/* GStreamer
 * Copyright (C) 2005 Stefan Kost <ensonic@users.sf.net>
 *
 * gstparent.c: interface for multi child elements
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Library 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
 * Library General Public License for more details.
 *
 * You should have received a copy of the GNU Library 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 "gst_private.h"

#include "gstparent.h"

/* Parent signals */
/*
enum
{
  CHILD_ADDED,
  CHILD_REMOVED,
  LAST_SIGNAL
};

static guint signals[LAST_SIGNAL] = { 0 };
*/

/**
 * gst_parent_get_child_by_name:
 * @parent: the parent object to get the child from
 * @name: the childs name
 *
 * Looks up a child element by the given name.
 *
 * Implementors can e.g. use #GstObject together with gst_object_set_name() or
 * GObject with g_object_set_data() to identify objects.
 *
 * Returns: the child object or %NULL if not found
 */
GObject * gst_parent_get_child_by_name (GstParent *parent, const gchar *name) {
  return(GST_PARENT_GET_CLASS (parent)->get_child_by_name (parent,name));
}

/**
 * gst_parent_get_child_by_index:
 * @parent: the parent object to get the child from
 * @index: the childs position in the child list
 *
 * Fetches a child by its number.
 *
 * Returns: the child object or %NULL if not found (index too high)
 */
GObject * gst_parent_get_child_by_index (GstParent *parent, guint index) {
  return(GST_PARENT_GET_CLASS (parent)->get_child_by_index (parent,index));
}

/**
 * gst_parent_get_children_count:
 * @parent: the parent object
 *
 * Gets the number of child objects this parent contains.
 *
 * Returns: the number of child objects
 */
guint gst_parent_get_children_count (GstParent *parent) {
  return(GST_PARENT_GET_CLASS (parent)->get_children_count (parent));
}

/**
 * gst_parent_get_valist:
 * @parent: the parent object
 * @first_property_name: name of the first property to get
 * @var_args: return location for the first property, followed optionally by more name/return location pairs, followed by NULL
 * Gets properties of the parents child objects.
 */
void gst_parent_get_valist (GstParent *parent, const gchar *first_property_name, va_list var_args) {
  GObject *child;
  const gchar *name;
  gchar *child_name, *prop_name;
  
  g_return_if_fail (G_IS_OBJECT (parent));
  
  g_object_ref (parent);
  
  name = first_property_name;
  
  // iterate of pairs
  while (name) {
    // split on '::' into child_name, prop_name
    prop_name=strstr(name,"::");
    if (prop_name) {
      child_name=g_strndup(name,((gulong)prop_name-(gulong)name));
      prop_name+=2;
      // get the child by name
      child=gst_parent_get_child_by_name(parent,child_name);
      g_object_get(child, prop_name, var_args, NULL);
    }
    else {
      GST_WARNING("property name '%s' has no '::' separator",name);
      break;
    }
    name = va_arg (var_args, gchar*);
  }

  g_object_unref (parent);
}

/**
 * gst_parent_get:
 * @parent: the parent object
 * @first_property_name: name of the first property to get
 * @...: return location for the first property, followed optionally by more name/return location pairs, followed by NULL
 * Gets properties of the parents child objects.
 */
void gst_parent_get (GstParent *parent, const gchar *first_property_name, ...) {
  va_list var_args;
  
  g_return_if_fail (G_IS_OBJECT (parent));
  
  va_start (var_args, first_property_name);
  gst_parent_get_valist (parent, first_property_name, var_args);
  va_end (var_args);
}

/**
 * gst_parent_set_valist:
 * @parent: the parent object
 * @first_property_name: name of the first property to set
 * @var_args: value for the first property, followed optionally by more name/value pairs, followed by NULL
 * Sets properties of the parents child objects.
 */
void gst_parent_set_valist (GstParent *parent, const gchar *first_property_name, va_list var_args) {
  GObject *child;
  const gchar *name;
  gchar *child_name, *prop_name;

  g_return_if_fail (G_IS_OBJECT (parent));
  
  g_object_ref (parent);

  name = first_property_name;
  
  // iterate of pairs
  while (name) {
    // split on '::' into child_name, prop_name
    prop_name=strstr(name,"::");
    if (prop_name) {
      child_name=g_strndup(name,((gulong)prop_name-(gulong)name));
      prop_name+=2;
      // get the child by name
      child=gst_parent_get_child_by_name(parent,child_name);
      g_object_set(child, prop_name, var_args, NULL);
    }
    else {
      GST_WARNING("property name '%s' has no '::' separator",name);
      break;
    }
    name = va_arg (var_args, gchar*);
  }

  g_object_unref (parent);
}

/**
 * gst_parent_set:
 * @parent: the parent object
 * @first_property_name: name of the first property to set
 * @...: value for the first property, followed optionally by more name/value pairs, followed by NULL
 * Sets properties of the parents child objects.
 */
void gst_parent_set (GstParent *parent, const gchar *first_property_name, ...) {
  va_list var_args;
  
  g_return_if_fail (G_IS_OBJECT (parent));
  
  va_start (var_args, first_property_name);
  gst_parent_set_valist (parent, first_property_name, var_args);
  va_end (var_args);
}

static void gst_parent_base_init(gpointer g_class) {
  static gboolean initialized = FALSE;

  if (!initialized) {
    /* create interface signals and properties here. */
    /*
    signals[CHILD_ADDED] =
        g_signal_new ("child-added", G_TYPE_FROM_CLASS (g_class),
        G_SIGNAL_RUN_FIRST, G_STRUCT_OFFSET (GstParentClass, child_added), NULL,
        NULL, gst_marshal_VOID__OBJECT, G_TYPE_NONE, 1, G_TYPE_OBJECT);

    signals[CHILD_REMOVED] =
        g_signal_new ("child-removed", G_TYPE_FROM_CLASS (g_class),
        G_SIGNAL_RUN_FIRST, G_STRUCT_OFFSET (GstParentClass, child_removed), NULL,
        NULL, gst_marshal_VOID__OBJECT, G_TYPE_NONE, 1, G_TYPE_OBJECT);
    */
    initialized = TRUE;
  }
}

GType gst_parent_get_type (void) {
  static GType type = 0;
  if (type == 0) {
    static const GTypeInfo info = {
      sizeof (GstParentClass),
      gst_parent_base_init,   /* base_init */
      NULL,   /* base_finalize */
      NULL,   /* class_init */
      NULL,   /* class_finalize */
      NULL,   /* class_data */
      0,
      0,      /* n_preallocs */
      NULL    /* instance_init */
    };
    type = g_type_register_static(G_TYPE_INTERFACE,"GstParent",&info,0);
  }
  return type;
}
