/* GObject - GLib Type, Object, Parameter and Signal Library

 * Copyright (C) 1998-1999, 2000-2001 Tim Janik and Red Hat, Inc.

 *

 * This library is free software; you can redistribute it and/or

 * modify it under the terms of the GNU Lesser General Public

 * License as published by the Free Software Foundation; either

 * version 2 of the License, or (at your option) any later version.

 *

 * This library is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

 * Lesser General Public License for more details.

 *

 * You should have received a copy of the GNU Lesser General

 * Public License along with this library; if not, write to the

 * Free Software Foundation, Inc., 59 Temple Place, Suite 330,

 * Boston, MA 02111-1307, USA.

 *

 * gvaluecollector.h: GValue varargs stubs

 */

/**

 * SECTION:value_collection

 * @Short_description: Converting varargs to generic values

 * @See_also:#GValueTable

 * @Title: Varargs Value Collection

 * 

 * The macros in this section provide the varargs parsing support needed

 * in variadic GObject functions such as g_object_new() or g_object_set().

 * They currently support the collection of integral types, floating point 

 * types and pointers.

 */

#ifndef __G_VALUE_COLLECTOR_H__

#define __G_VALUE_COLLECTOR_H__

#include <glib-object.h>

G_BEGIN_DECLS

/* we may want to add aggregate types here some day, if requested

 * by users. the basic C types are covered already, everything

 * smaller than an int is promoted to an integer and floats are

 * always promoted to doubles for varargs call constructions.

 */

enum	/*< skip >*/

{

  G_VALUE_COLLECT_INT		= 'i',

  G_VALUE_COLLECT_LONG		= 'l',

  G_VALUE_COLLECT_INT64         = 'q',

  G_VALUE_COLLECT_DOUBLE	= 'd',

  G_VALUE_COLLECT_POINTER	= 'p'

};

/* vararg union holding actuall values collected

 */

/**

 * GTypeCValue:

 * 

 * A union holding one collected value.

 */

union _GTypeCValue

{

  gint     v_int;

  glong    v_long;

  gint64   v_int64;

  gdouble  v_double;

  gpointer v_pointer;

};

/**

 * G_VALUE_COLLECT:

 * @value: a #GValue return location. @value is supposed to be initialized 

 *  according to the value type to be collected

 * @var_args: the va_list variable; it may be evaluated multiple times

 * @flags: flags which are passed on to the collect_value() function of

 *  the #GTypeValueTable of @value.

 * @__error: a #gchar** variable that will be modified to hold a g_new()

 *  allocated error messages if something fails

 * 

 * Collects a variable argument value from a va_list. We have to

 * implement the varargs collection as a macro, because on some systems

 * va_list variables cannot be passed by reference.

 */

#define G_VALUE_COLLECT(value, var_args, flags, __error)				\

G_STMT_START {										\

  GValue *_value = (value);								\

  guint _flags = (flags);								\

  GType _value_type = G_VALUE_TYPE (_value);						\

  GTypeValueTable *_vtable = g_type_value_table_peek (_value_type);			\

  gchar *_collect_format = _vtable->collect_format;					\

  GTypeCValue _cvalues[G_VALUE_COLLECT_FORMAT_MAX_LENGTH] = { { 0, }, };		\

  guint _n_values = 0;									\

                                                                                        \

  if (_vtable->value_free)								\

    _vtable->value_free (_value);							\

  _value->g_type = _value_type;		/* value_meminit() from gvalue.c */		\

  memset (_value->data, 0, sizeof (_value->data));					\

  while (*_collect_format)								\

    {											\

      GTypeCValue *_cvalue = _cvalues + _n_values++;					\

                                                                                        \

      switch (*_collect_format++)							\

	{										\

	case G_VALUE_COLLECT_INT:							\

	  _cvalue->v_int = va_arg ((var_args), gint);					\

	  break;									\

	case G_VALUE_COLLECT_LONG:							\

	  _cvalue->v_long = va_arg ((var_args), glong);					\

	  break;									\

	case G_VALUE_COLLECT_INT64:							\

	  _cvalue->v_int64 = va_arg ((var_args), gint64);				\

	  break;									\

	case G_VALUE_COLLECT_DOUBLE:							\

	  _cvalue->v_double = va_arg ((var_args), gdouble);				\

	  break;									\

	case G_VALUE_COLLECT_POINTER:							\

	  _cvalue->v_pointer = va_arg ((var_args), gpointer);				\

	  break;									\

	default:									\

	  g_assert_not_reached ();							\

	}										\

    }											\

  *(__error) = _vtable->collect_value (_value,						\

				       _n_values,					\

				       _cvalues,					\

				       _flags);						\

} G_STMT_END

/**

 * G_VALUE_LCOPY:

 * @value: a #GValue return location. @value is supposed to be initialized 

 *  according to the value type to be collected

 * @var_args: the va_list variable; it may be evaluated multiple times

 * @flags: flags which are passed on to the lcopy_value() function of

 *  the #GTypeValueTable of @value.

 * @__error: a #gchar** variable that will be modified to hold a g_new()

 *  allocated error messages if something fails

 * 

 * Collects a value's variable argument locations from a va_list. Usage is

 * analogous to G_VALUE_COLLECT().

 */

#define G_VALUE_LCOPY(value, var_args, flags, __error)					\

G_STMT_START {										\

  const GValue *_value = (value);							\

  guint _flags = (flags);								\

  GType _value_type = G_VALUE_TYPE (_value);						\

  GTypeValueTable *_vtable = g_type_value_table_peek (_value_type);			\

  gchar *_lcopy_format = _vtable->lcopy_format;						\

  GTypeCValue _cvalues[G_VALUE_COLLECT_FORMAT_MAX_LENGTH] = { { 0, }, };		\

  guint _n_values = 0;									\

                                                                                        \

  while (*_lcopy_format)								\

    {											\

      GTypeCValue *_cvalue = _cvalues + _n_values++;					\

                                                                                        \

      switch (*_lcopy_format++)								\

	{										\

	case G_VALUE_COLLECT_INT:							\

	  _cvalue->v_int = va_arg ((var_args), gint);					\

	  break;									\

	case G_VALUE_COLLECT_LONG:							\

	  _cvalue->v_long = va_arg ((var_args), glong);					\

	  break;									\

	case G_VALUE_COLLECT_INT64:							\

	  _cvalue->v_int64 = va_arg ((var_args), gint64);				\

	  break;									\

	case G_VALUE_COLLECT_DOUBLE:							\

	  _cvalue->v_double = va_arg ((var_args), gdouble);				\

	  break;									\

	case G_VALUE_COLLECT_POINTER:							\

	  _cvalue->v_pointer = va_arg ((var_args), gpointer);				\

	  break;									\

	default:									\

	  g_assert_not_reached ();							\

	}										\

    }											\

  *(__error) = _vtable->lcopy_value (_value,						\

				     _n_values,						\

				     _cvalues,						\

				     _flags);						\

} G_STMT_END

/**

 * G_VALUE_COLLECT_FORMAT_MAX_LENGTH:

 * 

 * The maximal number of #GTypeCValue<!-- -->s which can be collected for a 

 * single #GValue.

 */

#define	G_VALUE_COLLECT_FORMAT_MAX_LENGTH	(8)

G_END_DECLS

#endif /* __G_VALUE_COLLECTOR_H__ */