Windows: Add support for horizontal scroll on some touchpads.

While most (all?) touchpads send WM_MOUSEWHEEL for vertical scroll
the story is quite different for horizontal scroll. Some of them
send WM_HSCROLL instead of WM_MOUSEHWHEEL.

Some of them even send left/right key event but those are lost cases.

Task-number: QTBUG-45120
Change-Id: I3bf86e25a6f4f3ba03ac7e89a23f4b7bc432f2de
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@theqtcompany.com>

1 files changed, 5 insertions, 1 deletions

diff --git a/src/plugins/platforms/windows/qtwindowsglobal.h b/src/plugins/platforms/windows/qtwindowsglobal.h
index 083d82ed8c..74fa561e10 100644
--- a/src/plugins/platforms/windows/qtwindowsglobal.h
+++ b/src/plugins/platforms/windows/qtwindowsglobal.h
@@ -57,7 +57,8 @@ enum
     TouchEventFlag = 0x400000,
     ClipboardEventFlag = 0x800000,
     ApplicationEventFlag = 0x1000000,
-    ThemingEventFlag = 0x2000000
+    ThemingEventFlag = 0x2000000,
+    GenericEventFlag = 0x4000000, // Misc
 };
 
 enum WindowsEventType // Simplify event types
@@ -108,6 +109,7 @@ enum WindowsEventType // Simplify event types
     CompositionSettingsChanged = ThemingEventFlag + 2,
     DisplayChangedEvent = 437,
     SettingChangedEvent = DisplayChangedEvent + 1,
+    ScrollEvent = GenericEventFlag + 1,
     ContextMenu = 123,
     GestureEvent = 124,
     UnknownEvent = 542
@@ -145,6 +147,8 @@ inline QtWindows::WindowsEventType windowsEventType(UINT message, WPARAM wParamI
         return QtWindows::CursorEvent;
     case WM_MOUSELEAVE:
         return QtWindows::MouseEvent;
+    case WM_HSCROLL:
+        return QtWindows::ScrollEvent;
     case WM_MOUSEWHEEL:
     case WM_MOUSEHWHEEL:
         return QtWindows::MouseWheelEvent;