Refs #4141. Adding parallel projection implementation.

Code/Mantid/Vates/VatesSimpleGui/ViewWidgets/inc/MantidVatesSimpleGuiViewWidgets/ViewBase.h

@@ -138,6 +138,8 @@ public slots:
    * @param state flag to determine whether or not to use log color scaling
    */
   void onLogScale(int state);
+  /// Set the view to use a parallel projection.
+  void onParallelProjection(bool state);
   /// Reset center of rotation to center of data volume.
   void onResetCenterToData();
   /// Reset center of rotation to given point.
@@ -177,6 +179,8 @@ public slots:
 
   /// Return the active representation determined by ParaView.
   pqPipelineRepresentation *getPvActiveRep();
+  /// Return the active view determined by ParaView
+  pqRenderView *getPvActiveView();
   /// Find the number of true sources in the pipeline.
   unsigned int getNumSources();
   /// Collect time information for animation controls.

Code/Mantid/Vates/VatesSimpleGui/ViewWidgets/src/MdViewerWidget.cpp

@@ -313,11 +313,17 @@ void MdViewerWidget::setParaViewComponentsForView()
                    this->ui.timeControlWidget,
                    SLOT(updateAnimationControls(double, double, int)));
 
-  // Set the connections for the rotation center buttons
+  // Set the connections for the rotation center button
   QObject::connect(this->ui.resetCenterToDataButton,
                    SIGNAL(clicked()),
                    this->currentView,
                    SLOT(onResetCenterToData()));
+
+  // Set the connection for the parallel projection button
+  QObject::connect(this->ui.parallelProjButton,
+                   SIGNAL(toggled(bool)),
+                   this->currentView,
+                   SLOT(onParallelProjection(bool)));
 }
 
 void MdViewerWidget::onDataLoaded(pqPipelineSource* source)

Code/Mantid/Vates/VatesSimpleGui/ViewWidgets/src/ViewBase.cpp

@@ -311,6 +311,30 @@ void ViewBase::setAxisScales()
 {
 }
 
+/**
+ * This function is used to set the current state of the view between a
+ * parallel projection and the normal projection.
+ * @param state whether or not to use parallel projection
+ */
+void ViewBase::onParallelProjection(bool state)
+{
+  pqRenderView *cview = this->getPvActiveView();
+  vtkSMProxy *proxy = cview->getProxy();
+  vtkSMPropertyHelper(proxy, "CameraParallelProjection").Set(state);
+  proxy->UpdateVTKObjects();
+  cview->render();
+}
+
+/**
+ * Retrieve the active pqRenderView object according to ParaView's
+ * ActiveObjects mechanism.
+ * @return the currently active view
+ */
+pqRenderView *ViewBase::getPvActiveView()
+{
+  return qobject_cast<pqRenderView*>(pqActiveObjects::instance().activeView());
+}
+
 }
 }
 }