Windows QPA: Improve tablet mode detection

Change the code to detect mouse mode only the first packet after
receiving the enter proximity event, using the current tablet
position. This should prevent mis-detecting mouse mode due to lags, etc.

There is a theoretical chance of failing to detect mouse mode should the
positions match resulting in differing speeds of mouse/tablet positions, but
this seems to be a negligible risk.

Task-number: QTBUG-36937
Task-number: QTBUG-64781
Change-Id: I27ca4a17786164dc8b25c4614a88672e150d5fe3
Reviewed-by: Shawn Rutledge <shawn.rutledge@qt.io>

1 files changed, 15 insertions, 0 deletions

diff --git a/src/plugins/platforms/windows/qwindowstabletsupport.h b/src/plugins/platforms/windows/qwindowstabletsupport.h
index 7878e962e1..340818c3f7 100644
--- a/src/plugins/platforms/windows/qwindowstabletsupport.h
+++ b/src/plugins/platforms/windows/qwindowstabletsupport.h
@@ -112,6 +112,19 @@ class QWindowsTabletSupport
     explicit QWindowsTabletSupport(HWND window, HCTX context);
 
 public:
+    enum Mode
+    {
+        PenMode,
+        MouseMode
+    };
+
+    enum State
+    {
+        PenUp,
+        PenProximity,
+        PenDown
+    };
+
     ~QWindowsTabletSupport();
 
     static QWindowsTabletSupport *create();
@@ -137,6 +150,8 @@ private:
     QVector<QWindowsTabletDeviceData> m_devices;
     int m_currentDevice;
     QPointF m_oldGlobalPosF;
+    Mode m_mode = PenMode;
+    State m_state = PenUp;
 };
 
 QT_END_NAMESPACE