path: root/modules/calendar/e-task-shell-sidebar.c

/*
 * e-task-shell-sidebar.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-task-shell-sidebar.h"

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

#include "e-util/e-util.h"
#include "calendar/gui/e-task-list-selector.h"
#include "calendar/gui/misc.h"

#include "e-task-shell-view.h"
#include "e-task-shell-backend.h"
#include "e-task-shell-content.h"

#define E_TASK_SHELL_SIDEBAR_GET_PRIVATE(obj) \
    (G_TYPE_INSTANCE_GET_PRIVATE \
    ((obj), E_TYPE_TASK_SHELL_SIDEBAR, ETaskShellSidebarPrivate))

typedef struct _ConnectClosure ConnectClosure;

struct _ETaskShellSidebarPrivate {
    GtkWidget *selector;

    /* UID -> Client */
    GHashTable *client_table;

    /* The default client is for ECalModel.  It follows the
     * sidebar's primary selection, even if the highlighted
     * source is not selected.  The tricky part is we don't
     * update the property until the client is successfully
     * opened.  So the user first highlights a source, then
     * sometime later we update our default-client property
     * which is bound by an EBinding to ECalModel. */
    EClient *default_client;

    /* Not referenced, only for pointer comparison. */
    ESource *connecting_default_source_instance;

    GCancellable *connecting_default_client;
    GCancellable *loading_clients;
};

struct _ConnectClosure {
    ETaskShellSidebar *task_shell_sidebar;

    /* For error messages. */
    gchar *source_display_name;
    gchar *parent_display_name;
};

enum {
    PROP_0,
    PROP_DEFAULT_CLIENT,
    PROP_SELECTOR
};

enum {
    CLIENT_ADDED,
    CLIENT_REMOVED,
    STATUS_MESSAGE,
    LAST_SIGNAL
};

static guint signals[LAST_SIGNAL];

G_DEFINE_DYNAMIC_TYPE (
    ETaskShellSidebar,
    e_task_shell_sidebar,
    E_TYPE_SHELL_SIDEBAR)

static ConnectClosure *
connect_closure_new (ETaskShellSidebar *task_shell_sidebar,
                     ESource *source)
{
    ConnectClosure *closure;
    ESourceRegistry *registry;
    ESourceSelector *selector;
    ESource *parent;
    const gchar *parent_uid;

    selector = e_task_shell_sidebar_get_selector (task_shell_sidebar);
    registry = e_source_selector_get_registry (selector);
    parent_uid = e_source_get_parent (source);
    parent = e_source_registry_ref_source (registry, parent_uid);

    closure = g_slice_new0 (ConnectClosure);
    closure->task_shell_sidebar = g_object_ref (task_shell_sidebar);
    closure->source_display_name = e_source_dup_display_name (source);
    closure->parent_display_name = e_source_dup_display_name (parent);

    g_object_unref (parent);

    return closure;
}

static void
connect_closure_free (ConnectClosure *closure)
{
    g_object_unref (closure->task_shell_sidebar);

    g_free (closure->source_display_name);
    g_free (closure->parent_display_name);

    g_slice_free (ConnectClosure, closure);
}

static void
task_shell_sidebar_emit_client_added (ETaskShellSidebar *task_shell_sidebar,
                                      EClient *client)
{
    guint signal_id = signals[CLIENT_ADDED];

    g_signal_emit (task_shell_sidebar, signal_id, 0, client);
}

static void
task_shell_sidebar_emit_client_removed (ETaskShellSidebar *task_shell_sidebar,
                                        ECalClient *client)
{
    guint signal_id = signals[CLIENT_REMOVED];

    g_signal_emit (task_shell_sidebar, signal_id, 0, client);
}

static void
task_shell_sidebar_emit_status_message (ETaskShellSidebar *task_shell_sidebar,
                                        const gchar *status_message)
{
    guint signal_id = signals[STATUS_MESSAGE];

    g_signal_emit (task_shell_sidebar, signal_id, 0, status_message, -1.0);
}

static void
task_shell_sidebar_backend_died_cb (ETaskShellSidebar *task_shell_sidebar,
                                    ECalClient *client)
{
    GHashTable *client_table;
    ESource *source;
    gchar *uid;

    client_table = task_shell_sidebar->priv->client_table;

    source = e_client_get_source (E_CLIENT (client));
    uid = e_source_dup_uid (source);

    g_hash_table_remove (client_table, uid);
    task_shell_sidebar_emit_status_message (task_shell_sidebar, NULL);

    g_free (uid);
}

static void
task_shell_sidebar_backend_error_cb (ETaskShellSidebar *task_shell_sidebar,
                                     const gchar *message,
                                     ECalClient *client)
{
    EShell *shell;
    EShellView *shell_view;
    EShellBackend *shell_backend;
    EShellContent *shell_content;
    EShellSidebar *shell_sidebar;
    ESourceRegistry *registry;
    ESource *parent;
    ESource *source;
    const gchar *parent_uid;
    const gchar *parent_display_name;
    const gchar *source_display_name;

    shell_sidebar = E_SHELL_SIDEBAR (task_shell_sidebar);
    shell_view = e_shell_sidebar_get_shell_view (shell_sidebar);
    shell_backend = e_shell_view_get_shell_backend (shell_view);
    shell_content = e_shell_view_get_shell_content (shell_view);

    shell = e_shell_backend_get_shell (shell_backend);
    registry = e_shell_get_registry (shell);

    source = e_client_get_source (E_CLIENT (client));

    parent_uid = e_source_get_parent (source);
    parent = e_source_registry_ref_source (registry, parent_uid);
    g_return_if_fail (parent != NULL);

    parent_display_name = e_source_get_display_name (parent);
    source_display_name = e_source_get_display_name (source);

    e_alert_submit (
        E_ALERT_SINK (shell_content),
        "calendar:backend-error",
        parent_display_name,
        source_display_name,
        message, NULL);

    g_object_unref (parent);
}

static void
task_shell_sidebar_handle_connect_error (ETaskShellSidebar *task_shell_sidebar,
                                         const gchar *parent_display_name,
                                         const gchar *source_display_name,
                                         const GError *error)
{
    EShellView *shell_view;
    EShellContent *shell_content;
    EShellSidebar *shell_sidebar;
    gboolean cancelled = FALSE;
    gboolean offline_error;

    shell_sidebar = E_SHELL_SIDEBAR (task_shell_sidebar);
    shell_view = e_shell_sidebar_get_shell_view (shell_sidebar);
    shell_content = e_shell_view_get_shell_content (shell_view);

    cancelled |= g_error_matches (
        error, G_IO_ERROR, G_IO_ERROR_CANCELLED);
    cancelled |= g_error_matches (
        error, E_CLIENT_ERROR, E_CLIENT_ERROR_CANCELLED);

    offline_error = g_error_matches (
        error, E_CLIENT_ERROR, E_CLIENT_ERROR_REPOSITORY_OFFLINE);

    if (cancelled) {
        /* do nothing */
    } else if (offline_error) {
        e_alert_submit (
            E_ALERT_SINK (shell_content),
            "calendar:prompt-no-contents-offline-calendar",
            parent_display_name,
            source_display_name,
            NULL);
    } else {
        e_alert_submit (
            E_ALERT_SINK (shell_content),
            "calendar:failed-open-calendar",
            parent_display_name,
            source_display_name,
            error->message,
            NULL);
    }
}

static void
task_shell_sidebar_client_connect_cb (GObject *source_object,
                                      GAsyncResult *result,
                                      gpointer user_data)
{
    EClient *client;
    ConnectClosure *closure = user_data;
    ETaskShellContent *task_shell_content;
    EShellContent *shell_content;
    EShellSidebar *shell_sidebar;
    EShellView *shell_view;
    ECalModel *model;
    icaltimezone *timezone;
    GError *error = NULL;

    client = e_cal_client_connect_finish (result, &error);

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

    if (error != NULL) {
        task_shell_sidebar_handle_connect_error (
            closure->task_shell_sidebar,
            closure->parent_display_name,
            closure->source_display_name,
            error);
        g_error_free (error);
        goto exit;
    }

    /* FIXME Sidebar should not be accessing the EShellContent.
     *       This probably needs to be moved to ETaskShellView. */
    shell_sidebar = E_SHELL_SIDEBAR (closure->task_shell_sidebar);
    shell_view = e_shell_sidebar_get_shell_view (shell_sidebar);
    shell_content = e_shell_view_get_shell_content (shell_view);

    task_shell_content = E_TASK_SHELL_CONTENT (shell_content);
    model = e_task_shell_content_get_task_model (task_shell_content);
    timezone = e_cal_model_get_timezone (model);

    e_cal_client_set_default_timezone (E_CAL_CLIENT (client), timezone);

    e_task_shell_sidebar_add_client (closure->task_shell_sidebar, client);

    g_object_unref (client);

exit:
    connect_closure_free (closure);
}

static void
task_shell_sidebar_default_connect_cb (GObject *source_object,
                                       GAsyncResult *result,
                                       gpointer user_data)
{
    EClient *client;
    ESource *source;
    ConnectClosure *closure = user_data;
    ETaskShellSidebarPrivate *priv;
    EShellContent *shell_content;
    EShellSidebar *shell_sidebar;
    EShellView *shell_view;
    ETaskShellContent *task_shell_content;
    ECalModel *model;
    icaltimezone *timezone;
    GError *error = NULL;

    priv = E_TASK_SHELL_SIDEBAR_GET_PRIVATE (closure->task_shell_sidebar);

    client = e_cal_client_connect_finish (result, &error);

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

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

    if (error != NULL) {
        task_shell_sidebar_handle_connect_error (
            closure->task_shell_sidebar,
            closure->parent_display_name,
            closure->source_display_name,
            error);
        g_error_free (error);
        goto exit;
    }

    source = e_client_get_source (client);

    if (source == priv->connecting_default_source_instance)
        priv->connecting_default_source_instance = NULL;

    if (priv->default_client != NULL)
        g_object_unref (priv->default_client);

    priv->default_client = g_object_ref (client);

    /* FIXME Sidebar should not be accessing the EShellContent.
     *       This probably needs to be moved to ETaskShellView. */
    shell_sidebar = E_SHELL_SIDEBAR (closure->task_shell_sidebar);
    shell_view = e_shell_sidebar_get_shell_view (shell_sidebar);
    shell_content = e_shell_view_get_shell_content (shell_view);

    task_shell_content = E_TASK_SHELL_CONTENT (shell_content);
    model = e_task_shell_content_get_task_model (task_shell_content);
    timezone = e_cal_model_get_timezone (model);

    e_cal_client_set_default_timezone (E_CAL_CLIENT (client), timezone);

    g_object_notify (G_OBJECT (shell_sidebar), "default-client");

    g_object_unref (client);

exit:
    connect_closure_free (closure);
}

static void
task_shell_sidebar_set_default (ETaskShellSidebar *task_shell_sidebar,
                                ESource *source)
{
    ETaskShellSidebarPrivate *priv;
    EShellSidebar *shell_sidebar;
    ECalClient *client;
    const gchar *uid;

    priv = task_shell_sidebar->priv;

    /* already loading that source as default source */
    if (source == priv->connecting_default_source_instance)
        return;

    /* FIXME Sidebar should not be accessing the EShellContent.
     *       This probably needs to be moved to ETaskShellView. */
    shell_sidebar = E_SHELL_SIDEBAR (task_shell_sidebar);

    /* Cancel any unfinished previous request. */
    if (priv->connecting_default_client != NULL) {
        g_cancellable_cancel (priv->connecting_default_client);
        g_object_unref (priv->connecting_default_client);
        priv->connecting_default_client = NULL;
    }

    uid = e_source_get_uid (source);
    client = g_hash_table_lookup (priv->client_table, uid);

    /* If we already have an open connection for
     * this UID, we can finish immediately. */
    if (client != NULL) {
        if (priv->default_client != NULL)
            g_object_unref (priv->default_client);
        priv->default_client = g_object_ref (client);
        g_object_notify (G_OBJECT (shell_sidebar), "default-client");
        return;
    }

    /* it's only for pointer comparison, no need to ref it */
    priv->connecting_default_source_instance = source;
    priv->connecting_default_client = g_cancellable_new ();

    e_cal_client_connect (
        source, E_CAL_CLIENT_SOURCE_TYPE_TASKS,
        priv->connecting_default_client,
        task_shell_sidebar_default_connect_cb,
        connect_closure_new (task_shell_sidebar, source));
}

static void
task_shell_sidebar_row_changed_cb (ETaskShellSidebar *task_shell_sidebar,
                                   GtkTreePath *tree_path,
                                   GtkTreeIter *tree_iter,
                                   GtkTreeModel *tree_model)
{
    ESourceSelector *selector;
    ESource *source;

    selector = e_task_shell_sidebar_get_selector (task_shell_sidebar);
    source = e_source_selector_ref_source_by_path (selector, tree_path);

    /* XXX This signal gets emitted a lot while the model is being
     *     rebuilt, during which time we won't get a valid ESource.
     *     ESourceSelector should probably block this signal while
     *     rebuilding the model, but we'll be forgiving and not
     *     emit a warning. */
    if (source == NULL)
        return;

    if (e_source_selector_source_is_selected (selector, source))
        e_task_shell_sidebar_add_source (task_shell_sidebar, source);
    else
        e_task_shell_sidebar_remove_source (task_shell_sidebar, source);

    g_object_unref (source);
}

static void
task_shell_sidebar_primary_selection_changed_cb (ETaskShellSidebar *task_shell_sidebar,
                                                 ESourceSelector *selector)
{
    ESource *source;

    source = e_source_selector_ref_primary_selection (selector);
    if (source == NULL)
        return;

    task_shell_sidebar_set_default (task_shell_sidebar, source);

    g_object_unref (source);
}

static void
task_shell_sidebar_restore_state_cb (EShellWindow *shell_window,
                                     EShellView *shell_view,
                                     EShellSidebar *shell_sidebar)
{
    ETaskShellSidebarPrivate *priv;
    EShell *shell;
    EShellBackend *shell_backend;
    EShellSettings *shell_settings;
    ESourceRegistry *registry;
    ESourceSelector *selector;
    GtkTreeModel *model;

    priv = E_TASK_SHELL_SIDEBAR_GET_PRIVATE (shell_sidebar);

    shell = e_shell_window_get_shell (shell_window);
    shell_settings = e_shell_get_shell_settings (shell);

    shell_backend = e_shell_view_get_shell_backend (shell_view);
    g_return_if_fail (E_IS_TASK_SHELL_BACKEND (shell_backend));

    selector = E_SOURCE_SELECTOR (priv->selector);
    model = gtk_tree_view_get_model (GTK_TREE_VIEW (selector));

    registry = e_shell_get_registry (shell);

    g_signal_connect_swapped (
        model, "row-changed",
        G_CALLBACK (task_shell_sidebar_row_changed_cb),
        shell_sidebar);

    g_signal_connect_swapped (
        selector, "primary-selection-changed",
        G_CALLBACK (task_shell_sidebar_primary_selection_changed_cb),
        shell_sidebar);

    g_object_bind_property_full (
        shell_settings, "cal-primary-task-list",
        selector, "primary-selection",
        G_BINDING_BIDIRECTIONAL |
        G_BINDING_SYNC_CREATE,
        (GBindingTransformFunc) e_binding_transform_uid_to_source,
        (GBindingTransformFunc) e_binding_transform_source_to_uid,
        g_object_ref (registry),
        (GDestroyNotify) g_object_unref);
}

static void
task_shell_sidebar_get_property (GObject *object,
                                 guint property_id,
                                 GValue *value,
                                 GParamSpec *pspec)
{
    switch (property_id) {
        case PROP_DEFAULT_CLIENT:
            g_value_set_object (
                value,
                e_task_shell_sidebar_get_default_client (
                E_TASK_SHELL_SIDEBAR (object)));
            return;

        case PROP_SELECTOR:
            g_value_set_object (
                value,
                e_task_shell_sidebar_get_selector (
                E_TASK_SHELL_SIDEBAR (object)));
            return;
    }

    G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
}

static void
task_shell_sidebar_dispose (GObject *object)
{
    ETaskShellSidebarPrivate *priv;

    priv = E_TASK_SHELL_SIDEBAR_GET_PRIVATE (object);

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

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

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

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

    g_hash_table_remove_all (priv->client_table);

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

static void
task_shell_sidebar_finalize (GObject *object)
{
    ETaskShellSidebarPrivate *priv;

    priv = E_TASK_SHELL_SIDEBAR_GET_PRIVATE (object);

    g_hash_table_destroy (priv->client_table);

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

static void
task_shell_sidebar_constructed (GObject *object)
{
    ETaskShellSidebarPrivate *priv;
    EShell *shell;
    EShellView *shell_view;
    EShellWindow *shell_window;
    EShellSidebar *shell_sidebar;
    ESourceRegistry *registry;
    GtkContainer *container;
    GtkWidget *widget;
    AtkObject *a11y;

    priv = E_TASK_SHELL_SIDEBAR_GET_PRIVATE (object);

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

    shell_sidebar = E_SHELL_SIDEBAR (object);
    shell_view = e_shell_sidebar_get_shell_view (shell_sidebar);
    shell_window = e_shell_view_get_shell_window (shell_view);
    shell = e_shell_window_get_shell (shell_window);

    container = GTK_CONTAINER (shell_sidebar);

    widget = gtk_scrolled_window_new (NULL, NULL);
    gtk_scrolled_window_set_policy (
        GTK_SCROLLED_WINDOW (widget),
        GTK_POLICY_AUTOMATIC, GTK_POLICY_AUTOMATIC);
    gtk_scrolled_window_set_shadow_type (
        GTK_SCROLLED_WINDOW (widget), GTK_SHADOW_IN);
    gtk_container_add (container, widget);
    gtk_widget_show (widget);

    container = GTK_CONTAINER (widget);

    registry = e_shell_get_registry (shell);
    widget = e_task_list_selector_new (registry);
    e_source_selector_set_select_new (E_SOURCE_SELECTOR (widget), TRUE);
    gtk_container_add (container, widget);
    a11y = gtk_widget_get_accessible (widget);
    atk_object_set_name (a11y, _("Task List Selector"));
    priv->selector = g_object_ref (widget);
    gtk_widget_show (widget);

    /* Restore widget state from the last session once
     * the shell view is fully initialized and visible. */
    g_signal_connect (
        shell_window, "shell-view-created::tasks",
        G_CALLBACK (task_shell_sidebar_restore_state_cb),
        shell_sidebar);
}

static guint32
task_shell_sidebar_check_state (EShellSidebar *shell_sidebar)
{
    ETaskShellSidebar *task_shell_sidebar;
    ESourceSelector *selector;
    ESourceRegistry *registry;
    ESource *source;
    gboolean is_writable = FALSE;
    gboolean is_removable = FALSE;
    gboolean is_remote_creatable = FALSE;
    gboolean is_remote_deletable = FALSE;
    gboolean in_collection = FALSE;
    gboolean refresh_supported = FALSE;
    gboolean has_primary_source = FALSE;
    guint32 state = 0;

    task_shell_sidebar = E_TASK_SHELL_SIDEBAR (shell_sidebar);
    selector = e_task_shell_sidebar_get_selector (task_shell_sidebar);
    source = e_source_selector_ref_primary_selection (selector);
    registry = e_source_selector_get_registry (selector);

    if (source != NULL) {
        EClient *client;
        ESource *collection;
        const gchar *uid;

        has_primary_source = TRUE;
        is_writable = e_source_get_writable (source);
        is_removable = e_source_get_removable (source);
        is_remote_creatable = e_source_get_remote_creatable (source);
        is_remote_deletable = e_source_get_remote_deletable (source);

        collection = e_source_registry_find_extension (
            registry, source, E_SOURCE_EXTENSION_COLLECTION);
        if (collection != NULL) {
            in_collection = TRUE;
            g_object_unref (collection);
        }

        uid = e_source_get_uid (source);
        client = g_hash_table_lookup (
            task_shell_sidebar->priv->client_table, uid);
        refresh_supported =
            client != NULL &&
            e_client_check_refresh_supported (client);

        g_object_unref (source);
    }

    if (has_primary_source)
        state |= E_TASK_SHELL_SIDEBAR_HAS_PRIMARY_SOURCE;
    if (is_writable)
        state |= E_TASK_SHELL_SIDEBAR_PRIMARY_SOURCE_IS_WRITABLE;
    if (is_removable)
        state |= E_TASK_SHELL_SIDEBAR_PRIMARY_SOURCE_IS_REMOVABLE;
    if (is_remote_creatable)
        state |= E_TASK_SHELL_SIDEBAR_PRIMARY_SOURCE_IS_REMOTE_CREATABLE;
    if (is_remote_deletable)
        state |= E_TASK_SHELL_SIDEBAR_PRIMARY_SOURCE_IS_REMOTE_DELETABLE;
    if (in_collection)
        state |= E_TASK_SHELL_SIDEBAR_PRIMARY_SOURCE_IN_COLLECTION;
    if (refresh_supported)
        state |= E_TASK_SHELL_SIDEBAR_SOURCE_SUPPORTS_REFRESH;

    return state;
}

static void
task_shell_sidebar_client_removed (ETaskShellSidebar *task_shell_sidebar,
                                   ECalClient *client)
{
    ESourceSelector *selector;
    GHashTable *client_table;
    ESource *source;
    const gchar *uid;

    client_table = task_shell_sidebar->priv->client_table;
    selector = e_task_shell_sidebar_get_selector (task_shell_sidebar);

    g_signal_handlers_disconnect_matched (
        client, G_SIGNAL_MATCH_DATA, 0, 0,
        NULL, NULL, task_shell_sidebar);

    source = e_client_get_source (E_CLIENT (client));
    uid = e_source_get_uid (source);

    g_hash_table_remove (client_table, uid);
    e_source_selector_unselect_source (selector, source);

    task_shell_sidebar_emit_status_message (task_shell_sidebar, NULL);
}

static void
e_task_shell_sidebar_class_init (ETaskShellSidebarClass *class)
{
    GObjectClass *object_class;
    EShellSidebarClass *shell_sidebar_class;

    g_type_class_add_private (class, sizeof (ETaskShellSidebarPrivate));

    object_class = G_OBJECT_CLASS (class);
    object_class->get_property = task_shell_sidebar_get_property;
    object_class->dispose = task_shell_sidebar_dispose;
    object_class->finalize = task_shell_sidebar_finalize;
    object_class->constructed = task_shell_sidebar_constructed;

    shell_sidebar_class = E_SHELL_SIDEBAR_CLASS (class);
    shell_sidebar_class->check_state = task_shell_sidebar_check_state;

    class->client_removed = task_shell_sidebar_client_removed;

    g_object_class_install_property (
        object_class,
        PROP_DEFAULT_CLIENT,
        g_param_spec_object (
            "default-client",
            "Default Task ECalClient",
            "Default client for task operations",
            E_TYPE_CAL_CLIENT,
            G_PARAM_READABLE));

    g_object_class_install_property (
        object_class,
        PROP_SELECTOR,
        g_param_spec_object (
            "selector",
            "Source Selector Widget",
            "This widget displays groups of task lists",
            E_TYPE_SOURCE_SELECTOR,
            G_PARAM_READABLE));

    signals[CLIENT_ADDED] = g_signal_new (
        "client-added",
        G_OBJECT_CLASS_TYPE (object_class),
        G_SIGNAL_RUN_LAST,
        G_STRUCT_OFFSET (ETaskShellSidebarClass, client_added),
        NULL, NULL,
        g_cclosure_marshal_VOID__OBJECT,
        G_TYPE_NONE, 1,
        E_TYPE_CAL_CLIENT);

    signals[CLIENT_REMOVED] = g_signal_new (
        "client-removed",
        G_OBJECT_CLASS_TYPE (object_class),
        G_SIGNAL_RUN_LAST,
        G_STRUCT_OFFSET (ETaskShellSidebarClass, client_removed),
        NULL, NULL,
        g_cclosure_marshal_VOID__OBJECT,
        G_TYPE_NONE, 1,
        E_TYPE_CAL_CLIENT);

    signals[STATUS_MESSAGE] = g_signal_new (
        "status-message",
        G_OBJECT_CLASS_TYPE (object_class),
        G_SIGNAL_RUN_LAST | G_SIGNAL_ACTION,
        G_STRUCT_OFFSET (ETaskShellSidebarClass, status_message),
        NULL, NULL,
        e_marshal_VOID__STRING_DOUBLE,
        G_TYPE_NONE, 2,
        G_TYPE_STRING,
        G_TYPE_DOUBLE);
}

static void
e_task_shell_sidebar_class_finalize (ETaskShellSidebarClass *class)
{
}

static void
e_task_shell_sidebar_init (ETaskShellSidebar *task_shell_sidebar)
{
    GHashTable *client_table;

    client_table = g_hash_table_new_full (
        g_str_hash, g_str_equal,
        (GDestroyNotify) g_free,
        (GDestroyNotify) g_object_unref);

    task_shell_sidebar->priv =
        E_TASK_SHELL_SIDEBAR_GET_PRIVATE (task_shell_sidebar);

    task_shell_sidebar->priv->client_table = client_table;
    task_shell_sidebar->priv->loading_clients = g_cancellable_new ();

    /* Postpone widget construction until we have a shell view. */
}

void
e_task_shell_sidebar_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_task_shell_sidebar_register_type (type_module);
}

GtkWidget *
e_task_shell_sidebar_new (EShellView *shell_view)
{
    g_return_val_if_fail (E_IS_SHELL_VIEW (shell_view), NULL);

    return g_object_new (
        E_TYPE_TASK_SHELL_SIDEBAR,
        "shell-view", shell_view, NULL);
}

GList *
e_task_shell_sidebar_get_clients (ETaskShellSidebar *task_shell_sidebar)
{
    GHashTable *client_table;

    g_return_val_if_fail (
        E_IS_TASK_SHELL_SIDEBAR (task_shell_sidebar), NULL);

    client_table = task_shell_sidebar->priv->client_table;

    return g_hash_table_get_values (client_table);
}

ECalClient *
e_task_shell_sidebar_get_default_client (ETaskShellSidebar *task_shell_sidebar)
{
    g_return_val_if_fail (
        E_IS_TASK_SHELL_SIDEBAR (task_shell_sidebar), NULL);

    return (ECalClient *) task_shell_sidebar->priv->default_client;
}

ESourceSelector *
e_task_shell_sidebar_get_selector (ETaskShellSidebar *task_shell_sidebar)
{
    g_return_val_if_fail (
        E_IS_TASK_SHELL_SIDEBAR (task_shell_sidebar), NULL);

    return E_SOURCE_SELECTOR (task_shell_sidebar->priv->selector);
}

void
e_task_shell_sidebar_add_client (ETaskShellSidebar *task_shell_sidebar,
                                 EClient *client)
{
    ESource *source;
    ESourceSelector *selector;
    GHashTable *client_table;
    const gchar *message;
    const gchar *uid;

    g_return_if_fail (E_IS_TASK_SHELL_SIDEBAR (task_shell_sidebar));
    g_return_if_fail (E_IS_CAL_CLIENT (client));

    client_table = task_shell_sidebar->priv->client_table;

    source = e_client_get_source (client);
    uid = e_source_get_uid (source);

    if (g_hash_table_contains (client_table, uid))
        return;

    g_hash_table_insert (
        client_table, g_strdup (uid), g_object_ref (client));

    g_signal_connect_swapped (
        client, "backend-died",
        G_CALLBACK (task_shell_sidebar_backend_died_cb),
        task_shell_sidebar);

    g_signal_connect_swapped (
        client, "backend-error",
        G_CALLBACK (task_shell_sidebar_backend_error_cb),
        task_shell_sidebar);

    selector = e_task_shell_sidebar_get_selector (task_shell_sidebar);
    e_source_selector_select_source (selector, source);

    message = _("Loading task list");
    task_shell_sidebar_emit_status_message (task_shell_sidebar, message);
    task_shell_sidebar_emit_client_added (task_shell_sidebar, client);
    task_shell_sidebar_emit_status_message (task_shell_sidebar, NULL);
}

void
e_task_shell_sidebar_add_source (ETaskShellSidebar *task_shell_sidebar,
                                 ESource *source)
{
    ECalClientSourceType source_type;
    ESourceSelector *selector;
    GHashTable *client_table;
    EClient *default_client;
    const gchar *display_name;
    const gchar *uid;
    gchar *message;

    g_return_if_fail (E_IS_TASK_SHELL_SIDEBAR (task_shell_sidebar));
    g_return_if_fail (E_IS_SOURCE (source));

    source_type = E_CAL_CLIENT_SOURCE_TYPE_TASKS;
    client_table = task_shell_sidebar->priv->client_table;
    default_client = task_shell_sidebar->priv->default_client;
    selector = e_task_shell_sidebar_get_selector (task_shell_sidebar);

    uid = e_source_get_uid (source);

    if (g_hash_table_contains (client_table, uid))
        return;

    if (default_client != NULL) {
        ESource *default_source;

        default_source = e_client_get_source (default_client);

        if (e_source_equal (source, default_source)) {
            e_task_shell_sidebar_add_client (
                task_shell_sidebar, default_client);
            return;
        }
    }

    e_source_selector_select_source (selector, source);

    display_name = e_source_get_display_name (source);
    message = g_strdup_printf (_("Opening task list '%s'"), display_name);
    task_shell_sidebar_emit_status_message (task_shell_sidebar, message);
    g_free (message);

    e_cal_client_connect (
        source, source_type,
        task_shell_sidebar->priv->loading_clients,
        task_shell_sidebar_client_connect_cb,
        connect_closure_new (task_shell_sidebar, source));
}

void
e_task_shell_sidebar_remove_source (ETaskShellSidebar *task_shell_sidebar,
                                    ESource *source)
{
    GHashTable *client_table;
    ECalClient *client;
    const gchar *uid;

    g_return_if_fail (E_IS_TASK_SHELL_SIDEBAR (task_shell_sidebar));
    g_return_if_fail (E_IS_SOURCE (source));

    client_table = task_shell_sidebar->priv->client_table;

    uid = e_source_get_uid (source);
    client = g_hash_table_lookup (client_table, uid);

    if (client == NULL)
        return;

    task_shell_sidebar_emit_client_removed (task_shell_sidebar, client);
}