 @@ bool QWindowsPointerHandler::translateMouseWheelEvent(QWindow *window,
 
     QPoint localPos = QWindowsGeometryHint::mapFromGlobal(receiver, globalPos);
 
-    QWindowSystemInterface::handleWheelEvent(receiver, localPos, globalPos, QPoint(), angleDelta, keyModifiers);
+    QWindowSystemInterface::handleWheelEvent(receiver, msg.time, localPos, globalPos, QPoint(), angleDelta, keyModifiers);
     return true;
 }
 
@@ -828,14 +828,14 @@ bool QWindowsPointerHandler::translateMouseEvent(QWindow *window,
             && (m_lastEventButton & mouseButtons) == 0) {
             auto releaseType = mouseEvent.type == QEvent::NonClientAreaMouseMove ?
                 QEvent::NonClientAreaMouseButtonRelease : QEvent::MouseButtonRelease;
-            QWindowSystemInterface::handleMouseEvent(window, device, localPos, globalPos, mouseButtons, m_lastEventButton,
+            QWindowSystemInterface::handleMouseEvent(window, msg.time, device, localPos, globalPos, mouseButtons, m_lastEventButton,
                                                      releaseType, keyModifiers, source);
     }
     m_lastEventType = mouseEvent.type;
     m_lastEventButton = mouseEvent.button;
 
     if (mouseEvent.type >= QEvent::NonClientAreaMouseMove && mouseEvent.type <= QEvent::NonClientAreaMouseButtonDblClick) {
-        QWindowSystemInterface::handleMouseEvent(window, device, localPos, globalPos, mouseButtons,
+        QWindowSystemInterface::handleMouseEvent(window, msg.time, device, localPos, globalPos, mouseButtons,
                                                            mouseEvent.button, mouseEvent.type, keyModifiers, source);
         return false; // Allow further event processing
     }
@@ -855,7 +855,7 @@ bool QWindowsPointerHandler::translateMouseEvent(QWindow *window,
     handleEnterLeave(window, currentWindowUnderPointer, globalPos);
 
     if (!discardEvent && mouseEvent.type != QEvent::None) {
-        QWindowSystemInterface::handleMouseEvent(window, device, localPos, globalPos, mouseButtons,
+        QWindowSystemInterface::handleMouseEvent(window, msg.time, device, localPos, globalPos, mouseButtons,
                                                  mouseEvent.button, mouseEvent.type, keyModifiers, source);
     }