/* GTK - The GIMP Toolkit

 * Copyright (C) 1995-1997 Peter Mattis, Spencer Kimball and Josh MacDonald

 *

 * 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.

 */

/*

 * Modified by the GTK+ Team and others 1997-2000.  See the AUTHORS

 * file for a list of people on the GTK+ Team.  See the ChangeLog

 * files for a list of changes.  These files are distributed with

 * GTK+ at ftp://ftp.gtk.org/pub/gtk/. 

 */

/**

 * SECTION:gtkbin

 * @Short_description: A container with just one child

 * @Title: GtkBin

 *

 * The #GtkBin widget is a container with just one child.

 * It is not very useful itself, but it is useful for deriving subclasses,

 * since it provides common code needed for handling a single child widget.

 *

 * Many GTK+ widgets are subclasses of #GtkBin, including #GtkWindow,

 * #GtkButton, #GtkFrame, #GtkHandleBox or #GtkScrolledWindow.

 */

#include "config.h"

#include "gtkbin.h"

#include "gtkintl.h"

#include "gtkalias.h"

static void gtk_bin_add         (GtkContainer   *container,

			         GtkWidget      *widget);

static void gtk_bin_remove      (GtkContainer   *container,

			         GtkWidget      *widget);

static void gtk_bin_forall      (GtkContainer   *container,

				 gboolean	include_internals,

				 GtkCallback     callback,

				 gpointer        callback_data);

static GType gtk_bin_child_type (GtkContainer   *container);

G_DEFINE_ABSTRACT_TYPE (GtkBin, gtk_bin, GTK_TYPE_CONTAINER)

static void

gtk_bin_class_init (GtkBinClass *class)

{

  GtkContainerClass *container_class;

  container_class = (GtkContainerClass*) class;

  container_class->add = gtk_bin_add;

  container_class->remove = gtk_bin_remove;

  container_class->forall = gtk_bin_forall;

  container_class->child_type = gtk_bin_child_type;

}

static void

gtk_bin_init (GtkBin *bin)

{

  gtk_widget_set_has_window (GTK_WIDGET (bin), FALSE);

  bin->child = NULL;

}

static GType

gtk_bin_child_type (GtkContainer *container)

{

  if (!GTK_BIN (container)->child)

    return GTK_TYPE_WIDGET;

  else

    return G_TYPE_NONE;

}

static void

gtk_bin_add (GtkContainer *container,

	     GtkWidget    *child)

{

  GtkBin *bin = GTK_BIN (container);

  if (bin->child != NULL)

    {

      g_warning ("Attempting to add a widget with type %s to a %s, "

                 "but as a GtkBin subclass a %s can only contain one widget at a time; "

                 "it already contains a widget of type %s",

                 g_type_name (G_OBJECT_TYPE (child)),

                 g_type_name (G_OBJECT_TYPE (bin)),

                 g_type_name (G_OBJECT_TYPE (bin)),

                 g_type_name (G_OBJECT_TYPE (bin->child)));

      return;

    }

  gtk_widget_set_parent (child, GTK_WIDGET (bin));

  bin->child = child;

}

static void

gtk_bin_remove (GtkContainer *container,

		GtkWidget    *child)

{

  GtkBin *bin = GTK_BIN (container);

  gboolean widget_was_visible;

  g_return_if_fail (bin->child == child);

  widget_was_visible = gtk_widget_get_visible (child);

  gtk_widget_unparent (child);

  bin->child = NULL;

  /* queue resize regardless of gtk_widget_get_visible (container),

   * since that's what is needed by toplevels, which derive from GtkBin.

   */

  if (widget_was_visible)

    gtk_widget_queue_resize (GTK_WIDGET (container));

}

static void

gtk_bin_forall (GtkContainer *container,

		gboolean      include_internals,

		GtkCallback   callback,

		gpointer      callback_data)

{

  GtkBin *bin = GTK_BIN (container);

  if (bin->child)

    (* callback) (bin->child, callback_data);

}

/**

 * gtk_bin_get_child:

 * @bin: a #GtkBin

 * 

 * Gets the child of the #GtkBin, or %NULL if the bin contains

 * no child widget. The returned widget does not have a reference

 * added, so you do not need to unref it.

 *

 * Return value: (transfer none): pointer to child of the #GtkBin

 **/

GtkWidget*

gtk_bin_get_child (GtkBin *bin)

{

  g_return_val_if_fail (GTK_IS_BIN (bin), NULL);

  return bin->child;

}

#define __GTK_BIN_C__

#include "gtkaliasdef.c"