path: root/mail/e-mail-paned-view.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.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
 * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with this program; if not, see <http://www.gnu.org/licenses/>.
 *
 *
 * Authors:
 *      Srinivasa Ragavan <sragavan@gnome.org>
 *
 * Copyright (C) 2010 Intel corporation. (www.intel.com)
 *
 */

#include "e-mail-paned-view.h"

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

#include <shell/e-shell-window-actions.h>

#include <libemail-engine/libemail-engine.h>

#include "em-utils.h"
#include "message-list.h"
#include "e-mail-reader-utils.h"

#define E_MAIL_PANED_VIEW_GET_PRIVATE(obj) \
    (G_TYPE_INSTANCE_GET_PRIVATE \
    ((obj), E_TYPE_MAIL_PANED_VIEW, EMailPanedViewPrivate))

#define E_SHELL_WINDOW_ACTION_GROUP_MAIL(window) \
    E_SHELL_WINDOW_ACTION_GROUP ((window), "mail")

struct _EMailPanedViewPrivate {
    GtkWidget *paned;
    GtkWidget *scrolled_window;
    GtkWidget *message_list;
    GtkWidget *preview_pane;
    GtkWidget *search_bar;

    EMailDisplay *display;
    GalViewInstance *view_instance;

    /* ETable scrolling hack */
    gdouble default_scrollbar_position;

    guint paned_binding_id;

    /* Signal handler IDs */
    guint message_list_built_id;
};

enum {
    PROP_0,
    PROP_FORWARD_STYLE,
    PROP_GROUP_BY_THREADS,
    PROP_REPLY_STYLE
};

#define STATE_KEY_GROUP_BY_THREADS  "GroupByThreads"
#define STATE_KEY_SELECTED_MESSAGE  "SelectedMessage"
#define STATE_KEY_PREVIEW_VISIBLE   "PreviewVisible"
#define STATE_GROUP_GLOBAL_FOLDER   "GlobalFolder"

/* Forward Declarations */
static void e_mail_paned_view_reader_init (EMailReaderInterface *iface);

G_DEFINE_TYPE_WITH_CODE (
    EMailPanedView, e_mail_paned_view, E_TYPE_MAIL_VIEW,
    G_IMPLEMENT_INTERFACE (
        E_TYPE_MAIL_READER, e_mail_paned_view_reader_init)
    G_IMPLEMENT_INTERFACE (
        E_TYPE_EXTENSIBLE, NULL))

static void
mail_paned_view_save_boolean (EMailView *view,
                              const gchar *key,
                              gboolean value)
{
    EMailReader *reader;
    CamelFolder *folder;

    reader = E_MAIL_READER (view);
    folder = e_mail_reader_ref_folder (reader);

    if (folder != NULL) {
        EShellView *shell_view;
        GKeyFile *key_file;
        gchar *folder_uri;
        gchar *group_name;

        shell_view = e_mail_view_get_shell_view (view);
        key_file = e_shell_view_get_state_key_file (shell_view);

        folder_uri = e_mail_folder_uri_from_folder (folder);
        group_name = g_strdup_printf ("Folder %s", folder_uri);
        g_key_file_set_boolean (key_file, group_name, key, value);
        g_free (group_name);
        g_free (folder_uri);

        g_key_file_set_boolean (
            key_file, STATE_GROUP_GLOBAL_FOLDER, key, value);

        e_shell_view_set_state_dirty (shell_view);

        g_object_unref (folder);
    }
}

static void
mail_paned_view_message_list_built_cb (EMailView *view,
                                       MessageList *message_list)
{
    EMailPanedViewPrivate *priv;
    EShellView *shell_view;
    EShellWindow *shell_window;
    CamelFolder *folder;
    GKeyFile *key_file;

    priv = E_MAIL_PANED_VIEW_GET_PRIVATE (view);

    folder = message_list_ref_folder (message_list);

    g_signal_handler_disconnect (
        message_list, priv->message_list_built_id);
    priv->message_list_built_id = 0;

    shell_view = e_mail_view_get_shell_view (view);
    shell_window = e_shell_view_get_shell_window (shell_view);

    key_file = e_shell_view_get_state_key_file (shell_view);

    if (message_list->cursor_uid != NULL)
        ;  /* do nothing */

    else if (folder == NULL)
        ;  /* do nothing */

    else if (e_shell_window_get_safe_mode (shell_window))
        e_shell_window_set_safe_mode (shell_window, FALSE);

    else {
        const gchar *key;
        gchar *folder_uri;
        gchar *group_name;
        gchar *uid;

        folder_uri = e_mail_folder_uri_from_folder (folder);

        key = STATE_KEY_SELECTED_MESSAGE;
        group_name = g_strdup_printf ("Folder %s", folder_uri);
        uid = g_key_file_get_string (key_file, group_name, key, NULL);
        g_free (group_name);

        g_free (folder_uri);

        /* Use selection fallbacks if UID is not found. */
        message_list_select_uid (message_list, uid, TRUE);

        g_free (uid);
    }

    g_clear_object (&folder);
}

static void
mail_paned_view_message_selected_cb (EMailView *view,
                                     const gchar *message_uid,
                                     MessageList *message_list)
{
    EShellView *shell_view;
    CamelFolder *folder;
    GKeyFile *key_file;
    const gchar *key;
    gchar *folder_uri;
    gchar *group_name;

    folder = message_list_ref_folder (message_list);

    /* This also gets triggered when selecting a store name on
     * the sidebar such as "On This Computer", in which case
     * 'folder' will be NULL. */
    if (folder == NULL)
        return;

    shell_view = e_mail_view_get_shell_view (view);
    key_file = e_shell_view_get_state_key_file (shell_view);

    folder_uri = e_mail_folder_uri_from_folder (folder);

    key = STATE_KEY_SELECTED_MESSAGE;
    group_name = g_strdup_printf ("Folder %s", folder_uri);

    if (message_uid != NULL)
        g_key_file_set_string (key_file, group_name, key, message_uid);
    else
        g_key_file_remove_key (key_file, group_name, key, NULL);
    e_shell_view_set_state_dirty (shell_view);

    g_free (group_name);
    g_free (folder_uri);

    g_object_unref (folder);
}

static void
mail_paned_view_restore_state_cb (EShellWindow *shell_window,
                                  EShellView *shell_view,
                                  EMailPanedView *view)
{
    EMailPanedViewPrivate *priv;
    GSettings *settings;

    priv = E_MAIL_PANED_VIEW (view)->priv;

    /* Bind GObject properties to GSettings keys. */

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

    g_settings_bind (
        settings, "hpaned-size",
        priv->paned, "hposition",
        G_SETTINGS_BIND_DEFAULT);

    g_settings_bind (
        settings, "paned-size",
        priv->paned, "vposition",
        G_SETTINGS_BIND_DEFAULT);

    g_object_unref (settings);
}

static void
mail_paned_display_view_cb (GalViewInstance *view_instance,
                            GalView *gal_view,
                            EMailView *view)
{
    EMailReader *reader;
    EShellView *shell_view;
    GtkWidget *message_list;

    shell_view = e_mail_view_get_shell_view (view);
    e_shell_view_set_view_instance (shell_view, view_instance);

    reader = E_MAIL_READER (view);
    message_list = e_mail_reader_get_message_list (reader);

    if (GAL_IS_VIEW_ETABLE (gal_view))
        gal_view_etable_attach_tree (
            GAL_VIEW_ETABLE (gal_view),
            E_TREE (message_list));
}

static void
mail_paned_view_notify_group_by_threads_cb (EMailReader *reader)
{
    gboolean group_by_threads;

    group_by_threads = e_mail_reader_get_group_by_threads (reader);

    mail_paned_view_save_boolean (
        E_MAIL_VIEW (reader),
        STATE_KEY_GROUP_BY_THREADS, group_by_threads);
}

static void
mail_paned_view_set_property (GObject *object,
                              guint property_id,
                              const GValue *value,
                              GParamSpec *pspec)
{
    switch (property_id) {
        case PROP_FORWARD_STYLE:
            e_mail_reader_set_forward_style (
                E_MAIL_READER (object),
                g_value_get_enum (value));
            return;

        case PROP_GROUP_BY_THREADS:
            e_mail_reader_set_group_by_threads (
                E_MAIL_READER (object),
                g_value_get_boolean (value));
            return;

        case PROP_REPLY_STYLE:
            e_mail_reader_set_reply_style (
                E_MAIL_READER (object),
                g_value_get_enum (value));
            return;
    }

    G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
}

static void
mail_paned_view_get_property (GObject *object,
                              guint property_id,
                              GValue *value,
                              GParamSpec *pspec)
{
    switch (property_id) {
        case PROP_FORWARD_STYLE:
            g_value_set_enum (
                value,
                e_mail_reader_get_forward_style (
                E_MAIL_READER (object)));
            return;

        case PROP_GROUP_BY_THREADS:
            g_value_set_boolean (
                value,
                e_mail_reader_get_group_by_threads (
                E_MAIL_READER (object)));
            return;

        case PROP_REPLY_STYLE:
            g_value_set_enum (
                value,
                e_mail_reader_get_reply_style (
                E_MAIL_READER (object)));
            return;
    }

    G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
}

static void
mail_paned_view_dispose (GObject *object)
{
    EMailPanedViewPrivate *priv;

    priv = E_MAIL_PANED_VIEW_GET_PRIVATE (object);

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

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

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

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

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

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

static GtkActionGroup *
mail_paned_view_get_action_group (EMailReader *reader,
                                  EMailReaderActionGroup group)
{
    EMailView *view;
    EShellView *shell_view;
    EShellWindow *shell_window;
    const gchar *group_name;

    view = E_MAIL_VIEW (reader);
    shell_view = e_mail_view_get_shell_view (view);
    shell_window = e_shell_view_get_shell_window (shell_view);

    switch (group) {
        case E_MAIL_READER_ACTION_GROUP_STANDARD:
            group_name = "mail";
            break;
        case E_MAIL_READER_ACTION_GROUP_SEARCH_FOLDERS:
            group_name = "search-folders";
            break;
        default:
            g_return_val_if_reached (NULL);
    }

    return e_shell_window_get_action_group (shell_window, group_name);
}

static EAlertSink *
mail_paned_view_get_alert_sink (EMailReader *reader)
{
    EMailView *view;
    EShellView *shell_view;
    EShellContent *shell_content;

    view = E_MAIL_VIEW (reader);
    shell_view = e_mail_view_get_shell_view (view);
    shell_content = e_shell_view_get_shell_content (shell_view);

    return E_ALERT_SINK (shell_content);
}

static EMailBackend *
mail_paned_view_get_backend (EMailReader *reader)
{
    EMailView *view;
    EShellView *shell_view;
    EShellBackend *shell_backend;

    view = E_MAIL_VIEW (reader);
    shell_view = e_mail_view_get_shell_view (view);
    shell_backend = e_shell_view_get_shell_backend (shell_view);

    return E_MAIL_BACKEND (shell_backend);
}

static EMailDisplay *
mail_paned_view_get_mail_display (EMailReader *reader)
{
    EMailPanedViewPrivate *priv;

    priv = E_MAIL_PANED_VIEW (reader)->priv;

    return priv->display;
}

static gboolean
mail_paned_view_get_hide_deleted (EMailReader *reader)
{
    return !e_mail_view_get_show_deleted (E_MAIL_VIEW (reader));
}

static GtkWidget *
mail_paned_view_get_message_list (EMailReader *reader)
{
    EMailPanedView *paned_view;

    paned_view = E_MAIL_PANED_VIEW (reader);

    return paned_view->priv->message_list;
}

static GtkMenu *
mail_paned_view_get_popup_menu (EMailReader *reader)
{
    EMailView *view;
    EShellView *shell_view;
    EShellWindow *shell_window;
    GtkUIManager *ui_manager;
    GtkWidget *widget;

    view = E_MAIL_VIEW (reader);
    shell_view = e_mail_view_get_shell_view (view);
    shell_window = e_shell_view_get_shell_window (shell_view);

    ui_manager = e_shell_window_get_ui_manager (shell_window);
    widget = gtk_ui_manager_get_widget (ui_manager, "/mail-preview-popup");

    return GTK_MENU (widget);
}

static EPreviewPane *
mail_paned_view_get_preview_pane (EMailReader *reader)
{
    EMailPanedView *paned_view;

    paned_view = E_MAIL_PANED_VIEW (reader);

    return E_PREVIEW_PANE (paned_view->priv->preview_pane);
}

static GtkWindow *
mail_paned_view_get_window (EMailReader *reader)
{
    EMailView *view;
    EShellView *shell_view;
    EShellWindow *shell_window;

    view = E_MAIL_VIEW (reader);
    shell_view = e_mail_view_get_shell_view (view);
    shell_window = e_shell_view_get_shell_window (shell_view);

    return GTK_WINDOW (shell_window);
}

static void
mail_paned_view_set_folder (EMailReader *reader,
                            CamelFolder *folder)
{
    EMailPanedViewPrivate *priv;
    EMailView *view;
    EShell *shell;
    EShellView *shell_view;
    EShellWindow *shell_window;
    GSettings *settings;
    EMailReaderInterface *default_interface;
    GtkWidget *message_list;
    GKeyFile *key_file;
    gchar *folder_uri;
    gchar *group_name;
    const gchar *key;
    gboolean value, global_view_setting;
    GError *error = NULL;

    priv = E_MAIL_PANED_VIEW_GET_PRIVATE (reader);

    view = E_MAIL_VIEW (reader);
    shell_view = e_mail_view_get_shell_view (view);

    /* Can be NULL, if the shell window was closed meanwhile */
    if (!shell_view)
        return;

    shell_window = e_shell_view_get_shell_window (shell_view);

    shell = e_shell_window_get_shell (shell_window);

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

    /* FIXME This should be an EMailReader property. */
    global_view_setting = g_settings_get_boolean (
        settings, "global-view-setting");

    message_list = e_mail_reader_get_message_list (reader);

    message_list_freeze (MESSAGE_LIST (message_list));

    /* Chain up to interface's default set_folder() method. */
    default_interface = g_type_default_interface_peek (E_TYPE_MAIL_READER);
    default_interface->set_folder (reader, folder);

    if (folder == NULL)
        goto exit;

    /* Only refresh the folder if we're online. */
    if (e_shell_get_online (shell))
        e_mail_reader_refresh_folder (reader, folder);

    /* This is a one-time-only callback. */
    if (MESSAGE_LIST (message_list)->cursor_uid == NULL &&
        priv->message_list_built_id == 0)
        priv->message_list_built_id = g_signal_connect_swapped (
            message_list, "message-list-built",
            G_CALLBACK (mail_paned_view_message_list_built_cb),
            reader);

    /* Restore the folder's preview and threaded state. */

    folder_uri = e_mail_folder_uri_from_folder (folder);
    key_file = e_shell_view_get_state_key_file (shell_view);
    group_name = g_strdup_printf ("Folder %s", folder_uri);
    g_free (folder_uri);

    key = STATE_KEY_GROUP_BY_THREADS;
    value = g_key_file_get_boolean (key_file, global_view_setting ? STATE_GROUP_GLOBAL_FOLDER : group_name, key, &error);
    if (error != NULL) {
        g_clear_error (&error);

        value = !global_view_setting ||
            g_key_file_get_boolean (key_file, STATE_GROUP_GLOBAL_FOLDER, key, &error);
        if (error != NULL) {
            g_clear_error (&error);
            value = TRUE;
        }
    }

    e_mail_reader_set_group_by_threads (reader, value);

    key = STATE_KEY_PREVIEW_VISIBLE;
    value = g_key_file_get_boolean (key_file, global_view_setting ? STATE_GROUP_GLOBAL_FOLDER : group_name, key, &error);
    if (error != NULL) {
        g_clear_error (&error);

        value = !global_view_setting ||
            g_key_file_get_boolean (key_file, STATE_GROUP_GLOBAL_FOLDER, key, &error);
        if (error != NULL) {
            g_clear_error (&error);
            value = TRUE;
        }
    }

    /* XXX This is a little confusing and needs rethought.  The
     *     EShellWindow:safe-mode property blocks automatic message
     *     selection, but the "safe-list" setting blocks both the
     *     preview pane and automatic message selection. */
    if (g_settings_get_boolean (settings, "safe-list")) {
        g_settings_set_boolean (settings, "safe-list", FALSE);
        e_shell_window_set_safe_mode (shell_window, TRUE);
        value = FALSE;
    }

    e_mail_view_set_preview_visible (E_MAIL_VIEW (reader), value);

    g_free (group_name);

exit:
    message_list_thaw (MESSAGE_LIST (message_list));

    g_object_unref (settings);
}

static guint
mail_paned_view_reader_open_selected_mail (EMailReader *reader)
{
    EMailPanedView *paned_view;
    EMailPanedViewClass *class;

    paned_view = E_MAIL_PANED_VIEW (reader);

    class = E_MAIL_PANED_VIEW_GET_CLASS (paned_view);
    g_return_val_if_fail (class->open_selected_mail != NULL, 0);

    return class->open_selected_mail (paned_view);
}

static void
mail_paned_view_constructed (GObject *object)
{
    EMailPanedViewPrivate *priv;
    EShellBackend *shell_backend;
    EShellWindow *shell_window;
    EShellView *shell_view;
    GSettings *settings;
    EMailReader *reader;
    EMailBackend *backend;
    EMailSession *session;
    EMailView *view;
    GtkWidget *message_list;
    GtkWidget *container;
    GtkWidget *widget;

    priv = E_MAIL_PANED_VIEW_GET_PRIVATE (object);

    priv->display = g_object_new (
        E_TYPE_MAIL_DISPLAY,
        "headers-collapsable", TRUE, NULL);

    view = E_MAIL_VIEW (object);
    shell_view = e_mail_view_get_shell_view (view);
    shell_window = e_shell_view_get_shell_window (shell_view);
    shell_backend = e_shell_view_get_shell_backend (shell_view);

    backend = E_MAIL_BACKEND (shell_backend);
    session = e_mail_backend_get_session (backend);

    /* FIXME This should be an EMailPanedView property, so
     *       it can be configured from the settings module. */

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

    g_settings_bind (
        settings, "headers-collapsed",
        priv->display, "headers-collapsed",
        G_SETTINGS_BIND_DEFAULT);

    g_object_unref (settings);

    /* Build content widgets. */

    container = GTK_WIDGET (object);

    widget = e_paned_new (GTK_ORIENTATION_VERTICAL);
    gtk_container_add (GTK_CONTAINER (container), widget);
    priv->paned = g_object_ref (widget);
    gtk_widget_show (widget);

    g_object_bind_property (
        object, "orientation",
        widget, "orientation",
        G_BINDING_SYNC_CREATE);

    container = priv->paned;

    widget = gtk_scrolled_window_new (NULL, NULL);
    gtk_scrolled_window_set_policy (
        GTK_SCROLLED_WINDOW (widget),
        GTK_POLICY_NEVER, GTK_POLICY_ALWAYS);
    gtk_scrolled_window_set_shadow_type (
        GTK_SCROLLED_WINDOW (widget), GTK_SHADOW_IN);
    priv->scrolled_window = g_object_ref (widget);
    gtk_paned_pack1 (GTK_PANED (container), widget, TRUE, FALSE);
    gtk_widget_show (widget);

    container = widget;

    widget = message_list_new (session);
    gtk_container_add (GTK_CONTAINER (container), widget);
    priv->message_list = g_object_ref (widget);
    gtk_widget_show (widget);

    container = priv->paned;

    widget = e_preview_pane_new (E_WEB_VIEW (priv->display));
    gtk_paned_pack2 (GTK_PANED (container), widget, FALSE, FALSE);
    priv->preview_pane = g_object_ref (widget);
    gtk_widget_show (GTK_WIDGET (priv->display));
    gtk_widget_show (widget);

    g_object_bind_property (
        object, "preview-visible",
        widget, "visible",
        G_BINDING_SYNC_CREATE);

    /* Load the view instance. */

    e_mail_view_update_view_instance (E_MAIL_VIEW (object));

    /* Message list customizations. */

    e_mail_reader_init (E_MAIL_READER (object), FALSE, TRUE);

    reader = E_MAIL_READER (object);
    message_list = e_mail_reader_get_message_list (reader);

    g_signal_connect_swapped (
        message_list, "message-selected",
        G_CALLBACK (mail_paned_view_message_selected_cb),
        object);

    /* Restore pane positions from the last session once
     * the shell view is fully initialized and visible. */
    g_signal_connect (
        shell_window, "shell-view-created::mail",
        G_CALLBACK (mail_paned_view_restore_state_cb),
        object);

    /* Do this after creating the message list.  Our
     * set_preview_visible() method relies on it. */
    e_mail_view_set_preview_visible (view, TRUE);

    e_extensible_load_extensions (E_EXTENSIBLE (object));

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

static void
mail_paned_view_set_search_strings (EMailView *view,
                                    GSList *search_strings)
{
    EMailDisplay *display;
    EWebView *web_view;
    EMailReader *reader;

    reader = E_MAIL_READER (view);
    display = e_mail_reader_get_mail_display (reader);
    if (!display)
        return;

    web_view = E_WEB_VIEW (display);

    e_web_view_clear_highlights (web_view);

    while (search_strings != NULL) {
        e_web_view_add_highlight (web_view, search_strings->data);
        search_strings = g_slist_next (search_strings);
    }
}

static GalViewInstance *
mail_paned_view_get_view_instance (EMailView *view)
{
    EMailPanedView *paned_view;

    paned_view = E_MAIL_PANED_VIEW (view);

    return paned_view->priv->view_instance;
}

static gchar *
empv_create_view_id (CamelFolder *folder)
{
    GChecksum *checksum;
    gchar *res, *folder_uri;

    g_return_val_if_fail (folder != NULL, NULL);

    folder_uri = e_mail_folder_uri_from_folder (folder);
    g_return_val_if_fail (folder_uri != NULL, NULL);

    /* to be able to migrate previously saved views */
    e_filename_make_safe (folder_uri);

    /* use MD5 checksum of the folder URI, to not depend on its length */
    checksum = g_checksum_new (G_CHECKSUM_MD5);
    g_checksum_update (checksum, (const guchar *) folder_uri, -1);

    res = g_strdup (g_checksum_get_string (checksum));

    g_checksum_free (checksum);
    g_free (folder_uri);

    return res;
}

static void
mail_paned_view_update_view_instance (EMailView *view)
{
    EMailPanedViewPrivate *priv;
    EMailReader *reader;
    EShell *shell;
    EShellView *shell_view;
    EShellWindow *shell_window;
    EShellViewClass *shell_view_class;
    ESourceRegistry *registry;
    GalViewCollection *view_collection;
    GalViewInstance *view_instance;
    CamelFolder *folder;
    GtkOrientable *orientable;
    GtkOrientation orientation;
    GSettings *settings;
    gboolean outgoing_folder;
    gboolean show_vertical_view;
    gboolean global_view_setting;
    gchar *view_id;

    priv = E_MAIL_PANED_VIEW_GET_PRIVATE (view);

    shell_view = e_mail_view_get_shell_view (view);
    shell_view_class = E_SHELL_VIEW_GET_CLASS (shell_view);
    view_collection = shell_view_class->view_collection;

    shell_window = e_shell_view_get_shell_window (shell_view);
    shell = e_shell_window_get_shell (shell_window);
    registry = e_shell_get_registry (shell);

    reader = E_MAIL_READER (view);
    folder = e_mail_reader_ref_folder (reader);

    /* If no folder is selected, return silently. */
    if (folder == NULL)
        return;

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

    view_id = empv_create_view_id (folder);
    e_filename_make_safe (view_id);

    outgoing_folder =
        em_utils_folder_is_drafts (registry, folder) ||
        em_utils_folder_is_outbox (registry, folder) ||
        em_utils_folder_is_sent (registry, folder);

    settings = g_settings_new ("org.gnome.evolution.mail");
    global_view_setting = g_settings_get_boolean (
        settings, "global-view-setting");
    g_object_unref (settings);

    if (global_view_setting) {
        if (outgoing_folder) {
            view_instance = e_shell_view_new_view_instance (
                shell_view, "global_view_sent_setting");
        } else {
            view_instance = e_shell_view_new_view_instance (
                shell_view, "global_view_setting");
        }
    } else {
        view_instance = e_shell_view_new_view_instance (
            shell_view, view_id);
    }

    priv->view_instance = g_object_ref (view_instance);

    orientable = GTK_ORIENTABLE (view);
    orientation = gtk_orientable_get_orientation (orientable);
    show_vertical_view =
        !global_view_setting &&
        (orientation == GTK_ORIENTATION_HORIZONTAL);

    if (show_vertical_view) {
        const gchar *user_directory;
        gchar *filename;

        /* Force the view instance into vertical view. */

        g_free (view_instance->custom_filename);
        g_free (view_instance->current_view_filename);

        user_directory = gal_view_collection_get_user_directory (
            view_collection);

        filename = g_strdup_printf (
            "custom_wide_view-%s.xml", view_id);
        view_instance->custom_filename =
            g_build_filename (user_directory, filename, NULL);
        g_free (filename);

        filename = g_strdup_printf (
            "current_wide_view-%s.xml", view_id);
        view_instance->current_view_filename =
            g_build_filename (user_directory, filename, NULL);
        g_free (filename);
    }

    g_free (view_id);

    if (outgoing_folder) {
        if (show_vertical_view)
            gal_view_instance_set_default_view (
                view_instance, "Wide_View_Sent");
        else
            gal_view_instance_set_default_view (
                view_instance, "As_Sent_Folder");
    } else if (show_vertical_view) {
        gal_view_instance_set_default_view (
            view_instance, "Wide_View_Normal");
    }

    gal_view_instance_load (view_instance);

    if (!gal_view_instance_exists (view_instance)) {
        gchar *state_filename;

        state_filename = mail_config_folder_to_cachename (
            folder, "et-header-");

        if (g_file_test (state_filename, G_FILE_TEST_IS_REGULAR)) {
            GalView *view;

            view = gal_view_etable_new ("");

            /* XXX This only stashes the filename in the view.
             *     The state file is not actually loaded until
             *     the MessageList is attached to the view. */
            gal_view_load (view, state_filename);

            gal_view_instance_set_custom_view (
                view_instance, view);

            g_object_unref (view);
        }

        g_free (state_filename);
    }

    g_signal_connect (
        view_instance, "display-view",
        G_CALLBACK (mail_paned_display_view_cb), view);

    mail_paned_display_view_cb (
        view_instance,
        gal_view_instance_get_current_view (view_instance),
        view);

    g_object_unref (view_instance);

    g_clear_object (&folder);
}

static void
mail_paned_view_set_preview_visible (EMailView *view,
                                     gboolean preview_visible)
{
    EMailViewClass *parent_class;

    /* If we're showing the preview, tell EMailReader to reload the
     * selected message.  This should force it to download the full
     * message if necessary, so we don't get an empty preview. */
    if (preview_visible) {
        EMailReader *reader;
        GtkWidget *message_list;
        const gchar *cursor_uid;

        reader = E_MAIL_READER (view);
        message_list = e_mail_reader_get_message_list (reader);
        cursor_uid = MESSAGE_LIST (message_list)->cursor_uid;

        if (cursor_uid != NULL)
            e_mail_reader_set_message (reader, cursor_uid);
    }

    mail_paned_view_save_boolean (
        E_MAIL_VIEW (view),
        STATE_KEY_PREVIEW_VISIBLE, preview_visible);

    /* Chain up to parent's set_preview_visible() method. */
    parent_class = E_MAIL_VIEW_CLASS (e_mail_paned_view_parent_class);
    parent_class->set_preview_visible (view, preview_visible);
}

static guint
mail_paned_view_open_selected_mail (EMailPanedView *view)
{
    return e_mail_reader_open_selected (E_MAIL_READER (view));
}

static void
e_mail_paned_view_class_init (EMailPanedViewClass *class)
{
    GObjectClass *object_class;
    EMailViewClass *mail_view_class;

    g_type_class_add_private (class, sizeof (EMailPanedViewPrivate));

    object_class = G_OBJECT_CLASS (class);
    object_class->dispose = mail_paned_view_dispose;
    object_class->constructed = mail_paned_view_constructed;
    object_class->set_property = mail_paned_view_set_property;
    object_class->get_property = mail_paned_view_get_property;

    mail_view_class = E_MAIL_VIEW_CLASS (class);
    mail_view_class->set_search_strings = mail_paned_view_set_search_strings;
    mail_view_class->get_view_instance = mail_paned_view_get_view_instance;
    mail_view_class->update_view_instance = mail_paned_view_update_view_instance;

    mail_view_class->set_preview_visible = mail_paned_view_set_preview_visible;

    class->open_selected_mail = mail_paned_view_open_selected_mail;

    /* Inherited from EMailReader */
    g_object_class_override_property (
        object_class,
        PROP_FORWARD_STYLE,
        "forward-style");

    /* Inherited from EMailReader */
    g_object_class_override_property (
        object_class,
        PROP_GROUP_BY_THREADS,
        "group-by-threads");

    /* Inherited from EMailReader */
    g_object_class_override_property (
        object_class,
        PROP_REPLY_STYLE,
        "reply-style");
}

static void
e_mail_paned_view_reader_init (EMailReaderInterface *iface)
{
    iface->get_action_group = mail_paned_view_get_action_group;
    iface->get_alert_sink = mail_paned_view_get_alert_sink;
    iface->get_backend = mail_paned_view_get_backend;
    iface->get_mail_display = mail_paned_view_get_mail_display;
    iface->get_hide_deleted = mail_paned_view_get_hide_deleted;
    iface->get_message_list = mail_paned_view_get_message_list;
    iface->get_popup_menu = mail_paned_view_get_popup_menu;
    iface->get_preview_pane = mail_paned_view_get_preview_pane;
    iface->get_window = mail_paned_view_get_window;
    iface->set_folder = mail_paned_view_set_folder;
    iface->open_selected_mail = mail_paned_view_reader_open_selected_mail;
}

static void
e_mail_paned_view_init (EMailPanedView *view)
{
    view->priv = E_MAIL_PANED_VIEW_GET_PRIVATE (view);

    e_signal_connect_notify (
        view, "notify::group-by-threads",
        G_CALLBACK (mail_paned_view_notify_group_by_threads_cb),
        NULL);
}

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

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

void
e_mail_paned_view_hide_message_list_pane (EMailPanedView *view,
                                          gboolean visible)
{
    g_return_if_fail (E_IS_MAIL_PANED_VIEW (view));

    if (visible)
        gtk_widget_show (view->priv->scrolled_window);
    else
        gtk_widget_hide (view->priv->scrolled_window);
}

GtkWidget *
e_mail_paned_view_get_preview (EMailPanedView *view)
{
    g_return_val_if_fail (E_IS_MAIL_PANED_VIEW (view), NULL);

    return GTK_WIDGET (mail_paned_view_get_mail_display (E_MAIL_READER (view)));
}