/* GAIL - The GNOME Accessibility Enabling Library

 * Copyright 2001, 2002, 2003 Sun Microsystems 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 "config.h"

#include <string.h>

#include <gtk/gtk.h>

#include "gailscrolledwindow.h"

static void         gail_scrolled_window_class_init     (GailScrolledWindowClass  *klass); 

static void         gail_scrolled_window_init           (GailScrolledWindow       *window);

static void         gail_scrolled_window_real_initialize

                                                        (AtkObject     *obj,

                                                         gpointer      data);

static gint         gail_scrolled_window_get_n_children (AtkObject     *object);

static AtkObject*   gail_scrolled_window_ref_child      (AtkObject     *obj,

                                                         gint          child);

static void         gail_scrolled_window_scrollbar_visibility_changed 

                                                        (GObject       *object,

                                                         GParamSpec    *pspec,

                                                         gpointer      user_data);

G_DEFINE_TYPE (GailScrolledWindow, gail_scrolled_window, GAIL_TYPE_CONTAINER)

static void

gail_scrolled_window_class_init (GailScrolledWindowClass *klass)

{

  AtkObjectClass  *class = ATK_OBJECT_CLASS (klass);

  class->get_n_children = gail_scrolled_window_get_n_children;

  class->ref_child = gail_scrolled_window_ref_child;

  class->initialize = gail_scrolled_window_real_initialize;

}

static void

gail_scrolled_window_init (GailScrolledWindow *window)

{

}

static void

gail_scrolled_window_real_initialize (AtkObject *obj,

                                      gpointer  data)

{

  GtkScrolledWindow *window;

  ATK_OBJECT_CLASS (gail_scrolled_window_parent_class)->initialize (obj, data);

  window = GTK_SCROLLED_WINDOW (data);

  g_signal_connect_data (window->hscrollbar, "notify::visible",

    (GCallback)gail_scrolled_window_scrollbar_visibility_changed, 

    obj, NULL, FALSE);

  g_signal_connect_data (window->vscrollbar, "notify::visible",

    (GCallback)gail_scrolled_window_scrollbar_visibility_changed, 

    obj, NULL, FALSE);

  obj->role = ATK_ROLE_SCROLL_PANE;

}

static gint

gail_scrolled_window_get_n_children (AtkObject *object)

{

  GtkWidget *widget;

  GtkScrolledWindow *gtk_window;

  GList *children;

  gint n_children;

  widget = GTK_ACCESSIBLE (object)->widget;

  if (widget == NULL)

    /* Object is defunct */

    return 0;

  gtk_window = GTK_SCROLLED_WINDOW (widget);

  /* Get the number of children returned by the backing GtkScrolledWindow */

  children = gtk_container_get_children (GTK_CONTAINER(gtk_window));

  n_children = g_list_length (children);

  g_list_free (children);

  /* Add one to the count for each visible scrollbar */

  if (gtk_window->hscrollbar_visible)

    n_children++;

  if (gtk_window->vscrollbar_visible)

    n_children++;

  return n_children;

}

static AtkObject *

gail_scrolled_window_ref_child (AtkObject *obj, 

                                gint      child)

{

  GtkWidget *widget;

  GtkScrolledWindow *gtk_window;

  GList *children, *tmp_list;

  gint n_children;

  AtkObject  *accessible = NULL;

  g_return_val_if_fail (child >= 0, NULL);

  widget = GTK_ACCESSIBLE (obj)->widget;

  if (widget == NULL)

    /* Object is defunct */

    return NULL;

  gtk_window = GTK_SCROLLED_WINDOW (widget);

  children = gtk_container_get_children (GTK_CONTAINER (gtk_window));

  n_children = g_list_length (children);

  if (child == n_children)

    {

      if (gtk_window->hscrollbar_visible)

        accessible = gtk_widget_get_accessible (gtk_window->hscrollbar);

      else if (gtk_window->vscrollbar_visible)

        accessible = gtk_widget_get_accessible (gtk_window->vscrollbar);

    }

  else if (child == n_children+1 && 

           gtk_window->hscrollbar_visible &&

           gtk_window->vscrollbar_visible)

    accessible = gtk_widget_get_accessible (gtk_window->vscrollbar);

  else if (child < n_children)

    {

      tmp_list = g_list_nth (children, child);

      if (tmp_list)

	accessible = gtk_widget_get_accessible (

		GTK_WIDGET (tmp_list->data));

    }

  g_list_free (children);

  if (accessible)

    g_object_ref (accessible);

  return accessible; 

}

static void

gail_scrolled_window_scrollbar_visibility_changed (GObject    *object,

                                                   GParamSpec *pspec,

                                                   gpointer   user_data)

{

  if (!strcmp (pspec->name, "visible"))

    {

      gint index;

      gint n_children;

      gboolean child_added = FALSE;

      GList *children;

      AtkObject *child;

      GtkScrolledWindow *gtk_window;

      GailScrolledWindow *gail_window = GAIL_SCROLLED_WINDOW (user_data);

      gchar *signal_name;

      gtk_window = GTK_SCROLLED_WINDOW (GTK_ACCESSIBLE (user_data)->widget);

      if (gtk_window == NULL)

        return;

      children = gtk_container_get_children (GTK_CONTAINER (gtk_window));

      index = n_children = g_list_length (children);

      g_list_free (children);

      if ((gpointer) object == (gpointer) (gtk_window->hscrollbar))

        {

          if (gtk_window->hscrollbar_visible)

            child_added = TRUE;

          child = gtk_widget_get_accessible (gtk_window->hscrollbar);

        }

      else if ((gpointer) object == (gpointer) (gtk_window->vscrollbar))

        {

          if (gtk_window->vscrollbar_visible)

            child_added = TRUE;

          child = gtk_widget_get_accessible (gtk_window->vscrollbar);

          if (gtk_window->hscrollbar_visible)

            index = n_children+1;

        }

      else 

        {

          g_assert_not_reached ();

          return;

        }

      if (child_added)

        signal_name = "children_changed::add";

      else

        signal_name = "children_changed::delete";

      g_signal_emit_by_name (gail_window, signal_name, index, child, NULL);

    }

}