Add QGestureEvent::mapToScene for better graphicsView integration

3 files changed, 24 insertions, 0 deletions

diff --git a/src/gui/kernel/qevent.cpp b/src/gui/kernel/qevent.cpp
index 1c6a820..ef74f06 100644
--- a/src/gui/kernel/qevent.cpp
+++ b/src/gui/kernel/qevent.cpp
@@ -45,6 +45,7 @@
 #include "private/qapplication_p.h"
 #include "private/qkeysequence_p.h"
 #include "qwidget.h"
+#include "qgraphicsview.h"
 #include "qdebug.h"
 #include "qmime.h"
 #include "qdnd_p.h"
@@ -4345,6 +4346,23 @@ QWidget *QGestureEvent::widget() const
 }
 
 /*!
+    Returns the scene-local coordinates if the \a gesturePoint is inside a graphics view.
+
+    \sa QPointF::isNull().
+*/
+QPointF QGestureEvent::mapToScene(const QPointF &gesturePoint) const
+{
+    QWidget *w = widget();
+    if (w) // we get the viewport as widget, not the graphics view
+        w = w->parentWidget();
+    QGraphicsView *view = qobject_cast<QGraphicsView*>(w);
+    if (view) {
+        return view->mapToScene(view->mapFromGlobal(gesturePoint.toPoint()));
+    }
+    return QPointF();
+}
+
+/*!
     \internal
 */
 QGestureEventPrivate *QGestureEvent::d_func()
diff --git a/src/gui/kernel/qevent.h b/src/gui/kernel/qevent.h
index 5eefc2d..249c45a 100644
--- a/src/gui/kernel/qevent.h
+++ b/src/gui/kernel/qevent.h
@@ -855,6 +855,8 @@ public:
     void setWidget(QWidget *widget);
     QWidget *widget() const;
 
+    QPointF mapToScene(const QPointF &gesturePoint) const;
+
 private:
     QGestureEventPrivate *d_func();
     const QGestureEventPrivate *d_func() const;
diff --git a/src/gui/kernel/qgesture.cpp b/src/gui/kernel/qgesture.cpp
index e48fd8e..f044c09 100644
--- a/src/gui/kernel/qgesture.cpp
+++ b/src/gui/kernel/qgesture.cpp
@@ -129,6 +129,10 @@ QGesture::~QGesture()
 
     \brief The point that is used to find the receiver for the gesture event.
 
+    The hot-spot is a point in the global coordinate system, use
+    QWidget::mapFromGlobal() or QGestureEvent::mapToScene() to get a
+    local hot-spot.
+
     If the hot-spot is not set, the targetObject is used as the receiver of the
     gesture event.
 */