Rename QNativeGestureEvent::deltas() to delta(); clarify docs

In QPanGesture this is called delta().
OTOH we have QWheelEvent::pixelDeltas().
Delta is a vector, and there's only one (with two components).

Native gestures hold incremental values: e.g. the pinch gesture event
provides an incremental amount of either zooming or rotation (so most
events have QNativeGestureEvent::value() very close to 0).
It's the same with the pan gesture's delta().

Add better docs for swipe and pan gestures.

Change-Id: Ia147c7c9a22e084c3700b1620dec46427d792bd1
Reviewed-by: Povilas Kanapickas <povilas@radix.lt>
Reviewed-by: Volker Hilsheimer <volker.hilsheimer@qt.io>

1 files changed, 4 insertions, 4 deletions

diff --git a/src/gui/kernel/qwindowsysteminterface.cpp b/src/gui/kernel/qwindowsysteminterface.cpp
index 70db73b5d3..355ebb87ec 100644
--- a/src/gui/kernel/qwindowsysteminterface.cpp
+++ b/src/gui/kernel/qwindowsysteminterface.cpp
@@ -1056,14 +1056,14 @@ bool QWindowSystemInterface::handleGestureEventWithRealValue(QWindow *window, ul
     return QWindowSystemInterfacePrivate::handleWindowSystemEvent(e);
 }
 
-bool QWindowSystemInterface::handleGestureEventWithValueAndDeltas(QWindow *window, ulong timestamp, const QPointingDevice *device,
-                                                                  Qt::NativeGestureType type, qreal value, const QPointF &deltas,
-                                                                  const QPointF &local, const QPointF &global, int fingerCount)
+bool QWindowSystemInterface::handleGestureEventWithValueAndDelta(QWindow *window, ulong timestamp, const QPointingDevice *device,
+                                                                 Qt::NativeGestureType type, qreal value, const QPointF &delta,
+                                                                 const QPointF &local, const QPointF &global, int fingerCount)
 {
     QWindowSystemInterfacePrivate::GestureEvent *e =
             new QWindowSystemInterfacePrivate::GestureEvent(window, timestamp, type, device, fingerCount, local, global);
     e->realValue = value;
-    e->deltas = deltas;
+    e->delta = delta;
     return QWindowSystemInterfacePrivate::handleWindowSystemEvent(e);
 }
 #endif // QT_NO_GESTURES