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:
  ITK_DISALLOW_COPY_AND_ASSIGN(Command);

  using Self = Command;
  using Superclass = Object;
  using Pointer = SmartPointer< Self >;
  using ConstPointer = SmartPointer< const Self >;

  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() override;
};

// some implementations for several callback types

template< typename T >
class ITK_TEMPLATE_EXPORT MemberCommand:public Command
{
public:
  ITK_DISALLOW_COPY_AND_ASSIGN(MemberCommand);

  using TMemberFunctionPointer = void (T::*)(Object *, const EventObject &);
  using TConstMemberFunctionPointer = void (T::*)(const Object *, const EventObject &);

  using Self = MemberCommand;
  using Pointer = SmartPointer< Self >;

  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;
  }

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

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

protected:
  T *                         m_This;
  TMemberFunctionPointer      m_MemberFunction;
  TConstMemberFunctionPointer m_ConstMemberFunction;

  MemberCommand() :
    m_This( nullptr ),
    m_MemberFunction( nullptr ),
    m_ConstMemberFunction( nullptr )
  {}

  ~MemberCommand() override = default;
};

template< typename T >
class ITK_TEMPLATE_EXPORT ReceptorMemberCommand:public Command
{
public:
  ITK_DISALLOW_COPY_AND_ASSIGN(ReceptorMemberCommand);

  using TMemberFunctionPointer = void (T::*)(const EventObject &);

  using Self = ReceptorMemberCommand;
  using Pointer = SmartPointer< Self >;

  itkNewMacro(Self);

  itkTypeMacro(ReceptorMemberCommand, Command);

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

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

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

protected:
  T *                    m_This;
  TMemberFunctionPointer m_MemberFunction;

  ReceptorMemberCommand() :
    m_This( nullptr ),
    m_MemberFunction( nullptr )
  {}

  ~ReceptorMemberCommand() override = default;
};

template< typename T >
class ITK_TEMPLATE_EXPORT SimpleMemberCommand:public Command
{
public:
  ITK_DISALLOW_COPY_AND_ASSIGN(SimpleMemberCommand);

  using TMemberFunctionPointer = void (T::*)();

  using Self = SimpleMemberCommand;
  using Pointer = SmartPointer< Self >;

  itkTypeMacro(SimpleMemberCommand, Command);

  itkNewMacro(Self);

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

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

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

protected:
  T *                    m_This;
  TMemberFunctionPointer m_MemberFunction;

  SimpleMemberCommand() :
    m_This( nullptr ),
    m_MemberFunction( nullptr )
  {}

  ~SimpleMemberCommand() override = default;
};

template< typename T >
class ITK_TEMPLATE_EXPORT SimpleConstMemberCommand:public Command
{
public:
  ITK_DISALLOW_COPY_AND_ASSIGN(SimpleConstMemberCommand);

  using TMemberFunctionPointer = void (T::*)() const;

  using Self = SimpleConstMemberCommand;
  using Pointer = SmartPointer< Self >;

  itkTypeMacro(SimpleConstMemberCommand, Command);

  itkNewMacro(Self);

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

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

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

protected:
  const T *              m_This;
  TMemberFunctionPointer m_MemberFunction;

  SimpleConstMemberCommand() :
    m_This( nullptr ),
    m_MemberFunction( nullptr )
  {}

  ~SimpleConstMemberCommand() override = default;
};

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

  using Self = CStyleCommand;
  using Pointer = SmartPointer< Self >;

  itkTypeMacro(CStyleCommand, Command);

  itkNewMacro(Self);

  void SetClientData(void *cd);

  void SetCallback(FunctionPointer f);
  void SetConstCallback(ConstFunctionPointer f);

  void SetClientDataDeleteCallback(DeleteDataFunctionPointer f);

  void Execute(Object *caller, const EventObject & event) override;

  void Execute(const Object *caller, const EventObject & event) override;

protected:
  CStyleCommand();
  ~CStyleCommand() override;

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

#endif