itkCommand.h

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/*=========================================================================
 *
 *  Copyright NumFOCUS
 *
 *  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
 *
 *         https://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"
#include <functional>
 
namespace itk
{
 
// The superclass that all commands should be subclasses of
class ITKCommon_EXPORT Command : public Object
{
public:
  ITK_DISALLOW_COPY_AND_MOVE(Command);

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

  itkOverrideGetNameOfClassMacro(Command);

  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_MOVE(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);

  itkOverrideGetNameOfClassMacro(MemberCommand);

  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{ nullptr };
  TMemberFunctionPointer      m_MemberFunction{ nullptr };
  TConstMemberFunctionPointer m_ConstMemberFunction{ nullptr };
 
  MemberCommand() = default;
 
  ~MemberCommand() override = default;
};

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

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

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

  itkNewMacro(Self);

  itkOverrideGetNameOfClassMacro(ReceptorMemberCommand);

  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{ nullptr };
  TMemberFunctionPointer m_MemberFunction{ nullptr };
 
  ReceptorMemberCommand() = default;
 
  ~ReceptorMemberCommand() override = default;
};

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

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

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

  itkOverrideGetNameOfClassMacro(SimpleMemberCommand);

  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{ nullptr };
  TMemberFunctionPointer m_MemberFunction{ nullptr };
 
  SimpleMemberCommand() = default;
 
  ~SimpleMemberCommand() override = default;
};

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

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

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

  itkOverrideGetNameOfClassMacro(SimpleConstMemberCommand);

  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{ nullptr };
  TMemberFunctionPointer m_MemberFunction{ nullptr };
 
  SimpleConstMemberCommand() = default;
 
  ~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>;

  itkOverrideGetNameOfClassMacro(CStyleCommand);

  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 };
};
 

 
class ITKCommon_EXPORT FunctionCommand : public Command
{
public:
  using Self = FunctionCommand;
  using Pointer = SmartPointer<Self>;
 
  using FunctionObjectType = std::function<void(const EventObject &)>;

  itkOverrideGetNameOfClassMacro(FunctionCommand);

  itkNewMacro(Self);

  void
  SetCallback(FunctionObjectType f);

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

  void
  Execute(const Object *, const EventObject & event) override;
 
protected:
  FunctionCommand();
  ~FunctionCommand() override;
 
 
  FunctionObjectType m_FunctionObject{};
};
 
} // end namespace itk
 
#endif