implement remote loader logic in Python

The code becomes much simpler, cleaner and fixes as weird crash
with Qt 4.8

modules/gui/pymod/scene/immutable_loader_info_handler.py

-#------------------------------------------------------------------------------
-# This file is part of the OpenStructure project <www.openstructure.org>
-#
-# Copyright (C) 2008-2011 by the OpenStructure authors
-#
-# This library 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; either version 3.0 of the License, or (at your option)
-# any later version.
-# This library 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 Lesser General Public License for more
-# details.
-#
-# You should have received a copy of the GNU Lesser General Public License
-# along with this library; if not, write to the Free Software Foundation, Inc.,
-# 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
-#------------------------------------------------------------------------------
-# -*- coding: utf-8 -*-
-
-from ost import gui
-from ost import gfx
-from ost import info
-from PyQt4 import QtCore, QtGui
-
-from file_loader import GenericLoader
-
-class ImmutableLoaderInfoHandler:
-  LOADERS_GROUP_NAME = "GenericLoaders"
-  LOADER_GROUP_NAME = "GenericLoader"
-  NAME_ATTRIBUTE_NAME = "Name"
-  
-  def __init__(self, file_name):
-    self.file_name_ = file_name
-    self.handle_ = info.LoadOrCreateInfo(self.file_name_)
-    
-    self.root_ = self.handle_.Root()
-    
-    self.loaders_ = self.root_.RetrieveGroup(ImmutableLoaderInfoHandler.LOADERS_GROUP_NAME)
-
-    
-  def GetLoader(self, name):
-    group_list = self.loaders_.GetGroups(ImmutableLoaderInfoHandler.LOADER_GROUP_NAME)
-    for group in group_list:
-      if group.HasAttribute(ImmutableLoaderInfoHandler.NAME_ATTRIBUTE_NAME):
-        groupname = group.GetAttribute(ImmutableLoaderInfoHandler.NAME_ATTRIBUTE_NAME)
-        if name == groupname:
-          loader = GenericLoader.FromInfo(group)
-          return loader
-    return None
-  
-  def GetLoaders(self):
-    group_list = self.loaders_.GetGroups(ImmutableLoaderInfoHandler.LOADER_GROUP_NAME)
-    loaders = dict()
-    
-    for group in group_list:
-      if group.HasAttribute(ImmutableLoaderInfoHandler.NAME_ATTRIBUTE_NAME):
-        loader = GenericLoader.FromInfo(group)
-        loaders[group.GetAttribute(self.NAME_ATTRIBUTE_NAME)] = loader
-    return loaders