Fix key modifiers in mouse wheel events on Windows.

The Windows platform plugin was not checking for the control or
shift keyboard modifiers when processing mouse wheel events. Added
a function to convert Windows wheel events to Qt::KeyboardModifiers
and passed this through the event chain.

Task-number: QTBUG-25754
Change-Id: I6551e98b4eaebad5704058bddfb06502ded5155d
Reviewed-by: Martin Jones <martin.jones@nokia.com>
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@nokia.com>

1 files changed, 11 insertions, 0 deletions

diff --git a/src/plugins/platforms/windows/qwindowsmousehandler.h b/src/plugins/platforms/windows/qwindowsmousehandler.h
index b3d176db9b..a978840d67 100644
--- a/src/plugins/platforms/windows/qwindowsmousehandler.h
+++ b/src/plugins/platforms/windows/qwindowsmousehandler.h
@@ -67,6 +67,7 @@ public:
                              LRESULT *result);
 
     static inline Qt::MouseButtons keyStateToMouseButtons(int);
+    static inline Qt::KeyboardModifiers keyStateToModifiers(int);
     static inline int mouseButtonsToKeyState(Qt::MouseButtons);
 
     QWindow *windowUnderMouse() const { return m_windowUnderMouse.data(); }
@@ -96,6 +97,16 @@ Qt::MouseButtons QWindowsMouseHandler::keyStateToMouseButtons(int wParam)
     return mb;
 }
 
+Qt::KeyboardModifiers QWindowsMouseHandler::keyStateToModifiers(int wParam)
+{
+    Qt::KeyboardModifiers mods(Qt::NoModifier);
+    if (wParam & MK_CONTROL)
+      mods |= Qt::ControlModifier;
+    if (wParam & MK_SHIFT)
+      mods |= Qt::ShiftModifier;
+    return mods;
+}
+
 int QWindowsMouseHandler::mouseButtonsToKeyState(Qt::MouseButtons mb)
 {
     int result = 0;