gimp/libgimpconfig/gimpconfig-serialize.c

/* The GIMP -- an image manipulation program
 * Copyright (C) 1995 Spencer Kimball and Peter Mattis
 *
 * Object properties serialization routines
 * 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 <stdio.h>
#include <string.h>
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif

#include <glib-object.h>

#ifdef G_OS_WIN32
#include <io.h>
#endif

#include "gimpconfig.h"
#include "gimpconfig-serialize.h"
#include "gimpconfig-types.h"


static gboolean gimp_values_equal        (const GValue *a,
                                          const GValue *b);
static void     serialize_unknown_token  (const gchar  *key,
                                          const gchar  *value,
                                          gpointer      data);


/**
 * gimp_config_serialize_properties:
 * @object: a #GObject. 
 * @fd: a file descriptor to write to.
 * 
 * This function writes all object properties to the file descriptor @fd.
 **/
void
gimp_config_serialize_properties (GObject *object,
                                  gint     fd)
{
  GObjectClass  *klass;
  GParamSpec   **property_specs;
  guint          n_property_specs;
  guint          i;
  GString       *str;

  g_return_if_fail (G_IS_OBJECT (object));
  
  klass = G_OBJECT_GET_CLASS (object);

  property_specs = g_object_class_list_properties (klass, &n_property_specs);

  if (!property_specs)
    return;

  str = g_string_new (NULL);

  for (i = 0; i < n_property_specs; i++)
    {
      GParamSpec  *prop_spec;
      GValue       value = { 0, };

      prop_spec = property_specs[i];

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

      g_value_init (&value, prop_spec->value_type);
      g_object_get_property (object, prop_spec->name, &value);

      g_string_assign (str, "(");
      g_string_append (str, prop_spec->name);
      
      if (gimp_config_serialize_value (&value, str))
        {
          g_string_append (str, ")\n");
          write (fd, str->str, str->len);
        }
      else if (prop_spec->value_type != G_TYPE_STRING)
        {
          g_warning ("couldn't serialize property %s::%s of type %s",
                     g_type_name (G_TYPE_FROM_INSTANCE (object)),
                     prop_spec->name, 
                     g_type_name (prop_spec->value_type));
        }

      g_value_unset (&value);
    }

  g_free (property_specs);
  g_string_free (str, TRUE);
}


/**
 * gimp_config_serialize_properties:
 * @new: a #GObject. 
 * @old: a #GObject of the same type as @new. 
 * @fd: a file descriptor to write to.
 * 
 * This function compares the objects @new and @old and writes all properties
 * of @new that have different values than @old to the file descriptor @fd.
 **/
void
gimp_config_serialize_changed_properties (GObject *new,
                                          GObject *old,
                                          gint    fd)
{
  GObjectClass  *klass;
  GParamSpec   **property_specs;
  guint          n_property_specs;
  guint          i;
  GString       *str;

  g_return_if_fail (G_IS_OBJECT (new));
  g_return_if_fail (G_IS_OBJECT (old));
  g_return_if_fail (G_TYPE_FROM_INSTANCE (new) == G_TYPE_FROM_INSTANCE (old));

  klass = G_OBJECT_GET_CLASS (new);

  property_specs = g_object_class_list_properties (klass, &n_property_specs);

  if (!property_specs)
    return;

  str = g_string_new (NULL);

  for (i = 0; i < n_property_specs; i++)
    {
      GParamSpec  *prop_spec;
      GValue       new_value = { 0, };
      GValue       old_value = { 0, };

      prop_spec = property_specs[i];

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

      g_value_init (&new_value, prop_spec->value_type);
      g_value_init (&old_value, prop_spec->value_type);
      g_object_get_property (new, prop_spec->name, &new_value);
      g_object_get_property (old, prop_spec->name, &old_value);

      if (!gimp_values_equal (&new_value, &old_value))
        {
          g_string_assign (str, "(");
          g_string_append (str, prop_spec->name);
      
          if (gimp_config_serialize_value (&new_value, str))
            {
              g_string_append (str, ")\n");
              write (fd, str->str, str->len);
            }
          else if (prop_spec->value_type != G_TYPE_STRING)
            {
              g_warning ("couldn't serialize property %s::%s of type %s",
                         g_type_name (G_TYPE_FROM_INSTANCE (new)),
                         prop_spec->name, 
                         g_type_name (prop_spec->value_type));
            }
        }

      g_value_unset (&new_value);
      g_value_unset (&old_value);
    }

  g_free (property_specs);
  g_string_free (str, TRUE);
}

/**
 * gimp_config_serialize_value:
 * @value: a #GValue.
 * @str: a #Gstring.
 * 
 * This utility function appends a string representation of #GValue to @str.
 * 
 * Return value: %TRUE if serialization succeeded, %FALSE otherwise.
 **/
gboolean
gimp_config_serialize_value (const GValue *value,
                             GString      *str)
{
  if (G_VALUE_HOLDS_BOOLEAN (value))
    {
      gboolean bool;
      
      bool = g_value_get_boolean (value);
      g_string_append (str, bool ? " yes" : " no");
      return TRUE;
    }

  if (G_VALUE_HOLDS_ENUM (value))
    {
      GEnumClass *enum_class;
      GEnumValue *enum_value;
      
      enum_class = g_type_class_peek (G_VALUE_TYPE (value));
      enum_value = g_enum_get_value (G_ENUM_CLASS (enum_class),
                                     g_value_get_enum (value));

      if (enum_value && enum_value->value_nick)
        {
          g_string_append_c (str, ' ');
          g_string_append (str, enum_value->value_nick);
          return TRUE;
        }
      else
        {
          g_warning ("Couldn't get nick for enum_value of %s", 
                     G_ENUM_CLASS_TYPE_NAME (enum_class));
          return FALSE;
        }
    }
  
  if (G_VALUE_HOLDS_STRING (value))
    {
      gchar       *escaped;
      const gchar *cstr = g_value_get_string (value);

      if (!cstr)
        return FALSE;

      escaped = g_strescape (cstr, NULL);
      g_string_append_printf (str, " \"%s\"", escaped);
      g_free (escaped);
      return TRUE;
    }

  if (G_VALUE_HOLDS_DOUBLE (value) || G_VALUE_HOLDS_FLOAT (value))
    {
      gdouble v_double;
      gchar   buf[G_ASCII_DTOSTR_BUF_SIZE];

      if (G_VALUE_HOLDS_DOUBLE (value))
        v_double = g_value_get_double (value);
      else
        v_double = (gdouble) g_value_get_float (value);

      g_ascii_formatd (buf, sizeof (buf), "%f", v_double);
      g_string_append_c (str, ' ');
      g_string_append (str, buf);
      return TRUE;
    }

  if (g_value_type_transformable (G_VALUE_TYPE (value), G_TYPE_STRING))
    {
      GValue  tmp_value = { 0, };
      
      g_value_init (&tmp_value, G_TYPE_STRING);
      g_value_transform (value, &tmp_value);

      g_string_append_c (str, ' ');
      g_string_append (str, g_value_get_string (&tmp_value));

      g_value_unset (&tmp_value);
      return TRUE;
    }
  
  return FALSE;
}

/**
 * gimp_config_serialize_unknown_tokens:
 * @object: a #GObject.
 * @fd: a file descriptor to write to.
 * 
 * Writes all unknown tokens attached to #object to the file descriptor @fd.
 * See gimp_config_add_unknown_token().
 **/
void
gimp_config_serialize_unknown_tokens (GObject *object,
                                      gint     fd)
{
  GString *str;

  g_return_if_fail (G_IS_OBJECT (object));

  str = g_string_new (NULL);

  gimp_config_foreach_unknown_token (object, serialize_unknown_token, str);

  write (fd, str->str, str->len);
}

static void
serialize_unknown_token (const gchar *key,
                         const gchar *value,
                         gpointer     data)
{
  gchar *escaped = g_strescape (value, NULL);

  g_string_append_printf ((GString *) data, "(%s \"%s\")\n", key, escaped);

  g_free (escaped);
}

static gboolean
gimp_values_equal (const GValue *a,
                   const GValue *b)
{
  g_return_val_if_fail (G_VALUE_TYPE (a) == G_VALUE_TYPE (b), FALSE);

  if (g_value_fits_pointer (a))
    {
      if (a->data[0].v_pointer == b->data[0].v_pointer)
        return TRUE;

      if (G_VALUE_HOLDS_STRING (a))
        {
          const gchar *a_str = g_value_get_string (a);
          const gchar *b_str = g_value_get_string (b);

          if (a_str && b_str)
            return (strcmp (a_str, b_str) == 0);
          else
            return FALSE;
        }
      else
        {
          g_warning ("%s: Can not compare values of type %s.", 
                     G_STRLOC, G_VALUE_TYPE_NAME (a));
          return FALSE;
        }
    }
  else
    {
      return (a->data[0].v_uint64 == b->data[0].v_uint64); 
    }
}