class.h 3.84 KB
#ifndef __CLASS_H__
#define __CLASS_H__

#include <stdarg.h>
#include <sys/types.h>
#include <string.h>
#include <assert.h>

#include "interface.h"

#ifndef _ISOC99_SOURCE
#define _ISOC99_SOURCE
#endif

#define CLASS_MAGIC    0xFEFE

#define CLASS(name)                    \
	struct c_##name;                   \
	typedef struct c_##name * name;    \
	extern struct class * const _##name; \
	struct c_##name

#define EXTENDS(parent) \
	const char _[sizeof(struct c_##parent)]

#define _NULL	NULL
#define CREATE_CLASS(name,_parent,...) \
	static struct class c_##name;      \
	static void _classInit_(void) {    \
		c_##name.parent = _##_parent;  \
		c_##name.init   = NULL;        \
	}                                  \
	static struct class c_##name = {   \
		CLASS_MAGIC,                   \
		NULL,                          \
		sizeof(struct c_##name),       \
		_classInit_,                   \
		INIT_IMPL(__VA_ARGS__)         \
	}; struct class * const _##name = &c_##name

/**
 * @TODO: actually i use gcc feature ## for variadoc... think about
 * a way to make this standard.
 */
#define _CALL(object,_iface,method,...)                                           \
	do {                                                                          \
		class_ptr class = class_getClass((object));                               \
		if (class->init) class->init();                                           \
		iface = (struct i_##_iface *)class_getInterface(&class, &i_##_iface);     \
		while ((NULL == iface || NULL == iface->method) && HAS_PARENT(class)) {   \
			class = class->parent;                                                \
			if (class->init) class->init();                                       \
			iface = (struct i_##_iface *)class_getInterface(&class, &i_##_iface); \
		};                                                                        \
		assert(NULL != iface->method);                                            \
	} while(0)

#define CALL(object,_iface,method,...)                \
	do {                                              \
		struct i_##_iface * iface;                    \
		_CALL(object, _iface, method, ##__VA_ARGS__); \
		iface->method(object, ##__VA_ARGS__);         \
	} while(0)

#define RETCALL(object,_iface,method,ret,...)         \
	do {                                              \
		struct i_##_iface * iface;                    \
		_CALL(object, _iface, method, ##__VA_ARGS__); \
		ret = iface->method(object, ##__VA_ARGS__);   \
	} while(0)

#define PARENTCALL(object,_iface,method,...)                                  \
	do {                                                                      \
		struct i_##_iface * iface;                                            \
		class_ptr class = class_getClass((object));                           \
		if (class->init) class->init();                                       \
		assert(HAS_PARENT(class));                                            \
		class = class->parent;                                                \
		if (class->init) class->init();                                       \
		iface = (struct i_##_iface *)class_getInterface(&class, &i_##_iface); \
		assert(NULL != iface->method);                                        \
		iface->method(object, ##__VA_ARGS__);                                 \
	} while(0)


#define IFACE_GET(class,iface)		(interfaceGet(&((class)->impl),(iface)))
#define IFACE_EXISTS(class,iface)	(NULL != IFACE_GET((class),(iface)))

#define HAS_PARENT(class)			(NULL != ((class)->parent))

typedef void (* fptr_classInit)(void);

struct class;
typedef struct class * class_ptr;
struct class {
	const int         magic;
	class_ptr         parent;
	size_t            object_size;
	fptr_classInit    init;
	struct iface_impl impl;
};

extern void *    class_getInterface(class_ptr *, iface_ptr);
extern class_ptr class_getClass(void *);

#endif // __CLASS_H__

// vim: set ts=4 sw=4: