+static void
+modest_msg_view_window_on_row_changed (GtkTreeModel *header_model,
+ GtkTreePath *arg1,
+ GtkTreeIter *arg2,
+ ModestMsgViewWindow *window)
+{
+ check_dimming_rules_after_change (window);
+}
+
+static void
+modest_msg_view_window_on_row_deleted(GtkTreeModel *header_model,
+ GtkTreePath *arg1,
+ ModestMsgViewWindow *window)
+{
+ check_dimming_rules_after_change (window);
+}
+
+static gboolean
+check_dimming_rules_after_change_in_idle (gpointer data)
+{
+ /* The window could have dissapeared */
+ if (MODEST_IS_WINDOW (data)) {
+ ModestWindow *win = MODEST_WINDOW (data);
+ gdk_threads_enter ();
+ modest_ui_actions_check_menu_dimming_rules (win);
+ modest_ui_actions_check_toolbar_dimming_rules (win);
+ gdk_threads_leave ();
+ }
+
+ return FALSE;
+}
+
+static void
+check_dimming_rules_after_change (ModestMsgViewWindow *window)
+{
+ static guint dimming_delayer = 0;
+
+ if (dimming_delayer > 0)
+ g_source_remove (dimming_delayer);
+
+ /* We're expecting a lot of changes at the same time so don't
+ need to check dimming rules for every change that
+ happens */
+ dimming_delayer = g_timeout_add (100, check_dimming_rules_after_change_in_idle, window);
+}
+
+
+/* On insertions we check if the folder still has the message we are
+ * showing or do not. If do not, we do nothing. Which means we are still
+ * not attached to any header folder and thus next/prev buttons are
+ * still dimmed. Once the message that is shown by msg-view is found, the
+ * new model of header-view will be attached and the references will be set.
+ * On each further insertions dimming rules will be checked. However
+ * this requires extra CPU time at least works.
+ * (An message might be deleted from TnyFolder and thus will not be
+ * inserted into the model again for example if it is removed by the
+ * imap server and the header view is refreshed.)
+ */
+static void
+modest_msg_view_window_on_row_inserted (GtkTreeModel *model,
+ GtkTreePath *tree_path,
+ GtkTreeIter *tree_iter,
+ ModestMsgViewWindow *window)
+{
+ ModestMsgViewWindowPrivate *priv = NULL;
+ TnyHeader *header = NULL;
+
+ g_return_if_fail (MODEST_IS_MSG_VIEW_WINDOW (window));
+ priv = MODEST_MSG_VIEW_WINDOW_GET_PRIVATE (window);
+
+ g_assert (model == priv->header_model);
+
+ /* Check if the newly inserted message is the same we are actually
+ * showing. IF not, we should remain detached from the header model
+ * and thus prev and next toolbar buttons should remain dimmed. */
+ gtk_tree_model_get (model, tree_iter,
+ TNY_GTK_HEADER_LIST_MODEL_INSTANCE_COLUMN,
+ &header, -1);
+
+ if (TNY_IS_HEADER (header)) {
+ gchar *uid = NULL;
+
+ uid = modest_tny_folder_get_header_unique_id (header);
+ if (!g_str_equal(priv->msg_uid, uid)) {
+ check_dimming_rules_after_change (window);
+ g_free(uid);
+ g_object_unref (G_OBJECT(header));
+ return;
+ }
+ g_free(uid);
+ g_object_unref(G_OBJECT(header));
+ }
+
+ if (priv->row_reference) {
+ gtk_tree_row_reference_free (priv->row_reference);
+ }
+
+ /* Setup row_reference for the actual msg. */
+ priv->row_reference = gtk_tree_row_reference_new (priv->header_model, tree_path);
+ if (priv->row_reference == NULL) {
+ g_warning("No reference for msg header item.");
+ return;
+ }
+
+ /* Now set up next_row_reference. */
+ if (priv->next_row_reference) {
+ gtk_tree_row_reference_free (priv->next_row_reference);
+ }
+
+ priv->next_row_reference = gtk_tree_row_reference_copy (priv->row_reference);
+ select_next_valid_row (priv->header_model,
+ &(priv->next_row_reference), FALSE, priv->is_outbox);
+
+ /* Connect the remaining callbacks to become able to detect
+ * changes in header-view. */
+ priv->row_changed_handler =
+ g_signal_connect (priv->header_model, "row-changed",
+ G_CALLBACK (modest_msg_view_window_on_row_changed),
+ window);
+ priv->row_deleted_handler =
+ g_signal_connect (priv->header_model, "row-deleted",
+ G_CALLBACK (modest_msg_view_window_on_row_deleted),
+ window);
+ priv->rows_reordered_handler =
+ g_signal_connect (priv->header_model, "rows-reordered",
+ G_CALLBACK (modest_msg_view_window_on_row_reordered),
+ window);
+
+ check_dimming_rules_after_change (window);
+}
+
+static void
+modest_msg_view_window_on_row_reordered (GtkTreeModel *header_model,
+ GtkTreePath *arg1,
+ GtkTreeIter *arg2,
+ gpointer arg3,
+ ModestMsgViewWindow *window)
+{
+ ModestMsgViewWindowPrivate *priv = NULL;
+ gboolean already_changed = FALSE;
+
+ priv = MODEST_MSG_VIEW_WINDOW_GET_PRIVATE(window);
+
+ /* If the current row was reordered select the proper next
+ valid row. The same if the next row reference changes */
+ if (priv->row_reference &&
+ gtk_tree_row_reference_valid (priv->row_reference)) {
+ GtkTreePath *path;
+ path = gtk_tree_row_reference_get_path (priv->row_reference);
+ if (gtk_tree_path_compare (path, arg1) == 0) {
+ if (priv->next_row_reference) {
+ gtk_tree_row_reference_free (priv->next_row_reference);
+ }
+ priv->next_row_reference = gtk_tree_row_reference_copy (priv->row_reference);
+ select_next_valid_row (header_model, &(priv->next_row_reference), FALSE, priv->is_outbox);
+ already_changed = TRUE;
+ }
+ gtk_tree_path_free (path);
+ }
+ if (!already_changed &&
+ priv->next_row_reference &&
+ gtk_tree_row_reference_valid (priv->next_row_reference)) {
+ GtkTreePath *path;
+ path = gtk_tree_row_reference_get_path (priv->next_row_reference);
+ if (gtk_tree_path_compare (path, arg1) == 0) {
+ if (priv->next_row_reference) {
+ gtk_tree_row_reference_free (priv->next_row_reference);
+ }
+ priv->next_row_reference = gtk_tree_row_reference_copy (priv->row_reference);
+ select_next_valid_row (header_model, &(priv->next_row_reference), FALSE, priv->is_outbox);
+ }
+ gtk_tree_path_free (path);
+ }
+ check_dimming_rules_after_change (window);
+}
+
+/* The modest_msg_view_window_update_model_replaced implements update
+ * function for ModestHeaderViewObserver. Checks whether the TnyFolder
+ * actually belongs to the header-view is the same as the TnyFolder of
+ * the message of msg-view or not. If they are different, there is
+ * nothing to do. If they are the same, then the model has replaced and
+ * the reference in msg-view shall be replaced from the old model to
+ * the new model. In this case the view will be detached from it's
+ * header folder. From this point the next/prev buttons are dimmed.
+ */
+static void
+modest_msg_view_window_update_model_replaced (ModestHeaderViewObserver *observer,
+ GtkTreeModel *model,
+ const gchar *tny_folder_id)
+{
+ ModestMsgViewWindowPrivate *priv = NULL;
+ ModestMsgViewWindow *window = NULL;
+
+ g_assert(MODEST_IS_HEADER_VIEW_OBSERVER(observer));
+ g_assert(MODEST_IS_MSG_VIEW_WINDOW(observer));
+
+ window = MODEST_MSG_VIEW_WINDOW(observer);
+ priv = MODEST_MSG_VIEW_WINDOW_GET_PRIVATE(window);
+
+ /* If there is an other folder in the header-view then we do
+ * not care about it's model (msg list). Else if the
+ * header-view shows the folder the msg shown by us is in, we
+ * shall replace our model reference and make some check. */
+ if(model == NULL || tny_folder_id == NULL ||
+ (priv->header_folder_id && !g_str_equal(tny_folder_id, priv->header_folder_id)))
+ return;
+
+ /* Model is changed(replaced), so we should forget the old
+ * one. Because there might be other references and there
+ * might be some change on the model even if we unreferenced
+ * it, we need to disconnect our signals here. */
+ if (priv->header_model) {
+ if (g_signal_handler_is_connected(G_OBJECT (priv->header_model),
+ priv->row_changed_handler))
+ g_signal_handler_disconnect(G_OBJECT (priv->header_model),
+ priv->row_changed_handler);
+ if (g_signal_handler_is_connected(G_OBJECT (priv->header_model),
+ priv->row_deleted_handler))
+ g_signal_handler_disconnect(G_OBJECT (priv->header_model),
+ priv->row_deleted_handler);
+ if (g_signal_handler_is_connected(G_OBJECT (priv->header_model),
+ priv->row_inserted_handler))
+ g_signal_handler_disconnect(G_OBJECT (priv->header_model),
+ priv->row_inserted_handler);
+ if (g_signal_handler_is_connected(G_OBJECT (priv->header_model),
+ priv->rows_reordered_handler))
+ g_signal_handler_disconnect(G_OBJECT (priv->header_model),
+ priv->rows_reordered_handler);
+
+ /* Frees */
+ if (priv->row_reference)
+ gtk_tree_row_reference_free (priv->row_reference);
+ if (priv->next_row_reference)
+ gtk_tree_row_reference_free (priv->next_row_reference);
+ g_object_unref(priv->header_model);
+
+ /* Initialize */
+ priv->row_changed_handler = 0;
+ priv->row_deleted_handler = 0;
+ priv->row_inserted_handler = 0;
+ priv->rows_reordered_handler = 0;
+ priv->next_row_reference = NULL;
+ priv->row_reference = NULL;
+ priv->header_model = NULL;
+ }
+
+ priv->header_model = g_object_ref (model);
+
+ /* Also we must connect to the new model for row insertions.
+ * Only for insertions now. We will need other ones only after
+ * the msg is show by msg-view is added to the new model. */
+ priv->row_inserted_handler =
+ g_signal_connect (priv->header_model, "row-inserted",
+ G_CALLBACK(modest_msg_view_window_on_row_inserted),
+ window);
+
+ modest_ui_actions_check_menu_dimming_rules(MODEST_WINDOW(window));
+ modest_ui_actions_check_toolbar_dimming_rules(MODEST_WINDOW(window));
+}