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eel-canvas.c

/* -*- Mode: C; tab-width: 8; indent-tabs-mode: 8; c-basic-offset: 8 -*- */
/*
 * Copyright (C) 1997, 1998, 1999, 2000 Free Software Foundation
 * All rights reserved.
 *
 * This file is part of the Gnome Library.
 *
 * The Gnome 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.
 *
 * The Gnome 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 the Gnome Library; see the file COPYING.LIB.  If not,
 * write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 * Boston, MA 02111-1307, USA.
 */
/*
  @NOTATION@
 */
/*
 * EelCanvas widget - Tk-like canvas widget for Gnome
 *
 * EelCanvas is basically a port of the Tk toolkit's most excellent canvas widget.  Tk is
 * copyrighted by the Regents of the University of California, Sun Microsystems, and other parties.
 *
 *
 * Authors: Federico Mena <federico@nuclecu.unam.mx>
 *          Raph Levien <raph@gimp.org>
 */

/*
 * TO-DO list for the canvas:
 *
 * - Allow to specify whether EelCanvasImage sizes are in units or pixels (scale or don't scale).
 *
 * - Implement a flag for eel_canvas_item_reparent() that tells the function to keep the item
 *   visually in the same place, that is, to keep it in the same place with respect to the canvas
 *   origin.
 *
 * - GC put functions for items.
 *
 * - Widget item (finish it).
 *
 * - GList *eel_canvas_gimme_all_items_contained_in_this_area (EelCanvas *canvas, Rectangle area);
 *
 * - Retrofit all the primitive items with microtile support.
 *
 * - Curve support for line item.
 *
 * - Arc item (Havoc has it; to be integrated in EelCanvasEllipse).
 *
 * - Sane font handling API.
 *
 * - Get_arg methods for items:
 *   - How to fetch the outline width and know whether it is in pixels or units?
 */

#include <config.h>

#include <math.h>
#include <string.h>
#include <stdio.h>
#include <gdk/gdkprivate.h>
#include <gtk/gtk.h>
#include "eel-canvas.h"
#include "eel-i18n.h"

#include "eel-marshal.h"

static void eel_canvas_request_update (EelCanvas      *canvas);
static void group_add                   (EelCanvasGroup *group,
                               EelCanvasItem  *item);
static void group_remove                (EelCanvasGroup *group,
                               EelCanvasItem  *item);
static void redraw_and_repick_if_mapped (EelCanvasItem *item);

/*** EelCanvasItem ***/

/* Some convenience stuff */
#define GCI_UPDATE_MASK (EEL_CANVAS_UPDATE_REQUESTED | EEL_CANVAS_UPDATE_DEEP)
#define GCI_EPSILON 1e-18

enum {
      ITEM_PROP_0,
      ITEM_PROP_PARENT,
      ITEM_PROP_VISIBLE
};

enum {
      ITEM_EVENT,
      ITEM_LAST_SIGNAL
};

static void eel_canvas_item_class_init     (EelCanvasItemClass *klass);
static void eel_canvas_item_init           (EelCanvasItem      *item);
static int  emit_event                       (EelCanvas *canvas, GdkEvent *event);

static guint item_signals[ITEM_LAST_SIGNAL];

static GtkObjectClass *item_parent_class;

static gpointer accessible_item_parent_class;
static gpointer accessible_parent_class;


/**
 * eel_canvas_item_get_type:
 *
 * Registers the &EelCanvasItem class if necessary, and returns the type ID
 * associated to it.
 *
 * Return value:  The type ID of the &EelCanvasItem class.
 **/
GType
eel_canvas_item_get_type (void)
{
      static GType canvas_item_type = 0;

      if (!canvas_item_type) {
            static const GTypeInfo canvas_item_info = {
                  sizeof (EelCanvasItemClass),
                  (GBaseInitFunc) NULL,
                  (GBaseFinalizeFunc) NULL,
                  (GClassInitFunc) eel_canvas_item_class_init,
                  NULL,           /* class_finalize */
                  NULL,           /* class_data */
                  sizeof (EelCanvasItem),
                  0,              /* n_preallocs */
                  (GInstanceInitFunc) eel_canvas_item_init
            };

            canvas_item_type = g_type_register_static (gtk_object_get_type (),
                                             "EelCanvasItem",
                                             &canvas_item_info,
                                             0);
      }

      return canvas_item_type;
}

/* Object initialization function for EelCanvasItem */
static void
eel_canvas_item_init (EelCanvasItem *item)
{
      item->flags |= EEL_CANVAS_ITEM_VISIBLE;
}

/**
 * eel_canvas_item_new:
 * @parent: The parent group for the new item.
 * @type: The object type of the item.
 * @first_arg_name: A list of object argument name/value pairs, NULL-terminated,
 * used to configure the item.  For example, "fill_color", "black",
 * "width_units", 5.0, NULL.
 * @Varargs:
 *
 * Creates a new canvas item with @parent as its parent group.  The item is
 * created at the top of its parent's stack, and starts up as visible.  The item
 * is of the specified @type, for example, it can be
 * eel_canvas_rect_get_type().  The list of object arguments/value pairs is
 * used to configure the item.
 *
 * Return value: The newly-created item.
 **/
EelCanvasItem *
eel_canvas_item_new (EelCanvasGroup *parent, GType type, const gchar *first_arg_name, ...)
{
      EelCanvasItem *item;
      va_list args;

      g_return_val_if_fail (EEL_IS_CANVAS_GROUP (parent), NULL);
      g_return_val_if_fail (g_type_is_a (type, eel_canvas_item_get_type ()), NULL);

      item = EEL_CANVAS_ITEM (g_object_new (type, NULL));

      va_start (args, first_arg_name);
      eel_canvas_item_construct (item, parent, first_arg_name, args);
      va_end (args);

      return item;
}


/* Performs post-creation operations on a canvas item (adding it to its parent
 * group, etc.)
 */
static void
item_post_create_setup (EelCanvasItem *item)
{
      group_add (EEL_CANVAS_GROUP (item->parent), item);

      redraw_and_repick_if_mapped (item);
}

/* Set_property handler for canvas items */
static void
eel_canvas_item_set_property (GObject *gobject, guint param_id,
                        const GValue *value, GParamSpec *pspec)
{
      EelCanvasItem *item;

      g_return_if_fail (EEL_IS_CANVAS_ITEM (gobject));

      item = EEL_CANVAS_ITEM (gobject);

      switch (param_id) {
      case ITEM_PROP_PARENT:
            if (item->parent != NULL) {
                g_warning ("Cannot set `parent' argument after item has "
                         "already been constructed.");
            } else if (g_value_get_object (value)) {
                  item->parent = EEL_CANVAS_ITEM (g_value_get_object (value));
                  item->canvas = item->parent->canvas;
                  item_post_create_setup (item);
            }
            break;
      case ITEM_PROP_VISIBLE:
            if (g_value_get_boolean (value)) {
                  eel_canvas_item_show (item);
            } else {
                  eel_canvas_item_hide (item);
            }
            break;
      default:
            G_OBJECT_WARN_INVALID_PROPERTY_ID (gobject, param_id, pspec);
            break;
      }
}

/* Get_property handler for canvas items */
static void
eel_canvas_item_get_property (GObject *gobject, guint param_id,
                        GValue *value, GParamSpec *pspec)
{
      EelCanvasItem *item;

      g_return_if_fail (EEL_IS_CANVAS_ITEM (gobject));

      item = EEL_CANVAS_ITEM (gobject);

      switch (param_id) {
      case ITEM_PROP_VISIBLE:
            g_value_set_boolean (value, item->flags & EEL_CANVAS_ITEM_VISIBLE);
            break;
      default:
            G_OBJECT_WARN_INVALID_PROPERTY_ID (gobject, param_id, pspec);
            break;
      }
}

/**
 * eel_canvas_item_construct:
 * @item: An unconstructed canvas item.
 * @parent: The parent group for the item.
 * @first_arg_name: The name of the first argument for configuring the item.
 * @args: The list of arguments used to configure the item.
 *
 * Constructs a canvas item; meant for use only by item implementations.
 **/
void
eel_canvas_item_construct (EelCanvasItem *item, EelCanvasGroup *parent,
                     const gchar *first_arg_name, va_list args)
{
      g_return_if_fail (EEL_IS_CANVAS_GROUP (parent));
      g_return_if_fail (EEL_IS_CANVAS_ITEM (item));

      item->parent = EEL_CANVAS_ITEM (parent);
      item->canvas = item->parent->canvas;

      g_object_set_valist (G_OBJECT (item), first_arg_name, args);

      item_post_create_setup (item);
}


static void
redraw_and_repick_if_mapped (EelCanvasItem *item)
{
      if (item->flags & EEL_CANVAS_ITEM_MAPPED) {
            eel_canvas_item_request_redraw (item);
            item->canvas->need_repick = TRUE;
      }
}

/* Dispose handler for canvas items */
static void
eel_canvas_item_dispose (GObject *object)
{
      EelCanvasItem *item;

      g_return_if_fail (EEL_IS_CANVAS_ITEM (object));

      item = EEL_CANVAS_ITEM (object);

      if (item->canvas) {
            eel_canvas_item_request_redraw (item);

            /* Make the canvas forget about us */

            if (item == item->canvas->current_item) {
                  item->canvas->current_item = NULL;
                  item->canvas->need_repick = TRUE;
            }

            if (item == item->canvas->new_current_item) {
                  item->canvas->new_current_item = NULL;
                  item->canvas->need_repick = TRUE;
            }

            if (item == item->canvas->grabbed_item) {
                  GdkDisplay *display = gtk_widget_get_display (GTK_WIDGET (item->canvas));
                  item->canvas->grabbed_item = NULL;
                  gdk_display_pointer_ungrab (display, GDK_CURRENT_TIME);
            }

            if (item == item->canvas->focused_item)
                  item->canvas->focused_item = NULL;

            /* Normal destroy stuff */

            if (item->flags & EEL_CANVAS_ITEM_MAPPED)
                  (* EEL_CANVAS_ITEM_GET_CLASS (item)->unmap) (item);

            if (item->flags & EEL_CANVAS_ITEM_REALIZED)
                  (* EEL_CANVAS_ITEM_GET_CLASS (item)->unrealize) (item);

            if (item->parent)
                  group_remove (EEL_CANVAS_GROUP (item->parent), item);

            item->canvas = NULL;
      }

      G_OBJECT_CLASS (item_parent_class)->dispose (object);
}


/* Realize handler for canvas items */
static void
eel_canvas_item_realize (EelCanvasItem *item)
{
      if (item->parent && !(item->parent->flags & EEL_CANVAS_ITEM_REALIZED))
            (* EEL_CANVAS_ITEM_GET_CLASS (item->parent)->realize) (item->parent);
      
      if (item->parent == NULL && !gtk_widget_get_realized (GTK_WIDGET (item->canvas)))
            gtk_widget_realize (GTK_WIDGET (item->canvas));

      item->flags |= EEL_CANVAS_ITEM_REALIZED;

      eel_canvas_item_request_update (item);
}

/* Unrealize handler for canvas items */
static void
eel_canvas_item_unrealize (EelCanvasItem *item)
{
      if (item->flags & EEL_CANVAS_ITEM_MAPPED)
            (* EEL_CANVAS_ITEM_GET_CLASS (item)->unmap) (item);

      item->flags &= ~(EEL_CANVAS_ITEM_REALIZED);
}

/* Map handler for canvas items */
static void
eel_canvas_item_map (EelCanvasItem *item)
{
      item->flags |= EEL_CANVAS_ITEM_MAPPED;
}

/* Unmap handler for canvas items */
static void
eel_canvas_item_unmap (EelCanvasItem *item)
{
      item->flags &= ~(EEL_CANVAS_ITEM_MAPPED);
}

/* Update handler for canvas items */
static void
eel_canvas_item_update (EelCanvasItem *item, double i2w_dx, double i2w_dy, int flags)
{
      item->flags &= ~(EEL_CANVAS_ITEM_NEED_UPDATE);
      item->flags &= ~(EEL_CANVAS_ITEM_NEED_DEEP_UPDATE);
}

/*
 * This routine invokes the update method of the item
 * Please notice, that we take parent to canvas pixel matrix as argument
 * unlike virtual method ::update, whose argument is item 2 canvas pixel
 * matrix
 *
 * I will try to force somewhat meaningful naming for affines (Lauris)
 * General naming rule is FROM2TO, where FROM and TO are abbreviations
 * So p2cpx is Parent2CanvasPixel and i2cpx is Item2CanvasPixel
 * I hope that this helps to keep track of what really happens
 *
 */

static void
eel_canvas_item_invoke_update (EelCanvasItem *item,
                         double i2w_dx,
                         double i2w_dy,
                         int flags)
{
      int child_flags;

      child_flags = flags;

      /* apply object flags to child flags */
      child_flags &= ~EEL_CANVAS_UPDATE_REQUESTED;

      if (item->flags & EEL_CANVAS_ITEM_NEED_UPDATE)
            child_flags |= EEL_CANVAS_UPDATE_REQUESTED;

      if (item->flags & EEL_CANVAS_ITEM_NEED_DEEP_UPDATE)
            child_flags |= EEL_CANVAS_UPDATE_DEEP;

      if (child_flags & GCI_UPDATE_MASK) {
            if (EEL_CANVAS_ITEM_GET_CLASS (item)->update)
                  EEL_CANVAS_ITEM_GET_CLASS (item)->update (item, i2w_dx, i2w_dy, child_flags);
      }
 
      /* If this fail you probably forgot to chain up to
       * EelCanvasItem::update from a derived class */
      g_return_if_fail (!(item->flags & EEL_CANVAS_ITEM_NEED_UPDATE));
}

/*
 * This routine invokes the point method of the item.
 * The arguments x, y should be in the parent item local coordinates.
 */

static double
eel_canvas_item_invoke_point (EelCanvasItem *item, double x, double y, int cx, int cy, EelCanvasItem **actual_item)
{
      /* Calculate x & y in item local coordinates */

      if (EEL_CANVAS_ITEM_GET_CLASS (item)->point)
            return EEL_CANVAS_ITEM_GET_CLASS (item)->point (item, x, y, cx, cy, actual_item);

      return 1e18;
}

/**
 * eel_canvas_item_set:
 * @item: A canvas item.
 * @first_arg_name: The list of object argument name/value pairs used to configure the item.
 * @Varargs:
 *
 * Configures a canvas item.  The arguments in the item are set to the specified
 * values, and the item is repainted as appropriate.
 **/
void
eel_canvas_item_set (EelCanvasItem *item, const gchar *first_arg_name, ...)
{
      va_list args;

      va_start (args, first_arg_name);
      eel_canvas_item_set_valist (item, first_arg_name, args);
      va_end (args);
}


/**
 * eel_canvas_item_set_valist:
 * @item: A canvas item.
 * @first_arg_name: The name of the first argument used to configure the item.
 * @args: The list of object argument name/value pairs used to configure the item.
 *
 * Configures a canvas item.  The arguments in the item are set to the specified
 * values, and the item is repainted as appropriate.
 **/
void
eel_canvas_item_set_valist (EelCanvasItem *item, const gchar *first_arg_name, va_list args)
{
      g_return_if_fail (EEL_IS_CANVAS_ITEM (item));

      g_object_set_valist (G_OBJECT (item), first_arg_name, args);

#if 0
      /* I commented this out, because item implementations have to schedule update/redraw */
      eel_canvas_item_request_redraw (item);
#endif

      item->canvas->need_repick = TRUE;
}


/**
 * eel_canvas_item_move:
 * @item: A canvas item.
 * @dx: Horizontal offset.
 * @dy: Vertical offset.
 *
 * Moves a canvas item by creating an affine transformation matrix for
 * translation by using the specified values. This happens in item
 * local coordinate system, so if you have nontrivial transform, it
 * most probably does not do, what you want.
 **/
void
eel_canvas_item_move (EelCanvasItem *item, double dx, double dy)
{
        g_return_if_fail (item != NULL);
        g_return_if_fail (EEL_IS_CANVAS_ITEM (item));

        if (!EEL_CANVAS_ITEM_GET_CLASS (item)->translate) {
                g_warning ("Item type %s does not implement translate method.\n",
                           g_type_name (G_OBJECT_TYPE (item)));
                return;
        }

        (* EEL_CANVAS_ITEM_GET_CLASS (item)->translate) (item, dx, dy);

      if (item->flags & EEL_CANVAS_ITEM_MAPPED) 
            item->canvas->need_repick = TRUE;

      if (!(item->flags & EEL_CANVAS_ITEM_NEED_DEEP_UPDATE)) {
            item->flags |= EEL_CANVAS_ITEM_NEED_DEEP_UPDATE;
            if (item->parent != NULL)
                  eel_canvas_item_request_update (item->parent);
            else
                  eel_canvas_request_update (item->canvas);
      }

}

/* Convenience function to reorder items in a group's child list.  This puts the
 * specified link after the "before" link. Returns TRUE if the list was changed.
 */
static gboolean
put_item_after (GList *link, GList *before)
{
      EelCanvasGroup *parent;

      if (link == before)
            return FALSE;

      parent = EEL_CANVAS_GROUP (EEL_CANVAS_ITEM (link->data)->parent);

      if (before == NULL) {
            if (link == parent->item_list)
                  return FALSE;

            link->prev->next = link->next;

            if (link->next)
                  link->next->prev = link->prev;
            else
                  parent->item_list_end = link->prev;

            link->prev = before;
            link->next = parent->item_list;
            link->next->prev = link;
            parent->item_list = link;
      } else {
            if ((link == parent->item_list_end) && (before == parent->item_list_end->prev))
                  return FALSE;

            if (link->next)
                  link->next->prev = link->prev;

            if (link->prev)
                  link->prev->next = link->next;
            else {
                  parent->item_list = link->next;
                  parent->item_list->prev = NULL;
            }

            link->prev = before;
            link->next = before->next;

            link->prev->next = link;

            if (link->next)
                  link->next->prev = link;
            else
                  parent->item_list_end = link;
      }
      return TRUE;
}


/**
 * eel_canvas_item_raise:
 * @item: A canvas item.
 * @positions: Number of steps to raise the item.
 *
 * Raises the item in its parent's stack by the specified number of positions.
 * If the number of positions is greater than the distance to the top of the
 * stack, then the item is put at the top.
 **/
void
eel_canvas_item_raise (EelCanvasItem *item, int positions)
{
      GList *link, *before;
      EelCanvasGroup *parent;

      g_return_if_fail (EEL_IS_CANVAS_ITEM (item));
      g_return_if_fail (positions >= 0);

      if (!item->parent || positions == 0)
            return;

      parent = EEL_CANVAS_GROUP (item->parent);
      link = g_list_find (parent->item_list, item);
      g_assert (link != NULL);

      for (before = link; positions && before; positions--)
            before = before->next;

      if (!before)
            before = parent->item_list_end;

      if (put_item_after (link, before)) {
            redraw_and_repick_if_mapped (item);
      }
}


/**
 * eel_canvas_item_lower:
 * @item: A canvas item.
 * @positions: Number of steps to lower the item.
 *
 * Lowers the item in its parent's stack by the specified number of positions.
 * If the number of positions is greater than the distance to the bottom of the
 * stack, then the item is put at the bottom.
 **/
void
eel_canvas_item_lower (EelCanvasItem *item, int positions)
{
      GList *link, *before;
      EelCanvasGroup *parent;

      g_return_if_fail (EEL_IS_CANVAS_ITEM (item));
      g_return_if_fail (positions >= 1);

      if (!item->parent || positions == 0)
            return;

      parent = EEL_CANVAS_GROUP (item->parent);
      link = g_list_find (parent->item_list, item);
      g_assert (link != NULL);

      if (link->prev)
            for (before = link->prev; positions && before; positions--)
                  before = before->prev;
      else
            before = NULL;

      if (put_item_after (link, before)) {
            redraw_and_repick_if_mapped (item);
      }
}


/**
 * eel_canvas_item_raise_to_top:
 * @item: A canvas item.
 *
 * Raises an item to the top of its parent's stack.
 **/
void
eel_canvas_item_raise_to_top (EelCanvasItem *item)
{
      GList *link;
      EelCanvasGroup *parent;

      g_return_if_fail (EEL_IS_CANVAS_ITEM (item));

      if (!item->parent)
            return;

      parent = EEL_CANVAS_GROUP (item->parent);
      link = g_list_find (parent->item_list, item);
      g_assert (link != NULL);

      if (put_item_after (link, parent->item_list_end)) {
            redraw_and_repick_if_mapped (item);
      }
}


/**
 * eel_canvas_item_lower_to_bottom:
 * @item: A canvas item.
 *
 * Lowers an item to the bottom of its parent's stack.
 **/
void
eel_canvas_item_lower_to_bottom (EelCanvasItem *item)
{
      GList *link;
      EelCanvasGroup *parent;

      g_return_if_fail (EEL_IS_CANVAS_ITEM (item));

      if (!item->parent)
            return;

      parent = EEL_CANVAS_GROUP (item->parent);
      link = g_list_find (parent->item_list, item);
      g_assert (link != NULL);

      if (put_item_after (link, NULL)) {
            redraw_and_repick_if_mapped (item);
      }
}

/**
 * eel_canvas_item_send_behind:
 * @item: A canvas item.
 * @behind_item: The canvas item to put item behind, or NULL
 *
 * Moves item to a in the position in the stacking order so that
 * it is placed immediately below behind_item, or at the top if
 * behind_item is NULL.
 **/
void
eel_canvas_item_send_behind (EelCanvasItem *item,
                       EelCanvasItem *behind_item)
{
      GList *item_list;
      int item_position, behind_position;

      g_return_if_fail (EEL_IS_CANVAS_ITEM (item));

      if (behind_item == NULL) {
            eel_canvas_item_raise_to_top (item);
            return;
      }

      g_return_if_fail (EEL_IS_CANVAS_ITEM (behind_item));
      g_return_if_fail (item->parent == behind_item->parent);

      item_list = EEL_CANVAS_GROUP (item->parent)->item_list;

      item_position = g_list_index (item_list, item);
      g_assert (item_position != -1);
      behind_position = g_list_index (item_list, behind_item);
      g_assert (behind_position != -1);
      g_assert (item_position != behind_position);

      if (item_position == behind_position - 1) {
            return;
      }

      if (item_position < behind_position) {
            eel_canvas_item_raise (item, (behind_position - 1) - item_position);
      } else {
            eel_canvas_item_lower (item, item_position - behind_position);
      }
}

/**
 * eel_canvas_item_show:
 * @item: A canvas item.
 *
 * Shows a canvas item.  If the item was already shown, then no action is taken.
 **/
void
eel_canvas_item_show (EelCanvasItem *item)
{
      g_return_if_fail (EEL_IS_CANVAS_ITEM (item));

      if (!(item->flags & EEL_CANVAS_ITEM_VISIBLE)) {
            item->flags |= EEL_CANVAS_ITEM_VISIBLE;
            
            if (!(item->flags & EEL_CANVAS_ITEM_REALIZED))
                  (* EEL_CANVAS_ITEM_GET_CLASS (item)->realize) (item);

            if (item->parent != NULL) {
                  if (!(item->flags & EEL_CANVAS_ITEM_MAPPED) &&
                      item->parent->flags & EEL_CANVAS_ITEM_MAPPED)
                        (* EEL_CANVAS_ITEM_GET_CLASS (item)->map) (item);
            } else {
                  if (!(item->flags & EEL_CANVAS_ITEM_MAPPED) &&
                      gtk_widget_get_mapped (GTK_WIDGET (item->canvas)))
                        (* EEL_CANVAS_ITEM_GET_CLASS (item)->map) (item);
            }

            redraw_and_repick_if_mapped (item);
      }
}


/**
 * eel_canvas_item_hide:
 * @item: A canvas item.
 *
 * Hides a canvas item.  If the item was already hidden, then no action is
 * taken.
 **/
void
eel_canvas_item_hide (EelCanvasItem *item)
{
      g_return_if_fail (EEL_IS_CANVAS_ITEM (item));

      if (item->flags & EEL_CANVAS_ITEM_VISIBLE) {
            item->flags &= ~EEL_CANVAS_ITEM_VISIBLE;

            redraw_and_repick_if_mapped (item);
            
            if (item->flags & EEL_CANVAS_ITEM_MAPPED)
                  (* EEL_CANVAS_ITEM_GET_CLASS (item)->unmap) (item);

            /* No need to unrealize when we just want to hide */
      }
}


/**
 * eel_canvas_item_grab:
 * @item: A canvas item.
 * @event_mask: Mask of events that will be sent to this item.
 * @cursor: If non-NULL, the cursor that will be used while the grab is active.
 * @etime: The timestamp required for grabbing the mouse, or GDK_CURRENT_TIME.
 *
 * Specifies that all events that match the specified event mask should be sent
 * to the specified item, and also grabs the mouse by calling
 * gdk_pointer_grab().  The event mask is also used when grabbing the pointer.
 * If @cursor is not NULL, then that cursor is used while the grab is active.
 * The @etime parameter is the timestamp required for grabbing the mouse.
 *
 * Return value: If an item was already grabbed, it returns %GDK_GRAB_ALREADY_GRABBED.  If
 * the specified item was hidden by calling eel_canvas_item_hide(), then it
 * returns %GDK_GRAB_NOT_VIEWABLE.  Else, it returns the result of calling
 * gdk_pointer_grab().
 **/
int
eel_canvas_item_grab (EelCanvasItem *item, guint event_mask, GdkCursor *cursor, guint32 etime)
{
      int retval;

      g_return_val_if_fail (EEL_IS_CANVAS_ITEM (item), GDK_GRAB_NOT_VIEWABLE);
      g_return_val_if_fail (gtk_widget_get_mapped (GTK_WIDGET (item->canvas)),
                        GDK_GRAB_NOT_VIEWABLE);

      if (item->canvas->grabbed_item)
            return GDK_GRAB_ALREADY_GRABBED;

      if (!(item->flags & EEL_CANVAS_ITEM_MAPPED))
            return GDK_GRAB_NOT_VIEWABLE;

      retval = gdk_pointer_grab (gtk_layout_get_bin_window (&item->canvas->layout),
                           FALSE,
                           event_mask,
                           NULL,
                           cursor,
                           etime);

      if (retval != GDK_GRAB_SUCCESS)
            return retval;

      item->canvas->grabbed_item = item;
      item->canvas->grabbed_event_mask = event_mask;
      item->canvas->current_item = item; /* So that events go to the grabbed item */

      return retval;
}


/**
 * eel_canvas_item_ungrab:
 * @item: A canvas item that holds a grab.
 * @etime: The timestamp for ungrabbing the mouse.
 *
 * Ungrabs the item, which must have been grabbed in the canvas, and ungrabs the
 * mouse.
 **/
void
eel_canvas_item_ungrab (EelCanvasItem *item, guint32 etime)
{
      GdkDisplay *display;

      g_return_if_fail (EEL_IS_CANVAS_ITEM (item));

      if (item->canvas->grabbed_item != item)
            return;

      display = gtk_widget_get_display (GTK_WIDGET (item->canvas));
      item->canvas->grabbed_item = NULL;
      gdk_display_pointer_ungrab (display, etime);
}


/**
 * eel_canvas_item_w2i:
 * @item: A canvas item.
 * @x: X coordinate to convert (input/output value).
 * @y: Y coordinate to convert (input/output value).
 *
 * Converts a coordinate pair from world coordinates to item-relative
 * coordinates.
 **/
void
eel_canvas_item_w2i (EelCanvasItem *item, double *x, double *y)
{
      g_return_if_fail (EEL_IS_CANVAS_ITEM (item));
      g_return_if_fail (x != NULL);
      g_return_if_fail (y != NULL);

      item = item->parent;
      while (item) {
            if (EEL_IS_CANVAS_GROUP (item)) {
                  *x -= EEL_CANVAS_GROUP (item)->xpos;
                  *y -= EEL_CANVAS_GROUP (item)->ypos;
            }

            item = item->parent;
      }
}


/**
 * eel_canvas_item_i2w:
 * @item: A canvas item.
 * @x: X coordinate to convert (input/output value).
 * @y: Y coordinate to convert (input/output value).
 *
 * Converts a coordinate pair from item-relative coordinates to world
 * coordinates.
 **/
void
eel_canvas_item_i2w (EelCanvasItem *item, double *x, double *y)
{
      g_return_if_fail (EEL_IS_CANVAS_ITEM (item));
      g_return_if_fail (x != NULL);
      g_return_if_fail (y != NULL);

      item = item->parent;
      while (item) {
            if (EEL_IS_CANVAS_GROUP (item)) {
                  *x += EEL_CANVAS_GROUP (item)->xpos;
                  *y += EEL_CANVAS_GROUP (item)->ypos;
            }

            item = item->parent;
      }
}

/* Returns whether the item is an inferior of or is equal to the parent. */
static int
is_descendant (EelCanvasItem *item, EelCanvasItem *parent)
{
      for (; item; item = item->parent)
            if (item == parent)
                  return TRUE;

      return FALSE;
}

/**
 * eel_canvas_item_reparent:
 * @item: A canvas item.
 * @new_group: A canvas group.
 *
 * Changes the parent of the specified item to be the new group.  The item keeps
 * its group-relative coordinates as for its old parent, so the item may change
 * its absolute position within the canvas.
 **/
void
eel_canvas_item_reparent (EelCanvasItem *item, EelCanvasGroup *new_group)
{
      g_return_if_fail (EEL_IS_CANVAS_ITEM (item));
      g_return_if_fail (EEL_IS_CANVAS_GROUP (new_group));

      /* Both items need to be in the same canvas */
      g_return_if_fail (item->canvas == EEL_CANVAS_ITEM (new_group)->canvas);

      /* The group cannot be an inferior of the item or be the item itself --
       * this also takes care of the case where the item is the root item of
       * the canvas.  */
      g_return_if_fail (!is_descendant (EEL_CANVAS_ITEM (new_group), item));

      /* Everything is ok, now actually reparent the item */

      g_object_ref (G_OBJECT (item)); /* protect it from the unref in group_remove */

      eel_canvas_item_request_redraw (item);

      group_remove (EEL_CANVAS_GROUP (item->parent), item);
      item->parent = EEL_CANVAS_ITEM (new_group);
      /* item->canvas is unchanged.  */
      group_add (new_group, item);

      /* Redraw and repick */

      redraw_and_repick_if_mapped (item);

      g_object_unref (G_OBJECT (item));
}

/**
 * eel_canvas_item_grab_focus:
 * @item: A canvas item.
 *
 * Makes the specified item take the keyboard focus, so all keyboard events will
 * be sent to it.  If the canvas widget itself did not have the focus, it grabs
 * it as well.
 **/
void
eel_canvas_item_grab_focus (EelCanvasItem *item)
{
      EelCanvasItem *focused_item;
      GdkEvent ev;

      g_return_if_fail (EEL_IS_CANVAS_ITEM (item));
      g_return_if_fail (gtk_widget_get_can_focus (GTK_WIDGET (item->canvas)));

      focused_item = item->canvas->focused_item;

      if (focused_item) {
            ev.focus_change.type = GDK_FOCUS_CHANGE;
            ev.focus_change.window = gtk_layout_get_bin_window (GTK_LAYOUT (item->canvas));
            ev.focus_change.send_event = FALSE;
            ev.focus_change.in = FALSE;

            emit_event (item->canvas, &ev);
      }

      item->canvas->focused_item = item;
      gtk_widget_grab_focus (GTK_WIDGET (item->canvas));

      if (focused_item) {                                                     
            ev.focus_change.type = GDK_FOCUS_CHANGE;                        
            ev.focus_change.window = gtk_layout_get_bin_window (GTK_LAYOUT (item->canvas));
            ev.focus_change.send_event = FALSE;                             
            ev.focus_change.in = TRUE;                                      

            emit_event (item->canvas, &ev);                          
      }                               
}


/**
 * eel_canvas_item_get_bounds:
 * @item: A canvas item.
 * @x1: Leftmost edge of the bounding box (return value).
 * @y1: Upper edge of the bounding box (return value).
 * @x2: Rightmost edge of the bounding box (return value).
 * @y2: Lower edge of the bounding box (return value).
 *
 * Queries the bounding box of a canvas item.  The bounds are returned in the
 * coordinate system of the item's parent.
 **/
void
eel_canvas_item_get_bounds (EelCanvasItem *item, double *x1, double *y1, double *x2, double *y2)
{
      double tx1, ty1, tx2, ty2;

      g_return_if_fail (EEL_IS_CANVAS_ITEM (item));

      tx1 = ty1 = tx2 = ty2 = 0.0;

      /* Get the item's bounds in its coordinate system */

      if (EEL_CANVAS_ITEM_GET_CLASS (item)->bounds)
            (* EEL_CANVAS_ITEM_GET_CLASS (item)->bounds) (item, &tx1, &ty1, &tx2, &ty2);

      /* Return the values */

      if (x1)
            *x1 = tx1;

      if (y1)
            *y1 = ty1;

      if (x2)
            *x2 = tx2;

      if (y2)
            *y2 = ty2;
}


/**
 * eel_canvas_item_request_update
 * @item: A canvas item.
 *
 * To be used only by item implementations.  Requests that the canvas queue an
 * update for the specified item.
 **/
void
eel_canvas_item_request_update (EelCanvasItem *item)
{
      if (NULL == item->canvas)
            return;

      g_return_if_fail (!item->canvas->doing_update);

      if (item->flags & EEL_CANVAS_ITEM_NEED_UPDATE)
            return;

      item->flags |= EEL_CANVAS_ITEM_NEED_UPDATE;

      if (item->parent != NULL) {
            /* Recurse up the tree */
            eel_canvas_item_request_update (item->parent);
      } else {
            /* Have reached the top of the tree, make sure the update call gets scheduled. */
            eel_canvas_request_update (item->canvas);
      }
}

/**
 * eel_canvas_item_request_update
 * @item: A canvas item.
 *
 * Convenience function that informs a canvas that the specified item needs
 * to be repainted. To be used by item implementations
 **/
void
eel_canvas_item_request_redraw (EelCanvasItem *item)
{
      if (item->flags & EEL_CANVAS_ITEM_MAPPED)
            eel_canvas_request_redraw (item->canvas,
                                 item->x1, item->y1,
                                 item->x2 + 1, item->y2 + 1);
}



/*** EelCanvasGroup ***/


enum {
      GROUP_PROP_0,
      GROUP_PROP_X,
      GROUP_PROP_Y
};


static void eel_canvas_group_class_init  (EelCanvasGroupClass *klass);
static void eel_canvas_group_init        (EelCanvasGroup      *group);
static void eel_canvas_group_set_property(GObject               *object, 
                                  guint                  param_id,
                                  const GValue          *value,
                                  GParamSpec            *pspec);
static void eel_canvas_group_get_property(GObject               *object,
                                  guint                  param_id,
                                  GValue                *value,
                                  GParamSpec            *pspec);

static void eel_canvas_group_destroy     (GtkObject             *object);

static void   eel_canvas_group_update      (EelCanvasItem *item,
                                    double           i2w_dx,
                                    double           i2w_dy,
                                    int              flags);
static void   eel_canvas_group_unrealize   (EelCanvasItem *item);
static void   eel_canvas_group_map         (EelCanvasItem *item);
static void   eel_canvas_group_unmap       (EelCanvasItem *item);
static void   eel_canvas_group_draw        (EelCanvasItem *item, GdkDrawable *drawable,
                                    GdkEventExpose *expose);
static double eel_canvas_group_point       (EelCanvasItem *item, double x, double y,
                                    int cx, int cy,
                                    EelCanvasItem **actual_item);
static void   eel_canvas_group_translate   (EelCanvasItem *item, double dx, double dy);
static void   eel_canvas_group_bounds      (EelCanvasItem *item, double *x1, double *y1,
                                    double *x2, double *y2);


static EelCanvasItemClass *group_parent_class;


/**
 * eel_canvas_group_get_type:
 *
 * Registers the &EelCanvasGroup class if necessary, and returns the type ID
 * associated to it.
 *
 * Return value:  The type ID of the &EelCanvasGroup class.
 **/
GType
eel_canvas_group_get_type (void)
{
      static GType group_type = 0;

      if (!group_type) {
            static const GTypeInfo group_info = {
                  sizeof (EelCanvasGroupClass),
                  (GBaseInitFunc) NULL,
                  (GBaseFinalizeFunc) NULL,
                  (GClassInitFunc) eel_canvas_group_class_init,
                  NULL,           /* class_finalize */
                  NULL,           /* class_data */
                  sizeof (EelCanvasGroup),
                  0,              /* n_preallocs */
                  (GInstanceInitFunc) eel_canvas_group_init

      
            };

            group_type = g_type_register_static (eel_canvas_item_get_type (),
                                         "EelCanvasGroup",
                                         &group_info,
                                         0);
      }

      return group_type;
}

/* Class initialization function for EelCanvasGroupClass */
static void
eel_canvas_group_class_init (EelCanvasGroupClass *klass)
{
      GObjectClass *gobject_class;
      GtkObjectClass *object_class;
      EelCanvasItemClass *item_class;

      gobject_class = (GObjectClass *) klass;
      object_class = (GtkObjectClass *) klass;
      item_class = (EelCanvasItemClass *) klass;

      group_parent_class = g_type_class_peek_parent (klass);

      gobject_class->set_property = eel_canvas_group_set_property;
      gobject_class->get_property = eel_canvas_group_get_property;

      g_object_class_install_property
            (gobject_class, GROUP_PROP_X,
             g_param_spec_double ("x",
                              _("X"),
                              _("X"),
                              -G_MAXDOUBLE, G_MAXDOUBLE, 0.0,
                              G_PARAM_READWRITE));
      g_object_class_install_property
            (gobject_class, GROUP_PROP_Y,
             g_param_spec_double ("y",
                              _("Y"),
                              _("Y"),
                              -G_MAXDOUBLE, G_MAXDOUBLE, 0.0,
                              G_PARAM_READWRITE));

      object_class->destroy = eel_canvas_group_destroy;

      item_class->update = eel_canvas_group_update;
      item_class->unrealize = eel_canvas_group_unrealize;
      item_class->map = eel_canvas_group_map;
      item_class->unmap = eel_canvas_group_unmap;
      item_class->draw = eel_canvas_group_draw;
      item_class->point = eel_canvas_group_point;
      item_class->translate = eel_canvas_group_translate;
      item_class->bounds = eel_canvas_group_bounds;
}

/* Object initialization function for EelCanvasGroup */
static void
eel_canvas_group_init (EelCanvasGroup *group)
{
      group->xpos = 0.0;
      group->ypos = 0.0;
}

/* Set_property handler for canvas groups */
static void
eel_canvas_group_set_property (GObject *gobject, guint param_id,
                         const GValue *value, GParamSpec *pspec)
{
      EelCanvasItem *item;
      EelCanvasGroup *group;
      double old;
      gboolean moved;

      g_return_if_fail (EEL_IS_CANVAS_GROUP (gobject));

      item = EEL_CANVAS_ITEM (gobject);
      group = EEL_CANVAS_GROUP (gobject);

      moved = FALSE;
      switch (param_id) {
      case GROUP_PROP_X:
            old = group->xpos;
            group->xpos = g_value_get_double (value);
            if (old != group->xpos)
                  moved = TRUE;
            break;

      case GROUP_PROP_Y:
            old = group->ypos;
            group->ypos = g_value_get_double (value);
            if (old != group->ypos)
                  moved = TRUE;
            break;

      default:
            G_OBJECT_WARN_INVALID_PROPERTY_ID (gobject, param_id, pspec);
            break;
      }

      if (moved) {
            item->flags |= EEL_CANVAS_ITEM_NEED_DEEP_UPDATE;
            if (item->parent != NULL)
                  eel_canvas_item_request_update (item->parent);
            else
                  eel_canvas_request_update (item->canvas);
      }
}

/* Get_property handler for canvas groups */
static void
eel_canvas_group_get_property (GObject *gobject, guint param_id,
                         GValue *value, GParamSpec *pspec)
{
      EelCanvasItem *item;
      EelCanvasGroup *group;

      g_return_if_fail (EEL_IS_CANVAS_GROUP (gobject));

      item = EEL_CANVAS_ITEM (gobject);
      group = EEL_CANVAS_GROUP (gobject);

      switch (param_id) {
      case GROUP_PROP_X:
            g_value_set_double (value, group->xpos);
            break;

      case GROUP_PROP_Y:
            g_value_set_double (value, group->ypos);
            break;

      default:
            G_OBJECT_WARN_INVALID_PROPERTY_ID (gobject, param_id, pspec);
            break;
      }
}

/* Destroy handler for canvas groups */
static void
eel_canvas_group_destroy (GtkObject *object)
{
      EelCanvasGroup *group;
      EelCanvasItem *child;
      GList *list;

      g_return_if_fail (EEL_IS_CANVAS_GROUP (object));

      group = EEL_CANVAS_GROUP (object);

      list = group->item_list;
      while (list) {
            child = list->data;
            list = list->next;

            gtk_object_destroy (GTK_OBJECT (child));
      }

      if (GTK_OBJECT_CLASS (group_parent_class)->destroy)
            (* GTK_OBJECT_CLASS (group_parent_class)->destroy) (object);
}

/* Update handler for canvas groups */
static void
eel_canvas_group_update (EelCanvasItem *item, double i2w_dx, double i2w_dy, int flags)
{
      EelCanvasGroup *group;
      GList *list;
      EelCanvasItem *i;
      double bbox_x0, bbox_y0, bbox_x1, bbox_y1;
      gboolean first = TRUE;

      group = EEL_CANVAS_GROUP (item);

      (* group_parent_class->update) (item, i2w_dx, i2w_dy, flags);

      bbox_x0 = 0;
      bbox_y0 = 0;
      bbox_x1 = 0;
      bbox_y1 = 0;

      for (list = group->item_list; list; list = list->next) {
            i = list->data;

            eel_canvas_item_invoke_update (i, i2w_dx + group->xpos, i2w_dy + group->ypos, flags);

            if (first) {
                  first = FALSE;
                  bbox_x0 = i->x1;
                  bbox_y0 = i->y1;
                  bbox_x1 = i->x2;
                  bbox_y1 = i->y2;
            } else {
                  bbox_x0 = MIN (bbox_x0, i->x1);
                  bbox_y0 = MIN (bbox_y0, i->y1);
                  bbox_x1 = MAX (bbox_x1, i->x2);
                  bbox_y1 = MAX (bbox_y1, i->y2);
            }
      }
      item->x1 = bbox_x0;
      item->y1 = bbox_y0;
      item->x2 = bbox_x1;
      item->y2 = bbox_y1;
}

/* Unrealize handler for canvas groups */
static void
eel_canvas_group_unrealize (EelCanvasItem *item)
{
      EelCanvasGroup *group;
      GList *list;
      EelCanvasItem *i;

      group = EEL_CANVAS_GROUP (item);

      /* Unmap group before children to avoid flash */
      if (item->flags & EEL_CANVAS_ITEM_MAPPED)
            (* EEL_CANVAS_ITEM_GET_CLASS (item)->unmap) (item);

      for (list = group->item_list; list; list = list->next) {
            i = list->data;

            if (i->flags & EEL_CANVAS_ITEM_REALIZED)
                  (* EEL_CANVAS_ITEM_GET_CLASS (i)->unrealize) (i);
      }

      (* group_parent_class->unrealize) (item);
}

/* Map handler for canvas groups */
static void
eel_canvas_group_map (EelCanvasItem *item)
{
      EelCanvasGroup *group;
      GList *list;
      EelCanvasItem *i;

      group = EEL_CANVAS_GROUP (item);

      for (list = group->item_list; list; list = list->next) {
            i = list->data;

            if (i->flags & EEL_CANVAS_ITEM_VISIBLE &&
                !(i->flags & EEL_CANVAS_ITEM_MAPPED)) {
                  if (!(i->flags & EEL_CANVAS_ITEM_REALIZED))
                        (* EEL_CANVAS_ITEM_GET_CLASS (i)->realize) (i);
                        
                  (* EEL_CANVAS_ITEM_GET_CLASS (i)->map) (i);
            }
      }

      (* group_parent_class->map) (item);
}

/* Unmap handler for canvas groups */
static void
eel_canvas_group_unmap (EelCanvasItem *item)
{
      EelCanvasGroup *group;
      GList *list;
      EelCanvasItem *i;

      group = EEL_CANVAS_GROUP (item);

      for (list = group->item_list; list; list = list->next) {
            i = list->data;

            if (i->flags & EEL_CANVAS_ITEM_MAPPED)
                  (* EEL_CANVAS_ITEM_GET_CLASS (i)->unmap) (i);
      }

      (* group_parent_class->unmap) (item);
}

/* Draw handler for canvas groups */
static void
eel_canvas_group_draw (EelCanvasItem *item, GdkDrawable *drawable,
                   GdkEventExpose *expose)
{
      EelCanvasGroup *group;
      GList *list;
      EelCanvasItem *child = NULL;

      group = EEL_CANVAS_GROUP (item);

      for (list = group->item_list; list; list = list->next) {
            child = list->data;

            if ((child->flags & EEL_CANVAS_ITEM_MAPPED) &&
                (EEL_CANVAS_ITEM_GET_CLASS (child)->draw)) {
                  GdkRectangle child_rect;
                  
                  child_rect.x = child->x1;
                  child_rect.y = child->y1;
                  child_rect.width = child->x2 - child->x1 + 1;
                  child_rect.height = child->y2 - child->y1 + 1;

                  if (gdk_region_rect_in (expose->region, &child_rect) != GDK_OVERLAP_RECTANGLE_OUT)
                        (* EEL_CANVAS_ITEM_GET_CLASS (child)->draw) (child, drawable, expose);
            }
      }
}

/* Point handler for canvas groups */
static double
eel_canvas_group_point (EelCanvasItem *item, double x, double y, int cx, int cy,
                  EelCanvasItem **actual_item)
{
      EelCanvasGroup *group;
      GList *list;
      EelCanvasItem *child, *point_item;
      int x1, y1, x2, y2;
      double gx, gy;
      double dist, best;
      int has_point;

      group = EEL_CANVAS_GROUP (item);

      x1 = cx - item->canvas->close_enough;
      y1 = cy - item->canvas->close_enough;
      x2 = cx + item->canvas->close_enough;
      y2 = cy + item->canvas->close_enough;

      best = 0.0;
      *actual_item = NULL;

      gx = x - group->xpos;
      gy = y - group->ypos;

      dist = 0.0; /* keep gcc happy */

      for (list = group->item_list; list; list = list->next) {
            child = list->data;

            if ((child->x1 > x2) || (child->y1 > y2) || (child->x2 < x1) || (child->y2 < y1))
                  continue;

            point_item = NULL; /* cater for incomplete item implementations */

            if ((child->flags & EEL_CANVAS_ITEM_MAPPED)
                && EEL_CANVAS_ITEM_GET_CLASS (child)->point) {
                  dist = eel_canvas_item_invoke_point (child, gx, gy, cx, cy, &point_item);
                  has_point = TRUE;
            } else
                  has_point = FALSE;

            if (has_point
                && point_item
                && ((int) (dist * item->canvas->pixels_per_unit + 0.5)
                  <= item->canvas->close_enough)) {
                  best = dist;
                  *actual_item = point_item;
            }
      }

      return best;
}

void
eel_canvas_group_translate (EelCanvasItem *item, double dx, double dy)
{
        EelCanvasGroup *group;

        group = EEL_CANVAS_GROUP (item);

        group->xpos += dx;
        group->ypos += dy;
}

/* Bounds handler for canvas groups */
static void
eel_canvas_group_bounds (EelCanvasItem *item, double *x1, double *y1, double *x2, double *y2)
{
      EelCanvasGroup *group;
      EelCanvasItem *child;
      GList *list;
      double tx1, ty1, tx2, ty2;
      double minx, miny, maxx, maxy;
      int set;

      group = EEL_CANVAS_GROUP (item);

      /* Get the bounds of the first visible item */

      child = NULL; /* Unnecessary but eliminates a warning. */

      set = FALSE;

      for (list = group->item_list; list; list = list->next) {
            child = list->data;

            if (child->flags & EEL_CANVAS_ITEM_MAPPED) {
                  set = TRUE;
                  eel_canvas_item_get_bounds (child, &minx, &miny, &maxx, &maxy);
                  break;
            }
      }

      /* If there were no visible items, return an empty bounding box */

      if (!set) {
            *x1 = *y1 = *x2 = *y2 = 0.0;
            return;
      }

      /* Now we can grow the bounds using the rest of the items */

      list = list->next;

      for (; list; list = list->next) {
            child = list->data;

            if (!(child->flags & EEL_CANVAS_ITEM_MAPPED))
                  continue;

            eel_canvas_item_get_bounds (child, &tx1, &ty1, &tx2, &ty2);

            if (tx1 < minx)
                  minx = tx1;

            if (ty1 < miny)
                  miny = ty1;

            if (tx2 > maxx)
                  maxx = tx2;

            if (ty2 > maxy)
                  maxy = ty2;
      }

      /* Make the bounds be relative to our parent's coordinate system */

      if (item->parent) {
            minx += group->xpos;
            miny += group->ypos;
            maxx += group->xpos;
            maxy += group->ypos;
      }
      
      *x1 = minx;
      *y1 = miny;
      *x2 = maxx;
      *y2 = maxy;
}

/* Adds an item to a group */
static void
group_add (EelCanvasGroup *group, EelCanvasItem *item)
{
#if GLIB_CHECK_VERSION(2,10,0) && GTK_CHECK_VERSION(2,8,14)
      g_object_ref_sink (item);
#else
      g_object_ref (item);
      gtk_object_sink (GTK_OBJECT (item));
#endif

      if (!group->item_list) {
            group->item_list = g_list_append (group->item_list, item);
            group->item_list_end = group->item_list;
      } else
            group->item_list_end = g_list_append (group->item_list_end, item)->next;

      if (item->flags & EEL_CANVAS_ITEM_VISIBLE &&
          group->item.flags & EEL_CANVAS_ITEM_MAPPED) {
            if (!(item->flags & EEL_CANVAS_ITEM_REALIZED))
                  (* EEL_CANVAS_ITEM_GET_CLASS (item)->realize) (item);
            
            if (!(item->flags & EEL_CANVAS_ITEM_MAPPED))
                  (* EEL_CANVAS_ITEM_GET_CLASS (item)->map) (item);
      }
}

/* Removes an item from a group */
static void
group_remove (EelCanvasGroup *group, EelCanvasItem *item)
{
      GList *children;

      g_return_if_fail (EEL_IS_CANVAS_GROUP (group));
      g_return_if_fail (EEL_IS_CANVAS_ITEM (item));

      for (children = group->item_list; children; children = children->next)
            if (children->data == item) {
                  if (item->flags & EEL_CANVAS_ITEM_MAPPED)
                        (* EEL_CANVAS_ITEM_GET_CLASS (item)->unmap) (item);

                  if (item->flags & EEL_CANVAS_ITEM_REALIZED)
                        (* EEL_CANVAS_ITEM_GET_CLASS (item)->unrealize) (item);

                  /* Unparent the child */

                  item->parent = NULL;
                  /* item->canvas = NULL; */
                  g_object_unref (G_OBJECT (item));

                  /* Remove it from the list */

                  if (children == group->item_list_end)
                        group->item_list_end = children->prev;

                  group->item_list = g_list_remove_link (group->item_list, children);
                  g_list_free (children);
                  break;
            }
}


/*** EelCanvas ***/


enum {
      DRAW_BACKGROUND,
      LAST_SIGNAL
};

static void eel_canvas_class_init          (EelCanvasClass *klass);
static void eel_canvas_init                (EelCanvas      *canvas);
static void eel_canvas_destroy             (GtkObject        *object);
static void eel_canvas_map                 (GtkWidget        *widget);
static void eel_canvas_unmap               (GtkWidget        *widget);
static void eel_canvas_realize             (GtkWidget        *widget);
static void eel_canvas_unrealize           (GtkWidget        *widget);
static void eel_canvas_size_allocate       (GtkWidget        *widget,
                                    GtkAllocation    *allocation);
static gint eel_canvas_button              (GtkWidget        *widget,
                                    GdkEventButton   *event);
static gint eel_canvas_motion              (GtkWidget        *widget,
                                    GdkEventMotion   *event);
static gint eel_canvas_expose              (GtkWidget        *widget,
                                    GdkEventExpose   *event);
static gint eel_canvas_key                 (GtkWidget        *widget,
                                    GdkEventKey      *event);
static gint eel_canvas_crossing            (GtkWidget        *widget,
                                    GdkEventCrossing *event);
static gint eel_canvas_focus_in            (GtkWidget        *widget,
                                    GdkEventFocus    *event);
static gint eel_canvas_focus_out           (GtkWidget        *widget,
                                    GdkEventFocus    *event);
static void eel_canvas_request_update_real (EelCanvas      *canvas);
static void eel_canvas_draw_background     (EelCanvas      *canvas,
                                    int               x,
                                    int               y,
                                    int               width,
                                    int               height);


static GtkLayoutClass *canvas_parent_class;

static guint canvas_signals[LAST_SIGNAL];

/**
 * eel_canvas_get_type:
 *
 * Registers the &EelCanvas class if necessary, and returns the type ID
 * associated to it.
 *
 * Return value:  The type ID of the &EelCanvas class.
 **/
GType
eel_canvas_get_type (void)
{
      static GType canvas_type = 0;

      if (!canvas_type) {
            static const GTypeInfo canvas_info = {
                  sizeof (EelCanvasClass),
                  (GBaseInitFunc) NULL,
                  (GBaseFinalizeFunc) NULL,
                  (GClassInitFunc) eel_canvas_class_init,
                  NULL,           /* class_finalize */
                  NULL,           /* class_data */
                  sizeof (EelCanvas),
                  0,              /* n_preallocs */
                  (GInstanceInitFunc) eel_canvas_init
            };

            canvas_type = g_type_register_static (gtk_layout_get_type (),
                                          "EelCanvas",
                                          &canvas_info,
                                          0);
      }

      return canvas_type;
}

static void
eel_canvas_get_property (GObject    *object, 
                     guint       prop_id,
                     GValue     *value,
                     GParamSpec *pspec)
{
      switch (prop_id) {
      default:
            G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
            break;
      }
}

static void
eel_canvas_set_property (GObject      *object, 
                     guint         prop_id,
                     const GValue *value,
                     GParamSpec   *pspec)
{
      switch (prop_id) {
      default:
            G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
            break;
      }
}

static void
eel_canvas_accessible_adjustment_changed (GtkAdjustment *adjustment,
                                gpointer       data)
{
      AtkObject *atk_obj;

      /* The scrollbars have changed */
      atk_obj = ATK_OBJECT (data);

      g_signal_emit_by_name (atk_obj, "visible_data_changed");
}

static void
eel_canvas_accessible_initialize (AtkObject *obj, 
                          gpointer   data)
{
      EelCanvas *canvas;

      if (ATK_OBJECT_CLASS (accessible_parent_class)->initialize != NULL) 
            ATK_OBJECT_CLASS (accessible_parent_class)->initialize (obj, data);

      canvas = EEL_CANVAS (data);
      g_signal_connect (gtk_layout_get_hadjustment (&canvas->layout),
                    "value_changed",
                    G_CALLBACK (eel_canvas_accessible_adjustment_changed),
                    obj);
      g_signal_connect (gtk_layout_get_vadjustment (&canvas->layout),
                    "value_changed",
                    G_CALLBACK (eel_canvas_accessible_adjustment_changed),
                    obj);
      
      obj->role = ATK_ROLE_LAYERED_PANE;
}

static gint
eel_canvas_accessible_get_n_children (AtkObject* obj)
{
      GtkAccessible *accessible;
      GtkWidget *widget;
      EelCanvas *canvas;
      EelCanvasGroup *root_group;

      accessible = GTK_ACCESSIBLE (obj);
      widget = gtk_accessible_get_widget (accessible);
      if (widget == NULL) {
            /* State is defunct */
            return 0;
      }

      g_return_val_if_fail (EEL_IS_CANVAS (widget), 0);

      canvas = EEL_CANVAS (widget);
      root_group = eel_canvas_root (canvas);
      g_return_val_if_fail (root_group, 0);
      return 1;
}

static AtkObject*
eel_canvas_accessible_ref_child (AtkObject *obj,
                                 gint       i)
{
      GtkAccessible *accessible;
      GtkWidget *widget;
      EelCanvas *canvas;
      EelCanvasGroup *root_group;
      AtkObject *atk_object;

      /* Canvas only has one child, so return NULL if index is non zero */
      if (i != 0) {
            return NULL;
      }

      accessible = GTK_ACCESSIBLE (obj);
      widget = gtk_accessible_get_widget (accessible);
      if (widget == NULL) {
            /* State is defunct */
            return NULL;
      }

      canvas = EEL_CANVAS (widget);
      root_group = eel_canvas_root (canvas);
      g_return_val_if_fail (root_group, NULL);
      atk_object = atk_gobject_accessible_for_object (G_OBJECT (root_group));
      g_object_ref (atk_object);
      
      g_warning ("Accessible support for FooGroup needs to be implemented");
      
      return atk_object;
}

static void
eel_canvas_accessible_class_init (AtkObjectClass *klass)
{
      accessible_parent_class = g_type_class_peek_parent (klass);

      klass->initialize = eel_canvas_accessible_initialize;
      klass->get_n_children = eel_canvas_accessible_get_n_children;
      klass->ref_child = eel_canvas_accessible_ref_child;
}

static GType
eel_canvas_accessible_get_type (void)
{
      static GType type = 0;

      if (!type) {
            AtkObjectFactory *factory;
            GType parent_atk_type;
            GTypeQuery query;
            GTypeInfo tinfo = { 0 };

            factory = atk_registry_get_factory (atk_get_default_registry(),
                                        GTK_TYPE_WIDGET);
            if (!factory) {
                  return G_TYPE_INVALID;
            }
            parent_atk_type = atk_object_factory_get_accessible_type (factory);
            if (!parent_atk_type) {
                  return G_TYPE_INVALID;
            }
            g_type_query (parent_atk_type, &query);
            tinfo.class_init = (GClassInitFunc) eel_canvas_accessible_class_init;
            tinfo.class_size = query.class_size;
            tinfo.instance_size = query.instance_size;
            type = g_type_register_static (parent_atk_type,
                                     "EelCanvasAccessibility",
                                     &tinfo, 0);
      }
      return type;
}

static AtkObject *
eel_canvas_accessible_create (GObject *for_object)
{
      GType type;
      AtkObject *accessible;
      EelCanvas *canvas;

      canvas = EEL_CANVAS (for_object);
      g_return_val_if_fail (canvas != NULL, NULL);

      type = eel_canvas_accessible_get_type ();

      if (type == G_TYPE_INVALID) {
            return atk_no_op_object_new (for_object);
      }

      accessible = g_object_new (type, NULL);
      atk_object_initialize (accessible, for_object);
      return accessible;
}

static GType
eel_canvas_accessible_factory_get_accessible_type (void)
{
      return eel_canvas_accessible_get_type ();
}

static AtkObject*
eel_canvas_accessible_factory_create_accessible (GObject *obj)
{
      AtkObject *accessible;

      g_return_val_if_fail (G_IS_OBJECT (obj), NULL);

      accessible = eel_canvas_accessible_create (obj);

      return accessible;
}

static void
eel_canvas_accessible_factory_class_init (AtkObjectFactoryClass *klass)
{
      klass->create_accessible = eel_canvas_accessible_factory_create_accessible;
      klass->get_accessible_type = eel_canvas_accessible_factory_get_accessible_type;
}
 
static GType
eel_canvas_accessible_factory_get_type (void)
{
      static GType type = 0;

      if (!type) {
            static const GTypeInfo tinfo = {
                  sizeof (AtkObjectFactoryClass),
                  (GBaseInitFunc) NULL,
                  (GBaseFinalizeFunc) NULL,
                  (GClassInitFunc) eel_canvas_accessible_factory_class_init,
                  NULL,       /* class_finalize */
                  NULL,       /* class_data */
                  sizeof (AtkObjectFactory),
                  0,          /* n_preallocs */
                  NULL
            };
            type = g_type_register_static (ATK_TYPE_OBJECT_FACTORY,
                                     "EelCanvasAccessibilityFactory",
                                     &tinfo, 0);
      }

      return type;
}


/* Class initialization function for EelCanvasClass */
static void
eel_canvas_class_init (EelCanvasClass *klass)
{
      GObjectClass   *gobject_class;
      GtkObjectClass *object_class;
      GtkWidgetClass *widget_class;

      gobject_class = (GObjectClass *)klass;
      object_class  = (GtkObjectClass *) klass;
      widget_class  = (GtkWidgetClass *) klass;

      canvas_parent_class = g_type_class_peek_parent (klass);

      gobject_class->set_property = eel_canvas_set_property;
      gobject_class->get_property = eel_canvas_get_property;

      object_class->destroy = eel_canvas_destroy;

      widget_class->map = eel_canvas_map;
      widget_class->unmap = eel_canvas_unmap;
      widget_class->realize = eel_canvas_realize;
      widget_class->unrealize = eel_canvas_unrealize;
      widget_class->size_allocate = eel_canvas_size_allocate;
      widget_class->button_press_event = eel_canvas_button;
      widget_class->button_release_event = eel_canvas_button;
      widget_class->motion_notify_event = eel_canvas_motion;
      widget_class->expose_event = eel_canvas_expose;
      widget_class->key_press_event = eel_canvas_key;
      widget_class->key_release_event = eel_canvas_key;
      widget_class->enter_notify_event = eel_canvas_crossing;
      widget_class->leave_notify_event = eel_canvas_crossing;
      widget_class->focus_in_event = eel_canvas_focus_in;
      widget_class->focus_out_event = eel_canvas_focus_out;

      klass->draw_background = eel_canvas_draw_background;
      klass->request_update = eel_canvas_request_update_real;

      canvas_signals[DRAW_BACKGROUND] =
            g_signal_new ("draw_background",
                        G_TYPE_FROM_CLASS (object_class),
                        G_SIGNAL_RUN_LAST,
                        G_STRUCT_OFFSET (EelCanvasClass, draw_background),
                        NULL, NULL,
                        eel_marshal_VOID__INT_INT_INT_INT,
                        G_TYPE_NONE, 4, 
                        G_TYPE_INT, G_TYPE_INT, G_TYPE_INT, G_TYPE_INT);

      atk_registry_set_factory_type (atk_get_default_registry (),
                               EEL_TYPE_CANVAS,
                               eel_canvas_accessible_factory_get_type ());
}

/* Callback used when the root item of a canvas is destroyed.  The user should
 * never ever do this, so we panic if this happens.
 */
static void
panic_root_destroyed (GtkObject *object, gpointer data)
{
      g_error ("Eeeek, root item %p of canvas %p was destroyed!", object, data);
}

/* Object initialization function for EelCanvas */
static void
eel_canvas_init (EelCanvas *canvas)
{
      guint width, height;
      gtk_widget_set_can_focus (GTK_WIDGET (canvas), TRUE);

      gtk_widget_set_redraw_on_allocate (GTK_WIDGET (canvas), FALSE);

      canvas->scroll_x1 = 0.0;
      canvas->scroll_y1 = 0.0;
      gtk_layout_get_size (&canvas->layout,
                       &width, &height);
      canvas->scroll_x2 = width;
      canvas->scroll_y2 = height;

      canvas->pixels_per_unit = 1.0;

      canvas->pick_event.type = GDK_LEAVE_NOTIFY;
      canvas->pick_event.crossing.x = 0;
      canvas->pick_event.crossing.y = 0;

      gtk_layout_set_hadjustment (GTK_LAYOUT (canvas), NULL);
      gtk_layout_set_vadjustment (GTK_LAYOUT (canvas), NULL);

      /* Create the root item as a special case */

      canvas->root = EEL_CANVAS_ITEM (g_object_new (eel_canvas_group_get_type (), NULL));
      canvas->root->canvas = canvas;

#if GLIB_CHECK_VERSION(2,10,0) && GTK_CHECK_VERSION(2,8,14)
      g_object_ref_sink (canvas->root);
#else
      g_object_ref (canvas->root);
      gtk_object_sink (GTK_OBJECT (canvas->root));
#endif

      canvas->root_destroy_id = g_signal_connect (G_OBJECT (canvas->root),
            "destroy", G_CALLBACK (panic_root_destroyed), canvas);

      canvas->need_repick = TRUE;
      canvas->doing_update = FALSE;
}

/* Convenience function to remove the idle handler of a canvas */
static void
remove_idle (EelCanvas *canvas)
{
      if (canvas->idle_id == 0)
            return;

      g_source_remove (canvas->idle_id);
      canvas->idle_id = 0;
}

/* Removes the transient state of the canvas (idle handler, grabs). */
static void
shutdown_transients (EelCanvas *canvas)
{
      /* We turn off the need_redraw flag, since if the canvas is mapped again
       * it will request a redraw anyways.  We do not turn off the need_update
       * flag, though, because updates are not queued when the canvas remaps
       * itself.
       */
      if (canvas->need_redraw) {
            canvas->need_redraw = FALSE;
      }

      if (canvas->grabbed_item) {
            GdkDisplay *display = gtk_widget_get_display (GTK_WIDGET (canvas));
            canvas->grabbed_item = NULL;
            gdk_display_pointer_ungrab (display, GDK_CURRENT_TIME);
      }

      remove_idle (canvas);
}

/* Destroy handler for EelCanvas */
static void
eel_canvas_destroy (GtkObject *object)
{
      EelCanvas *canvas;

      g_return_if_fail (EEL_IS_CANVAS (object));

      /* remember, destroy can be run multiple times! */

      canvas = EEL_CANVAS (object);

      if (canvas->root_destroy_id) {
            g_signal_handler_disconnect (G_OBJECT (canvas->root), canvas->root_destroy_id);
            canvas->root_destroy_id = 0;
      }
      if (canvas->root) {
            EelCanvasItem *root = canvas->root;
            canvas->root = NULL;
            gtk_object_destroy (GTK_OBJECT (root));
            g_object_unref (root);
      }

      shutdown_transients (canvas);

      if (GTK_OBJECT_CLASS (canvas_parent_class)->destroy)
            (* GTK_OBJECT_CLASS (canvas_parent_class)->destroy) (object);
}

/**
 * eel_canvas_new:
 * @void:
 *
 * Creates a new empty canvas.  If you wish to use the
 * &EelCanvasImage item inside this canvas, then you must push the gdk_imlib
 * visual and colormap before calling this function, and they can be popped
 * afterwards.
 *
 * Return value: A newly-created canvas.
 **/
GtkWidget *
eel_canvas_new (void)
{
      return GTK_WIDGET (g_object_new (eel_canvas_get_type (), NULL));
}

/* Map handler for the canvas */
static void
eel_canvas_map (GtkWidget *widget)
{
      EelCanvas *canvas;

      g_return_if_fail (EEL_IS_CANVAS (widget));

      /* Normal widget mapping stuff */

      if (GTK_WIDGET_CLASS (canvas_parent_class)->map)
            (* GTK_WIDGET_CLASS (canvas_parent_class)->map) (widget);

      canvas = EEL_CANVAS (widget);

      /* Map items */

      if (canvas->root->flags & EEL_CANVAS_ITEM_VISIBLE &&
          !(canvas->root->flags & EEL_CANVAS_ITEM_MAPPED) &&
          EEL_CANVAS_ITEM_GET_CLASS (canvas->root)->map)
            (* EEL_CANVAS_ITEM_GET_CLASS (canvas->root)->map) (canvas->root);
}

/* Unmap handler for the canvas */
static void
eel_canvas_unmap (GtkWidget *widget)
{
      EelCanvas *canvas;

      g_return_if_fail (EEL_IS_CANVAS (widget));

      canvas = EEL_CANVAS (widget);

      shutdown_transients (canvas);

      /* Unmap items */

      if (EEL_CANVAS_ITEM_GET_CLASS (canvas->root)->unmap)
            (* EEL_CANVAS_ITEM_GET_CLASS (canvas->root)->unmap) (canvas->root);

      /* Normal widget unmapping stuff */

      if (GTK_WIDGET_CLASS (canvas_parent_class)->unmap)
            (* GTK_WIDGET_CLASS (canvas_parent_class)->unmap) (widget);
}

/* Realize handler for the canvas */
static void
eel_canvas_realize (GtkWidget *widget)
{
      EelCanvas *canvas;

      g_return_if_fail (EEL_IS_CANVAS (widget));

      /* Normal widget realization stuff */

      if (GTK_WIDGET_CLASS (canvas_parent_class)->realize)
            (* GTK_WIDGET_CLASS (canvas_parent_class)->realize) (widget);

      canvas = EEL_CANVAS (widget);

      gdk_window_set_events (gtk_layout_get_bin_window (&canvas->layout),
                         (gdk_window_get_events (gtk_layout_get_bin_window (&canvas->layout))
                         | GDK_EXPOSURE_MASK
                         | GDK_BUTTON_PRESS_MASK
                         | GDK_BUTTON_RELEASE_MASK
                         | GDK_POINTER_MOTION_MASK
                         | GDK_KEY_PRESS_MASK
                         | GDK_KEY_RELEASE_MASK
                         | GDK_ENTER_NOTIFY_MASK
                         | GDK_LEAVE_NOTIFY_MASK
                         | GDK_FOCUS_CHANGE_MASK));

      /* Create our own temporary pixmap gc and realize all the items */

      canvas->pixmap_gc = gdk_gc_new (gtk_layout_get_bin_window (&canvas->layout));

      (* EEL_CANVAS_ITEM_GET_CLASS (canvas->root)->realize) (canvas->root);
}

/* Unrealize handler for the canvas */
static void
eel_canvas_unrealize (GtkWidget *widget)
{
      EelCanvas *canvas;

      g_return_if_fail (EEL_IS_CANVAS (widget));

      canvas = EEL_CANVAS (widget);

      shutdown_transients (canvas);

      /* Unrealize items and parent widget */

      (* EEL_CANVAS_ITEM_GET_CLASS (canvas->root)->unrealize) (canvas->root);

      g_object_unref (canvas->pixmap_gc);
      canvas->pixmap_gc = NULL;

      if (GTK_WIDGET_CLASS (canvas_parent_class)->unrealize)
            (* GTK_WIDGET_CLASS (canvas_parent_class)->unrealize) (widget);
}

/* Handles scrolling of the canvas.  Adjusts the scrolling and zooming offset to
 * keep as much as possible of the canvas scrolling region in view.
 */
static void
scroll_to (EelCanvas *canvas, int cx, int cy)
{
      int scroll_width, scroll_height;
      int right_limit, bottom_limit;
      int old_zoom_xofs, old_zoom_yofs;
      int changed_x = FALSE, changed_y = FALSE;
      int canvas_width, canvas_height;
      GtkAllocation allocation;
      GtkAdjustment *vadjustment, *hadjustment;
      guint width, height;

      gtk_widget_get_allocation (GTK_WIDGET (canvas), &allocation);
      canvas_width = allocation.width;
      canvas_height = allocation.height;

      scroll_width = floor ((canvas->scroll_x2 - canvas->scroll_x1) * canvas->pixels_per_unit + 0.5);
      scroll_height = floor ((canvas->scroll_y2 - canvas->scroll_y1) * canvas->pixels_per_unit + 0.5);

      right_limit = scroll_width - canvas_width;
      bottom_limit = scroll_height - canvas_height;

      old_zoom_xofs = canvas->zoom_xofs;
      old_zoom_yofs = canvas->zoom_yofs;

      if (right_limit < 0) {
            cx = 0;
            if (canvas->center_scroll_region) {
                  canvas->zoom_xofs = (canvas_width - scroll_width) / 2;
                  scroll_width = canvas_width;
            } else {
                  canvas->zoom_xofs = 0;
            }
      } else if (cx < 0) {
            cx = 0;
            canvas->zoom_xofs = 0;
      } else if (cx > right_limit) {
            cx = right_limit;
            canvas->zoom_xofs = 0;
      } else
            canvas->zoom_xofs = 0;

      if (bottom_limit < 0) {
            cy = 0;
            if (canvas->center_scroll_region) {
                  canvas->zoom_yofs = (canvas_height - scroll_height) / 2;
                  scroll_height = canvas_height;
            } else {
                  canvas->zoom_yofs = 0;
            }
      } else if (cy < 0) {
            cy = 0;
            canvas->zoom_yofs = 0;
      } else if (cy > bottom_limit) {
            cy = bottom_limit;
            canvas->zoom_yofs = 0;
      } else
            canvas->zoom_yofs = 0;

      if ((canvas->zoom_xofs != old_zoom_xofs) || (canvas->zoom_yofs != old_zoom_yofs)) {
            /* This can only occur, if either canvas size or widget size changes */
            /* So I think we can request full redraw here */
            /* More stuff - we have to mark root as needing fresh affine (Lauris) */
            if (!(canvas->root->flags & EEL_CANVAS_ITEM_NEED_DEEP_UPDATE)) {
                  canvas->root->flags |= EEL_CANVAS_ITEM_NEED_DEEP_UPDATE;
                  eel_canvas_request_update (canvas);
            }
            gtk_widget_queue_draw (GTK_WIDGET (canvas));
      }

      hadjustment = gtk_layout_get_hadjustment (&canvas->layout);
      vadjustment = gtk_layout_get_vadjustment (&canvas->layout);

      if (((int) gtk_adjustment_get_value (hadjustment)) != cx) {
            gtk_adjustment_set_value (hadjustment, cx);
            changed_x = TRUE;
      }

      if (((int) gtk_adjustment_get_value (vadjustment)) != cy) {
            gtk_adjustment_set_value (vadjustment, cy);
            changed_y = TRUE;
      }

      gtk_layout_get_size (&canvas->layout, &width, &height);
      if ((scroll_width != (int) width )|| (scroll_height != (int) height)) {
            gtk_layout_set_size (GTK_LAYOUT (canvas), scroll_width, scroll_height);
      }
      
      /* Signal GtkLayout that it should do a redraw. */
      if (changed_x)
            g_signal_emit_by_name (hadjustment, "value_changed");
      if (changed_y)
            g_signal_emit_by_name (vadjustment, "value_changed");
}

/* Size allocation handler for the canvas */
static void
eel_canvas_size_allocate (GtkWidget *widget, GtkAllocation *allocation)
{
      EelCanvas *canvas;
      GtkAdjustment *vadjustment, *hadjustment;

      g_return_if_fail (EEL_IS_CANVAS (widget));
      g_return_if_fail (allocation != NULL);

      if (GTK_WIDGET_CLASS (canvas_parent_class)->size_allocate)
            (* GTK_WIDGET_CLASS (canvas_parent_class)->size_allocate) (widget, allocation);

      canvas = EEL_CANVAS (widget);

      /* Recenter the view, if appropriate */

      hadjustment = gtk_layout_get_hadjustment (&canvas->layout);
      vadjustment = gtk_layout_get_vadjustment (&canvas->layout);

      gtk_adjustment_set_page_size (hadjustment, allocation->width);
      gtk_adjustment_set_page_increment (hadjustment, allocation->width / 2);

      gtk_adjustment_set_page_size (vadjustment, allocation->height);
      gtk_adjustment_set_page_increment (vadjustment, allocation->height / 2);

      scroll_to (canvas,
               gtk_adjustment_get_value (hadjustment),
               gtk_adjustment_get_value (vadjustment));

      g_signal_emit_by_name (hadjustment, "changed");
      g_signal_emit_by_name (vadjustment, "changed");
}

/* Emits an event for an item in the canvas, be it the current item, grabbed
 * item, or focused item, as appropriate.
 */

static int
emit_event (EelCanvas *canvas, GdkEvent *event)
{
      GdkEvent ev;
      gint finished;
      EelCanvasItem *item;
      EelCanvasItem *parent;
      guint mask;

      /* Could be an old pick event */
      if (!gtk_widget_get_realized (GTK_WIDGET (canvas))) {
            return FALSE;
      }

      /* Perform checks for grabbed items */

      if (canvas->grabbed_item &&
          !is_descendant (canvas->current_item, canvas->grabbed_item)) {
            return FALSE;
        }

      if (canvas->grabbed_item) {
            switch (event->type) {
            case GDK_ENTER_NOTIFY:
                  mask = GDK_ENTER_NOTIFY_MASK;
                  break;

            case GDK_LEAVE_NOTIFY:
                  mask = GDK_LEAVE_NOTIFY_MASK;
                  break;

            case GDK_MOTION_NOTIFY:
                  mask = GDK_POINTER_MOTION_MASK;
                  break;

            case GDK_BUTTON_PRESS:
            case GDK_2BUTTON_PRESS:
            case GDK_3BUTTON_PRESS:
                  mask = GDK_BUTTON_PRESS_MASK;
                  break;

            case GDK_BUTTON_RELEASE:
                  mask = GDK_BUTTON_RELEASE_MASK;
                  break;

            case GDK_KEY_PRESS:
                  mask = GDK_KEY_PRESS_MASK;
                  break;

            case GDK_KEY_RELEASE:
                  mask = GDK_KEY_RELEASE_MASK;
                  break;

            default:
                  mask = 0;
                  break;
            }

            if (!(mask & canvas->grabbed_event_mask))
                  return FALSE;
      }

      /* Convert to world coordinates -- we have two cases because of diferent
       * offsets of the fields in the event structures.
       */

      ev = *event;

      switch (ev.type)
        {
      case GDK_ENTER_NOTIFY:
      case GDK_LEAVE_NOTIFY:
            eel_canvas_window_to_world (canvas,
                                    ev.crossing.x, ev.crossing.y,
                                    &ev.crossing.x, &ev.crossing.y);
            break;

      case GDK_MOTION_NOTIFY:
                eel_canvas_window_to_world (canvas,
                                              ev.motion.x, ev.motion.y,
                                              &ev.motion.x, &ev.motion.y);
                break;

      case GDK_BUTTON_PRESS:
      case GDK_2BUTTON_PRESS:
      case GDK_3BUTTON_PRESS:
                eel_canvas_window_to_world (canvas,
                                              ev.motion.x, ev.motion.y,
                                              &ev.motion.x, &ev.motion.y);
                break;

      case GDK_BUTTON_RELEASE:
            eel_canvas_window_to_world (canvas,
                                    ev.motion.x, ev.motion.y,
                                    &ev.motion.x, &ev.motion.y);
            break;

      default:
            break;
      }

      /* Choose where we send the event */

      item = canvas->current_item;

      if (canvas->focused_item
          && ((event->type == GDK_KEY_PRESS) ||
            (event->type == GDK_KEY_RELEASE) ||
            (event->type == GDK_FOCUS_CHANGE)))
            item = canvas->focused_item;

      /* The event is propagated up the hierarchy (for if someone connected to
       * a group instead of a leaf event), and emission is stopped if a
       * handler returns TRUE, just like for GtkWidget events.
       */

      finished = FALSE;

      while (item && !finished) {
            g_object_ref (GTK_OBJECT (item));

            g_signal_emit (
                   G_OBJECT (item), item_signals[ITEM_EVENT], 0,
                  &ev, &finished);
            
            parent = item->parent;
            g_object_unref (GTK_OBJECT (item));

            item = parent;
      }

      return finished;
}

/* Re-picks the current item in the canvas, based on the event's coordinates.
 * Also emits enter/leave events for items as appropriate.
 */
static int
pick_current_item (EelCanvas *canvas, GdkEvent *event)
{
      int button_down;
      double x, y;
      int cx, cy;
      int retval;

      retval = FALSE;

      /* If a button is down, we'll perform enter and leave events on the
       * current item, but not enter on any other item.  This is more or less
       * like X pointer grabbing for canvas items.
       */
      button_down = canvas->state & (GDK_BUTTON1_MASK
                               | GDK_BUTTON2_MASK
                               | GDK_BUTTON3_MASK
                               | GDK_BUTTON4_MASK
                               | GDK_BUTTON5_MASK);
      if (!button_down)
            canvas->left_grabbed_item = FALSE;

      /* Save the event in the canvas.  This is used to synthesize enter and
       * leave events in case the current item changes.  It is also used to
       * re-pick the current item if the current one gets deleted.  Also,
       * synthesize an enter event.
       */
      if (event != &canvas->pick_event) {
            if ((event->type == GDK_MOTION_NOTIFY) || (event->type == GDK_BUTTON_RELEASE)) {
                  /* these fields have the same offsets in both types of events */

                  canvas->pick_event.crossing.type       = GDK_ENTER_NOTIFY;
                  canvas->pick_event.crossing.window     = event->motion.window;
                  canvas->pick_event.crossing.send_event = event->motion.send_event;
                  canvas->pick_event.crossing.subwindow  = NULL;
                  canvas->pick_event.crossing.x          = event->motion.x;
                  canvas->pick_event.crossing.y          = event->motion.y;
                  canvas->pick_event.crossing.mode       = GDK_CROSSING_NORMAL;
                  canvas->pick_event.crossing.detail     = GDK_NOTIFY_NONLINEAR;
                  canvas->pick_event.crossing.focus      = FALSE;
                  canvas->pick_event.crossing.state      = event->motion.state;

                  /* these fields don't have the same offsets in both types of events */

                  if (event->type == GDK_MOTION_NOTIFY) {
                        canvas->pick_event.crossing.x_root = event->motion.x_root;
                        canvas->pick_event.crossing.y_root = event->motion.y_root;
                  } else {
                        canvas->pick_event.crossing.x_root = event->button.x_root;
                        canvas->pick_event.crossing.y_root = event->button.y_root;
                  }
            } else
                  canvas->pick_event = *event;
      }

      /* Don't do anything else if this is a recursive call */

      if (canvas->in_repick)
            return retval;

      /* LeaveNotify means that there is no current item, so we don't look for one */

      if (canvas->pick_event.type != GDK_LEAVE_NOTIFY) {
            /* these fields don't have the same offsets in both types of events */

            if (canvas->pick_event.type == GDK_ENTER_NOTIFY) {
                  x = canvas->pick_event.crossing.x;
                  y = canvas->pick_event.crossing.y;
            } else {
                  x = canvas->pick_event.motion.x;
                  y = canvas->pick_event.motion.y;
            }

            /* canvas pixel coords */

            cx = (int) (x + 0.5);
            cy = (int) (y + 0.5);

            /* world coords */
            eel_canvas_c2w (canvas, cx, cy, &x, &y);

            /* find the closest item */
            if (canvas->root->flags & EEL_CANVAS_ITEM_MAPPED)
                  eel_canvas_item_invoke_point (canvas->root, x, y, cx, cy,
                                          &canvas->new_current_item);
            else
                  canvas->new_current_item = NULL;
      } else
            canvas->new_current_item = NULL;

      if ((canvas->new_current_item == canvas->current_item) && !canvas->left_grabbed_item)
            return retval; /* current item did not change */

      /* Synthesize events for old and new current items */

      if ((canvas->new_current_item != canvas->current_item)
          && (canvas->current_item != NULL)
          && !canvas->left_grabbed_item) {
            GdkEvent new_event;
            EelCanvasItem *item;

            item = canvas->current_item;

            new_event = canvas->pick_event;
            new_event.type = GDK_LEAVE_NOTIFY;

            new_event.crossing.detail = GDK_NOTIFY_ANCESTOR;
            new_event.crossing.subwindow = NULL;
            canvas->in_repick = TRUE;
            retval = emit_event (canvas, &new_event);
            canvas->in_repick = FALSE;
      }

      /* new_current_item may have been set to NULL during the call to emit_event() above */

      if ((canvas->new_current_item != canvas->current_item) && button_down) {
            canvas->left_grabbed_item = TRUE;
            return retval;
      }

      /* Handle the rest of cases */

      canvas->left_grabbed_item = FALSE;
      canvas->current_item = canvas->new_current_item;

      if (canvas->current_item != NULL) {
            GdkEvent new_event;

            new_event = canvas->pick_event;
            new_event.type = GDK_ENTER_NOTIFY;
            new_event.crossing.detail = GDK_NOTIFY_ANCESTOR;
            new_event.crossing.subwindow = NULL;
            retval = emit_event (canvas, &new_event);
      }

      return retval;
}

/* Button event handler for the canvas */
static gint
eel_canvas_button (GtkWidget *widget, GdkEventButton *event)
{
      EelCanvas *canvas;
      int mask;
      int retval;

      g_return_val_if_fail (EEL_IS_CANVAS (widget), FALSE);
      g_return_val_if_fail (event != NULL, FALSE);

      retval = FALSE;

      canvas = EEL_CANVAS (widget);

      /*
       * dispatch normally regardless of the event's window if an item has
       * has a pointer grab in effect
       */
      if (!canvas->grabbed_item && event->window != gtk_layout_get_bin_window (&canvas->layout))
            return retval;

      switch (event->button) {
      case 1:
            mask = GDK_BUTTON1_MASK;
            break;
      case 2:
            mask = GDK_BUTTON2_MASK;
            break;
      case 3:
            mask = GDK_BUTTON3_MASK;
            break;
      case 4:
            mask = GDK_BUTTON4_MASK;
            break;
      case 5:
            mask = GDK_BUTTON5_MASK;
            break;
      default:
            mask = 0;
      }

      switch (event->type) {
      case GDK_BUTTON_PRESS:
      case GDK_2BUTTON_PRESS:
      case GDK_3BUTTON_PRESS:
            /* Pick the current item as if the button were not pressed, and
             * then process the event.
             */
            canvas->state = event->state;
            pick_current_item (canvas, (GdkEvent *) event);
            canvas->state ^= mask;
            retval = emit_event (canvas, (GdkEvent *) event);
            break;

      case GDK_BUTTON_RELEASE:
            /* Process the event as if the button were pressed, then repick
             * after the button has been released
             */
            canvas->state = event->state;
            retval = emit_event (canvas, (GdkEvent *) event);
            event->state ^= mask;
            canvas->state = event->state;
            pick_current_item (canvas, (GdkEvent *) event);
            event->state ^= mask;
            break;

      default:
            g_assert_not_reached ();
      }

      return retval;
}

/* Motion event handler for the canvas */
static gint
eel_canvas_motion (GtkWidget *widget, GdkEventMotion *event)
{
      EelCanvas *canvas;

      g_return_val_if_fail (EEL_IS_CANVAS (widget), FALSE);
      g_return_val_if_fail (event != NULL, FALSE);

      canvas = EEL_CANVAS (widget);

      if (event->window != gtk_layout_get_bin_window (&canvas->layout))
            return FALSE;

      canvas->state = event->state;
      pick_current_item (canvas, (GdkEvent *) event);
      return emit_event (canvas, (GdkEvent *) event);
}

/* Key event handler for the canvas */
static gint
eel_canvas_key (GtkWidget *widget, GdkEventKey *event)
{
      EelCanvas *canvas;
      
      g_return_val_if_fail (EEL_IS_CANVAS (widget), FALSE);
      g_return_val_if_fail (event != NULL, FALSE);

      canvas = EEL_CANVAS (widget);
      
      if (emit_event (canvas, (GdkEvent *) event))
            return TRUE;
      if (event->type == GDK_KEY_RELEASE)
            return GTK_WIDGET_CLASS (canvas_parent_class)->key_release_event (widget, event);
      else
            return GTK_WIDGET_CLASS (canvas_parent_class)->key_press_event (widget, event);
}


/* Crossing event handler for the canvas */
static gint
eel_canvas_crossing (GtkWidget *widget, GdkEventCrossing *event)
{
      EelCanvas *canvas;

      g_return_val_if_fail (EEL_IS_CANVAS (widget), FALSE);
      g_return_val_if_fail (event != NULL, FALSE);

      canvas = EEL_CANVAS (widget);

      if (event->window != gtk_layout_get_bin_window (&canvas->layout))
            return FALSE;

      canvas->state = event->state;
      return pick_current_item (canvas, (GdkEvent *) event);
}

/* Focus in handler for the canvas */
static gint
eel_canvas_focus_in (GtkWidget *widget, GdkEventFocus *event)
{
      EelCanvas *canvas;

      canvas = EEL_CANVAS (widget);

      if (canvas->focused_item)
            return emit_event (canvas, (GdkEvent *) event);
      else
            return FALSE;
}

/* Focus out handler for the canvas */
static gint
eel_canvas_focus_out (GtkWidget *widget, GdkEventFocus *event)
{
      EelCanvas *canvas;

      canvas = EEL_CANVAS (widget);

      if (canvas->focused_item)
            return emit_event (canvas, (GdkEvent *) event);
      else
            return FALSE;
}

/* Expose handler for the canvas */
static gint
eel_canvas_expose (GtkWidget *widget, GdkEventExpose *event)
{
      EelCanvas *canvas;

      canvas = EEL_CANVAS (widget);

      if (!gtk_widget_is_drawable (widget) || (event->window != gtk_layout_get_bin_window (&canvas->layout))) return FALSE;

#ifdef VERBOSE
      g_print ("Expose\n");
#endif
      /* If there are any outstanding items that need updating, do them now */
      if (canvas->idle_id) {
            g_source_remove (canvas->idle_id);
            canvas->idle_id = 0;
      }
      if (canvas->need_update) {
            g_return_val_if_fail (!canvas->doing_update, FALSE);

            canvas->doing_update = TRUE;
            eel_canvas_item_invoke_update (canvas->root, 0, 0, 0);

            g_return_val_if_fail (canvas->doing_update, FALSE);

            canvas->doing_update = FALSE;

            canvas->need_update = FALSE;
      }

      /* Hmmm. Would like to queue antiexposes if the update marked
         anything that is gonna get redrawn as invalid */
      
      
      g_signal_emit (G_OBJECT (canvas), canvas_signals[DRAW_BACKGROUND], 0, 
                   event->area.x, event->area.y,
                   event->area.width, event->area.height);
      
      if (canvas->root->flags & EEL_CANVAS_ITEM_MAPPED)
            (* EEL_CANVAS_ITEM_GET_CLASS (canvas->root)->draw) (canvas->root,
                                                      gtk_layout_get_bin_window (&canvas->layout),
                                                      event);



      /* Chain up to get exposes on child widgets */
      GTK_WIDGET_CLASS (canvas_parent_class)->expose_event (widget, event);

      return FALSE;
}

static void
eel_canvas_draw_background (EelCanvas *canvas,
                      int x, int y, int width, int height)
{
      /* By default, we use the style background. */
      gdk_gc_set_foreground (canvas->pixmap_gc,
                         &gtk_widget_get_style (GTK_WIDGET (canvas))->bg[GTK_STATE_NORMAL]);
      gdk_draw_rectangle (gtk_layout_get_bin_window (&canvas->layout),
                      canvas->pixmap_gc,
                      TRUE,
                      x, y,
                      width, height);
}

static void
do_update (EelCanvas *canvas)
{
      /* Cause the update if necessary */

update_again:
      if (canvas->need_update) {
            g_return_if_fail (!canvas->doing_update);

            canvas->doing_update = TRUE;
            eel_canvas_item_invoke_update (canvas->root, 0, 0, 0);

            g_return_if_fail (canvas->doing_update);

            canvas->doing_update = FALSE;

            canvas->need_update = FALSE;
      }

      /* Pick new current item */

      while (canvas->need_repick) {
            canvas->need_repick = FALSE;
            pick_current_item (canvas, &canvas->pick_event);
      }

      /* it is possible that during picking we emitted an event in which
         the user then called some function which then requested update
         of something.  Without this we'd be left in a state where
         need_update would have been left TRUE and the canvas would have
         been left unpainted. */
      if (canvas->need_update) {
            goto update_again;
      }
}

/* Idle handler for the canvas.  It deals with pending updates and redraws. */
static gint
idle_handler (gpointer data)
{
      EelCanvas *canvas;

      GDK_THREADS_ENTER ();

      canvas = EEL_CANVAS (data);
      do_update (canvas);

      /* Reset idle id */
      canvas->idle_id = 0;

      GDK_THREADS_LEAVE ();

      return FALSE;
}

/* Convenience function to add an idle handler to a canvas */
static void
add_idle (EelCanvas *canvas)
{
      if (!canvas->idle_id) {
            /* We let the update idle handler have higher priority
             * than the redraw idle handler so the canvas state
             * will be updated during the expose event.  canvas in
             * expose_event.
             */
            canvas->idle_id = g_idle_add_full (GDK_PRIORITY_REDRAW - 20,
                                       idle_handler, canvas, NULL);
      }
}

/**
 * eel_canvas_root:
 * @canvas: A canvas.
 *
 * Queries the root group of a canvas.
 *
 * Return value: The root group of the specified canvas.
 **/
EelCanvasGroup *
eel_canvas_root (EelCanvas *canvas)
{
      g_return_val_if_fail (EEL_IS_CANVAS (canvas), NULL);

      return EEL_CANVAS_GROUP (canvas->root);
}


/**
 * eel_canvas_set_scroll_region:
 * @canvas: A canvas.
 * @x1: Leftmost limit of the scrolling region.
 * @y1: Upper limit of the scrolling region.
 * @x2: Rightmost limit of the scrolling region.
 * @y2: Lower limit of the scrolling region.
 *
 * Sets the scrolling region of a canvas to the specified rectangle.  The canvas
 * will then be able to scroll only within this region.  The view of the canvas
 * is adjusted as appropriate to display as much of the new region as possible.
 **/
void
eel_canvas_set_scroll_region (EelCanvas *canvas, double x1, double y1, double x2, double y2)
{
      double wxofs, wyofs;
      int xofs, yofs;
      GtkAdjustment *vadjustment, *hadjustment;

      g_return_if_fail (EEL_IS_CANVAS (canvas));

      if ((canvas->scroll_x1 == x1) && (canvas->scroll_y1 == y1) &&
          (canvas->scroll_x2 == x2) && (canvas->scroll_y2 == y2)) {
            return;
      }
      
      /*
       * Set the new scrolling region.  If possible, do not move the visible contents of the
       * canvas.
       */
      hadjustment = gtk_layout_get_hadjustment (GTK_LAYOUT (canvas));
      vadjustment = gtk_layout_get_vadjustment (GTK_LAYOUT (canvas));

      eel_canvas_c2w (canvas,
                    gtk_adjustment_get_value (hadjustment) + canvas->zoom_xofs,
                    gtk_adjustment_get_value (vadjustment) + canvas->zoom_yofs,
                    /*canvas->zoom_xofs,
                    canvas->zoom_yofs,*/
                    &wxofs, &wyofs);

      canvas->scroll_x1 = x1;
      canvas->scroll_y1 = y1;
      canvas->scroll_x2 = x2;
      canvas->scroll_y2 = y2;

      eel_canvas_w2c (canvas, wxofs, wyofs, &xofs, &yofs);

      scroll_to (canvas, xofs, yofs);

      canvas->need_repick = TRUE;

      if (!(canvas->root->flags & EEL_CANVAS_ITEM_NEED_DEEP_UPDATE)) {
            canvas->root->flags |= EEL_CANVAS_ITEM_NEED_DEEP_UPDATE;
            eel_canvas_request_update (canvas);
      }
}


/**
 * eel_canvas_get_scroll_region:
 * @canvas: A canvas.
 * @x1: Leftmost limit of the scrolling region (return value).
 * @y1: Upper limit of the scrolling region (return value).
 * @x2: Rightmost limit of the scrolling region (return value).
 * @y2: Lower limit of the scrolling region (return value).
 *
 * Queries the scrolling region of a canvas.
 **/
void
eel_canvas_get_scroll_region (EelCanvas *canvas, double *x1, double *y1, double *x2, double *y2)
{
      g_return_if_fail (EEL_IS_CANVAS (canvas));

      if (x1)
            *x1 = canvas->scroll_x1;

      if (y1)
            *y1 = canvas->scroll_y1;

      if (x2)
            *x2 = canvas->scroll_x2;

      if (y2)
            *y2 = canvas->scroll_y2;
}

void
eel_canvas_set_center_scroll_region (EelCanvas *canvas,
                             gboolean center_scroll_region)
{
      GtkAdjustment *vadjustment, *hadjustment;

      g_return_if_fail (EEL_IS_CANVAS (canvas));

      canvas->center_scroll_region = center_scroll_region != 0;

      hadjustment = gtk_layout_get_hadjustment (&canvas->layout);
      vadjustment = gtk_layout_get_vadjustment (&canvas->layout);

      scroll_to (canvas,
               gtk_adjustment_get_value (hadjustment),
               gtk_adjustment_get_value (vadjustment));
}


/**
 * eel_canvas_set_pixels_per_unit:
 * @canvas: A canvas.
 * @n: The number of pixels that correspond to one canvas unit.
 *
 * Sets the zooming factor of a canvas by specifying the number of pixels that
 * correspond to one canvas unit.
 **/
void
eel_canvas_set_pixels_per_unit (EelCanvas *canvas, double n)
{
      GtkWidget *widget;
      double cx, cy;
      int x1, y1;
      int center_x, center_y;
      GdkWindow *window;
      GdkWindowAttr attributes;
      gint attributes_mask;
      GtkAllocation allocation;
      GtkAdjustment *vadjustment, *hadjustment;

      g_return_if_fail (EEL_IS_CANVAS (canvas));
      g_return_if_fail (n > EEL_CANVAS_EPSILON);

      widget = GTK_WIDGET (canvas);

      gtk_widget_get_allocation (widget, &allocation);
      center_x = allocation.width / 2;
      center_y = allocation.height / 2;

      /* Find the coordinates of the screen center in units. */
      hadjustment = gtk_layout_get_hadjustment (&canvas->layout);
      vadjustment = gtk_layout_get_vadjustment (&canvas->layout);
      cx = (gtk_adjustment_get_value (hadjustment) + center_x) / canvas->pixels_per_unit + canvas->scroll_x1 + canvas->zoom_xofs;
      cy = (gtk_adjustment_get_value (vadjustment) + center_y) / canvas->pixels_per_unit + canvas->scroll_y1 + canvas->zoom_yofs;

      /* Now calculate the new offset of the upper left corner. (round not truncate) */
      x1 = ((cx - canvas->scroll_x1) * n) - center_x + .5;
      y1 = ((cy - canvas->scroll_y1) * n) - center_y + .5;

      canvas->pixels_per_unit = n;

      if (!(canvas->root->flags & EEL_CANVAS_ITEM_NEED_DEEP_UPDATE)) {
            canvas->root->flags |= EEL_CANVAS_ITEM_NEED_DEEP_UPDATE;
            eel_canvas_request_update (canvas);
      }

      /* Map a background None window over the bin_window to avoid
       * scrolling the window scroll causing exposes.
       */
      window = NULL;
      if (gtk_widget_get_mapped (widget)) {
            GtkAllocation allocation;
            attributes.window_type = GDK_WINDOW_CHILD;
            gtk_widget_get_allocation (widget, &allocation);
            attributes.x = allocation.x;
            attributes.y = allocation.y;
            attributes.width = allocation.width;
            attributes.height = allocation.height;
            attributes.wclass = GDK_INPUT_OUTPUT;
            attributes.visual = gtk_widget_get_visual (widget);
            attributes.colormap = gtk_widget_get_colormap (widget);
            attributes.event_mask = GDK_VISIBILITY_NOTIFY_MASK;
            
            attributes_mask = GDK_WA_X | GDK_WA_Y | GDK_WA_VISUAL | GDK_WA_COLORMAP;
            
            window = gdk_window_new (gtk_widget_get_parent_window (widget),
                               &attributes, attributes_mask);
            gdk_window_set_back_pixmap (window, NULL, FALSE);
            gdk_window_set_user_data (window, widget);
            
            gdk_window_show (window);
      }

      scroll_to (canvas, x1, y1);

      /* If we created a an overlapping background None window, remove it how.
       *
       * TODO: We would like to temporarily set the bin_window background to
       * None to avoid clearing the bin_window to the background, but gdk doesn't
       * expose enought to let us do this, so we get a flash-effect here. At least
       * it looks better than scroll + expose.
       */
      if (window != NULL) {
            gdk_window_hide (window);
            gdk_window_set_user_data (window, NULL);
            gdk_window_destroy (window);
      }

      canvas->need_repick = TRUE;
}

/**
 * eel_canvas_scroll_to:
 * @canvas: A canvas.
 * @cx: Horizontal scrolling offset in canvas pixel units.
 * @cy: Vertical scrolling offset in canvas pixel units.
 *
 * Makes a canvas scroll to the specified offsets, given in canvas pixel units.
 * The canvas will adjust the view so that it is not outside the scrolling
 * region.  This function is typically not used, as it is better to hook
 * scrollbars to the canvas layout's scrolling adjusments.
 **/
void
eel_canvas_scroll_to (EelCanvas *canvas, int cx, int cy)
{
      g_return_if_fail (EEL_IS_CANVAS (canvas));

      scroll_to (canvas, cx, cy);
}

/**
 * eel_canvas_get_scroll_offsets:
 * @canvas: A canvas.
 * @cx: Horizontal scrolling offset (return value).
 * @cy: Vertical scrolling offset (return value).
 *
 * Queries the scrolling offsets of a canvas.  The values are returned in canvas
 * pixel units.
 **/
void
eel_canvas_get_scroll_offsets (EelCanvas *canvas, int *cx, int *cy)
{
      GtkAdjustment *vadjustment, *hadjustment;

      g_return_if_fail (EEL_IS_CANVAS (canvas));

      hadjustment = gtk_layout_get_hadjustment (&canvas->layout);
      vadjustment = gtk_layout_get_vadjustment (&canvas->layout);

      if (cx)
            *cx = gtk_adjustment_get_value (hadjustment);

      if (cy)
            *cy = gtk_adjustment_get_value (vadjustment);
}

/**
 * eel_canvas_update_now:
 * @canvas: A canvas.
 *
 * Forces an immediate update and redraw of a canvas.  If the canvas does not
 * have any pending update or redraw requests, then no action is taken.  This is
 * typically only used by applications that need explicit control of when the
 * display is updated, like games.  It is not needed by normal applications.
 */
void
eel_canvas_update_now (EelCanvas *canvas)
{
      g_return_if_fail (EEL_IS_CANVAS (canvas));

      if (!(canvas->need_update || canvas->need_redraw))
            return;
      remove_idle (canvas);
      do_update (canvas);
}

/**
 * eel_canvas_get_item_at:
 * @canvas: A canvas.
 * @x: X position in world coordinates.
 * @y: Y position in world coordinates.
 *
 * Looks for the item that is under the specified position, which must be
 * specified in world coordinates.
 *
 * Return value: The sought item, or NULL if no item is at the specified
 * coordinates.
 **/
EelCanvasItem *
eel_canvas_get_item_at (EelCanvas *canvas, double x, double y)
{
      EelCanvasItem *item;
      double dist;
      int cx, cy;

      g_return_val_if_fail (EEL_IS_CANVAS (canvas), NULL);

      eel_canvas_w2c (canvas, x, y, &cx, &cy);

      dist = eel_canvas_item_invoke_point (canvas->root, x, y, cx, cy, &item);
      if ((int) (dist * canvas->pixels_per_unit + 0.5) <= canvas->close_enough)
            return item;
      else
            return NULL;
}

/* Queues an update of the canvas */
static void
eel_canvas_request_update (EelCanvas *canvas)
{
      EEL_CANVAS_GET_CLASS (canvas)->request_update (canvas);
}

static void
eel_canvas_request_update_real (EelCanvas *canvas)
{
      canvas->need_update = TRUE;
      add_idle (canvas);
}

/**
 * eel_canvas_request_redraw:
 * @canvas: A canvas.
 * @x1: Leftmost coordinate of the rectangle to be redrawn.
 * @y1: Upper coordinate of the rectangle to be redrawn.
 * @x2: Rightmost coordinate of the rectangle to be redrawn, plus 1.
 * @y2: Lower coordinate of the rectangle to be redrawn, plus 1.
 *
 * Convenience function that informs a canvas that the specified rectangle needs
 * to be repainted.  The rectangle includes @x1 and @y1, but not @x2 and @y2.
 * To be used only by item implementations.
 **/
void
eel_canvas_request_redraw (EelCanvas *canvas, int x1, int y1, int x2, int y2)
{
      GdkRectangle bbox;

      g_return_if_fail (EEL_IS_CANVAS (canvas));

      if (!gtk_widget_is_drawable (GTK_WIDGET (canvas))
          || (x1 >= x2) || (y1 >= y2)) return;

      bbox.x = x1;
      bbox.y = y1;
      bbox.width = x2 - x1;
      bbox.height = y2 - y1;

      gdk_window_invalidate_rect (gtk_layout_get_bin_window (&canvas->layout),
                            &bbox, FALSE);
}

/**
 * eel_canvas_w2c:
 * @canvas: A canvas.
 * @wx: World X coordinate.
 * @wy: World Y coordinate.
 * @cx: X pixel coordinate (return value).
 * @cy: Y pixel coordinate (return value).
 *
 * Converts world coordinates into canvas pixel coordinates.
 **/
void
eel_canvas_w2c (EelCanvas *canvas, double wx, double wy, int *cx, int *cy)
{
      double zoom;

      g_return_if_fail (EEL_IS_CANVAS (canvas));
      
      zoom = canvas->pixels_per_unit;
      
      if (cx)
            *cx = floor ((wx - canvas->scroll_x1)*zoom + canvas->zoom_xofs + 0.5);
      if (cy)
            *cy = floor ((wy - canvas->scroll_y1)*zoom + canvas->zoom_yofs + 0.5);
}

/**
 * eel_canvas_w2c:
 * @canvas: A canvas.
 * @world: rectangle in world coordinates.
 * @canvas: rectangle in canvase coordinates.
 *
 * Converts rectangles in world coordinates into canvas pixel coordinates.
 **/
void
eel_canvas_w2c_rect_d (EelCanvas *canvas,
                   double *x1, double *y1,
                   double *x2, double *y2)
{
      eel_canvas_w2c_d (canvas,
                      *x1, *y1,
                      x1, y1);
      eel_canvas_w2c_d (canvas,
                      *x2, *y2,
                      x2, y2);
}



/**
 * eel_canvas_w2c_d:
 * @canvas: A canvas.
 * @wx: World X coordinate.
 * @wy: World Y coordinate.
 * @cx: X pixel coordinate (return value).
 * @cy: Y pixel coordinate (return value).
 *
 * Converts world coordinates into canvas pixel coordinates.  This version
 * produces coordinates in floating point coordinates, for greater precision.
 **/
void
eel_canvas_w2c_d (EelCanvas *canvas, double wx, double wy, double *cx, double *cy)
{
      double zoom;

      g_return_if_fail (EEL_IS_CANVAS (canvas));

      zoom = canvas->pixels_per_unit;
      
      if (cx)
            *cx = (wx - canvas->scroll_x1)*zoom + canvas->zoom_xofs;
      if (cy)
            *cy = (wy - canvas->scroll_y1)*zoom + canvas->zoom_yofs;
}


/**
 * eel_canvas_c2w:
 * @canvas: A canvas.
 * @cx: Canvas pixel X coordinate.
 * @cy: Canvas pixel Y coordinate.
 * @wx: X world coordinate (return value).
 * @wy: Y world coordinate (return value).
 *
 * Converts canvas pixel coordinates to world coordinates.
 **/
void
eel_canvas_c2w (EelCanvas *canvas, int cx, int cy, double *wx, double *wy)
{
      double zoom;

      g_return_if_fail (EEL_IS_CANVAS (canvas));

      zoom = canvas->pixels_per_unit;
      
      if (wx)
            *wx = (cx - canvas->zoom_xofs)/zoom + canvas->scroll_x1;
      if (wy)
            *wy = (cy - canvas->zoom_yofs)/zoom + canvas->scroll_y1;
}


/**
 * eel_canvas_window_to_world:
 * @canvas: A canvas.
 * @winx: Window-relative X coordinate.
 * @winy: Window-relative Y coordinate.
 * @worldx: X world coordinate (return value).
 * @worldy: Y world coordinate (return value).
 *
 * Converts window-relative coordinates into world coordinates.  You can use
 * this when you need to convert mouse coordinates into world coordinates, for
 * example.
 * Window coordinates are really the same as canvas coordinates now, but this
 * function is here for backwards compatibility reasons.
 **/
void
eel_canvas_window_to_world (EelCanvas *canvas, double winx, double winy,
                        double *worldx, double *worldy)
{
      g_return_if_fail (EEL_IS_CANVAS (canvas));

      if (worldx)
            *worldx = canvas->scroll_x1 + ((winx - canvas->zoom_xofs)
                                     / canvas->pixels_per_unit);

      if (worldy)
            *worldy = canvas->scroll_y1 + ((winy - canvas->zoom_yofs)
                                     / canvas->pixels_per_unit);
}


/**
 * eel_canvas_world_to_window:
 * @canvas: A canvas.
 * @worldx: World X coordinate.
 * @worldy: World Y coordinate.
 * @winx: X window-relative coordinate.
 * @winy: Y window-relative coordinate.
 *
 * Converts world coordinates into window-relative coordinates.
 * Window coordinates are really the same as canvas coordinates now, but this
 * function is here for backwards compatibility reasons.
 **/
void
eel_canvas_world_to_window (EelCanvas *canvas, double worldx, double worldy,
                      double *winx, double *winy)
{
      g_return_if_fail (EEL_IS_CANVAS (canvas));

      if (winx)
            *winx = (canvas->pixels_per_unit)*(worldx - canvas->scroll_x1) + canvas->zoom_xofs;

      if (winy)
            *winy = (canvas->pixels_per_unit)*(worldy - canvas->scroll_y1) + canvas->zoom_yofs;
}



/**
 * eel_canvas_get_color:
 * @canvas: A canvas.
 * @spec: X color specification, or NULL for "transparent".
 * @color: Returns the allocated color.
 *
 * Allocates a color based on the specified X color specification.  As a
 * convenience to item implementations, it returns TRUE if the color was
 * allocated, or FALSE if the specification was NULL.  A NULL color
 * specification is considered as "transparent" by the canvas.
 *
 * Return value: TRUE if @spec is non-NULL and the color is allocated.  If @spec
 * is NULL, then returns FALSE.
 **/
int
eel_canvas_get_color (EelCanvas *canvas, const char *spec, GdkColor *color)
{
      GdkColormap *colormap;

      g_return_val_if_fail (EEL_IS_CANVAS (canvas), FALSE);
      g_return_val_if_fail (color != NULL, FALSE);

      if (!spec) {
            color->pixel = 0;
            color->red = 0;
            color->green = 0;
            color->blue = 0;
            return FALSE;
      }

      gdk_color_parse (spec, color);

      colormap = gtk_widget_get_colormap (GTK_WIDGET (canvas));

      gdk_rgb_find_color (colormap, color);

      return TRUE;
}

/**
 * eel_canvas_get_color_pixel:
 * @canvas: A canvas.
 * @rgba: RGBA color specification.
 *
 * Allocates a color from the RGBA value passed into this function.  The alpha
 * opacity value is discarded, since normal X colors do not support it.
 *
 * Return value: Allocated pixel value corresponding to the specified color.
 **/
gulong
eel_canvas_get_color_pixel (EelCanvas *canvas, guint rgba)
{
      GdkColormap *colormap;
      GdkColor color;

      g_return_val_if_fail (EEL_IS_CANVAS (canvas), 0);

      color.red = ((rgba & 0xff000000) >> 16) + ((rgba & 0xff000000) >> 24);
      color.green = ((rgba & 0x00ff0000) >> 8) + ((rgba & 0x00ff0000) >> 16);
      color.blue = (rgba & 0x0000ff00) + ((rgba & 0x0000ff00) >> 8);
      color.pixel = 0;

      colormap = gtk_widget_get_colormap (GTK_WIDGET (canvas));

      gdk_rgb_find_color (colormap, &color);

      return color.pixel;
}


/* FIXME: This function is not useful anymore */
/**
 * eel_canvas_set_stipple_origin:
 * @canvas: A canvas.
 * @gc: GC on which to set the stipple origin.
 *
 * Sets the stipple origin of the specified GC as is appropriate for the canvas,
 * so that it will be aligned with other stipple patterns used by canvas items.
 * This is typically only needed by item implementations.
 **/
void
eel_canvas_set_stipple_origin (EelCanvas *canvas, GdkGC *gc)
{
      g_return_if_fail (EEL_IS_CANVAS (canvas));
      g_return_if_fail (GDK_IS_GC (gc));

      gdk_gc_set_ts_origin (gc, 0, 0);
}

static gboolean
boolean_handled_accumulator (GSignalInvocationHint *ihint,
                       GValue                *return_accu,
                       const GValue          *handler_return,
                       gpointer               dummy)
{
      gboolean continue_emission;
      gboolean signal_handled;
      
      signal_handled = g_value_get_boolean (handler_return);
      g_value_set_boolean (return_accu, signal_handled);
      continue_emission = !signal_handled;
      
      return continue_emission;
}

static guint
eel_canvas_item_accessible_add_focus_handler (AtkComponent    *component,
                                              AtkFocusHandler handler)
{
      GSignalMatchType match_type;
      guint signal_id;

      match_type = G_SIGNAL_MATCH_ID | G_SIGNAL_MATCH_FUNC;
      signal_id = g_signal_lookup ("focus-event", ATK_TYPE_OBJECT);

      if (!g_signal_handler_find (component, match_type, signal_id, 0, NULL,
                                    (gpointer) handler, NULL)) {
            return g_signal_connect_closure_by_id (component,
                                                       signal_id, 0,
                                                       g_cclosure_new (
                                                       G_CALLBACK (handler), NULL,
                                                       (GClosureNotify) NULL),
                                                       FALSE);
      } 
      return 0;
}

static void
eel_canvas_item_accessible_get_item_extents (EelCanvasItem *item,
                                             GdkRectangle  *rect)
{
      double bx1, bx2, by1, by2;
      gint scroll_x, scroll_y;
      gint x1, x2, y1, y2;

      eel_canvas_item_get_bounds (item, &bx1, &by1, &bx2, &by2);
      eel_canvas_w2c_rect_d (item->canvas, &bx1, &by1, &bx2, &by2);
      eel_canvas_get_scroll_offsets (item->canvas, &scroll_x, &scroll_y);
      x1 = floor (bx1 + .5);
      y1 = floor (by1 + .5);
      x2 = floor (bx2 + .5);
      y2 = floor (by2 + .5);
      rect->x = x1 - scroll_x;
      rect->y = y1 - scroll_y;
      rect->width = x2 - x1;
      rect->height = y2 - y1;
}

static gboolean
eel_canvas_item_accessible_is_item_in_window (EelCanvasItem *item,
                                              GdkRectangle  *rect)
{
      GtkWidget *widget;
      gboolean retval;

      widget = GTK_WIDGET (item->canvas);
      if (gtk_widget_get_window (widget)) {
            int window_width, window_height;

            gdk_window_get_geometry (gtk_widget_get_window (widget), NULL, NULL,
                                         &window_width, &window_height, NULL);
            /*
                 * Check whether rectangles intersect
             */
                if (rect->x + rect->width < 0 ||
                    rect->y + rect->height < 0 ||
                    rect->x > window_width  ||
                    rect->y > window_height) {
                  retval = FALSE;
            } else {
                        retval = TRUE;
            }
      } else {
                retval = FALSE;
      }
        return retval;
}


static void
eel_canvas_item_accessible_get_extents (AtkComponent *component,
                                        gint          *x,
                                        gint          *y,
                                        gint          *width,
                                        gint          *height,
                                        AtkCoordType coord_type)
{
      AtkGObjectAccessible *atk_gobj;
      GObject *obj;
      EelCanvasItem *item;
      gint window_x, window_y;
      gint toplevel_x, toplevel_y;
      GdkRectangle rect;
      GdkWindow *window;
      GtkWidget *canvas;

      atk_gobj = ATK_GOBJECT_ACCESSIBLE (component);
      obj = atk_gobject_accessible_get_object (atk_gobj);

      if (obj == NULL) {
            /* item is defunct */
            return;
      }

        /* Get the CanvasItem */
      item = EEL_CANVAS_ITEM (obj);

      /* If this item has no parent canvas, something's broken */
      g_return_if_fail (GTK_IS_WIDGET (item->canvas));

      eel_canvas_item_accessible_get_item_extents (item, &rect);
      *width = rect.width;
      *height = rect.height;
      if (!eel_canvas_item_accessible_is_item_in_window (item, &rect)) {
            *x = G_MININT;
            *y = G_MININT;
            return;
      }

        canvas = GTK_WIDGET (item->canvas);
      window = gtk_widget_get_parent_window (canvas);
      gdk_window_get_origin (window, &window_x, &window_y);
      *x = rect.x + window_x;
      *y = rect.y + window_y;
      if (coord_type == ATK_XY_WINDOW) {
            window = gdk_window_get_toplevel (gtk_widget_get_window (canvas));
            gdk_window_get_origin (window, &toplevel_x, &toplevel_y);
            *x -= toplevel_x;
            *y -= toplevel_y;
      }
        return;
}

static gint
eel_canvas_item_accessible_get_mdi_zorder (AtkComponent *component)
{
      AtkGObjectAccessible *atk_gobj;
      GObject *g_obj;
      EelCanvasItem *item;

      atk_gobj = ATK_GOBJECT_ACCESSIBLE (component);
      g_obj = atk_gobject_accessible_get_object (atk_gobj);
      if (g_obj == NULL) {
            /* Object is defunct */
            return -1;
      }

      item = EEL_CANVAS_ITEM (g_obj);
      if (item->parent) {
                  return g_list_index (EEL_CANVAS_GROUP (item->parent)->item_list, item);
      } else {
            g_return_val_if_fail (item->canvas->root == item, -1);
            return 0;
      }
}

static gboolean
eel_canvas_item_accessible_grab_focus (AtkComponent *component)
{
      AtkGObjectAccessible *atk_gobj;
      GObject *obj;
      EelCanvasItem *item;
      GtkWidget *toplevel;

      atk_gobj = ATK_GOBJECT_ACCESSIBLE (component);
      obj = atk_gobject_accessible_get_object (atk_gobj);

      item = EEL_CANVAS_ITEM (obj);
      if (item == NULL) {
            /* item is defunct */
            return FALSE;
      }

        eel_canvas_item_grab_focus (item);
      toplevel = gtk_widget_get_toplevel (GTK_WIDGET (item->canvas));
      if (gtk_widget_is_toplevel (toplevel)) {
            gtk_window_present (GTK_WINDOW (toplevel));
      }

      return TRUE;
}

static void
eel_canvas_item_accessible_remove_focus_handler (AtkComponent *component,
                                                 guint            handler_id)
{
      g_signal_handler_disconnect (component, handler_id);
}

static void
eel_canvas_item_accessible_component_interface_init (AtkComponentIface *iface)
{
      g_return_if_fail (iface != NULL);

      iface->add_focus_handler = eel_canvas_item_accessible_add_focus_handler;
      iface->get_extents = eel_canvas_item_accessible_get_extents;
      iface->get_mdi_zorder = eel_canvas_item_accessible_get_mdi_zorder;
      iface->grab_focus = eel_canvas_item_accessible_grab_focus;
            iface->remove_focus_handler = eel_canvas_item_accessible_remove_focus_handler;
}

static gboolean
eel_canvas_item_accessible_is_item_on_screen (EelCanvasItem *item)
{
      GdkRectangle rect;

      eel_canvas_item_accessible_get_item_extents (item, &rect);
      return eel_canvas_item_accessible_is_item_in_window (item, &rect);
}

static void
eel_canvas_item_accessible_initialize (AtkObject *obj, gpointer data)
{
      if (ATK_OBJECT_CLASS (accessible_item_parent_class)->initialize != NULL)
            ATK_OBJECT_CLASS (accessible_item_parent_class)->initialize (obj, data);
      g_object_set_data (G_OBJECT (obj), "atk-component-layer",
                     GINT_TO_POINTER (ATK_LAYER_MDI));
}

static AtkStateSet*
eel_canvas_item_accessible_ref_state_set (AtkObject *accessible)
{
      AtkGObjectAccessible *atk_gobj;
      GObject *obj;
      EelCanvasItem *item;
      AtkStateSet *state_set;

      state_set = ATK_OBJECT_CLASS (accessible_item_parent_class)->ref_state_set (accessible);
      atk_gobj = ATK_GOBJECT_ACCESSIBLE (accessible);
      obj = atk_gobject_accessible_get_object (atk_gobj);

      item = EEL_CANVAS_ITEM (obj);
      if (item == NULL) {
            atk_state_set_add_state (state_set, ATK_STATE_DEFUNCT);
      } else {
                if (item->flags & EEL_CANVAS_ITEM_VISIBLE) {
                  atk_state_set_add_state (state_set, ATK_STATE_VISIBLE);
                  
                  if (eel_canvas_item_accessible_is_item_on_screen (item)) {
                        atk_state_set_add_state (state_set, ATK_STATE_SHOWING);
                        }
            }
            if (gtk_widget_get_can_focus (GTK_WIDGET (item->canvas))) {
                  atk_state_set_add_state (state_set, ATK_STATE_FOCUSABLE);

                  if (item->canvas->focused_item == item) {
                        atk_state_set_add_state (state_set, ATK_STATE_FOCUSED);
                  }
            }
      }

        return state_set;
}

static void
eel_canvas_item_accessible_class_init (AtkObjectClass *klass)
{
      accessible_item_parent_class = g_type_class_peek_parent (klass);

      klass->initialize = eel_canvas_item_accessible_initialize;
      klass->ref_state_set = eel_canvas_item_accessible_ref_state_set;
}

static GType
eel_canvas_item_accessible_get_type (void)
{
      static GType type = 0;

      if (!type) {
            static const GInterfaceInfo atk_component_info = {
                  (GInterfaceInitFunc) eel_canvas_item_accessible_component_interface_init,
                  (GInterfaceFinalizeFunc) NULL,
                  NULL
            };
            AtkObjectFactory *factory;
            GType parent_atk_type;
            GTypeQuery query;
            GTypeInfo tinfo = { 0 };

            factory = atk_registry_get_factory (atk_get_default_registry(),
                                        GTK_TYPE_OBJECT);
            if (!factory) {
                  return G_TYPE_INVALID;
            }
            parent_atk_type = atk_object_factory_get_accessible_type (factory);
            if (!parent_atk_type) {
                  return G_TYPE_INVALID;
            }
            g_type_query (parent_atk_type, &query);
            tinfo.class_init = (GClassInitFunc) eel_canvas_item_accessible_class_init;
            tinfo.class_size = query.class_size;
            tinfo.instance_size = query.instance_size;
            type = g_type_register_static (parent_atk_type,
                                     "EelCanvasItemAccessibility",
                                     &tinfo, 0);

            g_type_add_interface_static (type, ATK_TYPE_COMPONENT,
                                   &atk_component_info);

      }

      return type;
}

static AtkObject *
eel_canvas_item_accessible_create (GObject *for_object)
{
      GType type;
      AtkObject *accessible;
      EelCanvasItem *item;

      item = EEL_CANVAS_ITEM (for_object);
      g_return_val_if_fail (item != NULL, NULL);

      type = eel_canvas_item_accessible_get_type ();
      if (type == G_TYPE_INVALID) {
            return atk_no_op_object_new (for_object);
      }

        accessible = g_object_new (type, NULL);
      atk_object_initialize (accessible, for_object);
      return accessible;
}

static GType
eel_canvas_item_accessible_factory_get_accessible_type (void)
{
      return eel_canvas_item_accessible_get_type ();
}

static AtkObject*
eel_canvas_item_accessible_factory_create_accessible (GObject *obj)
{
      AtkObject *accessible;

      g_return_val_if_fail (G_IS_OBJECT (obj), NULL);

      accessible = eel_canvas_item_accessible_create (obj);

      return accessible;
}

static void
eel_canvas_item_accessible_factory_class_init (AtkObjectFactoryClass *klass)
{
      klass->create_accessible = eel_canvas_item_accessible_factory_create_accessible;
      klass->get_accessible_type = eel_canvas_item_accessible_factory_get_accessible_type;
}
 
static GType
eel_canvas_item_accessible_factory_get_type (void)
{
      static GType type = 0;

      if (!type) {
            static const GTypeInfo tinfo = {
                  sizeof (AtkObjectFactoryClass),
                  (GBaseInitFunc) NULL,
                  (GBaseFinalizeFunc) NULL,
                  (GClassInitFunc) eel_canvas_item_accessible_factory_class_init,
                  NULL,       /* class_finalize */
                  NULL,       /* class_data */
                  sizeof (AtkObjectFactory),
                  0,          /* n_preallocs */
                  NULL
            };
            type = g_type_register_static (ATK_TYPE_OBJECT_FACTORY,
                                     "EelCanvasItemAccessibilityFactory",
                                     &tinfo, 0);
      }

      return type;
}

/* Class initialization function for EelCanvasItemClass */
static void
eel_canvas_item_class_init (EelCanvasItemClass *klass)
{
      GObjectClass *gobject_class = (GObjectClass *) klass;

      item_parent_class = g_type_class_peek_parent (klass);

      gobject_class->set_property = eel_canvas_item_set_property;
      gobject_class->get_property = eel_canvas_item_get_property;
      gobject_class->dispose = eel_canvas_item_dispose;

      g_object_class_install_property
            (gobject_class, ITEM_PROP_PARENT,
             g_param_spec_object ("parent", NULL, NULL,
                              EEL_TYPE_CANVAS_ITEM,
                              G_PARAM_READWRITE));
      
      g_object_class_install_property
            (gobject_class, ITEM_PROP_VISIBLE,
             g_param_spec_boolean ("visible", NULL, NULL,
                              TRUE,
                              G_PARAM_READWRITE));

      item_signals[ITEM_EVENT] =
            g_signal_new ("event",
                        G_TYPE_FROM_CLASS (klass),
                        G_SIGNAL_RUN_LAST,
                        G_STRUCT_OFFSET (EelCanvasItemClass, event),
                        boolean_handled_accumulator, NULL,
                        eel_marshal_BOOLEAN__BOXED,
                        G_TYPE_BOOLEAN, 1,
                        GDK_TYPE_EVENT | G_SIGNAL_TYPE_STATIC_SCOPE);

      klass->realize = eel_canvas_item_realize;
      klass->unrealize = eel_canvas_item_unrealize;
      klass->map = eel_canvas_item_map;
      klass->unmap = eel_canvas_item_unmap;
      klass->update = eel_canvas_item_update;

      atk_registry_set_factory_type (atk_get_default_registry (),
                                       EEL_TYPE_CANVAS_ITEM,
                                       eel_canvas_item_accessible_factory_get_type ());
}

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