itkCommand.h

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/*=========================================================================
 *
 *  Copyright Insight Software Consortium
 *
 *  Licensed under the Apache License, Version 2.0 (the "License");
 *  you may not use this file except in compliance with the License.
 *  You may obtain a copy of the License at
 *
 *         http://www.apache.org/licenses/LICENSE-2.0.txt
 *
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS,
 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  See the License for the specific language governing permissions and
 *  limitations under the License.
 *
 *=========================================================================*/
#ifndef __itkCommand_h
#define __itkCommand_h

#include "itkObject.h"
#include "itkObjectFactory.h"

namespace itk
{
// The superclass that all commands should be subclasses of
class ITKCommon_EXPORT Command:public Object
{
public:
  typedef Command                    Self;
  typedef Object                     Superclass;
  typedef SmartPointer< Self >       Pointer;
  typedef SmartPointer< const Self > ConstPointer;

  itkTypeMacro(Command, Object);

  virtual void Execute(Object *caller, const EventObject & event) = 0;

  virtual void Execute(const Object *caller, const EventObject & event) = 0;

protected:
  Command();
  ~Command();

private:
  Command(const Self &);        //purposely not implemented
  void operator=(const Self &); //purposely not implemented
};

// some implementations for several callback types

template< typename T >
class MemberCommand:public Command
{
public:
  typedef  void ( T::*TMemberFunctionPointer )(Object *, const EventObject &);
  typedef  void ( T::*TConstMemberFunctionPointer )(const Object *,
                                                    const EventObject &);

  typedef MemberCommand        Self;
  typedef SmartPointer< Self > Pointer;

  itkNewMacro(Self);

  itkTypeMacro(MemberCommand, Command);

  void SetCallbackFunction(T *object,
                           TMemberFunctionPointer memberFunction)
  {
    m_This = object;
    m_MemberFunction = memberFunction;
  }

  void SetCallbackFunction(T *object,
                           TConstMemberFunctionPointer memberFunction)
  {
    m_This = object;
    m_ConstMemberFunction = memberFunction;
  }

  virtual void Execute(Object *caller, const EventObject & event)
  {
    if ( m_MemberFunction )
      {
      ( ( *m_This ).*( m_MemberFunction ) )( caller, event );
      }
  }

  virtual void Execute(const Object *caller, const EventObject & event)
  {
    if ( m_ConstMemberFunction )
      {
      ( ( *m_This ).*( m_ConstMemberFunction ) )( caller, event );
      }
  }

protected:

  T *                         m_This;
  TMemberFunctionPointer      m_MemberFunction;
  TConstMemberFunctionPointer m_ConstMemberFunction;
  MemberCommand():
    m_This( NULL ),
    m_MemberFunction( NULL ),
    m_ConstMemberFunction( NULL )
  {}
  virtual ~MemberCommand(){}

private:
  MemberCommand(const Self &);  //purposely not implemented
  void operator=(const Self &); //purposely not implemented
};

template< typename T >
class ReceptorMemberCommand:public Command
{
public:
  typedef  void ( T::*TMemberFunctionPointer )(const EventObject &);

  typedef ReceptorMemberCommand Self;
  typedef SmartPointer< Self >  Pointer;

  itkNewMacro(Self);

  itkTypeMacro(ReceptorMemberCommand, Command);

  void SetCallbackFunction(T *object,
                           TMemberFunctionPointer memberFunction)
  {
    m_This = object;
    m_MemberFunction = memberFunction;
  }

  virtual void Execute(Object *, const EventObject & event)
  {
    if ( m_MemberFunction )
      {
      ( ( *m_This ).*( m_MemberFunction ) )( event );
      }
  }

  virtual void Execute(const Object *, const EventObject & event)
  {
    if ( m_MemberFunction )
      {
      ( ( *m_This ).*( m_MemberFunction ) )( event );
      }
  }

protected:
  T *                    m_This;
  TMemberFunctionPointer m_MemberFunction;
  ReceptorMemberCommand():m_MemberFunction(0) {}
  virtual ~ReceptorMemberCommand() {}

private:
  ReceptorMemberCommand(const Self &); //purposely not implemented
  void operator=(const Self &);        //purposely not implemented
};

template< typename T >
class SimpleMemberCommand:public Command
{
public:
  typedef  void ( T::*TMemberFunctionPointer )();

  typedef SimpleMemberCommand  Self;
  typedef SmartPointer< Self > Pointer;

  itkTypeMacro(SimpleMemberCommand, Command);

  itkNewMacro(Self);

  void SetCallbackFunction(T *object,
                           TMemberFunctionPointer memberFunction)
  {
    m_This = object;
    m_MemberFunction = memberFunction;
  }

  virtual void Execute(Object *, const EventObject &)
  {
    if ( m_MemberFunction )
      {
      ( ( *m_This ).*( m_MemberFunction ) )( );
      }
  }

  virtual void Execute(const Object *, const EventObject &)
  {
    if ( m_MemberFunction )
      {
      ( ( *m_This ).*( m_MemberFunction ) )( );
      }
  }

protected:
  T *                    m_This;
  TMemberFunctionPointer m_MemberFunction;
  SimpleMemberCommand():
    m_This( NULL ),
    m_MemberFunction( NULL )
  {}
  virtual ~SimpleMemberCommand() {}

private:
  SimpleMemberCommand(const Self &); //purposely not implemented
  void operator=(const Self &);      //purposely not implemented
};

template< typename T >
class SimpleConstMemberCommand:public Command
{
public:
  typedef  void ( T::*TMemberFunctionPointer )() const;

  typedef SimpleConstMemberCommand Self;
  typedef SmartPointer< Self >     Pointer;

  itkTypeMacro(SimpleConstMemberCommand, Command);

  itkNewMacro(Self);

  void SetCallbackFunction(const T *object,
                           TMemberFunctionPointer memberFunction)
  {
    m_This = object;
    m_MemberFunction = memberFunction;
  }

  virtual void Execute(Object *, const EventObject &)
  {
    if ( m_MemberFunction )
      {
      ( ( *m_This ).*( m_MemberFunction ) )( );
      }
  }

  virtual void Execute(const Object *, const EventObject &)
  {
    if ( m_MemberFunction )
      {
      ( ( *m_This ).*( m_MemberFunction ) )( );
      }
  }

protected:
  const T *              m_This;
  TMemberFunctionPointer m_MemberFunction;
  SimpleConstMemberCommand():
    m_This( NULL ),
    m_MemberFunction( NULL )
  {}
  virtual ~SimpleConstMemberCommand() {}

private:
  SimpleConstMemberCommand(const Self &); //purposely not implemented
  void operator=(const Self &);           //purposely not implemented
};

class CStyleCommand:public Command
{
public:
  typedef  void ( *FunctionPointer )(Object *, const EventObject &, void *);
  typedef  void ( *ConstFunctionPointer )(const Object *,
                                          const EventObject &, void *);
  typedef  void ( *DeleteDataFunctionPointer )(void *);

  typedef CStyleCommand        Self;
  typedef SmartPointer< Self > Pointer;

  itkTypeMacro(CStyleCommand, Command);

  itkNewMacro(Self);

  void SetClientData(void *cd) { m_ClientData = cd; }

  void SetCallback(FunctionPointer f)
  { m_Callback = f; }
  void SetConstCallback(ConstFunctionPointer f)
  { m_ConstCallback = f; }

  void SetClientDataDeleteCallback(DeleteDataFunctionPointer f)
  { m_ClientDataDeleteCallback = f; }

  void Execute(Object *caller, const EventObject & event)
  {
    if ( m_Callback )
      {
      m_Callback(caller, event, m_ClientData);
      }
  }

  void Execute(const Object *caller, const EventObject & event)
  {
    if ( m_ConstCallback )
      {
      m_ConstCallback(caller, event, m_ClientData);
      }
  }

protected:
  CStyleCommand():m_ClientData(0), m_Callback(0), m_ConstCallback(0),
    m_ClientDataDeleteCallback(0)
  {
    // not implemented
  }

  ~CStyleCommand()
  {
    if ( m_ClientDataDeleteCallback )
      {
      m_ClientDataDeleteCallback(m_ClientData);
      }
  }

  void *                    m_ClientData;
  FunctionPointer           m_Callback;
  ConstFunctionPointer      m_ConstCallback;
  DeleteDataFunctionPointer m_ClientDataDeleteCallback;
};
} // end namespace itk

#endif