winrt: Keep track of affected window for mouse events

With the previous implementation mouseLeave events were
broken as we did not remember, which window was initially
affected by events and naturally there was no window under
the mouse for these events.

Now we save the currently affected window and use this
information for leave events.

Change-Id: I4036ce5e6621b507232d258dbb54c7f40a345899
Reviewed-by: Maurice Kalinowski <maurice.kalinowski@qt.io>

1 files changed, 20 insertions, 18 deletions

diff --git a/src/plugins/platforms/winrt/qwinrtscreen.cpp b/src/plugins/platforms/winrt/qwinrtscreen.cpp
index 97e54d496a..e5b412a875 100644
--- a/src/plugins/platforms/winrt/qwinrtscreen.cpp
+++ b/src/plugins/platforms/winrt/qwinrtscreen.cpp
@@ -488,7 +488,8 @@ public:
 #endif // WINAPI_FAMILY_PARTITION(WINAPI_PARTITION_PHONE_APP)
     QAtomicPointer<QWinRTWindow> mouseGrabWindow;
     QAtomicPointer<QWinRTWindow> keyboardGrabWindow;
-    QWindow *currentPressWindow = 0;
+    QWindow *currentPressWindow = nullptr;
+    QWindow *currentTargetWindow = nullptr;
 };
 
 // To be called from the XAML thread
@@ -1082,11 +1083,11 @@ HRESULT QWinRTScreen::onPointerEntered(ICoreWindow *, IPointerEventArgs *args)
         pointerPoint->get_Position(&point);
         QPoint pos(point.X * d->scaleFactor, point.Y * d->scaleFactor);
 
-        QWindow *targetWindow = topWindow();
+        d->currentTargetWindow = topWindow();
         if (d->mouseGrabWindow)
-            targetWindow = d->mouseGrabWindow.load()->window();
+            d->currentTargetWindow = d->mouseGrabWindow.load()->window();
 
-        QWindowSystemInterface::handleEnterEvent(targetWindow, pos, pos);
+        QWindowSystemInterface::handleEnterEvent(d->currentTargetWindow, pos, pos);
     }
     return S_OK;
 }
@@ -1105,11 +1106,11 @@ HRESULT QWinRTScreen::onPointerExited(ICoreWindow *, IPointerEventArgs *args)
 
     d->touchPoints.remove(id);
 
-    QWindow *targetWindow = nullptr;
     if (d->mouseGrabWindow)
-        targetWindow = d->mouseGrabWindow.load()->window();
+        d->currentTargetWindow = d->mouseGrabWindow.load()->window();
 
-    QWindowSystemInterface::handleLeaveEvent(targetWindow);
+    QWindowSystemInterface::handleLeaveEvent(d->currentTargetWindow);
+    d->currentTargetWindow = nullptr;
     return S_OK;
 }
 
@@ -1132,14 +1133,14 @@ HRESULT QWinRTScreen::onPointerUpdated(ICoreWindow *, IPointerEventArgs *args)
 
     const QPoint posPoint = pos.toPoint();
     QWindow *windowUnderPointer = windowAt(QHighDpiScaling::mapPositionFromNative(posPoint, this));
-    QWindow *targetWindow = windowUnderPointer;
+    d->currentTargetWindow = windowUnderPointer;
 
     if (d->mouseGrabWindow)
-        targetWindow = d->mouseGrabWindow.load()->window();
+        d->currentTargetWindow = d->mouseGrabWindow.load()->window();
 
-    if (targetWindow) {
+    if (d->currentTargetWindow) {
         const QPointF globalPosDelta = pos - posPoint;
-        localPos = targetWindow->mapFromGlobal(posPoint) + globalPosDelta;
+        localPos = d->currentTargetWindow->mapFromGlobal(posPoint) + globalPosDelta;
     }
 
     VirtualKeyModifiers modifiers;
@@ -1174,7 +1175,7 @@ HRESULT QWinRTScreen::onPointerUpdated(ICoreWindow *, IPointerEventArgs *args)
             boolean isHorizontal;
             properties->get_IsHorizontalMouseWheel(&isHorizontal);
             QPoint angleDelta(isHorizontal ? delta : 0, isHorizontal ? 0 : delta);
-            QWindowSystemInterface::handleWheelEvent(targetWindow, localPos, pos, QPoint(), angleDelta, mods);
+            QWindowSystemInterface::handleWheelEvent(d->currentTargetWindow, localPos, pos, QPoint(), angleDelta, mods);
             break;
         }
 
@@ -1216,13 +1217,14 @@ HRESULT QWinRTScreen::onPointerUpdated(ICoreWindow *, IPointerEventArgs *args)
             d->currentPressWindow = nullptr;
         }
         // If the mouse button is released outside of a window, targetWindow is 0, but the event
-        // has to be delivered to the window, that initially received the mouse press.
-        if (buttons == Qt::NoButton && d->currentPressWindow && !targetWindow) {
-            targetWindow = d->currentPressWindow;
+        // has to be delivered to the window, that initially received the mouse press. Do not reset
+        // d->currentTargetWindow though, as it is used (and reset) in onPointerExited.
+        if (buttons == Qt::NoButton && d->currentPressWindow && !d->currentTargetWindow) {
+            d->currentTargetWindow = d->currentPressWindow;
             d->currentPressWindow = nullptr;
         }
 
-        QWindowSystemInterface::handleMouseEvent(targetWindow, localPos, pos, buttons, mods);
+        QWindowSystemInterface::handleMouseEvent(d->currentTargetWindow, localPos, pos, buttons, mods);
 
         break;
     }
@@ -1276,7 +1278,7 @@ HRESULT QWinRTScreen::onPointerUpdated(ICoreWindow *, IPointerEventArgs *args)
         it.value().normalPosition = QPointF(point.X/d->logicalRect.width(), point.Y/d->logicalRect.height());
         it.value().pressure = pressure;
 
-        QWindowSystemInterface::handleTouchEvent(targetWindow, d->touchDevice, d->touchPoints.values(), mods);
+        QWindowSystemInterface::handleTouchEvent(d->currentTargetWindow, d->touchDevice, d->touchPoints.values(), mods);
 
         // Fall-through for pen to generate tablet event
         if (pointerDeviceType != PointerDeviceType_Pen)
@@ -1295,7 +1297,7 @@ HRESULT QWinRTScreen::onPointerUpdated(ICoreWindow *, IPointerEventArgs *args)
         float rotation;
         properties->get_Twist(&rotation);
 
-        QWindowSystemInterface::handleTabletEvent(targetWindow, isPressed, pos, pos, 0,
+        QWindowSystemInterface::handleTabletEvent(d->currentTargetWindow, isPressed, pos, pos, 0,
                                                   pointerType, pressure, xTilt, yTilt,
                                                   0, rotation, 0, id, mods);