path: root/modules/composer-autosave/e-composer-autosave.c

/*
 * e-composer-autosave.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/>.
 *
 */

#include "e-composer-autosave.h"

#include <composer/e-msg-composer.h>

#include "e-autosave-utils.h"

#define E_COMPOSER_AUTOSAVE_GET_PRIVATE(obj) \
    (G_TYPE_INSTANCE_GET_PRIVATE \
    ((obj), E_TYPE_COMPOSER_AUTOSAVE, EComposerAutosavePrivate))

#define AUTOSAVE_INTERVAL   60 /* seconds */

struct _EComposerAutosavePrivate {
    GCancellable *cancellable;
    guint timeout_id;

    /* Composer contents have changed since
     * the last auto-save or explicit save. */
    gboolean changed;

    /* Prevent error dialogs from piling up. */
    gboolean error_shown;
};

G_DEFINE_DYNAMIC_TYPE (
    EComposerAutosave,
    e_composer_autosave,
    E_TYPE_EXTENSION)

static void
composer_autosave_finished_cb (GObject *source_object,
                               GAsyncResult *result,
                               gpointer user_data)
{
    EMsgComposer *composer;
    EComposerAutosave *autosave;
    GFile *snapshot_file;
    GError *local_error = NULL;

    composer = E_MSG_COMPOSER (source_object);
    autosave = E_COMPOSER_AUTOSAVE (user_data);

    snapshot_file = e_composer_get_snapshot_file (composer);
    e_composer_save_snapshot_finish (composer, result, &local_error);

    /* Return silently if we were cancelled. */
    if (g_error_matches (local_error, G_IO_ERROR, G_IO_ERROR_CANCELLED))
        g_error_free (local_error);

    else if (local_error != NULL) {
        gchar *basename;

        if (G_IS_FILE (snapshot_file))
            basename = g_file_get_basename (snapshot_file);
        else
            basename = g_strdup (" ");

        /* Only show one error dialog at a time. */
        if (!autosave->priv->error_shown) {
            autosave->priv->error_shown = TRUE;
            e_alert_run_dialog_for_args (
                GTK_WINDOW (composer),
                "mail-composer:no-autosave",
                basename, local_error->message, NULL);
            autosave->priv->error_shown = FALSE;
        } else
            g_warning ("%s: %s", basename, local_error->message);

        g_free (basename);
        g_error_free (local_error);
    }

    g_object_unref (autosave);
}

static gboolean
composer_autosave_timeout_cb (gpointer user_data)
{
    EComposerAutosave *autosave;
    EExtensible *extensible;

    autosave = E_COMPOSER_AUTOSAVE (user_data);
    extensible = e_extension_get_extensible (E_EXTENSION (autosave));

    /* User may have reverted or explicitly saved
     * the changes since the timeout was scheduled. */
    if (autosave->priv->changed) {

        /* Cancel the previous snapshot if it's still in
         * progress and start a new snapshot operation. */
        g_cancellable_cancel (autosave->priv->cancellable);
        g_object_unref (autosave->priv->cancellable);
        autosave->priv->cancellable = g_cancellable_new ();

        e_composer_save_snapshot (
            E_MSG_COMPOSER (extensible),
            autosave->priv->cancellable,
            composer_autosave_finished_cb,
            g_object_ref (autosave));
    }

    autosave->priv->timeout_id = 0;
    autosave->priv->changed = FALSE;

    return FALSE;
}

static void
composer_autosave_changed_cb (EComposerAutosave *autosave)
{
    GtkhtmlEditor *editor;
    EExtensible *extensible;

    extensible = e_extension_get_extensible (E_EXTENSION (autosave));

    editor = GTKHTML_EDITOR (extensible);
    autosave->priv->changed = gtkhtml_editor_get_changed (editor);

    if (autosave->priv->changed && autosave->priv->timeout_id == 0) {
        autosave->priv->timeout_id = e_named_timeout_add_seconds (
            AUTOSAVE_INTERVAL,
            composer_autosave_timeout_cb, autosave);
    }
}

static void
composer_autosave_dispose (GObject *object)
{
    EComposerAutosavePrivate *priv;

    priv = E_COMPOSER_AUTOSAVE_GET_PRIVATE (object);

    /* Cancel any snapshots in progress. */
    g_cancellable_cancel (priv->cancellable);

    if (priv->timeout_id > 0) {
        g_source_remove (priv->timeout_id);
        priv->timeout_id = 0;
    }

    g_clear_object (&priv->cancellable);

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

static void
composer_autosave_constructed (GObject *object)
{
    EExtensible *extensible;

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

    extensible = e_extension_get_extensible (E_EXTENSION (object));

    g_signal_connect_swapped (
        extensible, "notify::changed",
        G_CALLBACK (composer_autosave_changed_cb), object);
}

static void
e_composer_autosave_class_init (EComposerAutosaveClass *class)
{
    GObjectClass *object_class;
    EExtensionClass *extension_class;

    g_type_class_add_private (class, sizeof (EComposerAutosavePrivate));

    object_class = G_OBJECT_CLASS (class);
    object_class->dispose = composer_autosave_dispose;
    object_class->constructed = composer_autosave_constructed;

    extension_class = E_EXTENSION_CLASS (class);
    extension_class->extensible_type = E_TYPE_MSG_COMPOSER;
}

static void
e_composer_autosave_class_finalize (EComposerAutosaveClass *class)
{
}

static void
e_composer_autosave_init (EComposerAutosave *autosave)
{
    autosave->priv = E_COMPOSER_AUTOSAVE_GET_PRIVATE (autosave);
    autosave->priv->cancellable = g_cancellable_new ();
}

void
e_composer_autosave_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_composer_autosave_register_type (type_module);
}