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/libecal.h>

#include "shell/e-shell.h"
#include "shell/e-shell-backend.h"
#include "shell/e-shell-window.h"

#include "calendar/gui/comp-util.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-sidebar.h"
#include "e-cal-shell-view.h"

#include "e-calendar-preferences.h"

#define E_CAL_SHELL_BACKEND_GET_PRIVATE(obj) \
    (G_TYPE_INSTANCE_GET_PRIVATE \
    ((obj), E_TYPE_CAL_SHELL_BACKEND, ECalShellBackendPrivate))

struct _ECalShellBackendPrivate {
    gint placeholder;
};

G_DEFINE_DYNAMIC_TYPE (
    ECalShellBackend,
    e_cal_shell_backend,
    E_TYPE_SHELL_BACKEND)

static void
cal_shell_backend_new_event (ECalClient *cal_client,
                             EShell *shell,
                             CompEditorFlags flags,
                             gboolean all_day)
{
    ECalComponent *comp;
    GSettings *settings;
    CompEditor *editor;

    settings = g_settings_new ("org.gnome.evolution.calendar");

    editor = event_editor_new (cal_client, shell, flags);
    comp = cal_comp_event_new_with_current_time (
        cal_client, all_day,
        g_settings_get_boolean (settings, "use-default-reminder"),
        g_settings_get_int (settings, "default-reminder-interval"),
        g_settings_get_enum (settings, "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 (settings);
}

static void
cal_shell_backend_event_new_cb (GObject *source_object,
                                GAsyncResult *result,
                                gpointer user_data)
{
    EShell *shell = E_SHELL (user_data);
    EClient *client;
    CompEditorFlags flags = 0;
    gboolean all_day = FALSE;
    GError *error = NULL;

    flags |= COMP_EDITOR_NEW_ITEM;
    flags |= COMP_EDITOR_USER_ORG;

    client = e_client_cache_get_client_finish (
        E_CLIENT_CACHE (source_object), result, &error);

    /* Sanity check. */
    g_return_if_fail (
        ((client != NULL) && (error == NULL)) ||
        ((client == NULL) && (error != NULL)));

    if (client != NULL) {
        cal_shell_backend_new_event (
            E_CAL_CLIENT (client), shell, flags, all_day);
        g_object_unref (client);
    } else {
        /* XXX Handle errors better. */
        g_warning ("%s: %s", G_STRFUNC, error->message);
        g_error_free (error);
    }

    g_object_unref (shell);
}

static void
cal_shell_backend_event_all_day_new_cb (GObject *source_object,
                                        GAsyncResult *result,
                                        gpointer user_data)
{
    EShell *shell = E_SHELL (user_data);
    EClient *client;
    CompEditorFlags flags = 0;
    gboolean all_day = TRUE;
    GError *error = NULL;

    flags |= COMP_EDITOR_NEW_ITEM;
    flags |= COMP_EDITOR_USER_ORG;

    client = e_client_cache_get_client_finish (
        E_CLIENT_CACHE (source_object), result, &error);

    /* Sanity check. */
    g_return_if_fail (
        ((client != NULL) && (error == NULL)) ||
        ((client == NULL) && (error != NULL)));

    if (client != NULL) {
        cal_shell_backend_new_event (
            E_CAL_CLIENT (client), shell, flags, all_day);
        g_object_unref (client);
    } else {
        /* XXX Handle errors better. */
        g_warning ("%s: %s", G_STRFUNC, error->message);
        g_error_free (error);
    }

    g_object_unref (shell);
}

static void
cal_shell_backend_event_meeting_new_cb (GObject *source_object,
                                        GAsyncResult *result,
                                        gpointer user_data)
{
    EShell *shell = E_SHELL (user_data);
    EClient *client;
    CompEditorFlags flags = 0;
    gboolean all_day = FALSE;
    GError *error = NULL;

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

    client = e_client_cache_get_client_finish (
        E_CLIENT_CACHE (source_object), result, &error);

    /* Sanity check. */
    g_return_if_fail (
        ((client != NULL) && (error == NULL)) ||
        ((client == NULL) && (error != NULL)));

    if (client != NULL) {
        cal_shell_backend_new_event (
            E_CAL_CLIENT (client), shell, flags, all_day);
        g_object_unref (client);
    } else {
        /* XXX Handle errors better. */
        g_warning ("%s: %s", G_STRFUNC, error->message);
        g_error_free (error);
    }

    g_object_unref (shell);
}

static void
action_event_new_cb (GtkAction *action,
                     EShellWindow *shell_window)
{
    EShell *shell;
    EShellView *shell_view;
    EShellBackend *shell_backend;
    ESource *source;
    ESourceRegistry *registry;
    EClientCache *client_cache;
    const gchar *action_name;

    shell = e_shell_window_get_shell (shell_window);
    client_cache = e_shell_get_client_cache (shell);

    action_name = gtk_action_get_name (action);

    /* 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) {
        EShellWindow *shell_window;
        EShellContent *shell_content;
        GnomeCalendar *gcal;
        GnomeCalendarViewType view_type;
        ECalendarView *view;

        shell_backend = e_shell_view_get_shell_backend (shell_view);
        shell_content = e_shell_view_get_shell_content (shell_view);
        shell_window = e_shell_view_get_shell_window (shell_view);

        e_shell_backend_set_prefer_new_item (
            shell_backend, action_name);

        /* This forces the shell window to update the "New" toolbar
         * button menu, and the toolbar button will then update its
         * button image to reflect the "preferred new item" we just
         * set on the shell backend. */
        g_object_notify (G_OBJECT (shell_window), "active-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 != NULL) {
            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. */

    registry = e_shell_get_registry (shell);
    source = e_source_registry_ref_default_calendar (registry);

    shell_backend = e_shell_get_backend_by_name (shell, "calendar");
    e_shell_backend_set_prefer_new_item (shell_backend, action_name);

    /* Use a callback function appropriate for the action. */
    if (strcmp (action_name, "event-all-day-new") == 0)
        e_client_cache_get_client (
            client_cache, source,
            E_SOURCE_EXTENSION_CALENDAR,
            NULL,
            cal_shell_backend_event_all_day_new_cb,
            g_object_ref (shell));
    else if (strcmp (action_name, "event-meeting-new") == 0)
        e_client_cache_get_client (
            client_cache, source,
            E_SOURCE_EXTENSION_CALENDAR,
            NULL,
            cal_shell_backend_event_meeting_new_cb,
            g_object_ref (shell));
    else
        e_client_cache_get_client (
            client_cache, source,
            E_SOURCE_EXTENSION_CALENDAR,
            NULL,
            cal_shell_backend_event_new_cb,
            g_object_ref (shell));

    g_object_unref (source);
}

static void
action_calendar_new_cb (GtkAction *action,
                        EShellWindow *shell_window)
{
    EShell *shell;
    ESourceRegistry *registry;
    ECalClientSourceType source_type;
    GtkWidget *config;
    GtkWidget *dialog;
    const gchar *icon_name;

    shell = e_shell_window_get_shell (shell_window);

    registry = e_shell_get_registry (shell);
    source_type = E_CAL_CLIENT_SOURCE_TYPE_EVENTS;
    config = e_cal_source_config_new (registry, NULL, source_type);

    dialog = e_source_config_dialog_new (E_SOURCE_CONFIG (config));

    gtk_window_set_transient_for (
        GTK_WINDOW (dialog), GTK_WINDOW (shell_window));

    icon_name = gtk_action_get_icon_name (action);
    gtk_window_set_icon_name (GTK_WINDOW (dialog), icon_name);

    gtk_window_set_title (GTK_WINDOW (dialog), _("New Calendar"));

    gtk_widget_show (dialog);
}

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 void
populate_g_date (GDate *date,
                 time_t utc_time,
                 icaltimezone *zone)
{
    struct icaltimetype icaltm;

    g_return_if_fail (date != NULL);

    if ((gint) utc_time == -1)
        return;

    if (zone)
        icaltm = icaltime_from_timet_with_zone (utc_time, FALSE, zone);
    else
        icaltm = icaltime_from_timet (utc_time, FALSE);

    if (icaltime_is_null_time (icaltm) ||
        !icaltime_is_valid_time (icaltm))
        return;

    g_date_set_dmy (date, icaltm.day, icaltm.month, icaltm.year);
}

static gboolean
cal_shell_backend_handle_uri_cb (EShellBackend *shell_backend,
                                 const gchar *uri)
{
    EShell *shell;
    CompEditor *editor;
    CompEditorFlags flags = 0;
    EClient *client;
    EClientCache *client_cache;
    ECalComponent *comp;
    ESource *source;
    ESourceRegistry *registry;
    GSettings *settings;
    SoupURI *soup_uri;
    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;

    shell = e_shell_backend_get_shell (shell_backend);
    client_cache = e_shell_get_client_cache (shell);

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

    soup_uri = soup_uri_new (uri);

    if (soup_uri == NULL)
        return FALSE;

    cp = soup_uri_get_query (soup_uri);
    if (cp == NULL)
        goto exit;

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

    settings = g_settings_new ("org.gnome.evolution.calendar");

    if (g_settings_get_boolean (settings, "use-system-timezone"))
        zone = e_cal_util_get_system_timezone ();
    else {
        gchar *location;

        location = g_settings_get_string (settings, "timezone");

        if (location != NULL) {
            zone = icaltimezone_get_builtin_timezone (location);
            g_free (location);
        }
    }

    if (zone == NULL)
        zone = icaltimezone_get_utc_timezone ();

    g_object_unref (settings);

    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 + 1;

        content_len = strcspn (cp, "&");

        content = g_strndup (cp, content_len);
        if (g_ascii_strcasecmp (header, "startdate") == 0)
            populate_g_date (&start_date, time_from_isodate (content), zone);
        else if (g_ascii_strcasecmp (header, "enddate") == 0)
            populate_g_date (&end_date, 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;
        if (*cp == '&') {
            cp++;
            if (strncmp (cp, "amp;", 4) == 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;

    registry = e_shell_get_registry (shell);
    source = e_source_registry_ref_source (registry, source_uid);
    if (source == NULL) {
        g_printerr ("No source for UID '%s'\n", source_uid);
        goto exit;
    }

    client = e_client_cache_get_client_sync (
        client_cache, source,
        E_SOURCE_EXTENSION_CALENDAR,
        NULL, &error);

    /* Sanity check. */
    g_return_val_if_fail (
        ((client != NULL) && (error == NULL)) ||
        ((client == NULL) && (error != NULL)), FALSE);

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

    g_object_unref (source);
    source = NULL;

    /* 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 (
        E_CAL_CLIENT (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 (client);
        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 (registry, comp, E_CAL_CLIENT (client)))
        flags |= COMP_EDITOR_USER_ORG;

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

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

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

    g_object_unref (comp);

present:
    gtk_window_present (GTK_WINDOW (editor));

    g_object_unref (client);

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

    soup_uri_free (soup_uri);

    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
ensure_alarm_notify_is_running (void)
{
    const gchar *base_dir;
    gchar *filename;

    #ifdef G_OS_WIN32
    base_dir = EVOLUTION_BINDIR;
    #else
    base_dir = EVOLUTION_PRIVLIBEXECDIR;
    #endif

    filename = g_build_filename (base_dir, "evolution-alarm-notify", NULL);

    if (g_file_test (filename, G_FILE_TEST_IS_EXECUTABLE)) {
        gchar *argv[2];
        GError *error = NULL;

        argv[0] = filename;
        argv[1] = NULL;

        g_spawn_async (
            base_dir, argv, NULL, 0, NULL, NULL, NULL, &error);

        if (error != NULL) {
            g_message (
                "Failed to start '%s': %s",
                filename, error->message);
            g_error_free (error);
        }
    }

    g_free (filename);
}

static void
cal_shell_backend_use_system_timezone_changed_cb (GSettings *settings,
                                                  const gchar *key)
{
    g_signal_emit_by_name (settings, "changed::timezone", timezone);
}

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

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

    /* 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"),
        "index#calendar",
        e_calendar_preferences_new,
        600);

    settings = g_settings_new ("org.gnome.evolution.calendar");

    g_settings_bind (
        settings, "prefer-new-item",
        shell_backend, "prefer-new-item",
        G_SETTINGS_BIND_DEFAULT);

    /* Changing whether or not to use the system timezone may change
     * Evolution's current timezone.  Need to emit "changed" signals
     * for both keys. */
    g_signal_connect (
        settings, "changed::use-system-timezone",
        G_CALLBACK (cal_shell_backend_use_system_timezone_changed_cb),
        NULL);

    g_object_unref (settings);

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

    ensure_alarm_notify_is_running ();
}

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

    g_type_class_add_private (class, sizeof (ECalShellBackendPrivate));

    object_class = G_OBJECT_CLASS (class);
    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;

    /* Register relevant ESource extensions. */
    E_TYPE_SOURCE_CALENDAR;
}

static void
e_cal_shell_backend_class_finalize (ECalShellBackendClass *class)
{
}

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

    cal_shell_backend->priv =
        E_CAL_SHELL_BACKEND_GET_PRIVATE (cal_shell_backend);

    /* 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);
    }
}

void
e_cal_shell_backend_type_register (GTypeModule *type_module)
{
    /* XXX G_DEFINE_DYNAMIC_TYPE declares a static type registration
     *     function, so we have to wrap it with a public function in
     *     order to register types from a separate compilation unit. */
    e_cal_shell_backend_register_type (type_module);
}

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);
}