path: root/calendar/gui/e-cal-model.c

/* Evolution calendar - Data model for ETable
 *
 * Copyright (C) 2004 Novell, Inc.
 *
 * Authors: Rodrigo Moya <rodrigo@ximian.com>
 *
 * 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 */

#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

#include <string.h>
#include <glib/garray.h>
#include <glib/gi18n.h>
#include <libedataserver/e-time-utils.h>
#include <libecal/e-cal-time-util.h>
#include "comp-util.h"
#include "e-cal-model.h"
#include "itip-utils.h"
#include "misc.h"
#include "e-calendar-marshal.h"
#include "calendar-config.h"

typedef struct {
    ECal *client;
    ECalView *query;

    gboolean do_query;
} ECalModelClient;

struct _ECalModelPrivate {
    /* The list of clients we are managing. Each element is of type ECalModelClient */
    GList *clients;

    /* The default client in the list */
    ECal *default_client;
    
    /* Array for storing the objects. Each element is of type ECalModelComponent */
    GPtrArray *objects;

    icalcomponent_kind kind;
    ECalModelFlags flags;
    icaltimezone *zone;

    /* The time range to display */
    time_t start;
    time_t end;
    
    /* The search regular expression */
    gchar *search_sexp;

    /* The full regular expression, including time range */
    gchar *full_sexp;

    /* The default category */
    gchar *default_category;

    /* Addresses for determining icons */
    EAccountList *accounts;

    /* Whether we display dates in 24-hour format. */
        gboolean use_24_hour_format;
};

static void e_cal_model_dispose (GObject *object);
static void e_cal_model_finalize (GObject *object);

static int ecm_column_count (ETableModel *etm);
static int ecm_row_count (ETableModel *etm);
static void *ecm_value_at (ETableModel *etm, int col, int row);
static void ecm_set_value_at (ETableModel *etm, int col, int row, const void *value);
static gboolean ecm_is_cell_editable (ETableModel *etm, int col, int row);
static void ecm_append_row (ETableModel *etm, ETableModel *source, int row);
static void *ecm_duplicate_value (ETableModel *etm, int col, const void *value);
static void ecm_free_value (ETableModel *etm, int col, void *value);
static void *ecm_initialize_value (ETableModel *etm, int col);
static gboolean ecm_value_is_empty (ETableModel *etm, int col, const void *value);
static char *ecm_value_to_string (ETableModel *etm, int col, const void *value);

static const char *ecm_get_color_for_component (ECalModel *model, ECalModelComponent *comp_data);

static ECalModelClient *add_new_client (ECalModel *model, ECal *client, gboolean do_query);
static ECalModelClient *find_client_data (ECalModel *model, ECal *client);
static void remove_client_objects (ECalModel *model, ECalModelClient *client_data);
static void remove_client (ECalModel *model, ECalModelClient *client_data);

/* Signal IDs */
enum {
    TIME_RANGE_CHANGED,
    ROW_APPENDED,
    CAL_VIEW_PROGRESS,
    CAL_VIEW_DONE,
    LAST_SIGNAL
};

static guint signals[LAST_SIGNAL] = { 0 };

G_DEFINE_TYPE (ECalModel, e_cal_model, E_TABLE_MODEL_TYPE)

static void
e_cal_model_class_init (ECalModelClass *klass)
{
    GObjectClass *object_class = G_OBJECT_CLASS (klass);
    ETableModelClass *etm_class = E_TABLE_MODEL_CLASS (klass);

    object_class->dispose = e_cal_model_dispose;
    object_class->finalize = e_cal_model_finalize;

    etm_class->column_count = ecm_column_count;
    etm_class->row_count = ecm_row_count;
    etm_class->value_at = ecm_value_at;
    etm_class->set_value_at = ecm_set_value_at;
    etm_class->is_cell_editable = ecm_is_cell_editable;
    etm_class->append_row = ecm_append_row;
    etm_class->duplicate_value = ecm_duplicate_value;
    etm_class->free_value = ecm_free_value;
    etm_class->initialize_value = ecm_initialize_value;
    etm_class->value_is_empty = ecm_value_is_empty;
    etm_class->value_to_string = ecm_value_to_string;

    klass->get_color_for_component = ecm_get_color_for_component;
    klass->fill_component_from_model = NULL;

    signals[TIME_RANGE_CHANGED] =
        g_signal_new ("time_range_changed",
                  G_TYPE_FROM_CLASS (klass),
                  G_SIGNAL_RUN_LAST,
                  G_STRUCT_OFFSET (ECalModelClass, time_range_changed),
                  NULL, NULL,
                  e_calendar_marshal_VOID__LONG_LONG,
                  G_TYPE_NONE, 2, G_TYPE_LONG, G_TYPE_LONG);    

    signals[ROW_APPENDED] =
        g_signal_new ("row_appended",
                  G_TYPE_FROM_CLASS (klass),
                  G_SIGNAL_RUN_LAST,
                  G_STRUCT_OFFSET (ECalModelClass, row_appended),
                  NULL, NULL,
                  g_cclosure_marshal_VOID__VOID,
                  G_TYPE_NONE, 0);
    signals[CAL_VIEW_PROGRESS] =
        g_signal_new ("cal_view_progress",
                  G_TYPE_FROM_CLASS (klass),
                  G_SIGNAL_RUN_LAST,
                  G_STRUCT_OFFSET (ECalModelClass, cal_view_progress),
                  NULL, NULL,
                          e_calendar_marshal_VOID__STRING_INT_INT,
                  G_TYPE_NONE, 3, G_TYPE_STRING, G_TYPE_INT, G_TYPE_INT);
    signals[CAL_VIEW_DONE] =
        g_signal_new ("cal_view_done",
                  G_TYPE_FROM_CLASS (klass),
                  G_SIGNAL_RUN_LAST,
                  G_STRUCT_OFFSET (ECalModelClass, cal_view_done),
                  NULL, NULL,
                  e_calendar_marshal_VOID__INT_INT,
                  G_TYPE_NONE, 2, G_TYPE_INT, G_TYPE_INT);

}

static void
e_cal_model_init (ECalModel *model)
{
    ECalModelPrivate *priv;

    priv = g_new0 (ECalModelPrivate, 1);
    model->priv = priv;

    /* match none by default */
    priv->start = -1;
    priv->end = -1;
    priv->search_sexp = NULL;
    priv->full_sexp = g_strdup ("#f");

    priv->objects = g_ptr_array_new ();
    priv->kind = ICAL_NO_COMPONENT;
    priv->flags = 0;

    priv->accounts = itip_addresses_get ();

    priv->use_24_hour_format = TRUE;
}

static void
clear_objects_array (ECalModelPrivate *priv)
{
    gint i;

    for (i = 0; i < priv->objects->len; i++) {
        ECalModelComponent *comp_data;

        comp_data = g_ptr_array_index (priv->objects, i);
        if (comp_data == NULL) {
            g_warning ("comp_data is null\n");
            continue;
        }
        e_cal_model_free_component_data (comp_data);
    }

    g_ptr_array_set_size (priv->objects, 0);
}

static void
e_cal_model_dispose (GObject *object)
{
    ECalModelPrivate *priv;
    ECalModel *model = (ECalModel *) object;

    g_return_if_fail (E_IS_CAL_MODEL (model));

    priv = model->priv;

    if (priv->clients) {
        while (priv->clients != NULL) {
            ECalModelClient *client_data = (ECalModelClient *) priv->clients->data;
            
            g_signal_handlers_disconnect_matched (client_data->client, G_SIGNAL_MATCH_DATA,
                                  0, 0, NULL, NULL, model);
            if (client_data->query)
                g_signal_handlers_disconnect_matched (client_data->query, G_SIGNAL_MATCH_DATA,
                                      0, 0, NULL, NULL, model);
            
            priv->clients = g_list_remove (priv->clients, client_data);


            g_object_unref (client_data->client);
            if (client_data->query)
                g_object_unref (client_data->query);
            g_free (client_data);
        }

        priv->clients = NULL;
    }

    if (G_OBJECT_CLASS (e_cal_model_parent_class)->dispose)
        G_OBJECT_CLASS (e_cal_model_parent_class)->dispose (object);
}

static void
e_cal_model_finalize (GObject *object)
{
    ECalModelPrivate *priv;
    ECalModel *model = (ECalModel *) object;

    g_return_if_fail (E_IS_CAL_MODEL (model));

    priv = model->priv;

    g_free (priv->search_sexp);
    g_free (priv->full_sexp);

    g_free (priv->default_category);

    clear_objects_array (priv);
    g_ptr_array_free (priv->objects, FALSE);

    g_free (priv);

    if (G_OBJECT_CLASS (e_cal_model_parent_class)->finalize)
        G_OBJECT_CLASS (e_cal_model_parent_class)->finalize (object);
}

/* ETableModel methods */

static int
ecm_column_count (ETableModel *etm)
{
    return E_CAL_MODEL_FIELD_LAST;
}

static int
ecm_row_count (ETableModel *etm)
{
    ECalModelPrivate *priv;
    ECalModel *model = (ECalModel *) etm;

    g_return_val_if_fail (E_IS_CAL_MODEL (model), -1);

    priv = model->priv;

    return priv->objects->len;
}

static char *
get_categories (ECalModelComponent *comp_data)
{
    icalproperty *prop;

    prop = icalcomponent_get_first_property (comp_data->icalcomp, ICAL_CATEGORIES_PROPERTY);
    if (prop)
        return (char *) icalproperty_get_categories (prop);

    return "";
}

static char *
get_classification (ECalModelComponent *comp_data)
{
    icalproperty *prop;
    icalproperty_class class;

    prop = icalcomponent_get_first_property (comp_data->icalcomp, ICAL_CLASS_PROPERTY);

    if (!prop)
        return _("Public");

    class = icalproperty_get_class (prop);

    switch (class)
    {
    case ICAL_CLASS_PUBLIC:
        return _("Public");
    case ICAL_CLASS_PRIVATE:
        return _("Private");
    case ICAL_CLASS_CONFIDENTIAL:
        return _("Confidential");
    default:
        return _("Unknown");
    }
}

static const char *
get_color (ECalModel *model, ECalModelComponent *comp_data)
{
    g_return_val_if_fail (E_IS_CAL_MODEL (model), NULL);

    return e_cal_model_get_color_for_component (model, comp_data);
}

static char *
get_description (ECalModelComponent *comp_data)
{
    icalproperty *prop;
    static GString *str = NULL;

    if (str) {
        g_string_free (str, TRUE);
        str = NULL;
    }
    
    prop = icalcomponent_get_first_property (comp_data->icalcomp, ICAL_DESCRIPTION_PROPERTY);
    if (prop) {
        str = g_string_new (NULL);
        do {
            str = g_string_append (str, icalproperty_get_description (prop));
        } while ((prop = icalcomponent_get_next_property (comp_data->icalcomp, ICAL_DESCRIPTION_PROPERTY)));

        return str->str;
    }

    return "";
}

static ECellDateEditValue*
get_dtstart (ECalModel *model, ECalModelComponent *comp_data)
{
    ECalModelPrivate *priv;
        struct icaltimetype tt_start;

    priv = model->priv;

    if (!comp_data->dtstart) {
        icalproperty *prop;
        icaltimezone *zone;
        gboolean got_zone = FALSE;

        prop = icalcomponent_get_first_property (comp_data->icalcomp, ICAL_DTSTART_PROPERTY);
        if (!prop)
            return NULL;

        tt_start = icalproperty_get_dtstart (prop);

        if (icaltime_get_tzid (tt_start)
            && e_cal_get_timezone (comp_data->client, icaltime_get_tzid (tt_start), &zone, NULL))
            got_zone = TRUE;

        if (e_cal_model_get_flags (model) & E_CAL_MODEL_FLAGS_EXPAND_RECURRENCES) {
            if (got_zone) {
                tt_start = icaltime_from_timet_with_zone (comp_data->instance_start, tt_start.is_date, zone);
                if (priv->zone)
                    icaltimezone_convert_time (&tt_start, zone, priv->zone);
            } else
                if (priv->zone)
                    tt_start = icaltime_from_timet_with_zone (comp_data->instance_start, tt_start.is_date, priv->zone);
        }

        if (!icaltime_is_valid_time (tt_start) || icaltime_is_null_time (tt_start))
            return NULL;

        comp_data->dtstart = g_new0 (ECellDateEditValue, 1);
        comp_data->dtstart->tt = tt_start;

        if (got_zone)
            comp_data->dtstart->zone = zone;
        else
            comp_data->dtstart->zone = NULL;
    }

    return comp_data->dtstart;
}

static char *
get_summary (ECalModelComponent *comp_data)
{
    icalproperty *prop;

    prop = icalcomponent_get_first_property (comp_data->icalcomp, ICAL_SUMMARY_PROPERTY);
    if (prop)
        return (char *) icalproperty_get_summary (prop);

    return "";
}

static char *
get_uid (ECalModelComponent *comp_data)
{
    return (char *) icalcomponent_get_uid (comp_data->icalcomp);
}

static void *
ecm_value_at (ETableModel *etm, int col, int row)
{
    ECalModelPrivate *priv;
    ECalModelComponent *comp_data;
    ECalModel *model = (ECalModel *) etm;

    g_return_val_if_fail (E_IS_CAL_MODEL (model), NULL);

    priv = model->priv;

    g_return_val_if_fail (col >= 0 && col < E_CAL_MODEL_FIELD_LAST, NULL);
    g_return_val_if_fail (row >= 0 && row < priv->objects->len, NULL);

    comp_data = g_ptr_array_index (priv->objects, row);
    g_return_val_if_fail (comp_data != NULL, NULL);

    switch (col) {
    case E_CAL_MODEL_FIELD_CATEGORIES :
        return get_categories (comp_data);
    case E_CAL_MODEL_FIELD_CLASSIFICATION :
        return get_classification (comp_data);
    case E_CAL_MODEL_FIELD_COLOR :
        return (void *) get_color (model, comp_data);
    case E_CAL_MODEL_FIELD_COMPONENT :
        return comp_data->icalcomp;
    case E_CAL_MODEL_FIELD_DESCRIPTION :
        return get_description (comp_data);
    case E_CAL_MODEL_FIELD_DTSTART :
        return (void *) get_dtstart (model, comp_data);
    case E_CAL_MODEL_FIELD_HAS_ALARMS :
        return GINT_TO_POINTER ((icalcomponent_get_first_component (comp_data->icalcomp,
                                        ICAL_VALARM_COMPONENT) != NULL));
    case E_CAL_MODEL_FIELD_ICON :
    {
        ECalComponent *comp;
        icalcomponent *icalcomp;
        gint retval = 0;

        comp = e_cal_component_new ();
        icalcomp = icalcomponent_new_clone (comp_data->icalcomp);
        if (e_cal_component_set_icalcomponent (comp, icalcomp)) {
            if (e_cal_component_get_vtype (comp) == E_CAL_COMPONENT_JOURNAL) {
                g_object_unref (comp);
                return GINT_TO_POINTER (retval);
            }
                
            if (e_cal_component_has_recurrences (comp))
                retval = 1;
            else if (itip_organizer_is_user (comp, comp_data->client))
                retval = 3;
            else {
                GSList *attendees = NULL, *sl;

                e_cal_component_get_attendee_list (comp, &attendees);
                for (sl = attendees; sl != NULL; sl = sl->next) {
                    ECalComponentAttendee *ca = sl->data;
                    const char *text;

                    text = itip_strip_mailto (ca->value);
                    if (e_account_list_find (priv->accounts, E_ACCOUNT_FIND_ID_ADDRESS, text) != NULL) {
                        if (ca->delto != NULL)
                            retval = 3;
                        else
                            retval = 2;
                        break;
                    }
                }

                e_cal_component_free_attendee_list (attendees);
            }
        } else
            icalcomponent_free (icalcomp);

        g_object_unref (comp);

        return GINT_TO_POINTER (retval);
    }
    case E_CAL_MODEL_FIELD_SUMMARY :
        return get_summary (comp_data);
    case E_CAL_MODEL_FIELD_UID :
        return get_uid (comp_data);
    }

    return "";
}

static void
set_categories (ECalModelComponent *comp_data, const char *value)
{
    icalproperty *prop;

    prop = icalcomponent_get_first_property (comp_data->icalcomp, ICAL_CATEGORIES_PROPERTY);
    if (!value || !(*value)) {
        if (prop) {
            icalcomponent_remove_property (comp_data->icalcomp, prop);
            icalproperty_free (prop);
        }
    } else {
        if (!prop) {
            prop = icalproperty_new_categories (value);
            icalcomponent_add_property (comp_data->icalcomp, prop);
        } else
            icalproperty_set_categories (prop, value);
    }
}

static void
set_classification (ECalModelComponent *comp_data, const char *value)
{
    icalproperty *prop;

    prop = icalcomponent_get_first_property (comp_data->icalcomp, ICAL_CLASS_PROPERTY);
    if (!value || !(*value)) {
        if (prop) {
            icalcomponent_remove_property (comp_data->icalcomp, prop);
            icalproperty_free (prop);
        }
    } else {
      icalproperty_class ical_class;

      if (!g_ascii_strcasecmp (value, "PUBLIC"))
        ical_class = ICAL_CLASS_PUBLIC;
      else if (!g_ascii_strcasecmp (value, "PRIVATE"))
        ical_class = ICAL_CLASS_PRIVATE;
      else if (!g_ascii_strcasecmp (value, "CONFIDENTIAL"))
        ical_class = ICAL_CLASS_CONFIDENTIAL;
      else
        ical_class = ICAL_CLASS_NONE;

        if (!prop) {
            prop = icalproperty_new_class (ical_class);
            icalcomponent_add_property (comp_data->icalcomp, prop);
        } else
            icalproperty_set_class (prop, ical_class);
    }
}

static void
set_description (ECalModelComponent *comp_data, const char *value)
{
    icalproperty *prop;

    /* remove old description(s) */
    prop = icalcomponent_get_first_property (comp_data->icalcomp, ICAL_DESCRIPTION_PROPERTY);
    while (prop) {
        icalproperty *next;

        next = icalcomponent_get_next_property (comp_data->icalcomp, ICAL_DESCRIPTION_PROPERTY);

        icalcomponent_remove_property (comp_data->icalcomp, prop);
        icalproperty_free (prop);

        prop = next;
    }

    /* now add the new description */
    if (!value || !(*value))
        return;

    prop = icalproperty_new_description (value);
    icalcomponent_add_property (comp_data->icalcomp, prop);
}

static void
set_dtstart (ECalModel *model, ECalModelComponent *comp_data, const void *value)
{
    ECellDateEditValue *dv = (ECellDateEditValue *) value;
    icalproperty *prop;
    icalparameter *param;
    const char *tzid;
    
    prop = icalcomponent_get_first_property (comp_data->icalcomp, ICAL_DTSTART_PROPERTY);
    if (prop)
        param = icalproperty_get_first_parameter (prop, ICAL_TZID_PARAMETER);
    else
        param = NULL;

    /* If we are setting the property to NULL (i.e. removing it), then
       we remove it if it exists. */
    if (!dv) {
        if (prop) {
            icalcomponent_remove_property (comp_data->icalcomp, prop);
            icalproperty_free (prop);
        }

        return;
    }
    
    /* If the TZID is set to "UTC", we set the is_utc flag. */
    tzid = dv->zone ? icaltimezone_get_tzid (dv->zone) : "UTC";
    if (tzid && !strcmp (tzid, "UTC"))
        dv->tt.is_utc = 1;
    else
        dv->tt.is_utc = 0;

    if (prop) {
        icalproperty_set_dtstart (prop, dv->tt);
    } else {
        prop = icalproperty_new_dtstart (dv->tt);
        icalcomponent_add_property (comp_data->icalcomp, prop);
    }

    /* If the TZID is set to "UTC", we don't want to save the TZID. */
    if (tzid && strcmp (tzid, "UTC")) {
        if (param) {
            icalparameter_set_tzid (param, (char *) tzid);
        } else {
            param = icalparameter_new_tzid ((char *) tzid);
            icalproperty_add_parameter (prop, param);
        }
    } else if (param) {
        icalproperty_remove_parameter (prop, ICAL_TZID_PARAMETER);
    }
}

static void
set_summary (ECalModelComponent *comp_data, const char *value)
{
    icalproperty *prop;

    prop = icalcomponent_get_first_property (comp_data->icalcomp, ICAL_SUMMARY_PROPERTY);

    if (string_is_empty (value)) {
        if (prop) {
            icalcomponent_remove_property (comp_data->icalcomp, prop);
            icalproperty_free (prop);
        }
    } else {
        if (prop)
            icalproperty_set_summary (prop, value);
        else {
            prop = icalproperty_new_summary (value);
            icalcomponent_add_property (comp_data->icalcomp, prop);
        }
    }
}

static void
ecm_set_value_at (ETableModel *etm, int col, int row, const void *value)
{
    ECalModelPrivate *priv;
    ECalModelComponent *comp_data;
    ECalModel *model = (ECalModel *) etm;

    g_return_if_fail (E_IS_CAL_MODEL (model));

    priv = model->priv;

    g_return_if_fail (col >= 0 && col < E_CAL_MODEL_FIELD_LAST);
    g_return_if_fail (row >= 0 && row < priv->objects->len);

    comp_data = g_ptr_array_index (priv->objects, row);
    g_return_if_fail (comp_data != NULL);

    switch (col) {
    case E_CAL_MODEL_FIELD_CATEGORIES :
        set_categories (comp_data, value);
        break;
    case E_CAL_MODEL_FIELD_CLASSIFICATION :
        set_classification (comp_data, value);
        break;
    case E_CAL_MODEL_FIELD_DESCRIPTION :
        set_description (comp_data, value);
        break;
    case E_CAL_MODEL_FIELD_DTSTART :
        set_dtstart (model, comp_data, value);
        break;
    case E_CAL_MODEL_FIELD_SUMMARY :
        set_summary (comp_data, value);
        break;
    }

    /* FIXME ask about mod type */
    if (!e_cal_modify_object (comp_data->client, comp_data->icalcomp, CALOBJ_MOD_ALL, NULL)) {
        g_warning (G_STRLOC ": Could not modify the object!");
        
        /* FIXME Show error dialog */
    }
}

/**
 * e_cal_model_test_row_editable
 * Checks if component at row 'row' is editable or not. It doesn't check bounds for 'row'.
 *
 * @param model Calendar model.
 * @param row Row of our interest. -1 is editable only when default client is editable.
 * @return Whether row is editable or not.
 **/
gboolean
e_cal_model_test_row_editable (ECalModel *model, int row)
{
    gboolean readonly;
    ECal *cal = NULL;
    
    if (row != -1) {
        ECalModelComponent *comp_data;

        comp_data = e_cal_model_get_component_at (model, row);

        if (comp_data)
            cal = comp_data->client;

    } else {
        cal = e_cal_model_get_default_client (model);
    }

    readonly = cal == NULL;

    if (!readonly)
        if (!e_cal_is_read_only (cal, &readonly, NULL))
            readonly = TRUE;

    return !readonly;
}

static gboolean
ecm_is_cell_editable (ETableModel *etm, int col, int row)
{
    ECalModelPrivate *priv;
    ECalModel *model = (ECalModel *) etm;

    g_return_val_if_fail (E_IS_CAL_MODEL (model), FALSE);

    priv = model->priv;

    g_return_val_if_fail (col >= 0 && col <= E_CAL_MODEL_FIELD_LAST, FALSE);
    g_return_val_if_fail (row >= -1 || (row >= 0 && row < priv->objects->len), FALSE);

    if (!e_cal_model_test_row_editable (E_CAL_MODEL (etm), row))
        return FALSE;

    switch (col) {
    case E_CAL_MODEL_FIELD_CATEGORIES :
    case E_CAL_MODEL_FIELD_CLASSIFICATION :
    case E_CAL_MODEL_FIELD_DESCRIPTION :
    case E_CAL_MODEL_FIELD_DTSTART :
    case E_CAL_MODEL_FIELD_SUMMARY :
        return TRUE;
    }

    return FALSE;
}

static void
ecm_append_row (ETableModel *etm, ETableModel *source, int row)
{
    ECalModelClass *model_class;
    ECalModelComponent comp_data;
    ECalModel *model = (ECalModel *) etm;

    g_return_if_fail (E_IS_CAL_MODEL (model));
    g_return_if_fail (E_IS_TABLE_MODEL (source));

    memset (&comp_data, 0, sizeof (ECalModelComponent));
    comp_data.client = e_cal_model_get_default_client (model);

    /* guard against saving before the calendar is open */
    if (!(comp_data.client && e_cal_get_load_state (comp_data.client) == E_CAL_LOAD_LOADED))
        return;

    comp_data.icalcomp = e_cal_model_create_component_with_defaults (model);

    /* set values for our fields */
    set_categories (&comp_data, e_table_model_value_at (source, E_CAL_MODEL_FIELD_CATEGORIES, row));
    set_classification (&comp_data, e_table_model_value_at (source, E_CAL_MODEL_FIELD_CLASSIFICATION, row));
    set_description (&comp_data, e_table_model_value_at (source, E_CAL_MODEL_FIELD_DESCRIPTION, row));
    set_dtstart (model, &comp_data, e_table_model_value_at (source, E_CAL_MODEL_FIELD_DTSTART, row));
    set_summary (&comp_data, e_table_model_value_at (source, E_CAL_MODEL_FIELD_SUMMARY, row));

    /* call the class' method for filling the component */
    model_class = (ECalModelClass *) G_OBJECT_GET_CLASS (model);
    if (model_class->fill_component_from_model != NULL) {
        model_class->fill_component_from_model (model, &comp_data, source, row);
    }

    if (!e_cal_create_object (comp_data.client, comp_data.icalcomp, NULL, NULL)) {
        g_warning (G_STRLOC ": Could not create the object!");

        /* FIXME: show error dialog */
        icalcomponent_free (comp_data.icalcomp);
        return;
    }

    icalcomponent_free (comp_data.icalcomp);

    g_signal_emit (G_OBJECT (model), signals[ROW_APPENDED], 0); 
}

static void *
ecm_duplicate_value (ETableModel *etm, int col, const void *value)
{
    g_return_val_if_fail (col >= 0 && col < E_CAL_MODEL_FIELD_LAST, NULL);

    switch (col) {
    case E_CAL_MODEL_FIELD_CATEGORIES :
    case E_CAL_MODEL_FIELD_CLASSIFICATION :
    case E_CAL_MODEL_FIELD_DESCRIPTION :
    case E_CAL_MODEL_FIELD_SUMMARY :
        return g_strdup (value);
    case E_CAL_MODEL_FIELD_HAS_ALARMS :
    case E_CAL_MODEL_FIELD_ICON :
    case E_CAL_MODEL_FIELD_COLOR :
        return (void *) value;
    case E_CAL_MODEL_FIELD_COMPONENT :
        return icalcomponent_new_clone ((icalcomponent *) value);
    case E_CAL_MODEL_FIELD_DTSTART :
        if (value) {
            ECellDateEditValue *dv, *orig_dv;

            orig_dv = (ECellDateEditValue *) value;
            dv = g_new0 (ECellDateEditValue, 1);
            *dv = *orig_dv;

            return dv;
        }
        break;
    }

    return NULL;
}

static void
ecm_free_value (ETableModel *etm, int col, void *value)
{
    g_return_if_fail (col >= 0 && col < E_CAL_MODEL_FIELD_LAST);

    switch (col) {
    case E_CAL_MODEL_FIELD_CATEGORIES :
    case E_CAL_MODEL_FIELD_DESCRIPTION :
    case E_CAL_MODEL_FIELD_SUMMARY :
        if (value)
            g_free (value);
        break;
    case E_CAL_MODEL_FIELD_CLASSIFICATION :
    case E_CAL_MODEL_FIELD_HAS_ALARMS :
    case E_CAL_MODEL_FIELD_ICON :
    case E_CAL_MODEL_FIELD_COLOR :
        break;
    case E_CAL_MODEL_FIELD_DTSTART :
        if (value)
            g_free (value);
        break;
    case E_CAL_MODEL_FIELD_COMPONENT :
        if (value)
            icalcomponent_free ((icalcomponent *) value);
        break;
    }
}

static void *
ecm_initialize_value (ETableModel *etm, int col)
{
    ECalModelPrivate *priv;
    ECalModel *model = (ECalModel *) etm;

    g_return_val_if_fail (E_IS_CAL_MODEL (model), NULL);
    g_return_val_if_fail (col >= 0 && col < E_CAL_MODEL_FIELD_LAST, NULL);

    priv = model->priv;

    switch (col) {
    case E_CAL_MODEL_FIELD_CATEGORIES :
        return g_strdup (priv->default_category?priv->default_category:"");
    case E_CAL_MODEL_FIELD_CLASSIFICATION :
    case E_CAL_MODEL_FIELD_DESCRIPTION :
    case E_CAL_MODEL_FIELD_SUMMARY :
        return g_strdup ("");
    case E_CAL_MODEL_FIELD_DTSTART :
    case E_CAL_MODEL_FIELD_HAS_ALARMS :
    case E_CAL_MODEL_FIELD_ICON :
    case E_CAL_MODEL_FIELD_COLOR :
    case E_CAL_MODEL_FIELD_COMPONENT :
        return NULL;
    }

    return NULL;
}

static gboolean
ecm_value_is_empty (ETableModel *etm, int col, const void *value)
{
    ECalModelPrivate *priv;
    ECalModel *model = (ECalModel *) etm;

    g_return_val_if_fail (E_IS_CAL_MODEL (model), TRUE);
    g_return_val_if_fail (col >= 0 && col < E_CAL_MODEL_FIELD_LAST, TRUE);

    priv = model->priv;

    switch (col) {
    case E_CAL_MODEL_FIELD_CATEGORIES :
        /* This could be a hack or not.  If the categories field only
         * contains the default category, then it possibly means that
         * the user has not entered anything at all in the click-to-add;
         * the category is in the value because we put it there in
         * ecm_initialize_value().
         */
        if (priv->default_category && value && strcmp (priv->default_category, value) == 0)
            return TRUE;
        else
            return string_is_empty (value);
    case E_CAL_MODEL_FIELD_CLASSIFICATION :
    case E_CAL_MODEL_FIELD_DESCRIPTION :
    case E_CAL_MODEL_FIELD_SUMMARY :
        return string_is_empty (value);
    case E_CAL_MODEL_FIELD_DTSTART :
        return value ? FALSE : TRUE;
    case E_CAL_MODEL_FIELD_HAS_ALARMS :
    case E_CAL_MODEL_FIELD_ICON :
    case E_CAL_MODEL_FIELD_COLOR :
    case E_CAL_MODEL_FIELD_COMPONENT :
        return TRUE;
    }

    return TRUE;
}

static char *
ecm_value_to_string (ETableModel *etm, int col, const void *value)
{
    g_return_val_if_fail (col >= 0 && col < E_CAL_MODEL_FIELD_LAST, g_strdup (""));

    switch (col) {
    case E_CAL_MODEL_FIELD_CATEGORIES :
    case E_CAL_MODEL_FIELD_CLASSIFICATION :
    case E_CAL_MODEL_FIELD_DESCRIPTION :
    case E_CAL_MODEL_FIELD_SUMMARY :
        return g_strdup (value);
    case E_CAL_MODEL_FIELD_DTSTART :
        return e_cal_model_date_value_to_string (E_CAL_MODEL (etm), value);
    case E_CAL_MODEL_FIELD_ICON :
        if (GPOINTER_TO_INT (value) == 0)
            return g_strdup (_("Normal"));
        else if (GPOINTER_TO_INT (value) == 1)
            return g_strdup (_("Recurring"));
        else
            return g_strdup (_("Assigned"));
    case E_CAL_MODEL_FIELD_HAS_ALARMS :
        return g_strdup (value ? _("Yes") : _("No"));
    case E_CAL_MODEL_FIELD_COLOR :
    case E_CAL_MODEL_FIELD_COMPONENT :
        return g_strdup ("");
    }

    return g_strdup ("");
}

/* ECalModel class methods */

typedef struct {
    const gchar *color;
    GList *uris;
} AssignedColorData;

static const char *
ecm_get_color_for_component (ECalModel *model, ECalModelComponent *comp_data)
{
    ESource *source;
    const gchar *color_spec;
    gint i, first_empty = 0;
    static AssignedColorData assigned_colors[] = {
        { "#BECEDD", NULL }, /* 190 206 221     Blue */
        { "#E2F0EF", NULL }, /* 226 240 239     Light Blue */
        { "#C6E2B7", NULL }, /* 198 226 183     Green */
        { "#E2F0D3", NULL }, /* 226 240 211     Light Green */
        { "#E2D4B7", NULL }, /* 226 212 183     Khaki */
        { "#EAEAC1", NULL }, /* 234 234 193     Light Khaki */
        { "#F0B8B7", NULL }, /* 240 184 183     Pink */
        { "#FED4D3", NULL }, /* 254 212 211     Light Pink */
        { "#E2C6E1", NULL }, /* 226 198 225     Purple */
        { "#F0E2EF", NULL }  /* 240 226 239     Light Purple */
    };

    g_return_val_if_fail (E_IS_CAL_MODEL (model), NULL);

    source = e_cal_get_source (comp_data->client);
    color_spec = e_source_peek_color_spec (source);
    if (color_spec != NULL) {
        g_free (comp_data->color);
        comp_data->color = g_strdup (color_spec);
        return comp_data->color;
    }
                                                                   
    for (i = 0; i < G_N_ELEMENTS (assigned_colors); i++) {
        GList *l;

        if (assigned_colors[i].uris == NULL) {
            first_empty = i;
            continue;
        }

        for (l = assigned_colors[i].uris; l != NULL; l = l->next) {
            if (!strcmp ((const char *) l->data,
                     e_cal_get_uri (comp_data->client)))
            {
                return assigned_colors[i].color;
            }
        }
    }

    /* return the first unused color */
    assigned_colors[first_empty].uris = g_list_append (assigned_colors[first_empty].uris,
                               g_strdup (e_cal_get_uri (comp_data->client)));

    return assigned_colors[first_empty].color;
}

/**
 * e_cal_model_get_component_kind
 */
icalcomponent_kind
e_cal_model_get_component_kind (ECalModel *model)
{
    ECalModelPrivate *priv;

    g_return_val_if_fail (E_IS_CAL_MODEL (model), ICAL_NO_COMPONENT);

    priv = model->priv;
    return priv->kind;
}

/**
 * e_cal_model_set_component_kind
 */
void
e_cal_model_set_component_kind (ECalModel *model, icalcomponent_kind kind)
{
    ECalModelPrivate *priv;

    g_return_if_fail (E_IS_CAL_MODEL (model));

    priv = model->priv;
    priv->kind = kind;
}

/**
 * e_cal_model_get_flags
 */
ECalModelFlags
e_cal_model_get_flags (ECalModel *model)
{
    ECalModelPrivate *priv;

    g_return_val_if_fail (E_IS_CAL_MODEL (model), E_CAL_MODEL_FLAGS_INVALID);

    priv = model->priv;
    return priv->flags;
}

/**
 * e_cal_model_set_flags
 */
void
e_cal_model_set_flags (ECalModel *model, ECalModelFlags flags)
{
    ECalModelPrivate *priv;

    g_return_if_fail (E_IS_CAL_MODEL (model));

    priv = model->priv;
    priv->flags = flags;
}

/**
 * e_cal_model_get_timezone
 */
icaltimezone *
e_cal_model_get_timezone (ECalModel *model)
{
    g_return_val_if_fail (E_IS_CAL_MODEL (model), NULL);
    return model->priv->zone;
}

/**
 * e_cal_model_set_timezone
 */
void
e_cal_model_set_timezone (ECalModel *model, icaltimezone *zone)
{
    ECalModelPrivate *priv;
    GList *l;
    
    g_return_if_fail (E_IS_CAL_MODEL (model));

    priv = model->priv;
    if (priv->zone != zone) {
        e_table_model_pre_change (E_TABLE_MODEL (model));
        priv->zone = zone;

        for (l = priv->clients; l; l = l->next)
            e_cal_set_default_timezone (((ECalModelClient *)l->data)->client, priv->zone, NULL);
        
        /* the timezone affects the times shown for date fields,
           so we need to redisplay everything */
        e_table_model_changed (E_TABLE_MODEL (model));
    }
}

/**
 * e_cal_model_set_default_category
 */
void
e_cal_model_set_default_category (ECalModel *model, const gchar *default_cat)
{
    g_return_if_fail (E_IS_CAL_MODEL (model));

    if (model->priv->default_category)
        g_free (model->priv->default_category);

    model->priv->default_category = g_strdup (default_cat);
}

/**
 * e_cal_model_get_use_24_hour_format
 */
gboolean
e_cal_model_get_use_24_hour_format (ECalModel *model)
{
    g_return_val_if_fail (E_IS_CAL_MODEL (model), FALSE);

    return model->priv->use_24_hour_format;
}

/**
 * e_cal_model_set_use_24_hour_format
 */
void
e_cal_model_set_use_24_hour_format (ECalModel *model, gboolean use24)
{
    g_return_if_fail (E_IS_CAL_MODEL (model));

    if (model->priv->use_24_hour_format != use24) {
                e_table_model_pre_change (E_TABLE_MODEL (model));
                model->priv->use_24_hour_format = use24;
                /* Get the views to redraw themselves. */
                e_table_model_changed (E_TABLE_MODEL (model));
        }
}

/**
 * e_cal_model_get_default_client
 */
ECal *
e_cal_model_get_default_client (ECalModel *model)
{
    ECalModelPrivate *priv;
    ECalModelClient *client_data;

    g_return_val_if_fail (model != NULL, NULL);
    g_return_val_if_fail (E_IS_CAL_MODEL (model), NULL);
    
    priv = model->priv;

    /* FIXME Should we force the client to be open? */

    /* we always return a valid ECal, since we rely on it in many places */
    if (priv->default_client)
        return priv->default_client;

    if (!priv->clients)
        return NULL;

    client_data = (ECalModelClient *) priv->clients->data;

    return client_data ? client_data->client : NULL;
}

void
e_cal_model_set_default_client (ECalModel *model, ECal *client)
{
    ECalModelPrivate *priv;
    ECalModelClient *client_data;
    
    g_return_if_fail (model != NULL);
    g_return_if_fail (E_IS_CAL_MODEL (model));
    g_return_if_fail (client != NULL);
    g_return_if_fail (E_IS_CAL (client));

    priv = model->priv;

    if (priv->default_client) {
        client_data = find_client_data (model, priv->default_client);
        if (!client_data) {
            g_warning ("client_data is NULL\n");
        } else {
            if (!client_data->do_query)
                remove_client (model, client_data);
        }
    }
    
    /* Make sure its in the model */
    client_data = add_new_client (model, client, FALSE);

    /* Store the default client */  
    priv->default_client = client_data->client; 
}

/**
 * e_cal_model_get_client_list
 */
GList *
e_cal_model_get_client_list (ECalModel *model)
{
    GList *list = NULL, *l;

    g_return_val_if_fail (E_IS_CAL_MODEL (model), NULL);

    for (l = model->priv->clients; l != NULL; l = l->next) {
        ECalModelClient *client_data = (ECalModelClient *) l->data;

        list = g_list_append (list, client_data->client);
    }

    return list;
}

/**
 * e_cal_model_get_client_for_uri
 * @model: A calendar model.
 * @uri: Uri for the client to get.
 */
ECal *
e_cal_model_get_client_for_uri (ECalModel *model, const char *uri)
{
    GList *l;

    g_return_val_if_fail (E_IS_CAL_MODEL (model), NULL);
    g_return_val_if_fail (uri != NULL, NULL);

    for (l = model->priv->clients; l != NULL; l = l->next) {
        ECalModelClient *client_data = (ECalModelClient *) l->data;

        if (!strcmp (uri, e_cal_get_uri (client_data->client)))
            return client_data->client;
    }

    return NULL;
}

static ECalModelClient *
find_client_data (ECalModel *model, ECal *client)
{
    ECalModelPrivate *priv;
    GList *l;
    
    priv = model->priv;

    for (l = priv->clients; l != NULL; l = l->next) {
        ECalModelClient *client_data = (ECalModelClient *) l->data;

        if (client_data->client == client)
            return client_data;
    }   

    return NULL;
}

static ECalModelComponent *
search_by_id_and_client (ECalModelPrivate *priv, ECal *client, const ECalComponentId *id)
{
    gint i;

    for (i = 0; i < priv->objects->len; i++) {
        ECalModelComponent *comp_data = g_ptr_array_index (priv->objects, i);

        if (comp_data) {
            const char *uid, *rid;
            gboolean has_rid = (id->rid && *id->rid);

            uid = icalcomponent_get_uid (comp_data->icalcomp);
            rid = icaltime_as_ical_string (icalcomponent_get_recurrenceid (comp_data->icalcomp));

            if (uid && *uid) {
                if ((!client || comp_data->client == client) && !strcmp (id->uid, uid)) {
                    if (has_rid) {
                        if (!(rid && *rid && !strcmp (rid, id->rid)))   
                            continue;
                    }
                    return comp_data;
                }
            }
        }
    }

    return NULL;
}
    
typedef struct {
    ECal *client;
    ECalView *query;
    ECalModel *model;
    icalcomponent *icalcomp;
} RecurrenceExpansionData;

static gboolean
add_instance_cb (ECalComponent *comp, time_t instance_start, time_t instance_end, gpointer user_data)
{
    ECalModelComponent *comp_data;
    ECalModelPrivate *priv;
    RecurrenceExpansionData *rdata = user_data;
    icaltimetype time;
    ECalComponentDateTime datetime, to_set;
    icaltimezone *zone = NULL;

    g_return_val_if_fail (E_IS_CAL_COMPONENT (comp), TRUE);

    priv = rdata->model->priv;

    e_table_model_pre_change (E_TABLE_MODEL (rdata->model));

    /* set the right instance start date to component */
    e_cal_component_get_dtstart (comp, &datetime);
    e_cal_get_timezone (rdata->client, datetime.tzid, &zone, NULL);
    time = icaltime_from_timet_with_zone (instance_start, FALSE, zone ? zone : priv->zone);
    to_set.value = &time;
    to_set.tzid = datetime.tzid; 
    e_cal_component_set_dtstart (comp, &to_set);
    
    /* set the right instance end date to component*/
    e_cal_component_get_dtend (comp, &datetime);
    e_cal_get_timezone (rdata->client, datetime.tzid, &zone, NULL);
    time = icaltime_from_timet_with_zone (instance_end, FALSE, zone ? zone : priv->zone);
    to_set.value = &time;
    to_set.tzid = datetime.tzid; 
    e_cal_component_set_dtend (comp, &to_set);

    comp_data = g_new0 (ECalModelComponent, 1);
    comp_data->client = g_object_ref (rdata->client);
    comp_data->icalcomp = icalcomponent_new_clone (e_cal_component_get_icalcomponent (comp));
    comp_data->instance_start = instance_start;
    comp_data->instance_end = instance_end;
    comp_data->dtstart = comp_data->dtend = comp_data->due = comp_data->completed = NULL;
    comp_data->color = NULL;

    g_ptr_array_add (priv->objects, comp_data);
    e_table_model_row_inserted (E_TABLE_MODEL (rdata->model), priv->objects->len - 1);

    return TRUE;
}

/* We do this check since the calendar items are downloaded from the server in the open_method,
   since the default timezone might not be set there */
static void
ensure_dates_are_in_default_zone (icalcomponent *icalcomp)
{
    icaltimetype dt;
    icaltimezone *zone = calendar_config_get_icaltimezone ();

    if (!zone)
        return;

    dt = icalcomponent_get_dtstart (icalcomp);
    if (dt.is_utc) {
        dt = icaltime_convert_to_zone (dt, zone);
        icalcomponent_set_dtstart (icalcomp, dt);
    }

    dt = icalcomponent_get_dtend (icalcomp);
    if (dt.is_utc) {
        dt = icaltime_convert_to_zone (dt, zone);
        icalcomponent_set_dtend (icalcomp, dt);
    }
}

static void
e_cal_view_objects_added_cb (ECalView *query, GList *objects, gpointer user_data)
{
    ECalModel *model = (ECalModel *) user_data;
    ECalModelPrivate *priv;
    GList *l;

    priv = model->priv;

    for (l = objects; l; l = l->next) {
        ECalModelComponent *comp_data;
        ECalComponentId *id;
        ECalComponent *comp = e_cal_component_new ();
        ECal *client = e_cal_view_get_client (query);

        /* This will fail for alarm or VCalendar component */
        if (!e_cal_component_set_icalcomponent (comp, icalcomponent_new_clone (l->data))) {
            g_object_unref (comp);
            continue;
        }

        id = e_cal_component_get_id (comp);

        /* remove the components if they are already present and re-add them */
        while ((comp_data = search_by_id_and_client (priv, client,
                                  id))) {
            int pos;

            pos = get_position_in_array (priv->objects, comp_data);
            e_table_model_pre_change (E_TABLE_MODEL (model));
            e_table_model_row_deleted (E_TABLE_MODEL (model), pos);

            if (g_ptr_array_remove (priv->objects, comp_data))
                e_cal_model_free_component_data (comp_data);
        }

        e_cal_component_free_id (id);
        g_object_unref (comp);
        ensure_dates_are_in_default_zone (l->data);

        if (e_cal_util_component_has_recurrences (l->data) && (priv->flags & E_CAL_MODEL_FLAGS_EXPAND_RECURRENCES)) {
            RecurrenceExpansionData rdata;

            rdata.client = e_cal_view_get_client (query);
            rdata.query = query;
            rdata.model = model;
            rdata.icalcomp = l->data;
            e_cal_generate_instances_for_object (rdata.client, l->data,
                                 priv->start, priv->end,
                                 (ECalRecurInstanceFn) add_instance_cb,
                                 &rdata);
        } else {
            e_table_model_pre_change (E_TABLE_MODEL (model));

            comp_data = g_new0 (ECalModelComponent, 1);
            comp_data->client = g_object_ref (e_cal_view_get_client (query));
            comp_data->icalcomp = icalcomponent_new_clone (l->data);
            e_cal_model_set_instance_times (comp_data, priv->zone);
            comp_data->dtstart = comp_data->dtend = comp_data->due = comp_data->completed = NULL;
            comp_data->color = NULL;

            g_ptr_array_add (priv->objects, comp_data);
            e_table_model_row_inserted (E_TABLE_MODEL (model), priv->objects->len - 1);
        }
    }
}

static void
e_cal_view_objects_modified_cb (ECalView *query, GList *objects, gpointer user_data)
{
    ECalModel *model = (ECalModel *) user_data;

    /* now re-add all objects */
    e_cal_view_objects_added_cb (query, objects, model);
}

static void
e_cal_view_objects_removed_cb (ECalView *query, GList *ids, gpointer user_data)
{
    ECalModelPrivate *priv;
    ECalModel *model = (ECalModel *) user_data;
    GList *l;
    
    priv = model->priv;
    
    for (l = ids; l; l = l->next) {
        ECalModelComponent *comp_data = NULL;
        ECalComponentId *id = l->data;
        int pos;

        e_table_model_pre_change (E_TABLE_MODEL (model));
        
        /* make sure we remove all objects with this UID */
        while ((comp_data = search_by_id_and_client (priv, e_cal_view_get_client (query), id))) {
            pos = get_position_in_array (priv->objects, comp_data);
            e_table_model_row_deleted (E_TABLE_MODEL (model), pos);

            if (g_ptr_array_remove (priv->objects, comp_data))
                e_cal_model_free_component_data (comp_data);
        }
    }
}

static void
e_cal_view_progress_cb (ECalView *query, const char *message, int percent, gpointer user_data)
{
    ECalModel *model = (ECalModel *) user_data;
    ECal *client = e_cal_view_get_client (query);

    g_return_if_fail (E_IS_CAL_MODEL (model));

    g_signal_emit (G_OBJECT (model), signals[CAL_VIEW_PROGRESS], 0, message, 
            percent, e_cal_get_source_type (client));
}

static void
e_cal_view_done_cb (ECalView *query, ECalendarStatus status, gpointer user_data)
{
    ECalModel *model = (ECalModel *) user_data;
    ECal *client = e_cal_view_get_client (query);

    g_return_if_fail (E_IS_CAL_MODEL (model));

    /* emit the signal on the model and let the view catch it to display */
    g_signal_emit (G_OBJECT (model), signals[CAL_VIEW_DONE], 0, status,
            e_cal_get_source_type (client));
}

static void
update_e_cal_view_for_client (ECalModel *model, ECalModelClient *client_data)
{
    ECalModelPrivate *priv;

    priv = model->priv;

    /* Skip if this client has not finished loading yet */
    if (e_cal_get_load_state (client_data->client) != E_CAL_LOAD_LOADED)
        return;
    
    /* free the previous query, if any */
    if (client_data->query) {
        g_signal_handlers_disconnect_matched (client_data->query, G_SIGNAL_MATCH_DATA,
                              0, 0, NULL, NULL, model);
        g_object_unref (client_data->query);
        client_data->query = NULL;
    }

    /* prepare the query */
    g_return_if_fail (priv->full_sexp != NULL);

    /* Don't create the new query if we won't use it */
    if (!client_data->do_query)
        return;
    
    if (!e_cal_get_query (client_data->client, priv->full_sexp, &client_data->query, NULL)) {
        g_warning (G_STRLOC ": Unable to get query");

        return;
    }   

    g_signal_connect (client_data->query, "objects_added", G_CALLBACK (e_cal_view_objects_added_cb), model);
    g_signal_connect (client_data->query, "objects_modified", G_CALLBACK (e_cal_view_objects_modified_cb), model);
    g_signal_connect (client_data->query, "objects_removed", G_CALLBACK (e_cal_view_objects_removed_cb), model);
    g_signal_connect (client_data->query, "view_progress", G_CALLBACK (e_cal_view_progress_cb), model);
    g_signal_connect (client_data->query, "view_done", G_CALLBACK (e_cal_view_done_cb), model);

    e_cal_view_start (client_data->query);
}

static void
backend_died_cb (ECal *client, gpointer user_data)
{
    ECalModel *model;

    model = E_CAL_MODEL (user_data);

    e_cal_model_remove_client (model, client);
}

static void
cal_opened_cb (ECal *client, ECalendarStatus status, gpointer user_data)
{
    ECalModel *model = (ECalModel *) user_data;
    ECalModelClient *client_data;

    if (status == E_CALENDAR_STATUS_BUSY) {
        e_cal_open_async (client, FALSE);
        return;
    }
    
    if (status != E_CALENDAR_STATUS_OK) {
        e_cal_model_remove_client (model, client);

        return;
    }
    
    /* Stop listening for this calendar to be opened */
    g_signal_handlers_disconnect_matched (client, G_SIGNAL_MATCH_FUNC | G_SIGNAL_MATCH_DATA, 0, 0, NULL, cal_opened_cb, model);

    client_data = find_client_data (model, client);
    g_return_if_fail (client_data);
    
    update_e_cal_view_for_client (model, client_data);
}


static ECalModelClient *
add_new_client (ECalModel *model, ECal *client, gboolean do_query)
{
    ECalModelPrivate *priv;
    ECalModelClient *client_data;
    
    priv = model->priv;

    /* Look to see if we already have this client */
    client_data = find_client_data (model, client); 
    if (client_data) {
        if (client_data->do_query)
            return client_data;
        else
            client_data->do_query = do_query;
        
        goto load;
    }
    
    client_data = g_new0 (ECalModelClient, 1);
    client_data->client = g_object_ref (client);
    client_data->query = NULL;
    client_data->do_query = do_query;

    priv->clients = g_list_append (priv->clients, client_data);

    g_signal_connect (G_OBJECT (client_data->client), "backend_died",
              G_CALLBACK (backend_died_cb), model);

 load:
    if (e_cal_get_load_state (client) == E_CAL_LOAD_LOADED) {
        update_e_cal_view_for_client (model, client_data);
    } else {
        g_signal_connect (client, "cal_opened", G_CALLBACK (cal_opened_cb), model);
        e_cal_open_async (client, TRUE);
    }

    return client_data;
}

/**
 * e_cal_model_add_client
 */
void
e_cal_model_add_client (ECalModel *model, ECal *client)
{
    ECalModelClient *client_data;

    g_return_if_fail (E_IS_CAL_MODEL (model));
    g_return_if_fail (E_IS_CAL (client));
    /* Check this return value or drop the assignment? */
    client_data = add_new_client (model, client, TRUE); 
}

static void
remove_client_objects (ECalModel *model, ECalModelClient *client_data)
{
    int i;
    
    /* remove all objects belonging to this client */
    for (i = model->priv->objects->len; i > 0; i--) {
        ECalModelComponent *comp_data = (ECalModelComponent *) g_ptr_array_index (model->priv->objects, i - 1);

        g_return_if_fail (comp_data != NULL);

        if (comp_data->client == client_data->client) {
            e_table_model_pre_change (E_TABLE_MODEL (model));
            e_table_model_row_deleted (E_TABLE_MODEL (model), i - 1);

            g_ptr_array_remove (model->priv->objects, comp_data);
            e_cal_model_free_component_data (comp_data);
        }
    }
}

static void
remove_client (ECalModel *model, ECalModelClient *client_data)
{
    /* FIXME We might not want to disconnect the open signal for the default client */
    g_signal_handlers_disconnect_matched (client_data->client, G_SIGNAL_MATCH_DATA, 0, 0, NULL, NULL, model);
    if (client_data->query)
        g_signal_handlers_disconnect_matched (client_data->query, G_SIGNAL_MATCH_DATA, 0, 0, NULL, NULL, model);

    remove_client_objects (model, client_data);

    /* If this is the default client and we were querying (so it
     * was also a source), keep it around but don't query it */
    if (model->priv->default_client == client_data->client && client_data->do_query) {
        client_data->do_query = FALSE;
        
        return;
    }

    /* Remove the client from the list */
    model->priv->clients = g_list_remove (model->priv->clients, client_data);

    /* free all remaining memory */
    g_object_unref (client_data->client);
    if (client_data->query)
        g_object_unref (client_data->query);
    g_free (client_data);
}

/**
 * e_cal_model_remove_client
 */
void
e_cal_model_remove_client (ECalModel *model, ECal *client)
{
    ECalModelClient *client_data;
    
    g_return_if_fail (E_IS_CAL_MODEL (model));
    g_return_if_fail (E_IS_CAL (client));

    client_data = find_client_data (model, client);
    if (client_data)
        remove_client (model, client_data);
}

/**
 * e_cal_model_remove_all_clients
 */
void
e_cal_model_remove_all_clients (ECalModel *model)
{
    ECalModelPrivate *priv;

    g_return_if_fail (E_IS_CAL_MODEL (model));

    priv = model->priv;
    while (priv->clients != NULL) {
        ECalModelClient *client_data = (ECalModelClient *) priv->clients->data;
        remove_client (model, client_data);
    }
}

static void
redo_queries (ECalModel *model)
{
    ECalModelPrivate *priv;
    char *iso_start, *iso_end;
    GList *l;
    int len;
    
    priv = model->priv;

    if (priv->full_sexp)
        g_free (priv->full_sexp);

    if (priv->start != -1 && priv->end != -1) {
        iso_start = isodate_from_time_t (priv->start);
        iso_end = isodate_from_time_t (priv->end);
        
        priv->full_sexp = g_strdup_printf ("(and (occur-in-time-range? (make-time \"%s\")"
                           "                           (make-time \"%s\"))"
                           "     %s)",
                           iso_start, iso_end, 
                           priv->search_sexp ? priv->search_sexp : "");
    } else if (priv->search_sexp) {
        priv->full_sexp = g_strdup (priv->search_sexp);
    } else {
        priv->full_sexp = g_strdup ("#f");
    }   
    
    /* clean up the current contents */
    e_table_model_pre_change (E_TABLE_MODEL (model));
    len = priv->objects->len;
    e_table_model_rows_deleted (E_TABLE_MODEL (model), 0, len);
    clear_objects_array (priv);
    
    /* update the query for all clients */
    for (l = priv->clients; l != NULL; l = l->next) {
        ECalModelClient *client_data;
        
        client_data = (ECalModelClient *) l->data;
        update_e_cal_view_for_client (model, client_data);
    }
}

void
e_cal_model_get_time_range (ECalModel *model, time_t *start, time_t *end)
{
    ECalModelPrivate *priv;
    
    g_return_if_fail (model != NULL);
    g_return_if_fail (E_IS_CAL_MODEL (model));

    priv = model->priv;
    
    if (start)
        *start = priv->start;
    
    if (end)
        *end = priv->end;
}

void
e_cal_model_set_time_range (ECalModel *model, time_t start, time_t end)
{
    ECalModelPrivate *priv;
    
    g_return_if_fail (model != NULL);
    g_return_if_fail (E_IS_CAL_MODEL (model));
    g_return_if_fail (start >= 0 && end >= 0);
    g_return_if_fail (start <= end);

    priv = model->priv;

    if (priv->start == start && priv->end == end)
        return;
    
    priv->start = start;
    priv->end = end;

    g_signal_emit (G_OBJECT (model), signals[TIME_RANGE_CHANGED], 0, start, end);
    redo_queries (model);
}

const char *
e_cal_model_get_search_query (ECalModel *model)
{
    ECalModelPrivate *priv;
    
    g_return_val_if_fail (model != NULL, NULL);
    g_return_val_if_fail (E_IS_CAL_MODEL (model), NULL);

    priv = model->priv;
    
    return priv->search_sexp;
}

/**
 * e_cal_model_set_query
 */
void
e_cal_model_set_search_query (ECalModel *model, const char *sexp)
{
    ECalModelPrivate *priv;

    g_return_if_fail (E_IS_CAL_MODEL (model));

    priv = model->priv;

    if (!strcmp (sexp ? sexp : "", priv->search_sexp ? priv->search_sexp : ""))
        return;

    if (priv->search_sexp)
        g_free (priv->search_sexp);

    priv->search_sexp = g_strdup (sexp);

    redo_queries (model);
}

/**
 * e_cal_model_set_query
 */
void
e_cal_model_set_search_query_with_time_range (ECalModel *model, const char *sexp, time_t start, time_t end)
{
    ECalModelPrivate *priv;
    gboolean do_query = FALSE;

    g_return_if_fail (E_IS_CAL_MODEL (model));

    priv = model->priv;

    if (strcmp (sexp ? sexp : "", priv->search_sexp ? priv->search_sexp : "")) {
        if (priv->search_sexp)
            g_free (priv->search_sexp);

        priv->search_sexp = g_strdup (sexp);
        do_query = TRUE;
    }
        
    if (!(priv->start == start && priv->end == end)) {
        priv->start = start;
        priv->end = end;
        do_query = TRUE;
    }

    if (do_query)
        redo_queries (model);
}

/**
 * e_cal_model_create_component_with_defaults
 */
icalcomponent *
e_cal_model_create_component_with_defaults (ECalModel *model)
{
    ECalModelPrivate *priv;
    ECalComponent *comp;
    icalcomponent *icalcomp;
    ECal *client;

    g_return_val_if_fail (E_IS_CAL_MODEL (model), NULL);

    priv = model->priv;

    g_return_val_if_fail (priv->clients != NULL, NULL);

    client = e_cal_model_get_default_client (model);
    if (!client)
        return icalcomponent_new (priv->kind);

    switch (priv->kind) {
    case ICAL_VEVENT_COMPONENT :
        comp = cal_comp_event_new_with_defaults (client);
        break;
    case ICAL_VTODO_COMPONENT :
        comp = cal_comp_task_new_with_defaults (client);
        break;
    case ICAL_VJOURNAL_COMPONENT :
            comp = cal_comp_memo_new_with_defaults (client);
        break;
    default:
        return NULL;
    }

    if (!comp)
        return icalcomponent_new (priv->kind);

    icalcomp = icalcomponent_new_clone (e_cal_component_get_icalcomponent (comp));
    g_object_unref (comp);

    /* make sure the component has an UID */
    if (!icalcomponent_get_uid (icalcomp)) {
        char *uid;

        uid = e_cal_component_gen_uid ();
        icalcomponent_set_uid (icalcomp, uid);

        g_free (uid);
    }

    return icalcomp;
}

/**
 * e_cal_model_get_color_for_component
 */
const gchar *
e_cal_model_get_color_for_component (ECalModel *model, ECalModelComponent *comp_data)
{
    ECalModelClass *model_class;
    const gchar *color = NULL;

    g_return_val_if_fail (E_IS_CAL_MODEL (model), NULL);
    g_return_val_if_fail (comp_data != NULL, NULL);

    model_class = (ECalModelClass *) G_OBJECT_GET_CLASS (model);
    if (model_class->get_color_for_component != NULL)
        color = model_class->get_color_for_component (model, comp_data);

    if (!color)
        color = ecm_get_color_for_component (model, comp_data);

    return color;
}

/**
 * e_cal_model_get_rgb_color_for_component
 */
gboolean
e_cal_model_get_rgb_color_for_component (ECalModel *model, ECalModelComponent *comp_data, double *red, double *green, double *blue)
{
    GdkColor gdk_color;
    const gchar *color;

    color = e_cal_model_get_color_for_component (model, comp_data);
    if (color && gdk_color_parse (color, &gdk_color)) {

        if (red)
            *red = ((double) gdk_color.red)/0xffff;
        if (green)
            *green = ((double) gdk_color.green)/0xffff;
        if (blue)
            *blue = ((double) gdk_color.blue)/0xffff;

        return TRUE;
    }

    return FALSE;
}

/**
 * e_cal_model_get_component_at
 */
ECalModelComponent *
e_cal_model_get_component_at (ECalModel *model, gint row)
{
    ECalModelPrivate *priv;

    g_return_val_if_fail (E_IS_CAL_MODEL (model), NULL);

    priv = model->priv;

    g_return_val_if_fail (row >= 0 && row < priv->objects->len, NULL);

    return g_ptr_array_index (priv->objects, row);
}

ECalModelComponent *
e_cal_model_get_component_for_uid  (ECalModel *model, const ECalComponentId *id)
{
    ECalModelPrivate *priv;

    g_return_val_if_fail (E_IS_CAL_MODEL (model), NULL);

    priv = model->priv;

    return search_by_id_and_client (priv, NULL, id);
} 

/**
 * e_cal_model_date_value_to_string
 */
gchar*
e_cal_model_date_value_to_string (ECalModel *model, const void *value)
{
    ECalModelPrivate *priv;
    ECellDateEditValue *dv = (ECellDateEditValue *) value;
    struct icaltimetype tt;
    struct tm tmp_tm;
    char buffer[64];

    g_return_val_if_fail (E_IS_CAL_MODEL (model), g_strdup (""));

    priv = model->priv;

    if (!dv)
        return g_strdup ("");

    /* We currently convert all the dates to the current timezone. */
    tt = dv->tt;
    icaltimezone_convert_time (&tt, dv->zone, priv->zone);

    tmp_tm.tm_year = tt.year - 1900;
    tmp_tm.tm_mon = tt.month - 1;
    tmp_tm.tm_mday = tt.day;
    tmp_tm.tm_hour = tt.hour;
    tmp_tm.tm_min = tt.minute;
    tmp_tm.tm_sec = tt.second;
    tmp_tm.tm_isdst = -1;

    tmp_tm.tm_wday = time_day_of_week (tt.day, tt.month - 1, tt.year);

    memset (buffer, 0, sizeof (buffer));
    e_time_format_date_and_time (&tmp_tm, priv->use_24_hour_format,
                     TRUE, FALSE,
                     buffer, sizeof (buffer));
    return g_strdup (buffer);
}

static ECellDateEditValue *
copy_ecdv (ECellDateEditValue *ecdv)
{
    ECellDateEditValue *new_ecdv;
    
    new_ecdv = g_new0 (ECellDateEditValue, 1);
    new_ecdv->tt = ecdv ? ecdv->tt : icaltime_null_time ();
    new_ecdv->zone = ecdv ? ecdv->zone : NULL;

    return new_ecdv;
}

/**
 * e_cal_model_copy_component_data
 */
ECalModelComponent *
e_cal_model_copy_component_data (ECalModelComponent *comp_data)
{
    ECalModelComponent *new_data;

    g_return_val_if_fail (comp_data != NULL, NULL);

    new_data = g_new0 (ECalModelComponent, 1);

    new_data->instance_start = comp_data->instance_start;
    new_data->instance_end = comp_data->instance_end;
    if (comp_data->icalcomp)
        new_data->icalcomp = icalcomponent_new_clone (comp_data->icalcomp);
    if (comp_data->client)
        new_data->client = g_object_ref (comp_data->client);
    if (comp_data->dtstart)
        new_data->dtstart = copy_ecdv (comp_data->dtstart);
    if (comp_data->dtend)
        new_data->dtend = copy_ecdv (comp_data->dtend);
    if (comp_data->due)
        new_data->due = copy_ecdv (comp_data->due);
    if (comp_data->completed)
        new_data->completed = copy_ecdv (comp_data->completed);
    if (comp_data->color)
        new_data->color = g_strdup (comp_data->color);

    return new_data;
}

/**
 * e_cal_model_free_component_data
 */
void
e_cal_model_free_component_data (ECalModelComponent *comp_data)
{
    g_return_if_fail (comp_data != NULL);

    if (comp_data->client) {
        g_object_unref (comp_data->client);
        comp_data->client = NULL;
    }
    if (comp_data->icalcomp) {
        icalcomponent_free (comp_data->icalcomp);
        comp_data->icalcomp = NULL;
    }
    if (comp_data->dtstart) {
        g_free (comp_data->dtstart);
        comp_data->dtstart = NULL;
    }
    if (comp_data->dtend) {
        g_free (comp_data->dtend);
        comp_data->dtend = NULL;
    }
    if (comp_data->due) {
        g_free (comp_data->due);
        comp_data->due = NULL;
    }
    if (comp_data->completed) {
        g_free (comp_data->completed);
        comp_data->completed = NULL;
    }
    if (comp_data->color) {
        g_free (comp_data->color);
        comp_data->color = NULL;
    }

    g_free (comp_data);
}

/**
 * e_cal_model_generate_instances
 *
 * cb function is not called with cb_data, but with ECalModelGenerateInstancesData which contains cb_data
 */
void
e_cal_model_generate_instances (ECalModel *model, time_t start, time_t end,
                ECalRecurInstanceFn cb, gpointer cb_data)
{
    ECalModelGenerateInstancesData mdata;
    gint i, n;

    n = e_table_model_row_count (E_TABLE_MODEL (model));
    for (i = 0; i < n; i ++) {
        ECalModelComponent *comp_data = e_cal_model_get_component_at (model, i);

        mdata.comp_data = comp_data;
        mdata.cb_data = cb_data;
        e_cal_generate_instances_for_object (comp_data->client, comp_data->icalcomp, start, end, cb, &mdata);
    }
}

/**
 * e_cal_model_get_object_array
 */
GPtrArray *
e_cal_model_get_object_array (ECalModel *model)
{
    g_return_val_if_fail (E_IS_CAL_MODEL (model), NULL);

    return model->priv->objects;
}

void
e_cal_model_set_instance_times (ECalModelComponent *comp_data, const icaltimezone *zone)
{
    struct icaltimetype start_time, end_time;
    icalcomponent_kind kind;

    kind = icalcomponent_isa (comp_data->icalcomp);
    start_time = icalcomponent_get_dtstart (comp_data->icalcomp);
    end_time = icalcomponent_get_dtend (comp_data->icalcomp);

    if (kind == ICAL_VEVENT_COMPONENT) {
        if (start_time.is_date && icaltime_is_null_time (end_time)) {
            /* If end_time is null and it's an all day event,
             * just make start_time = end_time so that end_time
             * will be a valid date
             */
            end_time = start_time;
            icaltime_adjust (&end_time, 1, 0, 0, 0);
            icalcomponent_set_dtend (comp_data->icalcomp, end_time);
        } else if (start_time.is_date && end_time.is_date &&
               (icaltime_compare_date_only (start_time, end_time) == 0)) {
            /* If both DTSTART and DTEND are DATE values, and they are the
               same day, we add 1 day to DTEND. This means that most
               events created with the old Evolution behavior will still
               work OK. */
            icaltime_adjust (&end_time, 1, 0, 0, 0);
            icalcomponent_set_dtend (comp_data->icalcomp, end_time);
        }
    }

    if (start_time.zone)
        zone = start_time.zone;
    else {
        icalparameter *param = NULL;
        icalproperty *prop = icalcomponent_get_first_property (comp_data->icalcomp, ICAL_DTSTART_PROPERTY);
        
           if (prop)    {
            param = icalproperty_get_first_parameter (prop, ICAL_TZID_PARAMETER);

            if (param) {
                const char *tzid = NULL;
                icaltimezone *st_zone = NULL;

                tzid = icalparameter_get_tzid (param);
                e_cal_get_timezone (comp_data->client, tzid, &st_zone, NULL);

                if (st_zone)
                    zone = st_zone;
            }
           }
    }
    
    comp_data->instance_start = icaltime_as_timet_with_zone (start_time, zone);

    if (end_time.zone)
        zone = end_time.zone;
    else {
        icalparameter *param = NULL;
        icalproperty *prop = icalcomponent_get_first_property (comp_data->icalcomp, ICAL_DTSTART_PROPERTY);
    
           if (prop)    {
            param = icalproperty_get_first_parameter (prop, ICAL_TZID_PARAMETER);

            if (param) {
                const char *tzid = NULL;
                icaltimezone *end_zone = NULL;

                tzid = icalparameter_get_tzid (param);
                e_cal_get_timezone (comp_data->client, tzid, &end_zone, NULL);

                if (end_zone)
                    zone = end_zone;
            }
           }

    }
    comp_data->instance_end = icaltime_as_timet_with_zone (end_time, zone);
}