title: How to make GtkListStore store object attribute in a row?
body: <p>I'w trying to keep at ListStore non-text objects using snippet I found. These are the objects:</p>
  
  <pre><code>class Series(gobject.GObject, object):
   def __init__(self, title):
    super(Series, self).__init__()
    self.title = title
  
  gobject.type_register(Series)
  
  class SeriesListStore(gtk.ListStore):
   def __init__(self):
    super(SeriesListStore, self).__init__(Series)
    self._col_types = [Series]
  
   def get_n_columns(self):
    return len(self._col_types)
  
   def get_column_type(self, index):
    return self._col_types[index]
  
   def get_value(self, iter, column):
    obj = gtk.ListStore.get_value(self, iter, 0)
    return obj
  </code></pre>
  
  <p>And now I'm trying to make TreeView display it:</p>
  
  <pre><code>    ...
      liststore = SeriesListStore()
   liststore.clear()
  
   for title in full_conf['featuring']:
    series = Series(title)
    liststore.append([series])
  
   def get_series_title(column, cell, model, iter):
    cell.set_property('text', liststore.get_value(iter, column).title)
    return
  
   selected = builder.get_object("trvMain")
   selected.set_model(liststore)
  
   col = gtk.TreeViewColumn(_("Series title"))
   cell = gtk.CellRendererText()
   col.set_cell_data_func(cell, get_series_title)
   col.pack_start(cell)
   col.add_attribute(cell, "text", 0)
  
   selected.append_column(col)
      ...
  </code></pre>
  
  <p>But it fails with errors:</p>
  
  <blockquote>
    <p>GtkWarning:
    gtk_tree_view_column_cell_layout_set_cell_data_func:
    assertion <code>info != NULL' failed<br>
    col.set_cell_data_func(cell,
    get_series_title)
    Warning: unable to set property</code>text'
    of type <code>gchararray' from value of
    type</code>data+TrayIcon+Series'<br>
    window.show_all()
    Warning: unable to set property <code>text'
    of type</code>gchararray' from value of
    type `data+TrayIcon+Series'<br>
    gtk.main()gtk.main()</p>
  </blockquote>
  
  <p>What should I do to make it work?</p>