path: root/modules/calendar/e-cal-shell-backend.c

/*
 * e-cal-shell-backend.c
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) version 3.
 *
 * 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with the program; if not, see <http://www.gnu.org/licenses/>
 *
 *
 * Copyright (C) 1999-2008 Novell, Inc. (www.novell.com)
 *
 */

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

#include "e-cal-shell-backend.h"

#include <string.h>
#include <glib/gi18n.h>
#include <libecal/e-cal-client.h>
#include <libecal/e-cal-time-util.h>
#include <libedataserver/e-url.h>
#include <libedataserver/e-source.h>
#include <libedataserver/e-source-group.h>
#include <libedataserverui/e-client-utils.h>

#include "e-util/e-import.h"
#include "shell/e-shell.h"
#include "shell/e-shell-backend.h"
#include "shell/e-shell-window.h"
#include "widgets/misc/e-preferences-window.h"

#include "calendar/gui/comp-util.h"
#include "calendar/gui/dialogs/calendar-setup.h"
#include "calendar/gui/dialogs/event-editor.h"
#include "calendar/gui/e-calendar-view.h"
#include "calendar/gui/gnome-cal.h"
#include "calendar/importers/evolution-calendar-importer.h"

#include "e-cal-shell-content.h"
#include "e-cal-shell-migrate.h"
#include "e-cal-shell-settings.h"
#include "e-cal-shell-sidebar.h"
#include "e-cal-shell-view.h"

#include "e-calendar-preferences.h"

struct _ECalShellBackendPrivate {
    ESourceList *source_list;
};

enum {
    PROP_0,
    PROP_SOURCE_LIST
};

static gpointer parent_class;
static GType cal_shell_backend_type;

static void
cal_shell_backend_ensure_sources (EShellBackend *shell_backend)
{
    /* XXX This is basically the same algorithm across all backends.
     *     Maybe we could somehow integrate this into EShellBackend? */

    ECalShellBackend *cal_shell_backend;
    ESourceGroup *on_this_computer;
    ESourceGroup *contacts;
    ESourceList *source_list;
    ESource *birthdays;
    ESource *personal;
    EShell *shell;
    EShellSettings *shell_settings;
    GSList *sources, *iter;
    const gchar *name;
    gchar *property;
    gboolean save_list = FALSE;
    GError *error = NULL;

    birthdays = NULL;
    personal = NULL;

    cal_shell_backend = E_CAL_SHELL_BACKEND (shell_backend);

    shell = e_shell_backend_get_shell (shell_backend);
    shell_settings = e_shell_get_shell_settings (shell);

    e_cal_client_get_sources (
        &cal_shell_backend->priv->source_list,
        E_CAL_CLIENT_SOURCE_TYPE_EVENTS, &error);

    if (error != NULL) {
        g_warning (
            "%s: Could not get calendar sources: %s",
            G_STRFUNC, error->message);
        g_error_free (error);
        return;
    }

    source_list = cal_shell_backend->priv->source_list;

    on_this_computer = e_source_list_ensure_group (
        source_list, _("On This Computer"), "local:", TRUE);
    contacts = e_source_list_ensure_group (
        source_list, _("Contacts"), "contacts://", TRUE);
    e_source_list_ensure_group (
        source_list, _("On The Web"), "webcal://", FALSE);
    e_source_list_ensure_group (
        source_list, _("Weather"), "weather://", FALSE);

    g_return_if_fail (on_this_computer != NULL);
    g_return_if_fail (contacts != NULL);

    sources = e_source_group_peek_sources (on_this_computer);

    /* Make sure this group includes a "Personal" source. */
    for (iter = sources; iter != NULL; iter = iter->next) {
        ESource *source = iter->data;
        const gchar *relative_uri;

        relative_uri = e_source_peek_relative_uri (source);
        if (g_strcmp0 (relative_uri, "system") == 0) {
            personal = source;
            break;
        }
    }

    name = _("Personal");

    if (personal == NULL) {
        ESource *source;
        GSList *selected;
        gchar *primary;

        source = e_source_new (name, "system");
        e_source_set_color_spec (source, "#BECEDD");
        e_source_group_add_source (on_this_computer, source, -1);
        g_object_unref (source);
        save_list = TRUE;

        primary = e_shell_settings_get_string (
            shell_settings, "cal-primary-calendar");

        selected = e_cal_shell_backend_get_selected_calendars (
            cal_shell_backend);

        if (primary == NULL && selected == NULL) {
            const gchar *uid;

            uid = e_source_peek_uid (source);
            selected = g_slist_prepend (NULL, g_strdup (uid));

            e_shell_settings_set_string (
                shell_settings, "cal-primary-calendar", uid);
            e_cal_shell_backend_set_selected_calendars (
                cal_shell_backend, selected);
        }

        g_slist_foreach (selected, (GFunc) g_free, NULL);
        g_slist_free (selected);
        g_free (primary);
    } else {
        /* Force the source name to the current locale. */
        e_source_set_name (personal, name);
    }

    sources = e_source_group_peek_sources (contacts);

    if (sources != NULL) {
        GSList *trash;

        /* There is only one source under Contacts. */
        birthdays = E_SOURCE (sources->data);
        sources = g_slist_next (sources);

        /* Delete any other sources in this group.
         * Earlier versions allowed you to create
         * additional sources under Contacts. */
        trash = g_slist_copy (sources);
        while (trash != NULL) {
            ESource *source = trash->data;
            e_source_group_remove_source (contacts, source);
            trash = g_slist_delete_link (trash, trash);
            save_list = TRUE;
        }
    }

    /* XXX e_source_group_get_property() returns a newly-allocated
     *     string when it could just as easily return a const string.
     *     Unfortunately, fixing that would break the API. */
    property = e_source_group_get_property (contacts, "create_source");
    if (property == NULL)
        e_source_group_set_property (contacts, "create_source", "no");
    g_free (property);

    name = _("Birthdays & Anniversaries");

    if (birthdays == NULL) {
        ESource *source;

        source = e_source_new (name, "/");
        e_source_group_add_source (contacts, source, -1);
        g_object_unref (source);
        save_list = TRUE;

        /* This is now a borrowed reference. */
        birthdays = source;
    } else {
        /* Force the source name to the current locale. */
        e_source_set_name (birthdays, name);
    }

    if (e_source_get_property (birthdays, "delete") == NULL)
        e_source_set_property (birthdays, "delete", "no");

    if (e_source_peek_color_spec (birthdays) == NULL)
        e_source_set_color_spec (birthdays, "#DDBECE");

    g_object_unref (on_this_computer);
    g_object_unref (contacts);

    if (save_list)
        e_source_list_sync (source_list, NULL);
}

static void
cal_shell_backend_new_event (ESource *source,
                             GAsyncResult *result,
                             EShell *shell,
                             CompEditorFlags flags,
                             gboolean all_day)
{
    EClient *client = NULL;
    ECalClient *cal_client;
    ECalComponent *comp;
    EShellSettings *shell_settings;
    CompEditor *editor;
    GError *error = NULL;

    /* XXX Handle errors better. */
    e_client_utils_open_new_finish (source, result, &client, &error);

    if (error != NULL) {
        g_warn_if_fail (client == NULL);
        g_warning (
            "%s: Failed to open '%s': %s",
            G_STRFUNC, e_source_peek_name (source),
            error->message);
        g_error_free (error);
        return;
    }

    g_return_if_fail (E_IS_CAL_CLIENT (client));

    cal_client = E_CAL_CLIENT (client);
    shell_settings = e_shell_get_shell_settings (shell);

    editor = event_editor_new (cal_client, shell, flags);
    comp = cal_comp_event_new_with_current_time (
        cal_client, all_day,
        e_shell_settings_get_pointer (
            shell_settings, "cal-timezone"),
        e_shell_settings_get_boolean (
            shell_settings, "cal-use-default-reminder"),
        e_shell_settings_get_int (
            shell_settings, "cal-default-reminder-interval"),
        e_shell_settings_get_int (  /* enum, actually */
            shell_settings, "cal-default-reminder-units"));
    e_cal_component_commit_sequence (comp);
    comp_editor_edit_comp (editor, comp);

    gtk_window_present (GTK_WINDOW (editor));

    g_object_unref (comp);
    g_object_unref (client);
}

static void
cal_shell_backend_event_new_cb (GObject *source_object,
                                GAsyncResult *result,
                                gpointer shell)
{
    CompEditorFlags flags = 0;
    gboolean all_day = FALSE;

    flags |= COMP_EDITOR_NEW_ITEM;
    flags |= COMP_EDITOR_USER_ORG;

    cal_shell_backend_new_event (
        E_SOURCE (source_object), result, shell, flags, all_day);

    g_object_unref (shell);
}

static void
cal_shell_backend_event_all_day_new_cb (GObject *source_object,
                                        GAsyncResult *result,
                                        gpointer shell)
{
    CompEditorFlags flags = 0;
    gboolean all_day = TRUE;

    flags |= COMP_EDITOR_NEW_ITEM;
    flags |= COMP_EDITOR_USER_ORG;

    cal_shell_backend_new_event (
        E_SOURCE (source_object), result, shell, flags, all_day);

    g_object_unref (shell);
}

static void
cal_shell_backend_event_meeting_new_cb (GObject *source_object,
                                        GAsyncResult *result,
                                        gpointer shell)
{
    CompEditorFlags flags = 0;
    gboolean all_day = FALSE;

    flags |= COMP_EDITOR_NEW_ITEM;
    flags |= COMP_EDITOR_USER_ORG;
    flags |= COMP_EDITOR_MEETING;

    cal_shell_backend_new_event (
        E_SOURCE (source_object), result, shell, flags, all_day);

    g_object_unref (shell);
}

static void
action_event_new_cb (GtkAction *action,
                     EShellWindow *shell_window)
{
    EShell *shell;
    EShellView *shell_view;
    EShellBackend *shell_backend;
    EShellSettings *shell_settings;
    ESource *source = NULL;
    ESourceList *source_list;
    EClientSourceType source_type;
    const gchar *action_name;
    gchar *uid;

    /* With a 'calendar' active shell view pass the new appointment
     * request to it, thus the event will inherit selected time from
     * the view. */
    shell_view = e_shell_window_peek_shell_view (shell_window, "calendar");
    if (shell_view != NULL) {
        EShellContent *shell_content;
        GnomeCalendar *gcal;
        GnomeCalendarViewType view_type;
        ECalendarView *view;

        shell_content = e_shell_view_get_shell_content (shell_view);

        gcal = e_cal_shell_content_get_calendar (
            E_CAL_SHELL_CONTENT (shell_content));

        view_type = gnome_calendar_get_view (gcal);
        view = gnome_calendar_get_calendar_view (gcal, view_type);

        if (view) {
            action_name = gtk_action_get_name (action);

            e_calendar_view_new_appointment_full (
                view,
                g_str_equal (action_name, "event-all-day-new"),
                g_str_equal (action_name, "event-meeting-new"),
                TRUE);

            return;
        }
    }

    /* This callback is used for both appointments and meetings. */

    source_type = E_CLIENT_SOURCE_TYPE_EVENTS;

    shell = e_shell_window_get_shell (shell_window);
    shell_settings = e_shell_get_shell_settings (shell);
    shell_backend = e_shell_get_backend_by_name (shell, "calendar");

    g_object_get (shell_backend, "source-list", &source_list, NULL);
    g_return_if_fail (E_IS_SOURCE_LIST (source_list));

    uid = e_shell_settings_get_string (
        shell_settings, "cal-primary-calendar");

    if (uid != NULL) {
        source = e_source_list_peek_source_by_uid (source_list, uid);
        g_free (uid);
    }

    if (source == NULL)
        source = e_source_list_peek_default_source (source_list);

    g_return_if_fail (E_IS_SOURCE (source));

    /* Use a callback function appropriate for the action.
     * FIXME Need to obtain a better default time zone. */
    action_name = gtk_action_get_name (action);
    if (strcmp (action_name, "event-all-day-new") == 0)
        e_client_utils_open_new (source, source_type, FALSE, NULL,
            e_client_utils_authenticate_handler, GTK_WINDOW (shell_window),
            cal_shell_backend_event_all_day_new_cb, g_object_ref (shell));
    else if (strcmp (action_name, "event-meeting-new") == 0)
        e_client_utils_open_new (source, source_type, FALSE, NULL,
            e_client_utils_authenticate_handler, GTK_WINDOW (shell_window),
            cal_shell_backend_event_meeting_new_cb, g_object_ref (shell));
    else
        e_client_utils_open_new (source, source_type, FALSE, NULL,
            e_client_utils_authenticate_handler, GTK_WINDOW (shell_window),
            cal_shell_backend_event_new_cb, g_object_ref (shell));

    g_object_unref (source_list);
}

static void
action_calendar_new_cb (GtkAction *action,
                        EShellWindow *shell_window)
{
    calendar_setup_new_calendar (GTK_WINDOW (shell_window));
}

static GtkActionEntry item_entries[] = {

    { "event-new",
      "appointment-new",
      NC_("New", "_Appointment"),
      "<Shift><Control>a",
      N_("Create a new appointment"),
      G_CALLBACK (action_event_new_cb) },

    { "event-all-day-new",
      "stock_new-24h-appointment",
      NC_("New", "All Day A_ppointment"),
      NULL,
      N_("Create a new all-day appointment"),
      G_CALLBACK (action_event_new_cb) },

    { "event-meeting-new",
      "stock_new-meeting",
      NC_("New", "M_eeting"),
      "<Shift><Control>e",
      N_("Create a new meeting request"),
      G_CALLBACK (action_event_new_cb) }
};

static GtkActionEntry source_entries[] = {

    { "calendar-new",
      "x-office-calendar",
      NC_("New", "Cale_ndar"),
      NULL,
      N_("Create a new calendar"),
      G_CALLBACK (action_calendar_new_cb) }
};

static void
cal_shell_backend_init_importers (void)
{
    EImportClass *import_class;
    EImportImporter *importer;

    import_class = g_type_class_ref (e_import_get_type ());

    importer = gnome_calendar_importer_peek ();
    e_import_class_add_importer (import_class, importer, NULL, NULL);

    importer = ical_importer_peek ();
    e_import_class_add_importer (import_class, importer, NULL, NULL);

    importer = vcal_importer_peek ();
    e_import_class_add_importer (import_class, importer, NULL, NULL);
}

static time_t
utc_to_user_zone (time_t utc_time,
                  icaltimezone *zone)
{
    if (!zone || (gint) utc_time == -1)
        return utc_time;

    return icaltime_as_timet (
        icaltime_from_timet_with_zone (utc_time, FALSE, zone));
}

static gboolean
cal_shell_backend_handle_uri_cb (EShellBackend *shell_backend,
                                 const gchar *uri)
{
    EShell *shell;
    EShellSettings *shell_settings;
    CompEditor *editor;
    CompEditorFlags flags = 0;
    ECalClient *client;
    ECalComponent *comp;
    ESource *source;
    ESourceList *source_list;
    ECalClientSourceType source_type;
    EUri *euri;
    icalcomponent *icalcomp;
    icalproperty *icalprop;
    const gchar *cp;
    gchar *source_uid = NULL;
    gchar *comp_uid = NULL;
    gchar *comp_rid = NULL;
    GDate start_date;
    GDate end_date;
    icaltimezone *zone;
    gboolean handled = FALSE;
    GError *error = NULL;

    source_type = E_CAL_CLIENT_SOURCE_TYPE_EVENTS;
    shell = e_shell_backend_get_shell (shell_backend);
    shell_settings = e_shell_get_shell_settings (shell);

    zone = e_shell_settings_get_pointer (shell_settings, "cal-timezone");

    if (strncmp (uri, "calendar:", 9) != 0)
        return FALSE;

    euri = e_uri_new (uri);
    cp = euri->query;
    if (cp == NULL)
        goto exit;

    g_date_clear (&start_date, 1);
    g_date_clear (&end_date, 1);

    while (*cp != '\0') {
        gchar *header;
        gchar *content;
        gsize header_len;
        gsize content_len;

        header_len = strcspn (cp, "=&");

        /* It it's malformed, give up. */
        if (cp[header_len] != '=')
            break;

        header = (gchar *) cp;
        header[header_len] = '\0';
        cp += header_len + 2;

        content_len = strcspn (cp, "&");

        content = g_strndup (cp, content_len);
        if (g_ascii_strcasecmp (header, "startdate") == 0)
            g_date_set_time_t (
                &start_date, utc_to_user_zone (
                time_from_isodate (content), zone));
        else if (g_ascii_strcasecmp (header, "enddate") == 0)
            g_date_set_time_t (
                &end_date, utc_to_user_zone (
                time_from_isodate (content), zone));
        else if (g_ascii_strcasecmp (header, "source-uid") == 0)
            source_uid = g_strdup (content);
        else if (g_ascii_strcasecmp (header, "comp-uid") == 0)
            comp_uid = g_strdup (content);
        else if (g_ascii_strcasecmp (header, "comp-rid") == 0)
            comp_rid = g_strdup (content);
        g_free (content);

        cp += content_len + 1;
        if (*cp == '&') {
            cp++;
            if (strcmp (cp, "amp;") == 0)
                cp += 4;
        }
    }

    /* This is primarily for launching Evolution
     * from the calendar in the clock applet. */
    if (g_date_valid (&start_date)) {
        if (g_date_valid (&end_date))
            e_cal_shell_backend_open_date_range (
                E_CAL_SHELL_BACKEND (shell_backend),
                &start_date, &end_date);
        else
            e_cal_shell_backend_open_date_range (
                E_CAL_SHELL_BACKEND (shell_backend),
                &start_date, NULL);
        handled = TRUE;
        goto exit;
    }

    if (source_uid == NULL || comp_uid == NULL)
        goto exit;

    /* URI is valid, so consider it handled.  Whether
     * we successfully open it is another matter... */
    handled = TRUE;

    e_cal_client_get_sources (&source_list, source_type, &error);

    if (error != NULL) {
        g_warning (
            "%s: Could not get calendar sources: %s",
            G_STRFUNC, error->message);
        g_error_free (error);
        goto exit;
    }

    source = e_source_list_peek_source_by_uid (source_list, source_uid);

    if (source == NULL) {
        g_warning ("%s: No source for UID '%s'", G_STRFUNC, source_uid);
        g_object_unref (source_list);
        goto exit;
    }

    client = e_cal_client_new (source, source_type, &error);

    if (client != NULL)
        e_client_open_sync (E_CLIENT (client), TRUE, NULL, &error);

    if (error != NULL) {
        g_warning (
            "%s: Failed to create/open client '%s': %s",
            G_STRFUNC, e_source_peek_name (source),
            error->message);
        g_object_unref (source_list);
        g_error_free (error);
        goto exit;
    }

    /* XXX Copied from e_cal_shell_view_open_event().
     *     Clearly a new utility function is needed. */

    editor = comp_editor_find_instance (comp_uid);

    if (editor != NULL)
        goto present;

    e_cal_client_get_object_sync (
        client, comp_uid, comp_rid, &icalcomp, NULL, &error);

    if (error != NULL) {
        g_warning (
            "%s: Failed to get object from client: %s",
            G_STRFUNC, error->message);
        g_object_unref (source_list);
        g_error_free (error);
        goto exit;
    }

    comp = e_cal_component_new ();
    if (!e_cal_component_set_icalcomponent (comp, icalcomp)) {
        g_warning ("%s: Failed to set icalcomp to comp\n", G_STRFUNC);
        icalcomponent_free (icalcomp);
        icalcomp = NULL;
    }

    icalprop = icalcomp ? icalcomponent_get_first_property (
        icalcomp, ICAL_ATTENDEE_PROPERTY) : NULL;
    if (icalprop != NULL)
        flags |= COMP_EDITOR_MEETING;

    if (itip_organizer_is_user (comp, client))
        flags |= COMP_EDITOR_USER_ORG;

    if (itip_sentby_is_user (comp, client))
        flags |= COMP_EDITOR_USER_ORG;

    if (!e_cal_component_has_attendees (comp))
        flags |= COMP_EDITOR_USER_ORG;

    editor = event_editor_new (client, shell, flags);
    comp_editor_edit_comp (editor, comp);

    g_object_unref (comp);

present:
    gtk_window_present (GTK_WINDOW (editor));

    g_object_unref (source_list);
    g_object_unref (client);

exit:
    g_free (source_uid);
    g_free (comp_uid);
    g_free (comp_rid);

    e_uri_free (euri);

    return handled;
}

static void
cal_shell_backend_window_added_cb (EShellBackend *shell_backend,
                                   GtkWindow *window)
{
    const gchar *backend_name;

    if (!E_IS_SHELL_WINDOW (window))
        return;

    backend_name = E_SHELL_BACKEND_GET_CLASS (shell_backend)->name;

    e_shell_window_register_new_item_actions (
        E_SHELL_WINDOW (window), backend_name,
        item_entries, G_N_ELEMENTS (item_entries));

    e_shell_window_register_new_source_actions (
        E_SHELL_WINDOW (window), backend_name,
        source_entries, G_N_ELEMENTS (source_entries));
}

static void
cal_shell_backend_get_property (GObject *object,
                                guint property_id,
                                GValue *value,
                                GParamSpec *pspec)
{
    switch (property_id) {
        case PROP_SOURCE_LIST:
            g_value_set_object (
                value,
                e_cal_shell_backend_get_source_list (
                E_CAL_SHELL_BACKEND (object)));
            return;
    }

    G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
}

static void
cal_shell_backend_dispose (GObject *object)
{
    ECalShellBackendPrivate *priv;

    priv = E_CAL_SHELL_BACKEND (object)->priv;

    if (priv->source_list != NULL) {
        g_object_unref (priv->source_list);
        priv->source_list = NULL;
    }

    /* Chain up to parent's dispose() method. */
    G_OBJECT_CLASS (parent_class)->dispose (object);
}

static void
cal_shell_backend_constructed (GObject *object)
{
    EShell *shell;
    EShellBackend *shell_backend;
    GtkWidget *preferences_window;

    shell_backend = E_SHELL_BACKEND (object);
    shell = e_shell_backend_get_shell (shell_backend);

    cal_shell_backend_ensure_sources (shell_backend);

    g_signal_connect_swapped (
        shell, "handle-uri",
        G_CALLBACK (cal_shell_backend_handle_uri_cb),
        shell_backend);

    g_signal_connect_swapped (
        shell, "window-added",
        G_CALLBACK (cal_shell_backend_window_added_cb),
        shell_backend);

    cal_shell_backend_init_importers ();

    e_cal_shell_backend_init_settings (shell);

    /* Setup preference widget factories */
    preferences_window = e_shell_get_preferences_window (shell);

    e_preferences_window_add_page (
        E_PREFERENCES_WINDOW (preferences_window),
        "calendar-and-tasks",
        "preferences-calendar-and-tasks",
        _("Calendar and Tasks"),
        e_calendar_preferences_new,
        600);

    /* Chain up to parent's constructed() method. */
    G_OBJECT_CLASS (parent_class)->constructed (object);
}

static void
cal_shell_backend_class_init (ECalShellBackendClass *class)
{
    GObjectClass *object_class;
    EShellBackendClass *shell_backend_class;

    parent_class = g_type_class_peek_parent (class);
    g_type_class_add_private (class, sizeof (ECalShellBackendPrivate));

    object_class = G_OBJECT_CLASS (class);
    object_class->get_property = cal_shell_backend_get_property;
    object_class->dispose = cal_shell_backend_dispose;
    object_class->constructed = cal_shell_backend_constructed;

    shell_backend_class = E_SHELL_BACKEND_CLASS (class);
    shell_backend_class->shell_view_type = E_TYPE_CAL_SHELL_VIEW;
    shell_backend_class->name = "calendar";
    shell_backend_class->aliases = "";
    shell_backend_class->schemes = "calendar";
    shell_backend_class->sort_order = 400;
    shell_backend_class->preferences_page = "calendar-and-tasks";
    shell_backend_class->start = NULL;
    shell_backend_class->migrate = e_cal_shell_backend_migrate;

    g_object_class_install_property (
        object_class,
        PROP_SOURCE_LIST,
        g_param_spec_object (
            "source-list",
            "Source List",
            "The registry of calendars",
            E_TYPE_SOURCE_LIST,
            G_PARAM_READABLE));
}

static void
cal_shell_backend_init (ECalShellBackend *cal_shell_backend)
{
    icalarray *builtin_timezones;
    gint ii;

    cal_shell_backend->priv = G_TYPE_INSTANCE_GET_PRIVATE (
        cal_shell_backend, E_TYPE_CAL_SHELL_BACKEND,
        ECalShellBackendPrivate);

    /* XXX Pre-load all built-in timezones in libical.
     *
     *     Built-in time zones in libical 0.43 are loaded on demand,
     *     but not in a thread-safe manner, resulting in a race when
     *     multiple threads call icaltimezone_load_builtin_timezone()
     *     on the same time zone.  Until built-in time zone loading
     *     in libical is made thread-safe, work around the issue by
     *     loading all built-in time zones now, so libical's internal
     *     time zone array will be fully populated before any threads
     *     are spawned.
     */
    builtin_timezones = icaltimezone_get_builtin_timezones ();
    for (ii = 0; ii < builtin_timezones->num_elements; ii++) {
        icaltimezone *zone;

        zone = icalarray_element_at (builtin_timezones, ii);

        /* We don't care about the component right now,
         * we just need some function that will trigger
         * icaltimezone_load_builtin_timezone(). */
        icaltimezone_get_component (zone);
    }
}

GType
e_cal_shell_backend_get_type (void)
{
    return cal_shell_backend_type;
}

void
e_cal_shell_backend_register_type (GTypeModule *type_module)
{
    const GTypeInfo type_info = {
        sizeof (ECalShellBackendClass),
        (GBaseInitFunc) NULL,
        (GBaseFinalizeFunc) NULL,
        (GClassInitFunc) cal_shell_backend_class_init,
        (GClassFinalizeFunc) NULL,
        NULL,  /* class_data */
        sizeof (ECalShellBackend),
        0,     /* n_preallocs */
        (GInstanceInitFunc) cal_shell_backend_init,
        NULL   /* value_table */
    };

    cal_shell_backend_type = g_type_module_register_type (
        type_module, E_TYPE_SHELL_BACKEND,
        "ECalShellBackend", &type_info, 0);
}

ESourceList *
e_cal_shell_backend_get_source_list (ECalShellBackend *cal_shell_backend)
{
    g_return_val_if_fail (
        E_IS_CAL_SHELL_BACKEND (cal_shell_backend), NULL);

    return cal_shell_backend->priv->source_list;
}

GSList *
e_cal_shell_backend_get_selected_calendars (ECalShellBackend *cal_shell_backend)
{
    GConfClient *client;
    GSList *selected_calendars;
    const gchar *key;

    g_return_val_if_fail (
        E_IS_CAL_SHELL_BACKEND (cal_shell_backend), NULL);

    client = gconf_client_get_default ();
    key = "/apps/evolution/calendar/display/selected_calendars";
    selected_calendars = gconf_client_get_list (
        client, key, GCONF_VALUE_STRING, NULL);
    g_object_unref (client);

    return selected_calendars;
}

void
e_cal_shell_backend_set_selected_calendars (ECalShellBackend *cal_shell_backend,
                                            GSList *selected_calendars)
{
    GConfClient *client;
    const gchar *key;

    g_return_if_fail (E_IS_CAL_SHELL_BACKEND (cal_shell_backend));

    client = gconf_client_get_default ();
    key = "/apps/evolution/calendar/display/selected_calendars";
    gconf_client_set_list (
        client, key, GCONF_VALUE_STRING, selected_calendars, NULL);
    g_object_unref (client);
}

void
e_cal_shell_backend_open_date_range (ECalShellBackend *cal_shell_backend,
                                     const GDate *start_date,
                                     const GDate *end_date)
{
    EShell *shell;
    EShellView *shell_view;
    EShellBackend *shell_backend;
    EShellSidebar *shell_sidebar;
    GtkWidget *shell_window = NULL;
    GtkApplication *application;
    ECalendar *navigator;
    GList *list;

    g_return_if_fail (E_IS_CAL_SHELL_BACKEND (cal_shell_backend));

    shell_backend = E_SHELL_BACKEND (cal_shell_backend);
    shell = e_shell_backend_get_shell (shell_backend);

    application = GTK_APPLICATION (shell);
    list = gtk_application_get_windows (application);

    /* Try to find an EShellWindow already in calendar view. */
    while (list != NULL) {
        GtkWidget *window = GTK_WIDGET (list->data);

        if (E_IS_SHELL_WINDOW (window)) {
            const gchar *active_view;

            active_view = e_shell_window_get_active_view (
                E_SHELL_WINDOW (window));
            if (g_strcmp0 (active_view, "calendar") == 0) {
                gtk_window_present (GTK_WINDOW (window));
                shell_window = window;
                break;
            }
        }

        list = g_list_next (list);
    }

    /* Otherwise create a new EShellWindow in calendar view. */
    if (shell_window == NULL)
        shell_window = e_shell_create_shell_window (shell, "calendar");

    /* Now dig up the date navigator and select the date range. */

    shell_view = e_shell_window_get_shell_view (
        E_SHELL_WINDOW (shell_window), "calendar");
    shell_sidebar = e_shell_view_get_shell_sidebar (shell_view);
    navigator = e_cal_shell_sidebar_get_date_navigator (
        E_CAL_SHELL_SIDEBAR (shell_sidebar));

    e_calendar_item_set_selection (
        navigator->calitem, start_date, end_date);
}