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pyobjc / pyobjc-core / Modules / objc / objc-class.h

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#ifndef  PyObjC_OBJC_CLASS_H 
#define  PyObjC_OBJC_CLASS_H 
/*!
 * @header objc-class.m 
 * @abstract Definition of the wrapper for Objective-C classes
 * @discussion
 *	This module implements the wrappers for Objective-C classes, included
 *	subclasses defined in Python.
 *
 *	The class-wrapper maintains a full __dict__ to make it easier to 
 *	support introspection, and to make it easier to detect if someone 
 *	does a super() call of a method.
 *
 *	Maintaining a full dict is problematic because the Objective-C runtime 
 *	is fairly dynamic and does not have hooks to detect these changes. Our 
 *	only way to detect changes is to periodicly check the runtime if 
 *	something has changed. See the definition for PyObjCClassObject for 
 *	an explanation.
 */

/*!
 * @const PyObjCClass_Type
 * @abstract The type objc.objc_class
 */
extern PyTypeObject PyObjCClass_Type;

/*!
 * @function PyObjCClass_Check
 * @abstract Check if an object is an Objective-C class
 * @param obj An object
 * @result Returns True if the object is an Objective-C class, false otherwise
 */
#define PyObjCClass_Check(obj) PyObject_TypeCheck(obj, &PyObjCClass_Type)

// The @const is not correct, but what else can we use here?
/*!
 * @const PyObjC_ClassExtender
 * @discussion
 *     PyObjC_ClassExtender is either NULL or a Python function that can
 *     update a class dictionary.
 *
 *     The interface for the extender function is:
 *          extender(super_class, class_name, class_dict)
 *
 *     The return value of the function is ignored, it should update the
 *     class_dict (which represents the __dict__ of an Objective-C class.
 */
extern PyObject* PyObjC_ClassExtender;


/*!
 * @struct PyObjCClassObject
 * @abstract The type struct for Objective-C classes (Python 2.3 and later)
 * @field base      Type actual type object
 * @field sel_to_py Mapping to speed up finding the correct Python method
 *                  for a selector.
 * @field method_magic  The most recent PyObjC_methodlist_magic() for the class
 * @field dictoffset  Offset in the Objective-C instance for the instance 
 *                    __dict__
 * @field delmethod  The method that implements __del__
 * @field hasPythonImpl True if the class is implemented in Python
 * @field generation   The value of PyObjC_MappingCount at the last time
 *                     the method-list was updated.
 * @field useKVO    should the class implement automatic KVO notifications?
 * @field protectedMethods methods whose name starts with an underscore
 *
 * @discussion
 *      This struct is the type-object for on Objective-C class. It stores
 *      some additional information that is used to manage the interface
 *      with the Objective-C runtime.
 *
 *      (method_magic, generation) is used to detect if the method wrappers
 *      should be regenerated: if method_magic is no longer equal to 
 *      PyObjC_methodlist_magic() the Objective-C class changed, if generation
 *      is no longer equal to PyObjC_MappingCount there are new method-mappings
 *      and we should rescan just in case one of those mappings is needed for
 *      this class.
 *
 *	dictoffset is used by objc-object.m to find the __dict__ for instances.
 *	If the offset is 0 there is no __dict__.
 *
 *	We store the __del__ implementation here instead of in the type itself
 *	to ensure that our teardown code is correctly called.
 */
typedef struct _PyObjCClassObject {
	PyHeapTypeObject base;
	__strong Class class;
	PyObject* sel_to_py;
	int method_magic;
	Py_ssize_t dictoffset;
	PyObject* delmethod;
	int hasPythonImpl;
	int isCFWrapper;
	int generation;
	int useKVO;
	PyObject* protectedMethods;
	PyObject* hiddenSelectors;
	PyObject* hiddenClassSelectors;
	struct _PyObjCClassObject* meta_class; /* To be dropped */
} PyObjCClassObject;

extern PyObject* PyObjCClass_DefaultModule;
PyObject* PyObjCClass_New(Class objc_class);
Class PyObjCClass_GetClass(PyObject* object);
PyObject* PyObjCClass_FindSelector(PyObject* cls, SEL selector, BOOL class_method);
void PyObjCClass_MaybeRescan(PyObject* class);
int ObjC_RegisterClassProxy(Class cls, PyObject* classProxy);
void PyObjCClass_CheckMethodList(PyObject* cls, int recursive);
Py_ssize_t PyObjCClass_DictOffset(PyObject* cls);
PyObject* PyObjCClass_GetDelMethod(PyObject* cls);
void PyObjCClass_SetDelMethod(PyObject* cls, PyObject* newval);
int  PyObjCClass_HasPythonImplementation(PyObject* cls);
PyObject* PyObjCClass_ClassForMetaClass(PyObject* meta);
PyObject* PyObjCClass_HiddenSelector(PyObject* tp, SEL sel, BOOL classMethod); /* returns borrowed */
int PyObjCClass_SetHidden(PyObject* tp, SEL sel, BOOL classMethod, PyObject* metadata);
int PyObjCClass_AddMethods(PyObject* cls, PyObject** methods, Py_ssize_t count);

PyObject* PyObjCClass_ListProperties(PyObject* cls);


#endif /* PyObjC_OBJC_CLASS_H */