vtkObjectFactory.h

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// SPDX-FileCopyrightText: Copyright (c) Ken Martin, Will Schroeder, Bill Lorensen
// SPDX-License-Identifier: BSD-3-Clause
 
#ifndef vtkObjectFactory_h
#define vtkObjectFactory_h
 
#include "vtkCommonCoreModule.h"  // For export macro
#include "vtkDebugLeaksManager.h" // Must be included before singletons
#include "vtkFeatures.h"          // For VTK_ALL_NEW_OBJECT_FACTORY
#include "vtkObject.h"
 
#include <string> // for std::string
 
VTK_ABI_NAMESPACE_BEGIN
class vtkObjectFactoryCollection;
class vtkOverrideInformationCollection;
class vtkCollection;
 
class VTKCOMMONCORE_EXPORT vtkObjectFactory : public vtkObject
{
public:
  // Class Methods used to interface with the registered factories

  VTK_NEWINSTANCE
  static vtkObject* CreateInstance(const char* vtkclassname, bool isAbstract = false);

  static void CreateAllInstance(const char* vtkclassname, vtkCollection* retList);
  static void ReHash();
  static void RegisterFactory(vtkObjectFactory*);
  static void UnRegisterFactory(vtkObjectFactory*);
  static void UnRegisterAllFactories();

  static vtkObjectFactoryCollection* GetRegisteredFactories();

  static vtkTypeBool HasOverrideAny(const char* className);

  static void GetOverrideInformation(const char* name, vtkOverrideInformationCollection*);

  static void SetAllEnableFlags(vtkTypeBool flag, const char* className);
  static void SetAllEnableFlags(vtkTypeBool flag, const char* className, const char* subclassName);
 
  // Instance methods to be used on individual instances of vtkObjectFactory
 
  // Methods from vtkObject
  vtkTypeMacro(vtkObjectFactory, vtkObject);
  void PrintSelf(ostream& os, vtkIndent indent) override;

  virtual const char* GetVTKSourceVersion() VTK_FUTURE_CONST = 0;

  virtual const char* GetDescription() VTK_FUTURE_CONST = 0;

  virtual int GetNumberOfOverrides() VTK_FUTURE_CONST;

  virtual const char* GetClassOverrideName(int index) VTK_FUTURE_CONST;

  virtual const char* GetClassOverrideWithName(int index) VTK_FUTURE_CONST;

  virtual vtkTypeBool GetEnableFlag(int index) VTK_FUTURE_CONST;

  virtual const char* GetOverrideDescription(int index) VTK_FUTURE_CONST;


  virtual void SetEnableFlag(vtkTypeBool flag, const char* className, const char* subclassName);
  virtual vtkTypeBool GetEnableFlag(
    const char* className, const char* subclassName) VTK_FUTURE_CONST;

  virtual vtkTypeBool HasOverride(const char* className) VTK_FUTURE_CONST;
  virtual vtkTypeBool HasOverride(const char* className, const char* subclassName) VTK_FUTURE_CONST;

  virtual void Disable(const char* className);


  vtkGetFilePathMacro(LibraryPath);
 
  typedef vtkObject* (*CreateFunction)();
 
protected:
  void RegisterOverride(const char* classOverride, const char* overrideClassName,
    const char* description, int enableFlag, CreateFunction createFunction);

  virtual vtkObject* CreateObject(const char* vtkclassname);
 
  vtkObjectFactory();
  ~vtkObjectFactory() override;
 
  struct OverrideInformation
  {
    char* Description;
    char* OverrideWithName;
    vtkTypeBool EnabledFlag;
    CreateFunction CreateCallback;
  };
 
  OverrideInformation* OverrideArray;
  char** OverrideClassNames;
  int SizeOverrideArray;
  int OverrideArrayLength;
 
private:
  void GrowOverrideArray();

  static void Init();
  static void RegisterDefaults();
  static void LoadDynamicFactories();
  static void LoadLibrariesInPath(const std::string&);
 
  // list of registered factories
  static vtkObjectFactoryCollection* RegisteredFactories;
 
  // member variables for a factory set by the base class
  // at load or register time
  void* LibraryHandle;
  char* LibraryVTKVersion;
  char* LibraryPath;
 
  vtkObjectFactory(const vtkObjectFactory&) = delete;
  void operator=(const vtkObjectFactory&) = delete;
};
 
// Implementation detail for Schwarz counter idiom.
class VTKCOMMONCORE_EXPORT vtkObjectFactoryRegistryCleanup
{
public:
  vtkObjectFactoryRegistryCleanup();
  ~vtkObjectFactoryRegistryCleanup();
 
private:
  vtkObjectFactoryRegistryCleanup(const vtkObjectFactoryRegistryCleanup& other) = delete;
  vtkObjectFactoryRegistryCleanup& operator=(const vtkObjectFactoryRegistryCleanup& rhs) = delete;
};
static vtkObjectFactoryRegistryCleanup vtkObjectFactoryRegistryCleanupInstance;
 
// Macro to create an object creation function.
// The name of the function will by vtkObjectFactoryCreateclassname
// where classname is the name of the class being created
#define VTK_CREATE_CREATE_FUNCTION(classname)                                                      \
  static vtkObject* vtkObjectFactoryCreate##classname()                                            \
  {                                                                                                \
    return classname::New();                                                                       \
  }
 
VTK_ABI_NAMESPACE_END
#endif
 
#define VTK_FACTORY_INTERFACE_EXPORT VTKCOMMONCORE_EXPORT
 
// Macro to create the interface "C" functions used in
// a dll or shared library that contains a VTK object factory.
// Put this function in the .cxx file of your object factory,
// and pass in the name of the factory sub-class that you want
// the dll to create.
#define VTK_FACTORY_INTERFACE_IMPLEMENT(factoryName)                                               \
  extern "C" VTK_FACTORY_INTERFACE_EXPORT const char* vtkGetFactoryVersion()                       \
  {                                                                                                \
    return VTK_SOURCE_VERSION;                                                                     \
  }                                                                                                \
  extern "C" VTK_FACTORY_INTERFACE_EXPORT vtkObjectFactory* vtkLoad()                              \
  {                                                                                                \
    return factoryName ::New();                                                                    \
  }
 
// Macro to implement the body of the object factory form of the New() method.
#define VTK_OBJECT_FACTORY_NEW_BODY(thisClass)                                                     \
  vtkObject* ret = vtkObjectFactory::CreateInstance(#thisClass, false);                            \
  if (ret)                                                                                         \
  {                                                                                                \
    return static_cast<thisClass*>(ret);                                                           \
  }                                                                                                \
  auto result = new thisClass;                                                                     \
  result->InitializeObjectBase();                                                                  \
  return result
 
// Macro to implement the body of the abstract object factory form of the New()
// method, i.e. an abstract base class that can only be instantiated if the
// object factory overrides it.
#define VTK_ABSTRACT_OBJECT_FACTORY_NEW_BODY(thisClass)                                            \
  vtkObject* ret = vtkObjectFactory::CreateInstance(#thisClass, true);                             \
  if (ret)                                                                                         \
  {                                                                                                \
    return static_cast<thisClass*>(ret);                                                           \
  }                                                                                                \
  vtkGenericWarningMacro("Error: no override found for '" #thisClass "'.");                        \
  return nullptr
 
// Macro to implement the body of the standard form of the New() method.
#if defined(VTK_ALL_NEW_OBJECT_FACTORY)
#define VTK_STANDARD_NEW_BODY(thisClass) VTK_OBJECT_FACTORY_NEW_BODY(thisClass)
#else
#define VTK_STANDARD_NEW_BODY(thisClass)                                                           \
  auto result = new thisClass;                                                                     \
  result->InitializeObjectBase();                                                                  \
  return result
#endif
 
// Macro to implement the standard form of the New() method.
#define vtkStandardNewMacro(thisClass)                                                             \
  thisClass* thisClass::New()                                                                      \
  {                                                                                                \
    VTK_STANDARD_NEW_BODY(thisClass);                                                              \
  }
 
// Macro to implement the ExtendedNew() to create an object in a memkind extended memory space. If
// VTK is not compiled with VTK_USE_MEMKIND this is equivalent to New()
#define vtkStandardExtendedNewMacro(thisClass)                                                     \
  thisClass* thisClass::ExtendedNew()                                                              \
  {                                                                                                \
    auto mkhold = vtkMemkindRAII(true);                                                            \
    (void)mkhold;                                                                                  \
    return thisClass::New();                                                                       \
  }
 
// Macro to implement the object factory form of the New() method.
#define vtkObjectFactoryNewMacro(thisClass)                                                        \
  thisClass* thisClass::New()                                                                      \
  {                                                                                                \
    VTK_OBJECT_FACTORY_NEW_BODY(thisClass);                                                        \
  }
 
// Macro to implement the abstract object factory form of the New() method.
// That is an abstract base class that can only be instantiated if the
// object factory overrides it.
#define vtkAbstractObjectFactoryNewMacro(thisClass)                                                \
  thisClass* thisClass::New()                                                                      \
  {                                                                                                \
    VTK_ABSTRACT_OBJECT_FACTORY_NEW_BODY(thisClass);                                               \
  }