MouseArea: add scrollGestureEnabled property

If true, scroll gestures coming from the operating system can cause
wheel to be emitted; if false, only an actual mouse wheel will do that.
The photosurface example demostrates the use case.
1) the flick gesture on a trackpad should flick the underlying
Flickable, not zoom an individual image
2) mouse wheel should zoom an individual image if the cursor is
pointing to it
3) dragging an image on a touchscreen should be possible, independently
of flicking the Flickable.  This means multiPointTouchEnabled should be
true, so we cannot interpret multiPointTouchEnabled to mean that
multipoint touch scroll gestures should be disabled.

Change-Id: Ie063556866f07b3fbadc53990b110edeed532710
Reviewed-by: Morten Johan Sørvig <morten.sorvig@theqtcompany.com>

1 files changed, 1 insertions, 0 deletions

diff --git a/src/quick/items/qquickmousearea_p_p.h b/src/quick/items/qquickmousearea_p_p.h
index 73db6ea36f..630b60f1be 100644
--- a/src/quick/items/qquickmousearea_p_p.h
+++ b/src/quick/items/qquickmousearea_p_p.h
@@ -78,6 +78,7 @@ public:
     bool isWheelConnected();
 
     bool enabled : 1;
+    bool scrollGestureEnabled : 1;
     bool hovered : 1;
     bool longPress : 1;
     bool moved : 1;