path: root/a11y/widgets/ea-calendar-item.c

/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: t; c-basic-offset: 8 -*- */
/* vim:expandtab:shiftwidth=8:tabstop=8:
 */
/* Evolution Accessibility: ea-calendar-item.c
 *
 * Copyright (C) 2003 Ximian, Inc.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of version 2 of the GNU General Public
 * License as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public
 * License along with this program; if not, write to the
 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 * Boston, MA 02111-1307, USA.
 *
 * Author: Bolian Yin <bolian.yin@sun.com> Sun Microsystem Inc., 2003
 *
 */

#include <stdio.h>
#include <time.h>
#include <string.h>
#include <libgnomecanvas/gnome-canvas.h>
#include <glib/gdate.h>
#include "ea-calendar-item.h"
#include "ea-calendar-cell.h"
#include "ea-cell-table.h"

#define EA_CALENDAR_COLUMN_NUM E_CALENDAR_COLS_PER_MONTH

/* EaCalendarItem */
static void ea_calendar_item_class_init (EaCalendarItemClass *klass);
static void ea_calendar_item_finalize (GObject *object);

static G_CONST_RETURN gchar* ea_calendar_item_get_name (AtkObject *accessible);
static G_CONST_RETURN gchar* ea_calendar_item_get_description (AtkObject *accessible);
static gint ea_calendar_item_get_n_children (AtkObject *accessible);
static AtkObject *ea_calendar_item_ref_child (AtkObject *accessible, gint index);

/* atk table interface */
static void atk_table_interface_init (AtkTableIface *iface);
static gint table_interface_get_index_at (AtkTable *table,
                      gint     row,
                      gint     column);
static gint table_interface_get_column_at_index (AtkTable *table,
                         gint     index);
static gint table_interface_get_row_at_index (AtkTable *table,
                          gint     index);
static AtkObject* table_interface_ref_at (AtkTable *table,
                      gint     row, 
                      gint     column);
static gint table_interface_get_n_rows (AtkTable *table);
static gint table_interface_get_n_columns (AtkTable *table);
static gint table_interface_get_column_extent_at (AtkTable      *table,
                          gint          row,
                          gint          column);
static gint table_interface_get_row_extent_at (AtkTable      *table,
                           gint          row,
                           gint          column);

static gboolean table_interface_is_row_selected (AtkTable *table,
                         gint     row);
static gboolean table_interface_is_column_selected (AtkTable *table,
                            gint     row);
static gboolean table_interface_is_selected (AtkTable *table,
                         gint     row,
                         gint     column);
static gint table_interface_get_selected_rows (AtkTable *table,
                           gint **rows_selected);
static gint table_interface_get_selected_columns (AtkTable *table,
                          gint     **columns_selected);
static gboolean table_interface_add_row_selection (AtkTable *table, gint row);
static gboolean table_interface_remove_row_selection (AtkTable *table,
                              gint row);
static gboolean table_interface_add_column_selection (AtkTable *table,
                              gint column);
static gboolean table_interface_remove_column_selection (AtkTable *table,
                             gint column);
static AtkObject* table_interface_get_row_header (AtkTable *table, gint row);
static AtkObject* table_interface_get_column_header (AtkTable *table,
                             gint in_col);
static AtkObject* table_interface_get_caption (AtkTable *table);

static G_CONST_RETURN gchar*
table_interface_get_column_description (AtkTable *table, gint in_col);

static G_CONST_RETURN gchar*
table_interface_get_row_description (AtkTable *table, gint row);

static AtkObject* table_interface_get_summary (AtkTable *table);

/* atk selection interface */
static void atk_selection_interface_init (AtkSelectionIface *iface);
static gboolean selection_interface_add_selection (AtkSelection *selection,
                           gint i);
static gboolean selection_interface_clear_selection (AtkSelection *selection);
static AtkObject* selection_interface_ref_selection (AtkSelection *selection,
                             gint i);
static gint selection_interface_get_selection_count (AtkSelection *selection);
static gboolean selection_interface_is_child_selected (AtkSelection *selection,
                               gint i);

/* callbacks */
static void selection_preview_change_cb (ECalendarItem *calitem);
static void date_range_changed_cb (ECalendarItem *calitem);
static void selection_changed_cb (ECalendarItem *calitem);

/* helpers */
static EaCellTable *ea_calendar_item_get_cell_data (EaCalendarItem *ea_calitem);
static void ea_calendar_item_destory_cell_data (EaCalendarItem *ea_calitem);
static gboolean ea_calendar_item_get_column_label (EaCalendarItem *ea_calitem,
                           gint column,
                           gchar *buffer,
                           gint buffer_size);
static gboolean ea_calendar_item_get_row_label (EaCalendarItem *ea_calitem,
                        gint row,
                        gchar *buffer,
                        gint buffer_size);

#ifdef ACC_DEBUG
static gint n_ea_calendar_item_created = 0;
static gint n_ea_calendar_item_destroyed = 0;
#endif

static gpointer parent_class = NULL;

GType
ea_calendar_item_get_type (void)
{
    static GType type = 0;
    AtkObjectFactory *factory;
    GTypeQuery query;
    GType derived_atk_type;

    if (!type) {
        static GTypeInfo tinfo = {
            sizeof (EaCalendarItemClass),
            (GBaseInitFunc) NULL, /* base init */
            (GBaseFinalizeFunc) NULL, /* base finalize */
            (GClassInitFunc) ea_calendar_item_class_init, /* class init */
            (GClassFinalizeFunc) NULL, /* class finalize */
            NULL, /* class data */
            sizeof (EaCalendarItem), /* instance size */
            0, /* nb preallocs */
            (GInstanceInitFunc) NULL, /* instance init */
            NULL /* value table */
        };

        static const GInterfaceInfo atk_table_info = {
            (GInterfaceInitFunc) atk_table_interface_init,
            (GInterfaceFinalizeFunc) NULL,
            NULL
        };
        static const GInterfaceInfo atk_selection_info = {
            (GInterfaceInitFunc) atk_selection_interface_init,
            (GInterfaceFinalizeFunc) NULL,
            NULL
        };

        /*
         * Figure out the size of the class and instance
         * we are run-time deriving from (GailCanvasItem, in this case)
         */

        factory = atk_registry_get_factory (atk_get_default_registry (),
                            GNOME_TYPE_CANVAS_ITEM);
        derived_atk_type = atk_object_factory_get_accessible_type (factory);
        g_type_query (derived_atk_type, &query);

        tinfo.class_size = query.class_size;
        tinfo.instance_size = query.instance_size;

        type = g_type_register_static (derived_atk_type,
                           "EaCalendarItem", &tinfo, 0);
        g_type_add_interface_static (type, ATK_TYPE_TABLE,
                         &atk_table_info);
        g_type_add_interface_static (type, ATK_TYPE_SELECTION,
                         &atk_selection_info);
    }

    return type;
}

static void
ea_calendar_item_class_init (EaCalendarItemClass *klass)
{
    GObjectClass *gobject_class = G_OBJECT_CLASS (klass);
    AtkObjectClass *class = ATK_OBJECT_CLASS (klass);

    gobject_class->finalize = ea_calendar_item_finalize;
    parent_class = g_type_class_peek_parent (klass);

    class->get_name = ea_calendar_item_get_name;
    class->get_description = ea_calendar_item_get_description;

    class->get_n_children = ea_calendar_item_get_n_children;
    class->ref_child = ea_calendar_item_ref_child;
}

AtkObject* 
ea_calendar_item_new (GObject *obj)
{
    gpointer object;
    AtkObject *atk_object;

    g_return_val_if_fail (E_IS_CALENDAR_ITEM (obj), NULL);
    object = g_object_new (EA_TYPE_CALENDAR_ITEM, NULL);
    atk_object = ATK_OBJECT (object);
    atk_object_initialize (atk_object, obj);
    atk_object->role = ATK_ROLE_TABLE;
#ifdef ACC_DEBUG
    ++n_ea_calendar_item_created;
    g_print ("ACC_DEBUG: n_ea_calendar_item_created = %d\n",
        n_ea_calendar_item_created);
#endif
    /* connect signal handlers */
    g_signal_connect (obj, "selection_preview_changed",
              G_CALLBACK (selection_preview_change_cb),
              atk_object);
    g_signal_connect (obj, "date_range_changed",
              G_CALLBACK (date_range_changed_cb),
              atk_object);
    g_signal_connect (obj, "selection_preview_changed",
              G_CALLBACK (selection_changed_cb),
              atk_object);

    return atk_object;
}

static void
ea_calendar_item_finalize (GObject *object)
{
    EaCalendarItem *ea_calitem;

    g_return_if_fail (EA_IS_CALENDAR_ITEM (object));

    ea_calitem = EA_CALENDAR_ITEM (object);

    /* Free the allocated cell data */
    ea_calendar_item_destory_cell_data (ea_calitem);

    G_OBJECT_CLASS (parent_class)->finalize (object);
#ifdef ACC_DEBUG
    ++n_ea_calendar_item_destroyed;
    printf ("ACC_DEBUG: n_ea_calendar_item_destroyed = %d\n",
        n_ea_calendar_item_destroyed);
#endif
}

static G_CONST_RETURN gchar*
ea_calendar_item_get_name (AtkObject *accessible)
{
    GObject *g_obj;
    ECalendarItem *calitem;
    gint start_year, start_month, start_day;
    gint end_year, end_month, end_day;
    static gchar new_name[256] = "";

    g_return_val_if_fail (EA_IS_CALENDAR_ITEM (accessible), NULL);

    if (accessible->name)
        return accessible->name;

    g_obj = atk_gobject_accessible_get_object (ATK_GOBJECT_ACCESSIBLE(accessible));
    g_return_val_if_fail (E_IS_CALENDAR_ITEM (g_obj), NULL);

    calitem = E_CALENDAR_ITEM (g_obj);
    if (e_calendar_item_get_date_range (calitem,
                        &start_year, &start_month, &start_day,
                        &end_year, &end_month, &end_day)) {
        ++start_month;
        ++end_month;
        sprintf (new_name, "calendar (from %d-%d-%d to %d-%d-%d)",
             start_year, start_month, start_day,
             end_year, end_month, end_day);
    }

#if 0
    if (e_calendar_item_get_selection (calitem, &select_start, &select_end)) {
        GDate select_start, select_end;
        gint year1, year2, month1, month2, day1, day2;

        year1 = g_date_get_year (&select_start);
        month1  = g_date_get_month (&select_start);
        day1 = g_date_get_day (&select_start);

        year2 = g_date_get_year (&select_end);
        month2  = g_date_get_month (&select_end);
        day2 = g_date_get_day (&select_end);

        sprintf (new_name + strlen (new_name),
             " : current selection: from %d-%d-%d to %d-%d-%d.",
             year1, month1, day1,
             year2, month2, day2);
    }
#endif

    return new_name;
}

static G_CONST_RETURN gchar*
ea_calendar_item_get_description (AtkObject *accessible)
{
    if (accessible->description)
        return accessible->description;

    return "evolution calendar item";
}

static gint
ea_calendar_item_get_n_children (AtkObject *accessible)
{
    AtkGObjectAccessible *atk_gobj;
    GObject *g_obj;
    ECalendarItem *calitem;
    gint n_children = 0;
    gint start_year, start_month, start_day;
    gint end_year, end_month, end_day;
    GDate *start_date, *end_date;

    g_return_val_if_fail (EA_IS_CALENDAR_ITEM (accessible), -1);

    atk_gobj = ATK_GOBJECT_ACCESSIBLE (accessible);
    g_obj = atk_gobject_accessible_get_object (atk_gobj);
    if (!g_obj)
        return -1;

    calitem = E_CALENDAR_ITEM (g_obj);
    if (!e_calendar_item_get_date_range (calitem, &start_year,
                         &start_month, &start_day,
                         &end_year, &end_month,
                         &end_day))
        return 0;

    start_date = g_date_new_dmy (start_day, start_month + 1, start_year);
    end_date = g_date_new_dmy (end_day, end_month + 1, end_year);

    n_children = g_date_days_between (start_date, end_date) + 1;
    g_free (start_date);
    g_free (end_date);
    return n_children;
}

static AtkObject *
ea_calendar_item_ref_child (AtkObject *accessible, gint index)
{
    AtkGObjectAccessible *atk_gobj;
    GObject *g_obj;
    ECalendarItem *calitem;
    gint n_children;
    ECalendarCell *cell;
    EaCellTable *cell_data;
    EaCalendarItem *ea_calitem;

    g_return_val_if_fail (EA_IS_CALENDAR_ITEM (accessible), NULL);

    atk_gobj = ATK_GOBJECT_ACCESSIBLE (accessible);
    g_obj = atk_gobject_accessible_get_object (atk_gobj);
    if (!g_obj)
        return NULL;

    calitem = E_CALENDAR_ITEM (g_obj);

    n_children = ea_calendar_item_get_n_children (accessible);
    if (index < 0 || index >= n_children)
        return NULL;

    ea_calitem = EA_CALENDAR_ITEM (accessible);
    cell_data = ea_calendar_item_get_cell_data (ea_calitem);
    if (!cell_data)
        return NULL;

    cell = ea_cell_table_get_cell_at_index (cell_data, index);
    if (!cell) {
        cell = e_calendar_cell_new (calitem,
                        index / EA_CALENDAR_COLUMN_NUM,
                        index % EA_CALENDAR_COLUMN_NUM);
        ea_cell_table_set_cell_at_index (cell_data, index, cell);
        g_object_unref (cell);
    }

#ifdef ACC_DEBUG
    g_print ("AccDebug: ea_calendar_item children[%d]=%p\n", index,
         (gpointer)cell);
#endif
    return g_object_ref (atk_gobject_accessible_for_object (G_OBJECT(cell)));
}

/* atk table interface */

static void 
atk_table_interface_init (AtkTableIface *iface)
{
    g_return_if_fail (iface != NULL);

    iface->ref_at = table_interface_ref_at;

    iface->get_n_rows = table_interface_get_n_rows;
    iface->get_n_columns = table_interface_get_n_columns;
    iface->get_index_at = table_interface_get_index_at;
    iface->get_column_at_index = table_interface_get_column_at_index;
    iface->get_row_at_index = table_interface_get_row_at_index;
    iface->get_column_extent_at = table_interface_get_column_extent_at;
    iface->get_row_extent_at = table_interface_get_row_extent_at;

    iface->is_selected = table_interface_is_selected;
    iface->get_selected_rows = table_interface_get_selected_rows;
    iface->get_selected_columns = table_interface_get_selected_columns;
    iface->is_row_selected = table_interface_is_row_selected;
    iface->is_column_selected = table_interface_is_column_selected;
    iface->add_row_selection = table_interface_add_row_selection;
    iface->remove_row_selection = table_interface_remove_row_selection;
    iface->add_column_selection = table_interface_add_column_selection;
    iface->remove_column_selection = table_interface_remove_column_selection;

    iface->get_row_header = table_interface_get_row_header;
    iface->get_column_header = table_interface_get_column_header;
    iface->get_caption = table_interface_get_caption;
    iface->get_summary = table_interface_get_summary;
    iface->get_row_description = table_interface_get_row_description;
    iface->get_column_description = table_interface_get_column_description;
}

static AtkObject* 
table_interface_ref_at (AtkTable *table,
            gint     row, 
            gint     column)
{
    gint index;

    EaCalendarItem* ea_calitem = EA_CALENDAR_ITEM (table);
    index = EA_CALENDAR_COLUMN_NUM * row + column;
    return ea_calendar_item_ref_child (ATK_OBJECT (ea_calitem), index);
}

static gint 
table_interface_get_n_rows (AtkTable *table)
{
    AtkGObjectAccessible *atk_gobj;
    GObject *g_obj;
    EaCalendarItem* ea_calitem = EA_CALENDAR_ITEM (table);
    gint n_children;

    atk_gobj = ATK_GOBJECT_ACCESSIBLE (ea_calitem);
    g_obj = atk_gobject_accessible_get_object (atk_gobj);
    if (!g_obj)
        return -1;

    n_children = ea_calendar_item_get_n_children (ATK_OBJECT (ea_calitem));
    return (n_children - 1) / EA_CALENDAR_COLUMN_NUM + 1;
}

static gint 
table_interface_get_n_columns (AtkTable *table)
{
    AtkGObjectAccessible *atk_gobj;
    GObject *g_obj;
    EaCalendarItem* ea_calitem = EA_CALENDAR_ITEM (table);

    atk_gobj = ATK_GOBJECT_ACCESSIBLE (ea_calitem);
    g_obj = atk_gobject_accessible_get_object (atk_gobj);
    if (!g_obj)
        return -1;

    return EA_CALENDAR_COLUMN_NUM;
}

static gint
table_interface_get_index_at (AtkTable *table,
                  gint     row,
                  gint     column)
{
    AtkGObjectAccessible *atk_gobj;
    GObject *g_obj;
    EaCalendarItem* ea_calitem = EA_CALENDAR_ITEM (table);

    atk_gobj = ATK_GOBJECT_ACCESSIBLE (ea_calitem);
    g_obj = atk_gobject_accessible_get_object (atk_gobj);
    if (!g_obj)
        return -1;

    return row * EA_CALENDAR_COLUMN_NUM + column;
}

static gint
table_interface_get_column_at_index (AtkTable *table,
                     gint index)
{
    AtkGObjectAccessible *atk_gobj;
    GObject *g_obj;
    EaCalendarItem* ea_calitem = EA_CALENDAR_ITEM (table);
    gint n_children;

    atk_gobj = ATK_GOBJECT_ACCESSIBLE (ea_calitem);
    g_obj = atk_gobject_accessible_get_object (atk_gobj);
    if (!g_obj)
        return -1;

    n_children = ea_calendar_item_get_n_children (ATK_OBJECT (ea_calitem));
    if (index >= 0 && index < n_children)
        return index % EA_CALENDAR_COLUMN_NUM;
    return -1;
}

static gint
table_interface_get_row_at_index (AtkTable *table,
                  gint     index)
{
    AtkGObjectAccessible *atk_gobj;
    GObject *g_obj;
    EaCalendarItem* ea_calitem = EA_CALENDAR_ITEM (table);
    gint n_children;

    atk_gobj = ATK_GOBJECT_ACCESSIBLE (ea_calitem);
    g_obj = atk_gobject_accessible_get_object (atk_gobj);
    if (!g_obj)
        return -1;

    n_children = ea_calendar_item_get_n_children (ATK_OBJECT (ea_calitem));
    if (index >= 0 && index < n_children)
        return index / EA_CALENDAR_COLUMN_NUM;
    return -1;
}

static gint
table_interface_get_column_extent_at (AtkTable      *table,
                      gint          row,
                      gint          column)
{
    AtkGObjectAccessible *atk_gobj;
    GObject *g_obj;
    ECalendarItem *calitem;
    EaCalendarItem* ea_calitem = EA_CALENDAR_ITEM (table);

    atk_gobj = ATK_GOBJECT_ACCESSIBLE (ea_calitem);
    g_obj = atk_gobject_accessible_get_object (atk_gobj);
    if (!g_obj)
        return FALSE;

    calitem = E_CALENDAR_ITEM (g_obj);
    return calitem->cell_width;
}

static gint 
table_interface_get_row_extent_at (AtkTable *table,
                   gint row, gint column)
{
    AtkGObjectAccessible *atk_gobj;
    GObject *g_obj;
    ECalendarItem *calitem;
    EaCalendarItem* ea_calitem = EA_CALENDAR_ITEM (table);

    atk_gobj = ATK_GOBJECT_ACCESSIBLE (ea_calitem);
    g_obj = atk_gobject_accessible_get_object (atk_gobj);
    if (!g_obj)
        return FALSE;

    calitem = E_CALENDAR_ITEM (g_obj);
    return calitem->cell_height;
}

/* any day in the row is selected, the row is selected */
static gboolean 
table_interface_is_row_selected (AtkTable *table,
                 gint row)
{
    AtkGObjectAccessible *atk_gobj;
    GObject *g_obj;
    gint n_rows;
    ECalendarItem *calitem;
    gint row_index_start, row_index_end;
    gint sel_index_start, sel_index_end;

    GDate start_date, end_date;

    g_return_val_if_fail (EA_IS_CALENDAR_ITEM (table), FALSE);

    atk_gobj = ATK_GOBJECT_ACCESSIBLE (table);
    g_obj = atk_gobject_accessible_get_object (atk_gobj);
    if (!g_obj)
        return FALSE;

    n_rows = table_interface_get_n_rows (table);
    if (row < 0 || row >= n_rows)
        return FALSE;

    row_index_start = row * EA_CALENDAR_COLUMN_NUM;
    row_index_end = row_index_start + EA_CALENDAR_COLUMN_NUM - 1;

    calitem = E_CALENDAR_ITEM (g_obj);
    e_calendar_item_get_selection (calitem, &start_date, &end_date);

    sel_index_start =
        e_calendar_item_get_offset_for_date (calitem,
                             g_date_get_year (&start_date),
                             g_date_get_month (&start_date),
                             g_date_get_day (&start_date));
    sel_index_end =
        e_calendar_item_get_offset_for_date (calitem,
                             g_date_get_year (&end_date),
                             g_date_get_month (&end_date),
                             g_date_get_day (&end_date));

    if ((sel_index_start < row_index_start &&
         sel_index_end >= row_index_start) ||
        (sel_index_start >= row_index_start &&
         sel_index_start <= row_index_end))
        return TRUE;
    return FALSE;
}

static gboolean 
table_interface_is_selected (AtkTable *table, 
                 gint     row, 
                 gint     column)
{
    AtkGObjectAccessible *atk_gobj;
    GObject *g_obj;
    gint n_rows, n_columns;
    ECalendarItem *calitem;
    gint index;
    gint sel_index_start, sel_index_end;

    GDate start_date, end_date;

    g_return_val_if_fail (EA_IS_CALENDAR_ITEM (table), FALSE);

    atk_gobj = ATK_GOBJECT_ACCESSIBLE (table);
    g_obj = atk_gobject_accessible_get_object (atk_gobj);
    if (!g_obj)
        return FALSE;

    n_rows = table_interface_get_n_rows (table);
    if (row < 0 || row >= n_rows)
        return FALSE;
    n_columns = table_interface_get_n_columns (table);
    if (column < 0 || column >= n_columns)
        return FALSE;

    index = table_interface_get_index_at (table, row, column);

    calitem = E_CALENDAR_ITEM (g_obj);
    e_calendar_item_get_selection (calitem, &start_date, &end_date);

    sel_index_start =
        e_calendar_item_get_offset_for_date (calitem,
                             g_date_get_year (&start_date),
                             g_date_get_month (&start_date),
                             g_date_get_day (&start_date));
    sel_index_end =
        e_calendar_item_get_offset_for_date (calitem,
                             g_date_get_year (&end_date),
                             g_date_get_month (&end_date),
                             g_date_get_day (&end_date));

    if (sel_index_start <= index && sel_index_end >= index)
        return TRUE;
    return FALSE;
}

static gboolean 
table_interface_is_column_selected (AtkTable *table,
                    gint column)
{
    return FALSE;
}

static gint 
table_interface_get_selected_rows (AtkTable *table,
                   gint **rows_selected)
{
    *rows_selected = NULL;
    return -1;
}

static gint 
table_interface_get_selected_columns (AtkTable *table,
                      gint **columns_selected)
{
    columns_selected = NULL;
    return -1;
}

static gboolean 
table_interface_add_row_selection (AtkTable *table, 
                   gint row)
{
    return FALSE;
}

static gboolean 
table_interface_remove_row_selection (AtkTable *table, 
                      gint row)
{
    return FALSE;
}

static gboolean 
table_interface_add_column_selection (AtkTable *table, 
                      gint column)
{
    return FALSE;
}

static gboolean 
table_interface_remove_column_selection (AtkTable *table, 
                     gint     column)
{
    /* FIXME: NOT IMPLEMENTED */
    return FALSE;
}

static AtkObject* 
table_interface_get_row_header (AtkTable *table, 
                gint     row)
{
    /* FIXME: NOT IMPLEMENTED */
    return NULL;
}

static AtkObject* 
table_interface_get_column_header (AtkTable *table, 
                   gint     in_col)
{
    /* FIXME: NOT IMPLEMENTED */
    return NULL;
}

static AtkObject*
table_interface_get_caption (AtkTable   *table)
{
    /* FIXME: NOT IMPLEMENTED */
    return NULL;
}

static G_CONST_RETURN gchar*
table_interface_get_column_description (AtkTable *table, gint in_col)
{
    AtkGObjectAccessible *atk_gobj;
    GObject *g_obj;
    ECalendarItem *calitem;
    EaCalendarItem* ea_calitem = EA_CALENDAR_ITEM (table);
    const gchar *description = NULL;
    EaCellTable *cell_data;
    gint n_columns;

    atk_gobj = ATK_GOBJECT_ACCESSIBLE (ea_calitem);
    g_obj = atk_gobject_accessible_get_object (atk_gobj);
    if (!g_obj)
        return NULL;

    calitem = E_CALENDAR_ITEM (g_obj);
    n_columns = table_interface_get_n_columns (table);
    if (in_col < 0 || in_col >= n_columns)
        return NULL;
    cell_data = ea_calendar_item_get_cell_data (ea_calitem);
    if (!cell_data)
        return NULL;

    description = ea_cell_table_get_column_label (cell_data, in_col);
    if (!description) {
        gchar buffer[128] = "column description";
        ea_calendar_item_get_column_label (ea_calitem, in_col,
                           buffer, sizeof (buffer));
        ea_cell_table_set_column_label (cell_data, in_col, buffer);
        description = ea_cell_table_get_column_label (cell_data,
                                  in_col);
    }
    return description;
}

static G_CONST_RETURN gchar*
table_interface_get_row_description (AtkTable *table, gint row)
{
    AtkGObjectAccessible *atk_gobj;
    GObject *g_obj;
    ECalendarItem *calitem;
    EaCalendarItem* ea_calitem = EA_CALENDAR_ITEM (table);
    const gchar *description = NULL;
    EaCellTable *cell_data;
    gint n_rows;

    atk_gobj = ATK_GOBJECT_ACCESSIBLE (ea_calitem);
    g_obj = atk_gobject_accessible_get_object (atk_gobj);
    if (!g_obj)
        return NULL;

    calitem = E_CALENDAR_ITEM (g_obj);
    n_rows = table_interface_get_n_rows (table);
    if (row < 0 || row >= n_rows)
        return NULL;
    cell_data = ea_calendar_item_get_cell_data (ea_calitem);
    if (!cell_data)
        return NULL;

    description = ea_cell_table_get_row_label (cell_data, row);
    if (!description) {
        gchar buffer[128] = "row description";
        ea_calendar_item_get_row_label (ea_calitem, row,
                        buffer, sizeof (buffer));
        ea_cell_table_set_row_label (cell_data, row, buffer);
        description = ea_cell_table_get_row_label (cell_data,
                               row);
    }
    return description;
}

static AtkObject*
table_interface_get_summary (AtkTable   *table)
{
    /* FIXME: NOT IMPLEMENTED */
    return NULL;
}

/* atkselection interface */

static void
atk_selection_interface_init (AtkSelectionIface *iface)
{
    g_return_if_fail (iface != NULL);

    iface->add_selection = selection_interface_add_selection;
    iface->clear_selection = selection_interface_clear_selection;
    iface->ref_selection = selection_interface_ref_selection;
    iface->get_selection_count = selection_interface_get_selection_count;
    iface->is_child_selected = selection_interface_is_child_selected;
}

static gboolean
selection_interface_add_selection (AtkSelection *selection, gint index)
{
    AtkGObjectAccessible *atk_gobj;
    GObject *g_obj;
    ECalendarItem *calitem;
    EaCalendarItem* ea_calitem = EA_CALENDAR_ITEM (selection);
    gint year, month, day;
    GDate start_date, end_date;

    atk_gobj = ATK_GOBJECT_ACCESSIBLE (ea_calitem);
    g_obj = atk_gobject_accessible_get_object (atk_gobj);
    if (!g_obj)
        return FALSE;

    calitem = E_CALENDAR_ITEM (g_obj);
    if (!e_calendar_item_get_date_for_offset (calitem, index,
                          &year, &month, &day))
        return FALSE;

    /* FIXME: not support mulit-selection */
    g_date_set_dmy (&start_date, day, month + 1, year);
    end_date = start_date;
    e_calendar_item_set_selection (calitem, &start_date, &end_date);
    return TRUE;
}

static gboolean
selection_interface_clear_selection (AtkSelection *selection)
{
    AtkGObjectAccessible *atk_gobj;
    GObject *g_obj;
    ECalendarItem *calitem;
    EaCalendarItem* ea_calitem = EA_CALENDAR_ITEM (selection);

    atk_gobj = ATK_GOBJECT_ACCESSIBLE (ea_calitem);
    g_obj = atk_gobject_accessible_get_object (atk_gobj);
    if (!g_obj)
        return FALSE;

    calitem = E_CALENDAR_ITEM (g_obj);
    e_calendar_item_set_selection (calitem, NULL, NULL);

    return TRUE;
}

static AtkObject*  
selection_interface_ref_selection (AtkSelection *selection, gint i)
{
    GObject *g_obj;
    ECalendarItem *calitem;
    EaCalendarItem* ea_calitem = EA_CALENDAR_ITEM (selection);
    gint count, sel_offset;
    GDate start_date, end_date;

    count = selection_interface_get_selection_count (selection);
    if (i < 0 || i >= count)
        return NULL;

    g_obj = atk_gobject_accessible_get_object (ATK_GOBJECT_ACCESSIBLE (ea_calitem));

    calitem = E_CALENDAR_ITEM (g_obj);
    e_calendar_item_get_selection (calitem, &start_date, &end_date);
    sel_offset = e_calendar_item_get_offset_for_date (calitem,
                              g_date_get_year (&start_date),
                              g_date_get_month (&start_date),
                              g_date_get_day (&start_date));

    return ea_calendar_item_ref_child (ATK_OBJECT (selection), sel_offset + i);
}

static gint
selection_interface_get_selection_count (AtkSelection *selection)
{
    AtkGObjectAccessible *atk_gobj;
    GObject *g_obj;
    ECalendarItem *calitem;
    EaCalendarItem* ea_calitem = EA_CALENDAR_ITEM (selection);
    GDate start_date, end_date;

    atk_gobj = ATK_GOBJECT_ACCESSIBLE (ea_calitem);
    g_obj = atk_gobject_accessible_get_object (atk_gobj);
    if (!g_obj)
        return 0;

    calitem = E_CALENDAR_ITEM (g_obj);
    e_calendar_item_get_selection (calitem, &start_date, &end_date);

    return g_date_days_between (&start_date, &end_date) + 1;
}

static gboolean
selection_interface_is_child_selected (AtkSelection *selection, gint index)
{
    AtkGObjectAccessible *atk_gobj;
    GObject *g_obj;
    ECalendarItem *calitem;
    EaCalendarItem* ea_calitem = EA_CALENDAR_ITEM (selection);
    gint row, column, n_children;

    atk_gobj = ATK_GOBJECT_ACCESSIBLE (ea_calitem);
    g_obj = atk_gobject_accessible_get_object (atk_gobj);
    if (!g_obj)
        return FALSE;

    calitem = E_CALENDAR_ITEM (g_obj);
    n_children = atk_object_get_n_accessible_children (ATK_OBJECT (selection));
    if (index < 0 || index >= n_children)
        return FALSE;

    row = index / EA_CALENDAR_COLUMN_NUM;
    column = index % EA_CALENDAR_COLUMN_NUM;

    return table_interface_is_selected (ATK_TABLE (selection), row, column);
}

/* callbacks */

static void
selection_preview_change_cb (ECalendarItem *calitem)
{
    AtkObject *atk_obj;

    g_return_if_fail (E_IS_CALENDAR_ITEM (calitem));
    atk_obj = atk_gobject_accessible_for_object (G_OBJECT (calitem));

    g_signal_emit_by_name (atk_obj, "selection_changed");
}

static void
date_range_changed_cb (ECalendarItem *calitem)
{
    AtkObject *atk_obj;

    g_return_if_fail (E_IS_CALENDAR_ITEM (calitem));
    atk_obj = atk_gobject_accessible_for_object (G_OBJECT (calitem));
    ea_calendar_item_destory_cell_data (EA_CALENDAR_ITEM (atk_obj));

    g_signal_emit_by_name (atk_obj, "model_changed");
}

static void
selection_changed_cb (ECalendarItem *calitem)
{
    selection_preview_change_cb (calitem);
}

/* helpers */

static EaCellTable *
ea_calendar_item_get_cell_data (EaCalendarItem *ea_calitem)
{
    AtkGObjectAccessible *atk_gobj;
    GObject *g_obj;
    ECalendarItem *calitem;
    EaCellTable *cell_data;

    g_return_val_if_fail (ea_calitem, NULL);

    atk_gobj = ATK_GOBJECT_ACCESSIBLE (ea_calitem);
    g_obj = atk_gobject_accessible_get_object (atk_gobj);
    if (!g_obj)
        return NULL;

    calitem = E_CALENDAR_ITEM (g_obj);

    cell_data = g_object_get_data (G_OBJECT(ea_calitem),
                       "ea-calendar-cell-table");

    if (!cell_data) {
        gint n_cells = ea_calendar_item_get_n_children (ATK_OBJECT(ea_calitem));
        cell_data = ea_cell_table_create (n_cells/EA_CALENDAR_COLUMN_NUM,
                          EA_CALENDAR_COLUMN_NUM,
                          FALSE);
        g_object_set_data (G_OBJECT(ea_calitem),
                   "ea-calendar-cell-table", cell_data);
    }
    return cell_data;
}

static void
ea_calendar_item_destory_cell_data (EaCalendarItem *ea_calitem)
{
    EaCellTable *cell_data;

    g_return_if_fail (ea_calitem);

    cell_data = g_object_get_data (G_OBJECT(ea_calitem),
                       "ea-calendar-cell-table");
    if (cell_data) {
        ea_cell_table_destroy (cell_data);
        g_object_set_data (G_OBJECT(ea_calitem),
                   "ea-calendar-cell-table", NULL);
    }
}

static gboolean
ea_calendar_item_get_row_label (EaCalendarItem *ea_calitem, gint row,
                gchar *buffer, gint buffer_size)
{
    AtkGObjectAccessible *atk_gobj;
    GObject *g_obj;
    ECalendarItem *calitem;
    gint index, week_num;
    gint year, month, day;

    g_return_val_if_fail (ea_calitem, FALSE);

    atk_gobj = ATK_GOBJECT_ACCESSIBLE (ea_calitem);
    g_obj = atk_gobject_accessible_get_object (atk_gobj);
    if (!g_obj)
        return FALSE;

    calitem = E_CALENDAR_ITEM (g_obj);

    index = atk_table_get_index_at (ATK_TABLE (ea_calitem), row, 0);
    if (!e_calendar_item_get_date_for_offset (calitem, index,
                          &year, &month, &day))
        return FALSE;

    week_num = e_calendar_item_get_week_number (calitem,
                            day, month, year);

    g_snprintf (buffer, buffer_size, "week number : %d", week_num);
    return TRUE;
}

static gboolean
ea_calendar_item_get_column_label (EaCalendarItem *ea_calitem, gint column,
                   gchar *buffer, gint buffer_size)
{
    AtkGObjectAccessible *atk_gobj;
    GObject *g_obj;
    ECalendarItem *calitem;
    gchar *week_char;
    gint char_size;

    g_return_val_if_fail (ea_calitem, FALSE);

    atk_gobj = ATK_GOBJECT_ACCESSIBLE (ea_calitem);
    g_obj = atk_gobject_accessible_get_object (atk_gobj);
    if (!g_obj)
        return FALSE;

    calitem = E_CALENDAR_ITEM (g_obj);
    week_char = g_utf8_offset_to_pointer (calitem->days, column);
    char_size = strlen (calitem->days) -
        strlen (g_utf8_find_next_char (calitem->days, NULL));

    if (week_char && char_size < buffer_size) {
        memcpy (buffer, week_char, char_size);
        buffer[char_size] = '\0';
        return TRUE;
    }
    return FALSE;
}

/* the coordinate the e-calendar canvas coord */
gboolean
e_calendar_item_get_day_extents (ECalendarItem *calitem,
                 gint year, gint month, gint date,
                 gint *x, gint *y,
                 gint *width, gint *height)
{
    GnomeCanvasItem *item;
    GtkWidget *widget;
    GtkStyle *style;
    PangoFontDescription *font_desc;
    PangoContext *pango_context;
    PangoFontMetrics *font_metrics;
    gint char_height, xthickness, ythickness, text_y;
    gint new_year, new_month, num_months, months_offset;
    gint month_x, month_y, month_cell_x, month_cell_y;
    gint month_row, month_col;
    gint day_row, day_col;
    gint days_from_week_start;

    g_return_val_if_fail (E_IS_CALENDAR_ITEM (calitem), FALSE);

    item = GNOME_CANVAS_ITEM (calitem);
    widget = GTK_WIDGET (item->canvas);
    style = widget->style;

    /* Set up Pango prerequisites */
    font_desc = calitem->font_desc;
    if (!font_desc)
        font_desc = style->font_desc;
    pango_context = gtk_widget_get_pango_context (widget);
    font_metrics = pango_context_get_metrics (pango_context, font_desc,
                          pango_context_get_language (pango_context));

    char_height =
        PANGO_PIXELS (pango_font_metrics_get_ascent (font_metrics)) +
        PANGO_PIXELS (pango_font_metrics_get_descent (font_metrics));

    xthickness = style->xthickness;
    ythickness = style->ythickness;

    new_year = year;
    new_month = month;
    e_calendar_item_normalize_date  (calitem, &new_year, &new_month);
    num_months = calitem->rows * calitem->cols;
    months_offset = (new_year - calitem->year) * 12
        + new_month - calitem->month;

    if (months_offset > num_months || months_offset < 0)
        return FALSE;

    month_row = months_offset / calitem->cols;
    month_col = months_offset % calitem->cols;

    month_x = item->x1 + xthickness + calitem->x_offset
        + month_col * calitem->month_width;
    month_y = item->y1 + ythickness + month_row * calitem->month_height;

    month_cell_x = month_x + E_CALENDAR_ITEM_XPAD_BEFORE_WEEK_NUMBERS
        + calitem->month_lpad + E_CALENDAR_ITEM_XPAD_BEFORE_CELLS;
    text_y = month_y + ythickness * 2
        + E_CALENDAR_ITEM_YPAD_ABOVE_MONTH_NAME
        + char_height + E_CALENDAR_ITEM_YPAD_BELOW_MONTH_NAME
        + E_CALENDAR_ITEM_YPAD_ABOVE_DAY_LETTERS + calitem->month_tpad;

    month_cell_y = text_y + char_height
        + E_CALENDAR_ITEM_YPAD_BELOW_DAY_LETTERS + 1
        + E_CALENDAR_ITEM_YPAD_ABOVE_CELLS;

    days_from_week_start =
        e_calendar_item_get_n_days_from_week_start (calitem, new_year,
                                new_month);
    day_row = (date + days_from_week_start - 1) / EA_CALENDAR_COLUMN_NUM;
    day_col = (date + days_from_week_start - 1) % EA_CALENDAR_COLUMN_NUM;

    *x = month_cell_x + day_col * calitem->cell_width;
    *y = month_cell_y + day_row * calitem->cell_height;
    *width = calitem->cell_width;
    *height = calitem->cell_height;

    return TRUE;
}

/* month is from 0 to 11 */
gboolean
e_calendar_item_get_date_for_offset (ECalendarItem *calitem, gint day_offset,
                     gint *year, gint *month, gint *day)
{
    gint start_year, start_month, start_day;
    gint end_year, end_month, end_day;
    GDate *start_date;

    g_return_val_if_fail (E_IS_CALENDAR_ITEM (calitem), FALSE);

    if (!e_calendar_item_get_date_range (calitem, &start_year,
                         &start_month, &start_day,
                         &end_year, &end_month,
                         &end_day))
        return FALSE;

    start_date = g_date_new_dmy (start_day, start_month + 1, start_year);

    g_date_add_days (start_date, day_offset);

    *year = g_date_get_year (start_date);
    *month = g_date_get_month (start_date) - 1;
    *day = g_date_get_day (start_date);

    return TRUE;
}

/* month is from 0 to 11 */
gint
e_calendar_item_get_offset_for_date (ECalendarItem *calitem,
                     gint year, gint month, gint day)
{
    gint start_year, start_month, start_day;
    gint end_year, end_month, end_day;
    GDate *start_date, *end_date;
    gint n_days;

    g_return_val_if_fail (E_IS_CALENDAR_ITEM (calitem), -1);

    if (!e_calendar_item_get_date_range (calitem, &start_year,
                         &start_month, &start_day,
                         &end_year, &end_month,
                         &end_day))
        return FALSE;

    start_date = g_date_new_dmy (start_day, start_month + 1, start_year);
    end_date = g_date_new_dmy (day, month + 1, year);

    n_days = g_date_days_between (start_date, end_date);
    g_free (start_date);
    g_free (end_date);
    return n_days;
}

gint
e_calendar_item_get_n_days_from_week_start (ECalendarItem *calitem,
                        gint year, gint month)
{
    struct tm tmp_tm;
    gint start_weekday, days_from_week_start;

    memset (&tmp_tm, 0, sizeof (tmp_tm));
    tmp_tm.tm_year = year - 1900;
    tmp_tm.tm_mon = month;
    tmp_tm.tm_mday = 1;
    tmp_tm.tm_isdst = -1;
    mktime (&tmp_tm);
    start_weekday = (tmp_tm.tm_wday + 6) % 7;   /* 0 to 6 */
    days_from_week_start = (start_weekday + 7 - calitem->week_start_day)
        % 7;
    return days_from_week_start;
}