From 55d2d2728c9334c41bef85f95f9b2f6171ab50cd Mon Sep 17 00:00:00 2001
From: vsr <vsr@opencascade.com>
Date: Wed, 15 Dec 2010 14:53:37 +0000
Subject: [PATCH] 0020938: EDF 1450 GEOM: center of zoom

---
 src/OCCViewer/OCCViewer_ViewWindow.cxx   | 10 +++++++---
 src/SVTK/SVTK_InteractorStyle.cxx        | 20 ++++++++++++++++++++
 src/SVTK/SVTK_InteractorStyle.h          |  6 ++++++
 src/SVTK/SVTK_RenderWindowInteractor.cxx |  8 ++++++++
 4 files changed, 41 insertions(+), 3 deletions(-)

diff --git a/src/OCCViewer/OCCViewer_ViewWindow.cxx b/src/OCCViewer/OCCViewer_ViewWindow.cxx
index a8977bc2e..dd2952d1c 100755
--- a/src/OCCViewer/OCCViewer_ViewWindow.cxx
+++ b/src/OCCViewer/OCCViewer_ViewWindow.cxx
@@ -334,9 +334,13 @@ bool OCCViewer_ViewWindow::eventFilter( QObject* watched, QEvent* e )
     case QEvent::Wheel:
       {
         QWheelEvent* aEvent = (QWheelEvent*) e;
-        double aDelta = aEvent->delta();
-        double aScale = (aDelta < 0) ? 100./(-aDelta) : aDelta/100.;
-        myViewPort->getView()->SetZoom(aScale);
+	myViewPort->startZoomAtPoint( aEvent->x(), aEvent->y() );
+	double delta = (double)( aEvent->delta() ) / ( 15 * 8 );
+	int x  = aEvent->x();
+	int y  = aEvent->y();
+	int x1 = (int)( aEvent->x() + width()*delta/100 );
+	int y1 = (int)( aEvent->y() + height()*delta/100 );
+	myViewPort->zoom( x, y, x1, y1 );
       }
       return true;
 
diff --git a/src/SVTK/SVTK_InteractorStyle.cxx b/src/SVTK/SVTK_InteractorStyle.cxx
index ec679bdcb..483a3fbbb 100644
--- a/src/SVTK/SVTK_InteractorStyle.cxx
+++ b/src/SVTK/SVTK_InteractorStyle.cxx
@@ -430,6 +430,26 @@ void SVTK_InteractorStyle::OnRightButtonUp()
                          x, y );
 }
 
+/*!
+  To handle mouse wheel forward event (reimplemented from #vtkInteractorStyle)
+*/
+void SVTK_InteractorStyle::OnMouseWheelForward()
+{
+  int x, y;
+  GetEventPosition( this->Interactor, x, y );
+  myOtherPoint = QPoint(x, y);
+}
+
+/*!
+  To handle mouse wheel backward event (reimplemented from #vtkInteractorStyle)
+*/
+void SVTK_InteractorStyle::OnMouseWheelBackward()
+{
+  int x, y;
+  GetEventPosition( this->Interactor, x, y );
+  myOtherPoint = QPoint(x, y);
+}
+
 /*!
   To handle mouse move event
 */
diff --git a/src/SVTK/SVTK_InteractorStyle.h b/src/SVTK/SVTK_InteractorStyle.h
index 4eac463ce..88f523509 100644
--- a/src/SVTK/SVTK_InteractorStyle.h
+++ b/src/SVTK/SVTK_InteractorStyle.h
@@ -201,6 +201,12 @@ class SVTK_EXPORT SVTK_InteractorStyle: public vtkInteractorStyle
   //! To handle right mouse button up event (reimplemented from #vtkInteractorStyle)
   virtual void OnRightButtonUp();
 
+  //! To handle mouse wheel forward event (reimplemented from #vtkInteractorStyle)
+  virtual void OnMouseWheelForward();
+
+  //! To handle mouse wheel backward event (reimplemented from #vtkInteractorStyle)
+  virtual void OnMouseWheelBackward();
+
   //! To handle keyboard event (reimplemented from #vtkInteractorStyle)
   virtual void OnChar();
 
diff --git a/src/SVTK/SVTK_RenderWindowInteractor.cxx b/src/SVTK/SVTK_RenderWindowInteractor.cxx
index eef4ade04..4835c94e0 100644
--- a/src/SVTK/SVTK_RenderWindowInteractor.cxx
+++ b/src/SVTK/SVTK_RenderWindowInteractor.cxx
@@ -320,6 +320,14 @@ QVTK_RenderWindowInteractor
 {
   activateWindow();
   setFocus();
+  GetDevice()->SetEventInformationFlipY(event->x(), 
+                                        event->y(),
+                                        event->modifiers() & Qt::ControlModifier,
+                                        event->modifiers() & Qt::ShiftModifier);
+  if ( event->delta()>0)
+    GetDevice()->MouseWheelForwardEvent();
+  else
+    GetDevice()->MouseWheelBackwardEvent();
 }
 
 
-- 
2.39.2