/*=========================================================================

  Program:   Visualization Toolkit
  Module:    vtkWidgetCallbackMapper.h

  Copyright (c) Ken Martin, Will Schroeder, Bill Lorensen
  All rights reserved.
  See Copyright.txt or http://www.kitware.com/Copyright.htm 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 notice for more information.

=========================================================================*/
// .NAME vtkWidgetCallbackMapper - map widget events into callbacks
// .SECTION Description
// vtkWidgetCallbackMapper maps widget events (defined in vtkWidgetEvent.h)
// into static class methods, and provides facilities to invoke the methods.
// This class is templated and meant to be used as an internal helper class
// by the widget classes. The class works in combination with the class
// vtkWidgetEventTranslator, which translates VTK events into widget events.
//
// .SECTION See Also
// vtkWidgetEvent vtkWidgetEventTranslator

#ifndef __vtkWidgetCallbackMapper_h
#define __vtkWidgetCallbackMapper_h

#include "vtkObject.h"

class vtkWidgetEvent;
class vtkAbstractWidget;
class vtkWidgetEventTranslator;
class vtkCallbackMap; // PIMPL encapsulation of STL map


class VTK_WIDGETS_EXPORT vtkWidgetCallbackMapper : public vtkObject
{
public:
  // Description:
  // Instantiate the class.
  static vtkWidgetCallbackMapper *New();

  // Description:
  // Standard macros.
  vtkTypeMacro(vtkWidgetCallbackMapper,vtkObject);
  void PrintSelf(ostream& os, vtkIndent indent);

  // Description:
  // Specify the vtkWidgetEventTranslator to coordinate with.
  void SetEventTranslator(vtkWidgetEventTranslator *t);
  vtkGetObjectMacro(EventTranslator,vtkWidgetEventTranslator);

//BTX
  // Description:
  // Convenient typedef for working with callbacks.
  typedef void (*CallbackType)(vtkAbstractWidget*);
//ETX

  // Description:
  // This class works with the class vtkWidgetEventTranslator to set up the
  // initial coorespondence between VTK events, widget events, and callbacks.
  // Different flavors of the SetCallbackMethod() are available depending on
  // what sort of modifiers are to be associated with a particular event.
  // Typically the widgets should use this method to set up their event
  // callbacks. If modifiers are not provided (i.e., the VTKEvent is a 
  // unsigned long eventId) then modifiers are ignored. Otherwise, a vtkEvent
  // instance is used to fully quality the events.
  void SetCallbackMethod(unsigned long VTKEvent, unsigned long widgetEvent, 
                         vtkAbstractWidget *w, CallbackType f);
  void SetCallbackMethod(unsigned long VTKEvent, int modifiers, char keyCode, 
                         int repeatCount, const char* keySym,
                         unsigned long widgetEvent, 
                         vtkAbstractWidget *w, CallbackType f);
  //void SetCallbackMethod(vtkWidgetEvent *vtkEvent, unsigned long widgetEvent,
  //                       vtkAbstractWidget *w, CallbackType f);

  // Description:
  // This method invokes the callback given a widget event. A non-zero value
  // is returned if the listed event is registered.
  void InvokeCallback(unsigned long widgetEvent);
  
protected:
  vtkWidgetCallbackMapper();
  ~vtkWidgetCallbackMapper();

  // Translates VTK events into widget events
  vtkWidgetEventTranslator *EventTranslator;

  // Invoke the method associated with a particular widget event
  vtkCallbackMap *CallbackMap;
  
  // Description:
  // This method is used to assign a callback (implemented as a static class
  // method) to a particular widget event. This is an internal method used by
  // widgets to map widget events into invocations of class methods.
  void SetCallbackMethod(unsigned long widgetEvent, 
                         vtkAbstractWidget *w, CallbackType f);
  

private:
  vtkWidgetCallbackMapper(const vtkWidgetCallbackMapper&);  //Not implemented
  void operator=(const vtkWidgetCallbackMapper&);  //Not implemented

};


#endif /* __vtkWidgetCallbackMapper_h */
 
