glib/gistructinfo.c

/* GObject introspection: Struct 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:gistructinfo
 * @Short_description: Struct representing a C structure
 * @Title: GIStructInfo
 *
 * GIStructInfo represents a generic C structure type.
 *
 * A structure has methods and fields.
 *
 * <refsect1 id="gi-giobjectinfo.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>
 *          +----GIStructInfo
 * </synopsis>
 * </refsect1>
 */

/**
 * g_struct_info_get_n_fields:
 * @info: a #GIStructInfo
 *
 * Obtain the number of fields this structure has.
 *
 * Returns: number of fields
 */
gint
g_struct_info_get_n_fields (GIStructInfo *info)
{
  GIRealInfo *rinfo = (GIRealInfo *)info;
  StructBlob *blob = (StructBlob *)&rinfo->typelib->data[rinfo->offset];

  return blob->n_fields;
}

/**
 * g_struct_info_get_field_offset:
 * @info: a #GIStructInfo
 * @n: index of queried field
 *
 * Obtain the offset of the specified field.
 *
 * Returns: field offset in bytes
 */
static gint32
g_struct_get_field_offset (GIStructInfo *info,
			   gint         n)
{
  GIRealInfo *rinfo = (GIRealInfo *)info;
  Header *header = (Header *)rinfo->typelib->data;
  guint32 offset = rinfo->offset + header->struct_blob_size;
  gint i;
  FieldBlob *field_blob;

  for (i = 0; i < n; i++)
    {
      field_blob = (FieldBlob *)&rinfo->typelib->data[offset];
      offset += header->field_blob_size;
      if (field_blob->has_embedded_type)
        offset += header->callback_blob_size;
    }

  return offset;
}

/**
 * g_struct_info_get_field:
 * @info: a #GIStructInfo
 * @n: a field index
 *
 * Obtain the type information for field with specified index.
 *
 * Returns: (transfer full): the #GIFieldInfo, free it with g_base_info_unref()
 * when done.
 */
GIFieldInfo *
g_struct_info_get_field (GIStructInfo *info,
                         gint          n)
{
  GIRealInfo *rinfo = (GIRealInfo *)info;

  return (GIFieldInfo *) g_info_new (GI_INFO_TYPE_FIELD, (GIBaseInfo*)info, rinfo->typelib,
                                     g_struct_get_field_offset (info, n));
}

/**
 * g_struct_info_get_n_methods:
 * @info: a #GIStructInfo
 *
 * Obtain the number of methods this structure has.
 *
 * Returns: number of methods
 */
gint
g_struct_info_get_n_methods (GIStructInfo *info)
{
  GIRealInfo *rinfo = (GIRealInfo *)info;
  StructBlob *blob = (StructBlob *)&rinfo->typelib->data[rinfo->offset];

  return blob->n_methods;
}

/**
 * g_struct_info_get_method:
 * @info: a #GIStructInfo
 * @n: a method index
 *
 * Obtain the type information for method with specified index.
 *
 * Returns: (transfer full): the #GIFunctionInfo, free it with g_base_info_unref()
 * when done.
 */
GIFunctionInfo *
g_struct_info_get_method (GIStructInfo *info,
			  gint         n)
{
  GIRealInfo *rinfo = (GIRealInfo *)info;
  StructBlob *blob = (StructBlob *)&rinfo->typelib->data[rinfo->offset];
  Header *header = (Header *)rinfo->typelib->data;
  gint offset;

  offset = g_struct_get_field_offset (info, blob->n_fields) + n * header->function_blob_size;
  return (GIFunctionInfo *) g_info_new (GI_INFO_TYPE_FUNCTION, (GIBaseInfo*)info,
                                        rinfo->typelib, offset);
}

/**
 * g_struct_info_find_method:
 * @info: a #GIStructInfo
 * @name: a method name
 *
 * Obtain the type information for method named @name.
 *
 * Returns: (transfer full): the #GIFunctionInfo, free it with g_base_info_unref()
 * when done.
 */
GIFunctionInfo *
g_struct_info_find_method (GIStructInfo *info,
			   const gchar  *name)
{
  gint offset;
  GIRealInfo *rinfo = (GIRealInfo *)info;
  Header *header = (Header *)rinfo->typelib->data;
  StructBlob *blob = (StructBlob *)&rinfo->typelib->data[rinfo->offset];

  offset = rinfo->offset + header->struct_blob_size
    + blob->n_fields * header->field_blob_size;

  return _g_base_info_find_method ((GIBaseInfo*)info, offset, blob->n_methods, name);
}

/**
 * g_struct_info_get_size:
 * @info: a #GIStructInfo
 *
 * Obtain the total size of the structure.
 *
 * Returns: size of the structure in bytes
 */
gsize
g_struct_info_get_size (GIStructInfo *info)
{
  GIRealInfo *rinfo = (GIRealInfo *)info;
  StructBlob *blob = (StructBlob *)&rinfo->typelib->data[rinfo->offset];

  return blob->size;
}

/**
 * g_struct_info_get_alignment:
 * @info: a #GIStructInfo
 *
 * Obtain the required alignment of the structure.
 *
 * Returns: required alignment in bytes
 */
gsize
g_struct_info_get_alignment (GIStructInfo *info)
{
  GIRealInfo *rinfo = (GIRealInfo *)info;
  StructBlob *blob = (StructBlob *)&rinfo->typelib->data[rinfo->offset];

  return blob->alignment;
}

gboolean
g_struct_info_is_foreign (GIStructInfo *info)
{
  GIRealInfo *rinfo = (GIRealInfo *)info;
  StructBlob *blob = (StructBlob *)&rinfo->typelib->data[rinfo->offset];

  return blob->foreign;
}

/**
 * g_struct_info_is_gtype_struct:
 * @info: a #GIStructInfo
 *
 * Return true if this structure represents the "class structure" for some
 * #GObject or #GInterface.  This function is mainly useful to hide this kind of structure
 * from generated public APIs.
 *
 * Returns: %TRUE if this is a class struct, %FALSE otherwise
 */
gboolean
g_struct_info_is_gtype_struct (GIStructInfo *info)
{
  GIRealInfo *rinfo = (GIRealInfo *)info;
  StructBlob *blob = (StructBlob *)&rinfo->typelib->data[rinfo->offset];

  return blob->is_gtype_struct;
}