diff --git a/include/Utils/qtSimple.h b/include/Utils/qtSimple.h
index aae270a16ded2570326fa91d22e04d907cab4afd..a67559a84b5d9c464d8b4617442232438e057281 100644
--- a/include/Utils/qtSimple.h
+++ b/include/Utils/qtSimple.h
@@ -291,6 +291,11 @@ public:
 	 */
 	virtual void cb_mouseMove(int button, int x, int y) {}
 
+	/**
+	 * the mouse has been move (with button still pressed)
+	 */
+	virtual void cb_wheelEvent(int delta, int x, int y) {}
+
 	/**
 	 * key press CB (context is ok)
 	 */
@@ -365,7 +370,6 @@ public:
 	 */
 	std::string selectFileSave(const std::string& title = "open file", const std::string& dir =  ".", const std::string& filters = "all (*.*)");
 
-
 public slots:
 	virtual void cb_New() { std::cerr << "callback not implemented" << std::endl; }
 	virtual void cb_Open() { std::cerr << "callback not implemented" << std::endl; }
diff --git a/src/Utils/qtgl.cpp b/src/Utils/qtgl.cpp
index 5eaf2f8d5844f8925de6d7be6e6d52967e9bcbb7..095db9aa610019f5030dc60990c09f519e28dc20 100644
--- a/src/Utils/qtgl.cpp
+++ b/src/Utils/qtgl.cpp
@@ -241,6 +241,9 @@ void GLWidget::wheelEvent(QWheelEvent* event)
 
 	newModel = 1;
 	updateGL();
+
+	if (m_cbs)
+		m_cbs->cb_wheelEvent(event->delta(), event->x(), getHeight() - event->y());
 }
 
 void GLWidget::keyPressEvent(QKeyEvent* event)