gimp/libgimpconfig/gimpconfig-iface.c

/* The GIMP -- an image manipulation program
 * Copyright (C) 1995 Spencer Kimball and Peter Mattis
 *
 * Config file serialization and deserialization interface
 * Copyright (C) 2001-2002  Sven Neumann <sven@gimp.org>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
 */

#include "config.h"

#include <string.h>

#include <glib-object.h>

#include "libgimpbase/gimpbase.h"

#include "config-types.h"

#include "gimpconfig.h"
#include "gimpconfig-serialize.h"
#include "gimpconfig-deserialize.h"
#include "gimpconfig-utils.h"
#include "gimpconfigwriter.h"
#include "gimpscanner.h"

#include "gimp-intl.h"


/*
 * The GimpConfig serialization and deserialization interface.
 */

static void         gimp_config_iface_init    (GimpConfigInterface  *gimp_config_iface);

static gboolean     gimp_config_iface_serialize   (GimpConfig       *config,
                                                   GimpConfigWriter *writer,
                                                   gpointer          data);
static gboolean     gimp_config_iface_deserialize (GimpConfig       *config,
                                                   GScanner         *scanner,
                                                   gint              nest_level,
                                                   gpointer          data);
static GimpConfig * gimp_config_iface_duplicate   (GimpConfig       *config);
static gboolean     gimp_config_iface_equal       (GimpConfig       *a,
                                                   GimpConfig       *b);
static void         gimp_config_iface_reset       (GimpConfig       *config);


GType
gimp_config_interface_get_type (void)
{
  static GType config_iface_type = 0;

  if (!config_iface_type)
    {
      static const GTypeInfo config_iface_info =
      {
        sizeof (GimpConfigInterface),
	(GBaseInitFunc)     gimp_config_iface_init,
	(GBaseFinalizeFunc) NULL,
      };

      config_iface_type = g_type_register_static (G_TYPE_INTERFACE,
                                                  "GimpConfigInterface",
                                                  &config_iface_info,
                                                  0);

      g_type_interface_add_prerequisite (config_iface_type, G_TYPE_OBJECT);
    }

  return config_iface_type;
}

static void
gimp_config_iface_init (GimpConfigInterface *gimp_config_iface)
{
  gimp_config_iface->serialize            = gimp_config_iface_serialize;
  gimp_config_iface->deserialize          = gimp_config_iface_deserialize;
  gimp_config_iface->serialize_property   = NULL;
  gimp_config_iface->deserialize_property = NULL;
  gimp_config_iface->duplicate            = gimp_config_iface_duplicate;
  gimp_config_iface->equal                = gimp_config_iface_equal;
  gimp_config_iface->reset                = gimp_config_iface_reset;
}

static gboolean
gimp_config_iface_serialize (GimpConfig       *config,
			     GimpConfigWriter *writer,
                             gpointer          data)
{
  return gimp_config_serialize_properties (config, writer);
}

static gboolean
gimp_config_iface_deserialize (GimpConfig *config,
                               GScanner   *scanner,
                               gint        nest_level,
                               gpointer    data)
{
  return gimp_config_deserialize_properties (config,
                                             scanner, nest_level, FALSE);
}

static GimpConfig *
gimp_config_iface_duplicate (GimpConfig *config)
{
  GObjectClass  *klass;
  GParamSpec   **property_specs;
  guint          n_property_specs;
  GParameter    *construct_params   = NULL;
  gint           n_construct_params = 0;
  guint          i;
  GimpConfig    *dup;

  klass = G_OBJECT_GET_CLASS (config);

  property_specs = g_object_class_list_properties (klass, &n_property_specs);

  construct_params = g_new0 (GParameter, n_property_specs);

  for (i = 0; i < n_property_specs; i++)
    {
      GParamSpec *prop_spec = property_specs[i];

      if ((prop_spec->flags & G_PARAM_READABLE) &&
          (prop_spec->flags & G_PARAM_WRITABLE) &&
          (prop_spec->flags & G_PARAM_CONSTRUCT_ONLY))
        {
          GParameter *construct_param;

          construct_param = &construct_params[n_construct_params++];

          construct_params->name = prop_spec->name;

          g_value_init (&construct_params->value, prop_spec->value_type);
          g_object_get_property (G_OBJECT (config), prop_spec->name,
                                 &construct_param->value);
        }
    }

  g_free (property_specs);

  dup = g_object_newv (G_TYPE_FROM_INSTANCE (config),
                       n_construct_params, construct_params);

  for (i = 0; i < n_construct_params; i++)
    g_value_unset (&construct_params[i].value);

  g_free (construct_params);

  gimp_config_copy_properties (config, dup);

  return dup;
}

static gboolean
gimp_config_iface_equal (GimpConfig *a,
                         GimpConfig *b)
{
  GObjectClass  *klass;
  GParamSpec   **property_specs;
  guint          n_property_specs;
  guint          i;
  gboolean       equal = TRUE;

  klass = G_OBJECT_GET_CLASS (a);

  property_specs = g_object_class_list_properties (klass, &n_property_specs);

  for (i = 0; equal && i < n_property_specs; i++)
    {
      GParamSpec  *prop_spec;
      GValue       a_value = { 0, };
      GValue       b_value = { 0, };

      prop_spec = property_specs[i];

      if (! (prop_spec->flags & G_PARAM_READABLE))
        continue;

      g_value_init (&a_value, prop_spec->value_type);
      g_value_init (&b_value, prop_spec->value_type);
      g_object_get_property (G_OBJECT (a), prop_spec->name, &a_value);
      g_object_get_property (G_OBJECT (b), prop_spec->name, &b_value);

      equal = (g_param_values_cmp (prop_spec, &a_value, &b_value) == 0);

      g_value_unset (&a_value);
      g_value_unset (&b_value);
    }

  g_free (property_specs);

  return equal;
}

static void
gimp_config_iface_reset (GimpConfig *config)
{
  gimp_config_reset_properties (config);
}

/**
 * gimp_config_serialize_to_file:
 * @config: a #GObject that implements the #GimpConfigInterface.
 * @filename: the name of the file to write the configuration to.
 * @header: optional file header (must be ASCII only)
 * @footer: optional file footer (must be ASCII only)
 * @data: user data passed to the serialize implementation.
 * @error:
 *
 * Serializes the object properties of @config to the file specified
 * by @filename. If a file with that name already exists, it is
 * overwritten. Basically this function opens @filename for you and
 * calls the serialize function of the @config's #GimpConfigInterface.
 *
 * Return value: %TRUE if serialization succeeded, %FALSE otherwise.
 **/
gboolean
gimp_config_serialize_to_file (GimpConfig   *config,
			       const gchar  *filename,
			       const gchar  *header,
			       const gchar  *footer,
			       gpointer      data,
			       GError      **error)
{
  GimpConfigWriter *writer;

  g_return_val_if_fail (GIMP_IS_CONFIG (config), FALSE);
  g_return_val_if_fail (filename != NULL, FALSE);
  g_return_val_if_fail (error == NULL || *error == NULL, FALSE);

  writer = gimp_config_writer_new_file (filename, TRUE, header, error);
  if (!writer)
    return FALSE;

  GIMP_CONFIG_GET_INTERFACE (config)->serialize (config, writer, data);

  return gimp_config_writer_finish (writer, footer, error);
}

gboolean
gimp_config_serialize_to_fd (GimpConfig *config,
                             gint        fd,
                             gpointer    data)
{
  GimpConfigWriter *writer;

  g_return_val_if_fail (GIMP_IS_CONFIG (config), FALSE);
  g_return_val_if_fail (fd > 0, FALSE);

  writer = gimp_config_writer_new_fd (fd);
  if (!writer)
    return FALSE;

  GIMP_CONFIG_GET_INTERFACE (config)->serialize (config, writer, data);

  return gimp_config_writer_finish (writer, NULL, NULL);
}

/**
 * gimp_config_serialize_to_string:
 * @config: a #GObject that implements the #GimpConfigInterface.
 * @data: user data passed to the serialize implementation.
 *
 * Serializes the object properties of @config to a string.
 *
 * Return value: a newly allocated %NUL-terminated string.
 **/
gchar *
gimp_config_serialize_to_string (GimpConfig *config,
				 gpointer    data)
{
  GimpConfigWriter *writer;
  GString          *str;

  g_return_val_if_fail (GIMP_IS_CONFIG (config), NULL);

  str = g_string_new (NULL);
  writer = gimp_config_writer_new_string (str);

  GIMP_CONFIG_GET_INTERFACE (config)->serialize (config, writer, data);

  gimp_config_writer_finish (writer, NULL, NULL);

  return g_string_free (str, FALSE);
}

/**
 * gimp_config_deserialize:
 * @config: a #GObject that implements the #GimpConfigInterface.
 * @filename: the name of the file to read configuration from.
 * @data: user data passed to the deserialize implementation.
 * @error:
 *
 * Opens the file specified by @filename, reads configuration data
 * from it and configures @config accordingly. Basically this function
 * creates a properly configured #GScanner for you and calls the
 * deserialize function of the @config's #GimpConfigInterface.
 *
 * Return value: %TRUE if deserialization succeeded, %FALSE otherwise.
 **/
gboolean
gimp_config_deserialize_file (GimpConfig   *config,
			      const gchar  *filename,
			      gpointer      data,
			      GError      **error)
{
  GScanner *scanner;
  gboolean  success;

  g_return_val_if_fail (GIMP_IS_CONFIG (config), FALSE);
  g_return_val_if_fail (filename != NULL, FALSE);
  g_return_val_if_fail (error == NULL || *error == NULL, FALSE);

  scanner = gimp_scanner_new_file (filename, error);
  if (! scanner)
    return FALSE;

  success = GIMP_CONFIG_GET_INTERFACE (config)->deserialize (config,
                                                             scanner, 0, data);

  gimp_scanner_destroy (scanner);

  if (! success)
    g_assert (error == NULL || *error != NULL);

  return success;
}

/**
 * gimp_config_deserialize_string:
 * @config: a #GObject that implements the #GimpConfigInterface.
 * @text: string to deserialize (in UTF-8 encoding)
 * @text_len: length of @text in bytes or -1
 * @data:
 * @error:
 *
 * Configures @config from @text. Basically this function creates a
 * properly configured #GScanner for you and calls the deserialize
 * function of the @config's #GimpConfigInterface.
 *
 * Returns: %TRUE if deserialization succeeded, %FALSE otherwise.
 **/
gboolean
gimp_config_deserialize_string (GimpConfig      *config,
                                const gchar  *text,
                                gint          text_len,
				gpointer      data,
                                GError      **error)
{
  GScanner *scanner;
  gboolean  success;

  g_return_val_if_fail (GIMP_IS_CONFIG (config), FALSE);
  g_return_val_if_fail (text != NULL || text_len == 0, FALSE);
  g_return_val_if_fail (error == NULL || *error == NULL, FALSE);

  scanner = gimp_scanner_new_string (text, text_len, error);

  success = GIMP_CONFIG_GET_INTERFACE (config)->deserialize (config,
                                                             scanner, 0, data);

  gimp_scanner_destroy (scanner);

  if (! success)
    g_assert (error == NULL || *error != NULL);

  return success;
}

gboolean
gimp_config_deserialize_return (GScanner     *scanner,
                                GTokenType    expected_token,
                                gint          nest_level)
{
  GTokenType next_token;

  g_return_val_if_fail (scanner != NULL, FALSE);

  next_token = g_scanner_peek_next_token (scanner);

  if (expected_token != G_TOKEN_LEFT_PAREN)
    {
      g_scanner_get_next_token (scanner);
      g_scanner_unexp_token (scanner, expected_token, NULL, NULL, NULL,
                             _("fatal parse error"), TRUE);
      return FALSE;
    }
  else
    {
      if (nest_level > 0 && next_token == G_TOKEN_RIGHT_PAREN)
        {
          return TRUE;
        }
      else if (next_token != G_TOKEN_EOF)
        {
          g_scanner_get_next_token (scanner);
          g_scanner_unexp_token (scanner, expected_token, NULL, NULL, NULL,
                                 _("fatal parse error"), TRUE);
          return FALSE;
        }
    }

  return TRUE;
}


/**
 * gimp_config_duplicate:
 * @config: a #GObject that implements the #GimpConfigInterface.
 *
 * Creates a copy of the passed object by copying all object
 * properties. The default implementation of the #GimpConfigInterface
 * only works for objects that are completely defined by their
 * properties.
 *
 * Return value: the duplicated #GObject.
 **/
GimpConfig *
gimp_config_duplicate (GimpConfig *config)
{
  g_return_val_if_fail (GIMP_IS_CONFIG (config), NULL);

  return GIMP_CONFIG_GET_INTERFACE (config)->duplicate (config);
}

/**
 * gimp_config_is_equal_to:
 * @a: a #GObject that implements the #GimpConfigInterface.
 * @b: another #GObject of the same type as @a.
 *
 * Compares the two objects. The default implementation of the
 * #GimpConfigInterface compares the object properties and thus only
 * works for objects that are completely defined by their
 * properties.
 *
 * Return value: %TRUE if the two objects are equal.
 **/
gboolean
gimp_config_is_equal_to (GimpConfig *a,
                         GimpConfig *b)
{
  g_return_val_if_fail (GIMP_IS_CONFIG (a), FALSE);
  g_return_val_if_fail (GIMP_IS_CONFIG (b), FALSE);
  g_return_val_if_fail (G_TYPE_FROM_INSTANCE (a) == G_TYPE_FROM_INSTANCE (b),
                        FALSE);

  return GIMP_CONFIG_GET_INTERFACE (a)->equal (a, b);
}

/**
 * gimp_config_reset:
 * @config: a #GObject that implements the #GimpConfigInterface.
 *
 * Resets the object to its default state. The default implementation of the
 * #GimpConfigInterface only works for objects that are completely defined by
 * their properties.
 **/
void
gimp_config_reset (GimpConfig *config)
{
  g_return_if_fail (GIMP_IS_CONFIG (config));

  GIMP_CONFIG_GET_INTERFACE (config)->reset (config);
}


/*
 * Code to store and lookup unknown tokens (string key/value pairs).
 */

#define GIMP_CONFIG_UNKNOWN_TOKENS "gimp-config-unknown-tokens"

typedef struct
{
  gchar *key;
  gchar *value;
} GimpConfigToken;

static void  gimp_config_destroy_unknown_tokens (GSList   *unknown_tokens);


/**
 * gimp_config_add_unknown_token:
 * @config: a #GObject.
 * @key: a nul-terminated string to identify the value.
 * @value: a nul-terminated string representing the value.
 *
 * This function allows to add arbitrary key/value pairs to a GObject.
 * It's purpose is to attach additional data to a #GimpConfig object
 * that can be stored along with the object properties when
 * serializing the object to a configuration file. Please note however
 * that the default gimp_config_serialize() implementation does not
 * serialize unknown tokens.
 *
 * If you want to remove a key/value pair from the object, call this
 * function with a %NULL @value.
 **/
void
gimp_config_add_unknown_token (GimpConfig     *config,
                               const gchar *key,
                               const gchar *value)
{
  GimpConfigToken *token;
  GSList          *unknown_tokens;
  GSList          *last;
  GSList          *list;

  g_return_if_fail (GIMP_IS_CONFIG (config));
  g_return_if_fail (key != NULL);

  unknown_tokens = (GSList *) g_object_get_data (G_OBJECT (config),
                                                 GIMP_CONFIG_UNKNOWN_TOKENS);

  for (last = NULL, list = unknown_tokens;
       list;
       last = list, list = g_slist_next (list))
    {
      token = (GimpConfigToken *) list->data;

      if (strcmp (token->key, key) == 0)
        {
          g_free (token->value);

          if (value)
            {
              token->value = g_strdup (value);
            }
          else
            {
              g_free (token->key);

              unknown_tokens = g_slist_remove (unknown_tokens, token);
              g_object_set_data_full (G_OBJECT (config),
                                      GIMP_CONFIG_UNKNOWN_TOKENS,
                                      unknown_tokens,
                     (GDestroyNotify) gimp_config_destroy_unknown_tokens);
            }

          return;
        }
    }

  if (!value)
    return;

  token = g_new (GimpConfigToken, 1);
  token->key   = g_strdup (key);
  token->value = g_strdup (value);

  if (last)
    {
      g_slist_append (last, token);
    }
  else
    {
      unknown_tokens = g_slist_append (NULL, token);

      g_object_set_data_full (G_OBJECT (config),
                              GIMP_CONFIG_UNKNOWN_TOKENS,
                              unknown_tokens,
             (GDestroyNotify) gimp_config_destroy_unknown_tokens);
    }
}

/**
 * gimp_config_lookup_unknown_token:
 * @config: a #GObject.
 * @key: a nul-terminated string to identify the value.
 *
 * This function retrieves data that was previously attached using
 * gimp_config_add_unknown_token(). You should not free or modify
 * the returned string.
 *
 * Returns: a pointer to a constant string.
 **/
const gchar *
gimp_config_lookup_unknown_token (GimpConfig     *config,
                                  const gchar *key)
{
  GimpConfigToken *token;
  GSList          *unknown_tokens;
  GSList          *list;

  g_return_val_if_fail (GIMP_IS_CONFIG (config), NULL);
  g_return_val_if_fail (key != NULL, NULL);

  unknown_tokens = (GSList *) g_object_get_data (G_OBJECT (config),
                                                 GIMP_CONFIG_UNKNOWN_TOKENS);

  for (list = unknown_tokens; list; list = g_slist_next (list))
    {
      token = (GimpConfigToken *) list->data;

      if (strcmp (token->key, key) == 0)
        return token->value;
    }

  return NULL;
}

/**
 * gimp_config_foreach_unknown_token:
 * @config: a #GObject.
 * @func: a function to call for each key/value pair.
 * @user_data: data to pass to @func.
 *
 * Calls @func for each key/value stored with the @config using
 * gimp_config_add_unknown_token().
 **/
void
gimp_config_foreach_unknown_token (GimpConfig               *config,
                                   GimpConfigForeachFunc  func,
                                   gpointer               user_data)
{
  GimpConfigToken *token;
  GSList          *unknown_tokens;
  GSList          *list;

  g_return_if_fail (GIMP_IS_CONFIG (config));
  g_return_if_fail (func != NULL);

  unknown_tokens = (GSList *) g_object_get_data (G_OBJECT (config),
                                                 GIMP_CONFIG_UNKNOWN_TOKENS);

  for (list = unknown_tokens; list; list = g_slist_next (list))
    {
      token = (GimpConfigToken *) list->data;

      func (token->key, token->value, user_data);
    }
}

static void
gimp_config_destroy_unknown_tokens (GSList *unknown_tokens)
{
  GimpConfigToken *token;
  GSList          *list;

  for (list = unknown_tokens; list; list = g_slist_next (list))
    {
      token = (GimpConfigToken *) list->data;

      g_free (token->key);
      g_free (token->value);
      g_free (token);
    }

  g_slist_free (unknown_tokens);
}