path: root/shell/e-shell.c

/*
 * e-shell.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)
 *
 */

/**
 * SECTION: e-shell
 * @short_description: the backbone of Evolution
 * @include: shell/e-shell.h
 **/

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

#include "e-shell.h"

#include <glib/gi18n.h>
#include <libebackend/libebackend.h>

#include "e-util/e-util-private.h"

#include "e-shell-backend.h"
#include "e-shell-enumtypes.h"
#include "e-shell-window.h"
#include "e-shell-utils.h"

#define E_SHELL_GET_PRIVATE(obj) \
    (G_TYPE_INSTANCE_GET_PRIVATE \
    ((obj), E_TYPE_SHELL, EShellPrivate))

struct _EShellPrivate {
    GQueue alerts;
    ESourceRegistry *registry;
    EClientCache *client_cache;
    GtkWidget *preferences_window;

    /* Shell Backends */
    GList *loaded_backends;              /* not referenced */
    GHashTable *backends_by_name;
    GHashTable *backends_by_scheme;

    gpointer preparing_for_line_change;  /* weak pointer */
    gpointer preparing_for_quit;         /* weak pointer */

    gchar *geometry;
    gchar *module_directory;

    guint inhibit_cookie;

    gulong backend_died_handler_id;

    guint auto_reconnect        : 1;
    guint express_mode      : 1;
    guint modules_loaded        : 1;
    guint network_available     : 1;
    guint network_available_locked  : 1;
    guint online            : 1;
    guint quit_cancelled        : 1;
    guint safe_mode         : 1;
};

enum {
    PROP_0,
    PROP_CLIENT_CACHE,
    PROP_EXPRESS_MODE,
    PROP_GEOMETRY,
    PROP_MODULE_DIRECTORY,
    PROP_NETWORK_AVAILABLE,
    PROP_ONLINE,
    PROP_REGISTRY
};

enum {
    EVENT,
    HANDLE_URI,
    PREPARE_FOR_OFFLINE,
    PREPARE_FOR_ONLINE,
    PREPARE_FOR_QUIT,
    QUIT_REQUESTED,
    LAST_SIGNAL
};

static gpointer default_shell;
static guint signals[LAST_SIGNAL];

/* Forward Declarations */
static void e_shell_initable_init (GInitableIface *interface);

G_DEFINE_TYPE_WITH_CODE (
    EShell,
    e_shell,
    GTK_TYPE_APPLICATION,
    G_IMPLEMENT_INTERFACE (
        G_TYPE_INITABLE, e_shell_initable_init)
    G_IMPLEMENT_INTERFACE (
        E_TYPE_EXTENSIBLE, NULL))

static void
shell_alert_response_cb (EShell *shell,
                         gint response_id,
                         EAlert *alert)
{
    g_signal_handlers_disconnect_by_func (
        alert, shell_alert_response_cb, shell);

    g_queue_remove (&shell->priv->alerts, alert);

    g_object_unref (alert);
}

static void
shell_notify_online_cb (EShell *shell)
{
    gboolean online;

    online = e_shell_get_online (shell);
    e_passwords_set_online (online);
}

static gboolean
shell_window_delete_event_cb (GtkWindow *window,
                              GdkEvent *event,
                              GtkApplication *application)
{
    /* If other windows are open we can safely close this one. */
    if (g_list_length (gtk_application_get_windows (application)) > 1)
        return FALSE;

    /* Otherwise we initiate application quit. */
    e_shell_quit (E_SHELL (application), E_SHELL_QUIT_LAST_WINDOW);

    return TRUE;
}

static void
shell_action_new_window_cb (GSimpleAction *action,
                            GVariant *parameter,
                            EShell *shell)
{
    GtkApplication *application;
    GList *list;
    const gchar *view_name;

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

    view_name = g_variant_get_string (parameter, NULL);

    /* Present the first EShellWindow showing 'view_name'. */
    while (list != NULL) {
        GtkWindow *window = GTK_WINDOW (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, view_name) == 0) {
                gtk_window_present (window);
                return;
            }
        }

        list = g_list_next (list);
    }

    /* No suitable EShellWindow found, so create one. */
    e_shell_create_shell_window (shell, view_name);
}

static void
shell_action_handle_uris_cb (GSimpleAction *action,
                             GVariant *parameter,
                             EShell *shell)
{
    const gchar **uris;

    /* Do not use g_strfreev() here. */
    uris = g_variant_get_strv (parameter, NULL);
    e_shell_handle_uris (shell, uris, FALSE);
    g_free (uris);
}

static void
shell_action_quit_cb (GSimpleAction *action,
                      GVariant *parameter,
                      EShell *shell)
{
    e_shell_quit (shell, E_SHELL_QUIT_REMOTE_REQUEST);
}

static void
shell_add_actions (GApplication *application)
{
    GActionMap *action_map;
    GSimpleAction *action;

    action_map = G_ACTION_MAP (application);

    /* Add actions that remote instances can invoke. */

    action = g_simple_action_new ("new-window", G_VARIANT_TYPE_STRING);
    g_signal_connect (
        action, "activate",
        G_CALLBACK (shell_action_new_window_cb), application);
    g_action_map_add_action (action_map, G_ACTION (action));
    g_object_unref (action);

    action = g_simple_action_new (
        "handle-uris", G_VARIANT_TYPE_STRING_ARRAY);
    g_signal_connect (
        action, "activate",
        G_CALLBACK (shell_action_handle_uris_cb), application);
    g_action_map_add_action (action_map, G_ACTION (action));
    g_object_unref (action);

    action = g_simple_action_new ("quit", NULL);
    g_signal_connect (
        action, "activate",
        G_CALLBACK (shell_action_quit_cb), application);
    g_action_map_add_action (action_map, G_ACTION (action));
    g_object_unref (action);
}

static void
shell_ready_for_offline (EShell *shell,
                         EActivity *activity,
                         gboolean is_last_ref)
{
    if (!is_last_ref)
        return;

    /* Increment the reference count so we can safely emit
     * a signal without triggering the toggle reference. */
    g_object_ref (activity);

    e_activity_set_state (activity, E_ACTIVITY_COMPLETED);

    g_object_remove_toggle_ref (
        G_OBJECT (activity), (GToggleNotify)
        shell_ready_for_offline, shell);

    /* Finalize the activity. */
    g_object_unref (activity);

    shell->priv->online = FALSE;
    g_object_notify (G_OBJECT (shell), "online");
}

static void
shell_prepare_for_offline (EShell *shell)
{
    /* Are preparations already in progress? */
    if (shell->priv->preparing_for_line_change != NULL)
        return;

    shell->priv->preparing_for_line_change = e_activity_new ();

    e_activity_set_text (
        shell->priv->preparing_for_line_change,
        _("Preparing to go offline..."));

    g_object_add_toggle_ref (
        G_OBJECT (shell->priv->preparing_for_line_change),
        (GToggleNotify) shell_ready_for_offline, shell);

    g_object_add_weak_pointer (
        G_OBJECT (shell->priv->preparing_for_line_change),
        &shell->priv->preparing_for_line_change);

    g_signal_emit (
        shell, signals[PREPARE_FOR_OFFLINE], 0,
        shell->priv->preparing_for_line_change);

    g_object_unref (shell->priv->preparing_for_line_change);
}

static void
shell_ready_for_online (EShell *shell,
                        EActivity *activity,
                        gboolean is_last_ref)
{
    if (!is_last_ref)
        return;

    /* Increment the reference count so we can safely emit
     * a signal without triggering the toggle reference. */
    g_object_ref (activity);

    e_activity_set_state (activity, E_ACTIVITY_COMPLETED);

    g_object_remove_toggle_ref (
        G_OBJECT (activity), (GToggleNotify)
        shell_ready_for_online, shell);

    /* Finalize the activity. */
    g_object_unref (activity);

    shell->priv->online = TRUE;
    g_object_notify (G_OBJECT (shell), "online");
}

static void
shell_prepare_for_online (EShell *shell)
{
    /* Are preparations already in progress? */
    if (shell->priv->preparing_for_line_change != NULL)
        return;

    shell->priv->preparing_for_line_change = e_activity_new ();

    e_activity_set_text (
        shell->priv->preparing_for_line_change,
        _("Preparing to go online..."));

    g_object_add_toggle_ref (
        G_OBJECT (shell->priv->preparing_for_line_change),
        (GToggleNotify) shell_ready_for_online, shell);

    g_object_add_weak_pointer (
        G_OBJECT (shell->priv->preparing_for_line_change),
        &shell->priv->preparing_for_line_change);

    g_signal_emit (
        shell, signals[PREPARE_FOR_ONLINE], 0,
        shell->priv->preparing_for_line_change);

    g_object_unref (shell->priv->preparing_for_line_change);
}

static void
shell_ready_for_quit (EShell *shell,
                      EActivity *activity,
                      gboolean is_last_ref)
{
    GtkApplication *application;
    GList *list;

    if (!is_last_ref)
        return;

    application = GTK_APPLICATION (shell);

    /* Increment the reference count so we can safely emit
     * a signal without triggering the toggle reference. */
    g_object_ref (activity);

    e_activity_set_state (activity, E_ACTIVITY_COMPLETED);

    g_object_remove_toggle_ref (
        G_OBJECT (activity), (GToggleNotify)
        shell_ready_for_quit, shell);

    /* Finalize the activity. */
    g_object_unref (activity);

    /* XXX Inhibiting session manager actions currently only
     *     works on GNOME, so check that we obtained a valid
     *     inhibit cookie before attempting to uninhibit. */
    if (shell->priv->inhibit_cookie > 0) {
        gtk_application_uninhibit (
            application, shell->priv->inhibit_cookie);
        shell->priv->inhibit_cookie = 0;
    }

    /* Destroy all watched windows.  Note, we iterate over a -copy-
     * of the watched windows list because the act of destroying a
     * watched window will modify the watched windows list, which
     * would derail the iteration. */
    list = g_list_copy (gtk_application_get_windows (application));
    g_list_foreach (list, (GFunc) gtk_widget_destroy, NULL);
    g_list_free (list);

    if (gtk_main_level () > 0)
        gtk_main_quit ();
}

static void
shell_prepare_for_quit (EShell *shell)
{
    GtkApplication *application;
    GList *list, *iter;

    /* Are preparations already in progress? */
    if (shell->priv->preparing_for_quit != NULL)
        return;

    application = GTK_APPLICATION (shell);

    shell->priv->inhibit_cookie = gtk_application_inhibit (
        application, NULL,
        GTK_APPLICATION_INHIBIT_SWITCH |
        GTK_APPLICATION_INHIBIT_LOGOUT |
        GTK_APPLICATION_INHIBIT_SUSPEND,
        _("Preparing to quit"));

    shell->priv->preparing_for_quit = e_activity_new ();

    e_activity_set_text (
        shell->priv->preparing_for_quit,
        _("Preparing to quit..."));

    g_object_add_toggle_ref (
        G_OBJECT (shell->priv->preparing_for_quit),
        (GToggleNotify) shell_ready_for_quit, shell);

    g_object_add_weak_pointer (
        G_OBJECT (shell->priv->preparing_for_quit),
        &shell->priv->preparing_for_quit);

    g_signal_emit (
        shell, signals[PREPARE_FOR_QUIT], 0,
        shell->priv->preparing_for_quit);

    g_object_unref (shell->priv->preparing_for_quit);

    /* Desensitize all watched windows to prevent user action. */
    list = gtk_application_get_windows (application);
    for (iter = list; iter != NULL; iter = iter->next)
        gtk_widget_set_sensitive (GTK_WIDGET (iter->data), FALSE);
}

static gboolean
shell_request_quit (EShell *shell,
                    EShellQuitReason reason)
{
    /* Are preparations already in progress? */
    if (shell->priv->preparing_for_quit != NULL)
        return TRUE;

    /* Give the application a chance to cancel quit. */
    shell->priv->quit_cancelled = FALSE;
    g_signal_emit (shell, signals[QUIT_REQUESTED], 0, reason);

    return !shell->priv->quit_cancelled;
}

/* Helper for shell_add_backend() */
static void
shell_split_and_insert_items (GHashTable *hash_table,
                              const gchar *items,
                              EShellBackend *shell_backend)
{
    gpointer key;
    gchar **strv;
    gint ii;

    strv = g_strsplit_set (items, ":", -1);

    for (ii = 0; strv[ii] != NULL; ii++) {
        key = (gpointer) g_intern_string (strv[ii]);
        g_hash_table_insert (hash_table, key, shell_backend);
    }

    g_strfreev (strv);
}

static void
shell_process_backend (EShellBackend *shell_backend,
                       EShell *shell)
{
    EShellBackendClass *class;
    GHashTable *backends_by_name;
    GHashTable *backends_by_scheme;
    const gchar *string;

    class = E_SHELL_BACKEND_GET_CLASS (shell_backend);
    backends_by_name = shell->priv->backends_by_name;
    backends_by_scheme = shell->priv->backends_by_scheme;

    if ((string = class->name) != NULL)
        g_hash_table_insert (
            backends_by_name, (gpointer)
            g_intern_string (string), shell_backend);

    if ((string = class->aliases) != NULL)
        shell_split_and_insert_items (
            backends_by_name, string, shell_backend);

    if ((string = class->schemes) != NULL)
        shell_split_and_insert_items (
            backends_by_scheme, string, shell_backend);
}

static void
shell_backend_died_cb (EClientCache *client_cache,
                       EClient *client,
                       EAlert *alert,
                       EShell *shell)
{
    /* Backend crashes are quite serious.
     * Post the alert to all shell views. */
    e_shell_submit_alert (shell, alert);
}

static void
shell_sm_quit_cb (EShell *shell,
                  gpointer user_data)
{
    shell_prepare_for_quit (shell);
}

static void
shell_set_express_mode (EShell *shell,
                        gboolean express_mode)
{
    shell->priv->express_mode = express_mode;
}

static void
shell_set_geometry (EShell *shell,
                    const gchar *geometry)
{
    g_return_if_fail (shell->priv->geometry == NULL);

    shell->priv->geometry = g_strdup (geometry);
}

static void
shell_set_module_directory (EShell *shell,
                            const gchar *module_directory)
{
    g_return_if_fail (shell->priv->module_directory == NULL);

    shell->priv->module_directory = g_strdup (module_directory);
}

static void
shell_set_property (GObject *object,
                    guint property_id,
                    const GValue *value,
                    GParamSpec *pspec)
{
    switch (property_id) {
        case PROP_EXPRESS_MODE:
            shell_set_express_mode (
                E_SHELL (object),
                g_value_get_boolean (value));
            return;

        case PROP_GEOMETRY:
            shell_set_geometry (
                E_SHELL (object),
                g_value_get_string (value));
            return;

        case PROP_MODULE_DIRECTORY:
            shell_set_module_directory (
                E_SHELL (object),
                g_value_get_string (value));
            return;

        case PROP_NETWORK_AVAILABLE:
            e_shell_set_network_available (
                E_SHELL (object),
                g_value_get_boolean (value));
            return;

        case PROP_ONLINE:
            e_shell_set_online (
                E_SHELL (object),
                g_value_get_boolean (value));
            return;
    }

    G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
}

static void
shell_get_property (GObject *object,
                    guint property_id,
                    GValue *value,
                    GParamSpec *pspec)
{
    switch (property_id) {
        case PROP_CLIENT_CACHE:
            g_value_set_object (
                value, e_shell_get_client_cache (
                E_SHELL (object)));
            return;

        case PROP_EXPRESS_MODE:
            g_value_set_boolean (
                value, e_shell_get_express_mode (
                E_SHELL (object)));
            return;

        case PROP_MODULE_DIRECTORY:
            g_value_set_string (
                value, e_shell_get_module_directory (
                E_SHELL (object)));
            return;

        case PROP_NETWORK_AVAILABLE:
            g_value_set_boolean (
                value, e_shell_get_network_available (
                E_SHELL (object)));
            return;

        case PROP_ONLINE:
            g_value_set_boolean (
                value, e_shell_get_online (
                E_SHELL (object)));
            return;

        case PROP_REGISTRY:
            g_value_set_object (
                value, e_shell_get_registry (
                E_SHELL (object)));
            return;
    }

    G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
}

static void
shell_dispose (GObject *object)
{
    EShellPrivate *priv;
    EAlert *alert;

    priv = E_SHELL_GET_PRIVATE (object);

    while ((alert = g_queue_pop_head (&priv->alerts)) != NULL) {
        g_signal_handlers_disconnect_by_func (
            alert, shell_alert_response_cb, object);
        g_object_unref (alert);
    }

    while ((alert = g_queue_pop_head (&priv->alerts)) != NULL) {
        g_signal_handlers_disconnect_by_func (
            alert, shell_alert_response_cb, object);
        g_object_unref (alert);
    }

    if (priv->backend_died_handler_id > 0) {
        g_signal_handler_disconnect (
            priv->client_cache,
            priv->backend_died_handler_id);
        priv->backend_died_handler_id = 0;
    }

    g_clear_object (&priv->registry);
    g_clear_object (&priv->client_cache);
    g_clear_object (&priv->preferences_window);

    if (priv->preparing_for_line_change != NULL) {
        g_object_remove_weak_pointer (
            G_OBJECT (priv->preparing_for_line_change),
            &priv->preparing_for_line_change);
    }

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

static void
shell_finalize (GObject *object)
{
    EShellPrivate *priv;

    priv = E_SHELL_GET_PRIVATE (object);

    g_hash_table_destroy (priv->backends_by_name);
    g_hash_table_destroy (priv->backends_by_scheme);

    g_list_foreach (priv->loaded_backends, (GFunc) g_object_unref, NULL);
    g_list_free (priv->loaded_backends);

    g_free (priv->geometry);
    g_free (priv->module_directory);

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

static void
shell_constructed (GObject *object)
{
    GNetworkMonitor *monitor;

    /* The first EShell instance is the default. */
    if (default_shell == NULL) {
        default_shell = object;
        g_object_add_weak_pointer (object, &default_shell);
    }

    /* Synchronize network monitoring. */

    monitor = g_network_monitor_get_default ();

    g_object_bind_property (
        monitor, "network-available",
        object, "network-available",
        G_BINDING_SYNC_CREATE);

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

static void
shell_startup (GApplication *application)
{
    e_file_lock_create ();

    /* Destroy the lock file when the EShell is finalized
     * to indicate a clean shut down to the next session. */
    g_object_weak_ref (
        G_OBJECT (application),
        (GWeakNotify) e_file_lock_destroy, NULL);

    /* Chain up to parent's startup() method. */
    G_APPLICATION_CLASS (e_shell_parent_class)->startup (application);
}

static void
shell_activate (GApplication *application)
{
    GList *list;

    /* Do not chain up.  Default method just emits a warning. */

    list = gtk_application_get_windows (GTK_APPLICATION (application));

    /* Present the first EShellWindow, if found. */
    while (list != NULL) {
        GtkWindow *window = GTK_WINDOW (list->data);

        if (E_IS_SHELL_WINDOW (window)) {
            gtk_window_present (window);
            return;
        }

        list = g_list_next (list);
    }

    /* No EShellWindow found, so create one. */
    e_shell_create_shell_window (E_SHELL (application), NULL);
}

static void
shell_window_added (GtkApplication *application,
                    GtkWindow *window)
{
    gchar *role;

    /* Chain up to parent's window_added() method. */
    GTK_APPLICATION_CLASS (e_shell_parent_class)->
        window_added (application, window);

    g_signal_connect (
        window, "delete-event",
        G_CALLBACK (shell_window_delete_event_cb), application);

    /* We use the window's own type name and memory
     * address to form a unique window role for X11. */
    role = g_strdup_printf (
        "%s-%" G_GINTPTR_FORMAT,
        G_OBJECT_TYPE_NAME (window),
        (gintptr) window);
    gtk_window_set_role (window, role);
    g_free (role);
}

static gboolean
shell_initable_init (GInitable *initable,
                     GCancellable *cancellable,
                     GError **error)
{
    GApplication *application = G_APPLICATION (initable);
    EShell *shell = E_SHELL (initable);
    ESourceRegistry *registry;
    gulong handler_id;

    shell_add_actions (application);

    if (!g_application_register (application, cancellable, error))
        return FALSE;

    registry = e_source_registry_new_sync (cancellable, error);
    if (registry == NULL)
        return FALSE;

    shell->priv->registry = g_object_ref (registry);
    shell->priv->client_cache = e_client_cache_new (registry);

    handler_id = g_signal_connect (
        shell->priv->client_cache, "backend-died",
        G_CALLBACK (shell_backend_died_cb), shell);
    shell->priv->backend_died_handler_id = handler_id;

    g_object_unref (registry);

    return TRUE;
}

static void
e_shell_class_init (EShellClass *class)
{
    GObjectClass *object_class;
    GApplicationClass *application_class;
    GtkApplicationClass *gtk_application_class;

    g_type_class_add_private (class, sizeof (EShellPrivate));

    object_class = G_OBJECT_CLASS (class);
    object_class->set_property = shell_set_property;
    object_class->get_property = shell_get_property;
    object_class->dispose = shell_dispose;
    object_class->finalize = shell_finalize;
    object_class->constructed = shell_constructed;

    application_class = G_APPLICATION_CLASS (class);
    application_class->startup = shell_startup;
    application_class->activate = shell_activate;

    gtk_application_class = GTK_APPLICATION_CLASS (class);
    gtk_application_class->window_added = shell_window_added;

    /**
     * EShell:client-cache:
     *
     * Shared #EClient instances.
     **/
    g_object_class_install_property (
        object_class,
        PROP_CLIENT_CACHE,
        g_param_spec_object (
            "client-cache",
            "Client Cache",
            "Shared EClient instances",
            E_TYPE_CLIENT_CACHE,
            G_PARAM_READABLE |
            G_PARAM_STATIC_STRINGS));

    /**
     * EShell:express-mode
     *
     * Express mode alters Evolution's user interface to be mode
     * usable on devices with small screens.
     **/
    g_object_class_install_property (
        object_class,
        PROP_EXPRESS_MODE,
        g_param_spec_boolean (
            "express-mode",
            "Express Mode",
            "Whether express mode is enabled",
            FALSE,
            G_PARAM_READWRITE |
            G_PARAM_CONSTRUCT_ONLY |
            G_PARAM_STATIC_STRINGS));

    /**
     * EShell:geometry
     *
     * User-specified initial window geometry string to apply
     * to the first #EShellWindow created.
     **/
    g_object_class_install_property (
        object_class,
        PROP_GEOMETRY,
        g_param_spec_string (
            "geometry",
            "Geometry",
            "Initial window geometry string",
            NULL,
            G_PARAM_WRITABLE |
            G_PARAM_CONSTRUCT_ONLY |
            G_PARAM_STATIC_STRINGS));

    /**
     * EShell:module-directory
     *
     * The directory from which to load #EModule<!-- -->s.
     **/
    g_object_class_install_property (
        object_class,
        PROP_MODULE_DIRECTORY,
        g_param_spec_string (
            "module-directory",
            "Module Directory",
            "The directory from which to load EModules",
            NULL,
            G_PARAM_READWRITE |
            G_PARAM_CONSTRUCT_ONLY |
            G_PARAM_STATIC_STRINGS));

    /**
     * EShell:network-available
     *
     * Whether the network is available.
     **/
    g_object_class_install_property (
        object_class,
        PROP_NETWORK_AVAILABLE,
        g_param_spec_boolean (
            "network-available",
            "Network Available",
            "Whether the network is available",
            TRUE,
            G_PARAM_READWRITE |
            G_PARAM_STATIC_STRINGS));

    /**
     * EShell:online
     *
     * Whether the shell is online.
     **/
    g_object_class_install_property (
        object_class,
        PROP_ONLINE,
        g_param_spec_boolean (
            "online",
            "Online",
            "Whether the shell is online",
            FALSE,
            G_PARAM_READWRITE |
            G_PARAM_CONSTRUCT |
            G_PARAM_STATIC_STRINGS));

    /**
     * EShell:registry
     *
     * The #ESourceRegistry manages #ESource instances.
     **/
    g_object_class_install_property (
        object_class,
        PROP_REGISTRY,
        g_param_spec_object (
            "registry",
            "Registry",
            "Data source registry",
            E_TYPE_SOURCE_REGISTRY,
            G_PARAM_READABLE |
            G_PARAM_STATIC_STRINGS));

    /**
     * EShell::event
     * @shell: the #EShell which emitted the signal
     * @event_data: data associated with the event
     *
     * This signal is used to broadcast custom events to the entire
     * application.  The nature of @event_data depends on the event
     * being broadcast.  The signal's detail denotes the event.
     **/
    signals[EVENT] = g_signal_new (
        "event",
        G_OBJECT_CLASS_TYPE (object_class),
        G_SIGNAL_RUN_FIRST | G_SIGNAL_DETAILED | G_SIGNAL_ACTION,
        0, NULL, NULL,
        g_cclosure_marshal_VOID__POINTER,
        G_TYPE_NONE, 1,
        G_TYPE_POINTER);

    /**
     * EShell::handle-uri
     * @shell: the #EShell which emitted the signal
     * @uri: the URI to be handled
     *
     * Emitted when @shell receives a URI to be handled, usually by
     * way of a command-line argument.  An #EShellBackend should listen
     * for this signal and try to handle the URI, usually by opening an
     * editor window for the identified resource.
     *
     * Returns: %TRUE if the URI could be handled, %FALSE otherwise
     **/
    signals[HANDLE_URI] = g_signal_new (
        "handle-uri",
        G_OBJECT_CLASS_TYPE (object_class),
        G_SIGNAL_RUN_LAST | G_SIGNAL_ACTION,
        G_STRUCT_OFFSET (EShellClass, handle_uri),
        g_signal_accumulator_true_handled, NULL,
        e_marshal_BOOLEAN__STRING,
        G_TYPE_BOOLEAN, 1,
        G_TYPE_STRING);

    /**
     * EShell::prepare-for-offline
     * @shell: the #EShell which emitted the signal
     * @activity: the #EActivity for offline preparations
     *
     * Emitted when the user elects to work offline.  An #EShellBackend
     * should listen for this signal and make preparations for working
     * in offline mode.
     *
     * If preparations for working offline cannot immediately be
     * completed (such as when synchronizing with a remote server),
     * the #EShellBackend should reference the @activity until
     * preparations are complete, and then unreference the @activity.
     * This will delay Evolution from actually going to offline mode
     * until all backends have unreferenced @activity.
     **/
    signals[PREPARE_FOR_OFFLINE] = g_signal_new (
        "prepare-for-offline",
        G_OBJECT_CLASS_TYPE (object_class),
        G_SIGNAL_RUN_FIRST,
        G_STRUCT_OFFSET (EShellClass, prepare_for_offline),
        NULL, NULL,
        g_cclosure_marshal_VOID__OBJECT,
        G_TYPE_NONE, 1,
        E_TYPE_ACTIVITY);

    /**
     * EShell::prepare-for-online
     * @shell: the #EShell which emitted the signal
     * @activity: the #EActivity for offline preparations
     *
     * Emitted when the user elects to work online.  An #EShellBackend
     * should listen for this signal and make preparations for working
     * in online mode.
     *
     * If preparations for working online cannot immediately be
     * completed (such as when re-connecting to a remote server), the
     * #EShellBackend should reference the @activity until preparations
     * are complete, and then unreference the @activity.  This will
     * delay Evolution from actually going to online mode until all
     * backends have unreferenced @activity.
     **/
    signals[PREPARE_FOR_ONLINE] = g_signal_new (
        "prepare-for-online",
        G_OBJECT_CLASS_TYPE (object_class),
        G_SIGNAL_RUN_FIRST,
        G_STRUCT_OFFSET (EShellClass, prepare_for_online),
        NULL, NULL,
        g_cclosure_marshal_VOID__OBJECT,
        G_TYPE_NONE, 1,
        E_TYPE_ACTIVITY);

    /**
     * EShell::prepare-for-quit
     * @shell: the #EShell which emitted the signal
     * @activity: the #EActivity for quit preparations
     *
     * Emitted when the user elects to quit the application, after
     * #EShell::quit-requested.  An #EShellBackend should listen for
     * this signal and make preparations for shutting down.
     *
     * If preparations for shutting down cannot immediately be completed
     * (such as when there are uncompleted network operations), the
     * #EShellBackend should reference the @activity until preparations
     * are complete, and then unreference the @activity.  This will
     * delay Evolution from actually shutting down until all backends
     * have unreferenced @activity.
     **/
    signals[PREPARE_FOR_QUIT] = g_signal_new (
        "prepare-for-quit",
        G_OBJECT_CLASS_TYPE (object_class),
        G_SIGNAL_RUN_FIRST,
        G_STRUCT_OFFSET (EShellClass, prepare_for_quit),
        NULL, NULL,
        g_cclosure_marshal_VOID__OBJECT,
        G_TYPE_NONE, 1,
        E_TYPE_ACTIVITY);

    /**
     * EShell::quit-requested
     * @shell: the #EShell which emitted the signal
     * @reason: the reason for quitting
     *
     * Emitted when the user elects to quit the application, before
     * #EShell::prepare-for-quit.
     *
     * #EShellBackend<!-- -->s and editor windows can listen for
     * this signal to prompt the user to save changes or finish
     * scheduled operations immediately (such as sending mail in
     * Outbox).  If the user elects to cancel, the signal handler
     * should call e_shell_cancel_quit() to abort the quit.
     **/
    signals[QUIT_REQUESTED] = g_signal_new (
        "quit-requested",
        G_OBJECT_CLASS_TYPE (object_class),
        G_SIGNAL_RUN_FIRST,
        G_STRUCT_OFFSET (EShellClass, quit_requested),
        NULL, NULL,
        g_cclosure_marshal_VOID__ENUM,
        G_TYPE_NONE, 1,
        E_TYPE_SHELL_QUIT_REASON);
}

static void
e_shell_initable_init (GInitableIface *interface)
{
    interface->init = shell_initable_init;
}

static void
e_shell_init (EShell *shell)
{
    GHashTable *backends_by_name;
    GHashTable *backends_by_scheme;
    GtkIconTheme *icon_theme;

    shell->priv = E_SHELL_GET_PRIVATE (shell);

    backends_by_name = g_hash_table_new (g_str_hash, g_str_equal);
    backends_by_scheme = g_hash_table_new (g_str_hash, g_str_equal);

    g_queue_init (&shell->priv->alerts);

    shell->priv->preferences_window = e_preferences_window_new (shell);
    shell->priv->backends_by_name = backends_by_name;
    shell->priv->backends_by_scheme = backends_by_scheme;
    shell->priv->safe_mode = e_file_lock_exists ();

    g_object_ref_sink (shell->priv->preferences_window);

    /* Add our icon directory to the theme's search path
     * here instead of in main() so Anjal picks it up. */
    icon_theme = gtk_icon_theme_get_default ();
    gtk_icon_theme_append_search_path (icon_theme, EVOLUTION_ICONDIR);

    g_signal_connect (
        shell, "notify::online",
        G_CALLBACK (shell_notify_online_cb), NULL);

    g_signal_connect_swapped (
        G_APPLICATION (shell), "shutdown",
        G_CALLBACK (shell_sm_quit_cb), shell);
}

/**
 * e_shell_get_default:
 *
 * Returns the #EShell created by <function>main()</function>.
 *
 * Try to obtain the #EShell from elsewhere if you can.  This function
 * is intended as a temporary workaround for when that proves difficult.
 *
 * Returns: the #EShell singleton
 **/
EShell *
e_shell_get_default (void)
{
    return default_shell;
}

/**
 * e_shell_load_modules:
 * @shell: an #EShell
 *
 * Loads all installed modules and performs some internal bookkeeping.
 * This function should be called after creating the #EShell instance
 * but before initiating migration or starting the main loop.
 **/
void
e_shell_load_modules (EShell *shell)
{
    EClientCache *client_cache;
    const gchar *module_directory;
    GList *list;

    g_return_if_fail (E_IS_SHELL (shell));

    if (shell->priv->modules_loaded)
        return;

    /* Load all shared library modules. */

    module_directory = e_shell_get_module_directory (shell);
    g_return_if_fail (module_directory != NULL);

    list = e_module_load_all_in_directory (module_directory);
    g_list_foreach (list, (GFunc) g_type_module_unuse, NULL);
    g_list_free (list);

    /* Process shell backends. */

    list = g_list_sort (
        e_extensible_list_extensions (
        E_EXTENSIBLE (shell), E_TYPE_SHELL_BACKEND),
        (GCompareFunc) e_shell_backend_compare);
    g_list_foreach (list, (GFunc) shell_process_backend, shell);
    shell->priv->loaded_backends = list;

    /* XXX The client cache needs extra help loading its extensions,
     *     since it gets instantiated before any modules are loaded. */
    client_cache = e_shell_get_client_cache (shell);
    e_extensible_load_extensions (E_EXTENSIBLE (client_cache));

    shell->priv->modules_loaded = TRUE;
}

/**
 * e_shell_get_shell_backends:
 * @shell: an #EShell
 *
 * Returns a list of loaded #EShellBackend instances.  The list is
 * owned by @shell and should not be modified or freed.
 *
 * Returns: a list of loaded #EShellBackend instances
 **/
GList *
e_shell_get_shell_backends (EShell *shell)
{
    g_return_val_if_fail (E_IS_SHELL (shell), NULL);

    return shell->priv->loaded_backends;
}

/**
 * e_shell_get_canonical_name:
 * @shell: an #EShell
 * @name: the name or alias of an #EShellBackend
 *
 * Returns the canonical name for the #EShellBackend whose name or alias
 * is @name.
 *
 * Returns: the canonical #EShellBackend name
 **/
const gchar *
e_shell_get_canonical_name (EShell *shell,
                            const gchar *name)
{
    EShellBackend *shell_backend;

    g_return_val_if_fail (E_IS_SHELL (shell), NULL);

    /* Handle NULL or empty name arguments silently. */
    if (name == NULL || *name == '\0')
        return NULL;

    shell_backend = e_shell_get_backend_by_name (shell, name);

    if (shell_backend == NULL)
        return NULL;

    return E_SHELL_BACKEND_GET_CLASS (shell_backend)->name;
}

/**
 * e_shell_get_backend_by_name:
 * @shell: an #EShell
 * @name: the name or alias of an #EShellBackend
 *
 * Returns the corresponding #EShellBackend for the given name or alias,
 * or %NULL if @name is not recognized.
 *
 * Returns: the #EShellBackend named @name, or %NULL
 **/
EShellBackend *
e_shell_get_backend_by_name (EShell *shell,
                             const gchar *name)
{
    GHashTable *hash_table;

    g_return_val_if_fail (E_IS_SHELL (shell), NULL);
    g_return_val_if_fail (name != NULL, NULL);

    hash_table = shell->priv->backends_by_name;

    return g_hash_table_lookup (hash_table, name);
}

/**
 * e_shell_get_backend_by_scheme:
 * @shell: an #EShell
 * @scheme: a URI scheme
 *
 * Returns the #EShellBackend that implements the given URI scheme,
 * or %NULL if @scheme is not recognized.
 *
 * Returns: the #EShellBackend that implements @scheme, or %NULL
 **/
EShellBackend *
e_shell_get_backend_by_scheme (EShell *shell,
                               const gchar *scheme)
{
    GHashTable *hash_table;

    g_return_val_if_fail (E_IS_SHELL (shell), NULL);
    g_return_val_if_fail (scheme != NULL, NULL);

    hash_table = shell->priv->backends_by_scheme;

    return g_hash_table_lookup (hash_table, scheme);
}

/**
 * e_shell_get_client_cache:
 * @shell: an #EShell
 *
 * Returns the #EClientCache instance for @shell.
 *
 * Returns: the #EClientCache instance for @shell
 **/
EClientCache *
e_shell_get_client_cache (EShell *shell)
{
    g_return_val_if_fail (E_IS_SHELL (shell), NULL);

    return shell->priv->client_cache;
}

/**
 * e_shell_get_registry:
 * @shell: an #EShell
 *
 * Returns the shell's #ESourceRegistry which holds all #ESource instances.
 *
 * Returns: the #ESourceRegistry
 **/
ESourceRegistry *
e_shell_get_registry (EShell *shell)
{
    g_return_val_if_fail (E_IS_SHELL (shell), NULL);

    return shell->priv->registry;
}

/**
 * e_shell_create_shell_window:
 * @shell: an #EShell
 * @view_name: name of the initial shell view, or %NULL
 *
 * Creates a new #EShellWindow.  Use this function instead of
 * e_shell_window_new() so that @shell can properly configure
 * the window.
 *
 * Returns: a new #EShellWindow
 **/
GtkWidget *
e_shell_create_shell_window (EShell *shell,
                             const gchar *view_name)
{
    GtkWidget *shell_window;
    GList *link;

    g_return_val_if_fail (E_IS_SHELL (shell), NULL);

    if (g_application_get_is_remote (G_APPLICATION (shell)))
        goto remote;

    view_name = e_shell_get_canonical_name (shell, view_name);

    /* EShellWindow initializes its active view from a GSetting key,
     * so set the key ahead of time to control the intial view. */
    if (view_name != NULL) {
        GSettings *settings;

        settings = g_settings_new ("org.gnome.evolution.shell");
        g_settings_set_string (
            settings, "default-component-id", view_name);
        g_object_unref (settings);
    }

    shell_window = e_shell_window_new (
        shell,
        shell->priv->safe_mode,
        shell->priv->geometry);

    /* Submit any outstanding alerts. */
    link = g_queue_peek_head_link (&shell->priv->alerts);
    while (link != NULL) {
        e_alert_sink_submit_alert (
            E_ALERT_SINK (shell_window),
            E_ALERT (link->data));
        link = g_list_next (link);
    }

    /* Clear the first-time-only options. */
    shell->priv->safe_mode = FALSE;
    g_free (shell->priv->geometry);
    shell->priv->geometry = NULL;

    gtk_widget_show (shell_window);

    return shell_window;

remote:  /* Send a message to the other Evolution process. */

    if (view_name != NULL) {
        g_action_group_activate_action (
            G_ACTION_GROUP (shell), "new-window",
            g_variant_new_string (view_name));
    } else
        g_application_activate (G_APPLICATION (shell));

    return NULL;
}

/**
 * e_shell_handle_uris:
 * @shell: an #EShell
 * @uris: %NULL-terminated list of URIs
 * @do_import: request an import of the URIs
 *
 * Emits the #EShell::handle-uri signal for each URI.
 *
 * Returns: the number of URIs successfully handled
 **/
guint
e_shell_handle_uris (EShell *shell,
                     const gchar * const *uris,
                     gboolean do_import)
{
    guint n_handled = 0;
    guint ii;

    g_return_val_if_fail (E_IS_SHELL (shell), FALSE);
    g_return_val_if_fail (uris != NULL, FALSE);

    if (g_application_get_is_remote (G_APPLICATION (shell)))
        goto remote;

    if (do_import) {
        n_handled = e_shell_utils_import_uris (shell, uris);
    } else {
        for (ii = 0; uris[ii] != NULL; ii++) {
            gboolean handled;

            g_signal_emit (
                shell, signals[HANDLE_URI],
                0, uris[ii], &handled);
            n_handled += handled ? 1 : 0;
        }

        if (n_handled == 0)
            n_handled = e_shell_utils_import_uris (shell, uris);
    }

    return n_handled;

remote:  /* Send a message to the other Evolution process. */

    g_action_group_activate_action (
        G_ACTION_GROUP (shell), "handle-uris",
        g_variant_new_strv (uris, -1));

    /* As far as we're concerned, all URIs have been handled. */

    return g_strv_length ((gchar **) uris);
}

/**
 * e_shell_submit_alert:
 * @shell: an #EShell
 * @alert: an #EAlert
 *
 * Broadcasts @alert to all #EShellWindow<!-- -->s.  This should only
 * be used for application-wide alerts such as a network outage.  Submit
 * view-specific alerts to the appropriate #EShellContent instance.
 **/
void
e_shell_submit_alert (EShell *shell,
                      EAlert *alert)
{
    GtkApplication *application;
    GList *list, *iter;

    g_return_if_fail (E_IS_SHELL (shell));
    g_return_if_fail (E_IS_ALERT (alert));

    application = GTK_APPLICATION (shell);

    g_queue_push_tail (&shell->priv->alerts, g_object_ref (alert));

    g_signal_connect_swapped (
        alert, "response",
        G_CALLBACK (shell_alert_response_cb), shell);

    list = gtk_application_get_windows (application);

    /* Submit the alert to all available EShellWindows. */
    for (iter = list; iter != NULL; iter = g_list_next (iter))
        if (E_IS_SHELL_WINDOW (iter->data))
            e_alert_sink_submit_alert (
                E_ALERT_SINK (iter->data), alert);
}

/**
 * e_shell_get_active_window:
 * @shell: an #EShell or %NULL to use the default shell
 *
 * Returns the most recently focused watched window, according to
 * gtk_application_get_windows().  Convenient for finding a parent
 * for a transient window.
 *
 * Note the returned window is not necessarily an #EShellWindow.
 *
 * Returns: the most recently focused watched window
 **/
GtkWindow *
e_shell_get_active_window (EShell *shell)
{
    GtkApplication *application;
    GList *list;

    if (shell == NULL)
        shell = e_shell_get_default ();

    g_return_val_if_fail (E_IS_SHELL (shell), NULL);

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

    if (list == NULL)
        return NULL;

    /* Sanity check */
    g_return_val_if_fail (GTK_IS_WINDOW (list->data), NULL);

    return GTK_WINDOW (list->data);
}

/**
 * e_shell_get_express_mode:
 * @shell: an #EShell
 *
 * Returns %TRUE if Evolution is in express mode.
 *
 * Returns: %TRUE if Evolution is in express mode
 **/
gboolean
e_shell_get_express_mode (EShell *shell)
{
    g_return_val_if_fail (E_IS_SHELL (shell), FALSE);

    return shell->priv->express_mode;
}

/**
 * e_shell_get_module_directory:
 * @shell: an #EShell
 *
 * Returns the directory from which #EModule<!-- -->s were loaded.
 *
 * Returns: the #EModule directory
 **/
const gchar *
e_shell_get_module_directory (EShell *shell)
{
    g_return_val_if_fail (E_IS_SHELL (shell), NULL);

    return shell->priv->module_directory;
}

/**
 * e_shell_get_network_available:
 * @shell: an #EShell
 *
 * Returns %TRUE if a network is available.
 *
 * Returns: %TRUE if a network is available
 **/
gboolean
e_shell_get_network_available (EShell *shell)
{
    g_return_val_if_fail (E_IS_SHELL (shell), FALSE);

    return shell->priv->network_available;
}

/**
 * e_shell_set_network_available:
 * @shell: an #EShell
 * @network_available: whether a network is available
 *
 * Sets whether a network is available.  This is usually called in
 * response to a status change signal from NetworkManager.  If the
 * network becomes unavailable while #EShell:online is %TRUE, the
 * @shell will force #EShell:online to %FALSE until the network
 * becomes available again.
 **/
void
e_shell_set_network_available (EShell *shell,
                               gboolean network_available)
{
    g_return_if_fail (E_IS_SHELL (shell));

    if (shell->priv->network_available_locked)
        return;

    if (shell->priv->network_available == network_available)
        return;

    shell->priv->network_available = network_available;
    g_object_notify (G_OBJECT (shell), "network-available");

    /* If we're being forced offline, perhaps due to a network outage,
     * reconnect automatically when the network becomes available. */
    if (!network_available && shell->priv->online) {
        g_message ("Network disconnected.  Forced offline.");
        e_shell_set_online (shell, FALSE);
        shell->priv->auto_reconnect = TRUE;
    } else if (network_available && shell->priv->auto_reconnect) {
        g_message ("Connection established.  Going online.");
        e_shell_set_online (shell, TRUE);
        shell->priv->auto_reconnect = FALSE;
    }
}

/**
 * e_shell_lock_network_available:
 * @shell: an #EShell
 *
 * Locks the value of #EShell:network-available to %TRUE.  Further
 * attempts to set the property will be ignored.
 *
 * This is used for the --force-online command-line option, which is
 * intended to override the network availability status as reported
 * by NetworkManager or other network monitoring software.
 **/
void
e_shell_lock_network_available (EShell *shell)
{
    g_return_if_fail (E_IS_SHELL (shell));

    e_shell_set_network_available (shell, TRUE);
    shell->priv->network_available_locked = TRUE;
}

/**
 * e_shell_get_online:
 * @shell: an #EShell
 *
 * Returns %TRUE if Evolution is online, %FALSE if Evolution is offline.
 * Evolution may be offline because the user elected to work offline, or
 * because the network has become unavailable.
 *
 * Returns: %TRUE if Evolution is online
 **/
gboolean
e_shell_get_online (EShell *shell)
{
    g_return_val_if_fail (E_IS_SHELL (shell), FALSE);

    return shell->priv->online;
}

/**
 * e_shell_set_online:
 * @shell: an #EShell
 * @online: %TRUE to go online, %FALSE to go offline
 *
 * Asynchronously places Evolution in online or offline mode.
 **/
void
e_shell_set_online (EShell *shell,
                    gboolean online)
{
    g_return_if_fail (E_IS_SHELL (shell));

    if (online == shell->priv->online)
        return;

    if (online)
        shell_prepare_for_online (shell);
    else
        shell_prepare_for_offline (shell);
}

/**
 * e_shell_get_preferences_window:
 * @shell: an #EShell
 *
 * Returns the Evolution Preferences window.
 *
 * Returns: the preferences window
 **/
GtkWidget *
e_shell_get_preferences_window (EShell *shell)
{
    g_return_val_if_fail (E_IS_SHELL (shell), NULL);

    return shell->priv->preferences_window;
}

/**
 * e_shell_event:
 * @shell: an #EShell
 * @event_name: the name of the event
 * @event_data: data associated with the event
 *
 * The #EShell::event signal acts as a cheap mechanism for broadcasting
 * events to the rest of the application, such as new mail arriving.  The
 * @event_name is used as the signal detail, and @event_data may point to
 * an object or data structure associated with the event.
 **/
void
e_shell_event (EShell *shell,
               const gchar *event_name,
               gpointer event_data)
{
    GQuark detail;

    g_return_if_fail (E_IS_SHELL (shell));
    g_return_if_fail (event_name != NULL);

    detail = g_quark_from_string (event_name);
    g_signal_emit (shell, signals[EVENT], detail, event_data);
}

/**
 * e_shell_quit:
 * @shell: an #EShell
 * @reason: the reason for quitting
 *
 * Requests an application shutdown.  This happens in two phases: the
 * first is synchronous, the second is asynchronous.
 *
 * In the first phase, the @shell emits a #EShell::quit-requested signal
 * to potentially give the user a chance to cancel shutdown.  If the user
 * cancels shutdown, the function returns %FALSE.  Otherwise it proceeds
 * into the second phase.
 *
 * In the second phase, the @shell emits a #EShell::prepare-for-quit
 * signal and immediately returns %TRUE.  Signal handlers may delay the
 * actual application shutdown while they clean up resources, but there
 * is no way to cancel shutdown at this point.
 *
 * Consult the documentation for these two signals for details on how
 * to handle them.
 *
 * Returns: %TRUE if shutdown is underway, %FALSE if it was cancelled
 **/
gboolean
e_shell_quit (EShell *shell,
              EShellQuitReason reason)
{
    g_return_val_if_fail (E_IS_SHELL (shell), FALSE);

    if (g_application_get_is_remote (G_APPLICATION (shell)))
        goto remote;

    if (!shell_request_quit (shell, reason))
        return FALSE;

    shell_prepare_for_quit (shell);

    return TRUE;

remote:  /* Send a message to the other Evolution process. */

    g_action_group_activate_action (
        G_ACTION_GROUP (shell), "quit", NULL);

    return TRUE;
}

/**
 * e_shell_cancel_quit:
 * @shell: an #EShell
 *
 * This function may only be called from #EShell::quit-requested signal
 * handlers to prevent Evolution from quitting.  Calling this will stop
 * further emission of the #EShell::quit-requested signal.
 *
 * Note: This function has no effect during a #EShell::prepare-for-quit
 * signal emission.
 **/
void
e_shell_cancel_quit (EShell *shell)
{
    g_return_if_fail (E_IS_SHELL (shell));

    shell->priv->quit_cancelled = TRUE;

    g_signal_stop_emission (shell, signals[QUIT_REQUESTED], 0);
}