glib/gienuminfo.c

/* GObject introspection: Enum implementation
 *
 * Copyright (C) 2005 Matthias Clasen
 * Copyright (C) 2008,2009 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.
 */

#include <glib.h>

#include <girepository.h>
#include "girepository-private.h"
#include "gitypelib-internal.h"

/**
 * SECTION:gienuminfo
 * @Short_description: Structs representing an enumeration and its values
 * @Title: GIEnumInfo
 *
 * A GIEnumInfo represents an enumeration and a GIValueInfo struct represents a value
 * of an enumeration. The GIEnumInfo contains a set of values and a type
 * The GIValueInfo is fetched by calling g_enum_info_get_value() on a #GIEnumInfo.
 *
 * <refsect1 id="gi-gienuminfo.struct-hierarchy" role="struct_hierarchy">
 * <title role="struct_hierarchy.title">Struct hierarchy</title>
 * <synopsis>
 *   <link linkend="gi-GIBaseInfo">GIBaseInfo</link>
 *    +----<link linkend="gi-GIRegisteredTypeInfo">GIRegisteredTypeInfo</link>
 *          +----GIEnumInfo
 * </synopsis>
 * </refsect1>
 */

/**
* g_enum_info_get_n_values:
* @info: a #GIEnumInfo
*
* Obtain the number of values this enumeration contains.
*
* Returns: the number of enumeration values
*/
gint
g_enum_info_get_n_values (GIEnumInfo *info)
{
  GIRealInfo *rinfo = (GIRealInfo *)info;
  EnumBlob *blob;

  g_return_val_if_fail (info != NULL, 0);
  g_return_val_if_fail (GI_IS_ENUM_INFO (info), 0);

  blob = (EnumBlob *)&rinfo->typelib->data[rinfo->offset];

  return blob->n_values;
}

/**
 * g_enum_info_get_value:
 * @info: a #GIEnumInfo
 * @n: index of value to fetch
 *
 * Obtain a value for this enumeration.
 *
 * Returns: (transfer full): the enumeration value or %NULL if type tag is wrong,
 * free the struct with g_base_info_unref() when done.
 */
GIValueInfo *
g_enum_info_get_value (GIEnumInfo *info,
		       gint        n)
{
  GIRealInfo *rinfo = (GIRealInfo *)info;
  Header *header;
  gint offset;

  g_return_val_if_fail (info != NULL, NULL);
  g_return_val_if_fail (GI_IS_ENUM_INFO (info), NULL);

  header = (Header *)rinfo->typelib->data;
  offset = rinfo->offset + header->enum_blob_size
    + n * header->value_blob_size;

  return (GIValueInfo *) g_info_new (GI_INFO_TYPE_VALUE, (GIBaseInfo*)info, rinfo->typelib, offset);
}

/**
 * g_enum_info_get_storage_type:
 * @info: a #GIEnumInfo
 *
 * Obtain the tag of the type used for the enum in the C ABI. This will
 * will be a signed or unsigned integral type.

 * Note that in the current implementation the width of the type is
 * computed correctly, but the signed or unsigned nature of the type
 * may not match the sign of the type used by the C compiler.
 *
 * Return Value: the storage type for the enumeration
 */
GITypeTag
g_enum_info_get_storage_type (GIEnumInfo *info)
{
  GIRealInfo *rinfo = (GIRealInfo *)info;
  EnumBlob *blob;

  g_return_val_if_fail (info != NULL, GI_TYPE_TAG_BOOLEAN);
  g_return_val_if_fail (GI_IS_ENUM_INFO (info), GI_TYPE_TAG_BOOLEAN);

  blob = (EnumBlob *)&rinfo->typelib->data[rinfo->offset];

  return blob->storage_type;
}

/**
 * g_value_info_get_value:
 * @info: a #GIValueInfo
 *
 * Obtain the enumeration value of the #GIValueInfo.
 *
 * Returns: the enumeration value. This will always be representable
 *   as a 32-bit signed or unsigned value. The use of gint64 as the
 *   return type is to allow both.
 */
gint64
g_value_info_get_value (GIValueInfo *info)
{
  GIRealInfo *rinfo = (GIRealInfo *)info;
  ValueBlob *blob;

  g_return_val_if_fail (info != NULL, -1);
  g_return_val_if_fail (GI_IS_VALUE_INFO (info), -1);

  blob = (ValueBlob *)&rinfo->typelib->data[rinfo->offset];

  if (blob->unsigned_value)
    return (gint64)(guint32)blob->value;
  else
    return (gint64)blob->value;
}