ENH: (Visu Refactoring) Adding an action handler to change zoom scale

Code/VisuRefac/otbChangeScaleActionHandler.h

+/*=========================================================================
+
+  Program:   ORFEO Toolbox
+  Language:  C++
+  Date:      $Date$
+  Version:   $Revision$
+
+
+  Copyright (c) Centre National d'Etudes Spatiales. All rights reserved.
+  See OTBCopyright.txt for details.
+
+
+     This software is distributed WITHOUT ANY WARRANTY; without even
+     the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
+     PURPOSE.  See the above copyright notices for more information.
+
+=========================================================================*/
+#ifndef __otbChangeScaleActionHandler_h
+#define __otbChangeScaleActionHandler_h
+
+#include "otbImageWidgetActionHandler.h"
+
+namespace otb
+{
+/** \class ChangeScaleActionHandler
+*   \brief Implements basic Scroll, Full and Zoom  widgets resizing.
+* 
+*   \sa ImageWidgetController
+*   \sa ImageWidgetActionHandler
+*/
+
+template <class TModel, class TView> 
+class ChangeScaleActionHandler
+  : public ImageWidgetActionHandler
+{
+public:
+  /** Standard class typedefs */
+  typedef ChangeScaleActionHandler Self;
+  typedef ImageWidgetActionHandler               Superclass;
+  typedef itk::SmartPointer<Self>                Pointer;
+  typedef itk::SmartPointer<const Self>          ConstPointer;
+  
+  /** Method for creation through the object factory */
+  itkNewMacro(Self);
+  
+  /** Runtime information */
+  itkTypeMacro(ChangeScaleActionHandler,ImageWidgetActionHandler);
+
+  /** Model typedefs */
+  typedef TModel                         ModelType;
+  typedef typename ModelType::Pointer    ModelPointerType;
+  typedef typename ModelType::RegionType RegionType;
+
+  /** View typedefs */
+  typedef TView                          ViewType;
+  typedef typename ViewType::Pointer     ViewPointerType;
+
+
+  /** Handle widget event
+   * \param widgetId The id of the moved widget
+   * \param event The event
+   * \return The handling return code
+   */
+  virtual bool HandleWidgetEvent(std::string widgetId, int event)
+  {
+    if( m_View.IsNotNull() && m_Model.IsNotNull() )
+      {
+      if(widgetId == m_View->GetZoomWidget()->GetIdentifier()
+	 && event == FL_MOUSEWHEEL)
+	{
+	otbMsgDevMacro(<<"ChangeScaleActionHandler::HandleWidgetEvent(): handling ("<<widgetId<<", "<<event<<")");
+        // Get the mousewhell offset
+	int dy = Fl::event_dy();
+	
+	// Compute new scale
+	double newScale = m_View->GetZoomWidget()->GetIsotropicZoom() * vcl_pow(m_ScaleRatio,-dy);
+	if(newScale>=1.0)
+	  {
+	  m_View->GetZoomWidget()->SetIsotropicZoom(newScale);
+	  RegionType region = m_Model->GetScaledExtractRegion();
+	  
+	  typename RegionType::IndexType index = region.GetIndex();
+	  typename RegionType::SizeType size = region.GetSize();
+	  index[0]+=size[0]/2;
+	  index[1]+=size[1]/2;
+	  size[0] = static_cast<unsigned int>(m_View->GetZoomWidget()->w()/m_View->GetZoomWidget()->GetIsotropicZoom());
+	  size[1] = static_cast<unsigned int>(m_View->GetZoomWidget()->h()/m_View->GetZoomWidget()->GetIsotropicZoom());
+	  region.SetSize(size);
+	  m_Model->SetScaledExtractRegion(region);
+	  m_Model->SetScaledExtractRegionCenter(index);
+	  // Update the model
+	  m_Model->Update();
+	  }
+	return true;
+	}
+      }
+    return false;
+  }
+  
+  /** Set/Get the pointer to the view */
+  itkSetObjectMacro(View,ViewType);
+  itkGetObjectMacro(View,ViewType);
+
+  /** Set/Get the pointer to the model */
+  itkSetObjectMacro(Model,ModelType);
+  itkGetObjectMacro(Model,ModelType);
+
+  /** Set/Get scale ratio */
+  itkSetMacro(ScaleRatio,double);
+  itkGetMacro(ScaleRatio,double);
+
+protected:
+  /** Constructor */
+  ChangeScaleActionHandler() : m_View(), m_Model()
+  {}
+
+  /** Destructor */
+  virtual ~ChangeScaleActionHandler(){}
+  /** Printself method */
+  void PrintSelf(std::ostream& os, itk::Indent indent) const
+  {
+    Superclass::PrintSelf(os,indent);
+  }
+ 
+private:
+  ChangeScaleActionHandler(const Self&);    // purposely not implemented
+  void operator=(const Self&); // purposely not implemented
+
+  // Pointer to the view
+  ViewPointerType m_View;
+  
+  // Pointer to the model
+  ModelPointerType m_Model;
+  
+  /** Scale Ratio */
+  double m_ScaleRatio;
+
+}; // end class 
+} // end namespace otb
+#endif
+
+