'On click, check if it was a right click. If it was,
create a menu with the delete option. On click on that option,
delete the workspace that occupied the position where the user
clicked. Returns True if it was a right click'

def on_right_click(self, view, event):

    if (event.button != 3):
        return False
    try:
        path = view.get_path_at_pos(int(event.x), int(event.y))[0]
    except TypeError:
        return False
    menu = Gtk.Menu()
    delete_item = Gtk.MenuItem('Delete')
    menu.append(delete_item)
    tree_iter = self.workspace_model.get_iter(path)
    ws_name = self.workspace_model[tree_iter][0]
    delete_item.connect('activate', self.remove_ws, ws_name)
    delete_item.show()
    menu.popup(None, None, None, None, event.button, event.time)
    return True
