Gtk.TextBuffer undo

// 对于TextBuffer的Modify处理这里是关键，使之能对文本的改变做出响应
static gint undo_connect_signal(GtkTextBuffer *buffer)
{
    g_signal_connect(G_OBJECT(buffer), "delete-range",
        G_CALLBACK(cb_delete_range), buffer);
    g_signal_connect_after(G_OBJECT(buffer), "insert-text",
        G_CALLBACK(cb_insert_text), buffer);
    return
    g_signal_connect(G_OBJECT(buffer), "modified-changed",
        G_CALLBACK(cb_modified_changed), NULL);
}

// 还有：
static void undo_check_step_modif(GtkTextBuffer *buffer)
{
    if (g_list_length(undo_list) == step_modif) {
        g_signal_handlers_block_by_func(G_OBJECT(buffer), G_CALLBACK(cb_modified_changed), NULL);
        gtk_text_buffer_set_modified(buffer, FALSE);
        g_signal_handlers_unblock_by_func(G_OBJECT(buffer), G_CALLBACK(cb_modified_changed), NULL);
        set_main_window_title_with_asterisk(FALSE);
    }
}

continue...