QPanGestureRecognizer: Make the number of touch points a parameter.

Prepare for determining the suitable number of touch points
from the device type. For now, 2 points are used as
before, which can be overridden by setting the environment
variable QT_PAN_TOUCHPOINTS. Add member variable
to QPanGesturePrivate which is set on gesture creation and later
used for comparison.

Task-number: QTBUG-40461
Change-Id: I6d9e35ca752375bc6a54435482ca0925195b8142
Reviewed-by: Shawn Rutledge <shawn.rutledge@digia.com>

1 files changed, 4 insertions, 1 deletions

diff --git a/src/widgets/kernel/qstandardgestures_p.h b/src/widgets/kernel/qstandardgestures_p.h
index aeabd9cc7e..15ba31f26a 100644
--- a/src/widgets/kernel/qstandardgestures_p.h
+++ b/src/widgets/kernel/qstandardgestures_p.h
@@ -55,11 +55,14 @@ QT_BEGIN_NAMESPACE
 class QPanGestureRecognizer : public QGestureRecognizer
 {
 public:
-    QPanGestureRecognizer();
+    explicit QPanGestureRecognizer(int pointCount = 2) : m_pointCount(pointCount) {}
 
     QGesture *create(QObject *target);
     QGestureRecognizer::Result recognize(QGesture *state, QObject *watched, QEvent *event);
     void reset(QGesture *state);
+
+private:
+    const int m_pointCount;
 };
 
 class QPinchGestureRecognizer : public QGestureRecognizer