straw/MVP.py

   1 """ MVP.py
   2
   3 Module that provides a Model-View-Presenter framework for use with Straw
   4 """
   5 __copyright__ = "Copyright (c) 2002-2005 Free Software Foundation, Inc."
   6 __license__ = """
   7 Straw is free software; you can redistribute it and/or modify it under the
   8 terms of the GNU General Public License as published by the Free Software
   9 Foundation; either version 2 of the License, or (at your option) any later
  10 version.
  11
  12 Straw is distributed in the hope that it will be useful, but WITHOUT ANY
  13 WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
  14 A PARTICULAR PURPOSE. See the GNU General Public License for more details.
  15
  16 You should have received a copy of the GNU General Public License along with
  17 this program; if not, write to the Free Software Foundation, Inc., 59 Temple
  18 Place - Suite 330, Boston, MA 02111-1307, USA. """
  19
  20
  21 import gettext
  22 import pygtk
  23 pygtk.require('2.0')
  24 from gtk import glade
  25
  26 __doc__ = "A MVP framework. Contains base classes for views and presenters."
  27
  28 class View(object):
  29     """Base class for widget-based view objects."""
  30     def __init__(self, widget, model = None, presenter = None):
  31         self._widget = widget
  32         self._model = model
  33         self._presenter = presenter
  34
  35         if model is not None:
  36             self._model_set()
  37         if presenter is not None:
  38             self._presenter_set()
  39
  40         self._initialize()
  41         self._connect_signals(widget)
  42
  43     def _connect_signals(self, widget):
  44         raise NotImplemented
  45
  46     def _initialize(self):
  47         """Called from the constructor after the instance variables have
  48         been set and the corresponding initialization functions have been
  49         called, but before connecting gtk signals."""
  50         pass
  51
  52     def _model_set(self):
  53         """Called when the model is set."""
  54         pass
  55
  56     def _presenter_set(self):
  57         """Called when the presenter is set."""
  58         pass
  59
  60     def get_model(self):
  61         return self._model
  62
  63     def set_model(self, model):
  64         self._model = model
  65         if model:
  66             # don't call model_set if model is None. This prevents objects
  67             # relying on model_set to fail (or gtk throwing a warning when
  68             # model is not a gtk.TreeModel).
  69             self._model_set()
  70     model = property(get_model, set_model, None, doc="The model object.")
  71
  72     def get_presenter(self):
  73         return self._presenter
  74
  75     def set_presenter(self, presenter):
  76         self._presenter = presenter
  77         self._presenter_set()
  78     presenter = property(get_presenter, set_presenter, None,
  79                          "The presenter object.")
  80
  81 class WidgetView(View):
  82     def __init__(self, widget, model=None, presenter=None):
  83         View.__init__(self, widget, model, presenter)
  84
  85     def _connect_signals(self, widget):
  86         xml = glade.get_widget_tree(widget)
  87         nameFuncMap = {}
  88         for key in dir(self.__class__):
  89             if key[:4] == '_on_':
  90                 nameFuncMap[key[1:]] = getattr(self, key)
  91         xml.signal_autoconnect(nameFuncMap)
  92
  93 class GladeView(View):
  94     def __init__(self, widget, model=None, presenter=None):
  95         View.__init__(self, widget, model, presenter)
  96
  97     def _connect_signals(self, widget):
  98         nameFuncMap = {}
  99         for key in dir(self.__class__):
 100             if key[:4] == '_on_':
 101                 nameFuncMap[key[1:]] = getattr(self, key)
 102         widget.signal_autoconnect(nameFuncMap)
 103
 104 class BasicPresenter(object):
 105     """Base class for basic (non-composite) presenters."""
 106     def __init__(self, model = None, view = None):
 107
 108         self._model = model
 109         self._view = view
 110
 111         if model is not None:
 112             self._model_set()
 113         if view is not None:
 114             view.model = model
 115             view.presenter = self
 116             self._view_set()
 117
 118         self._initialize()
 119
 120     def _initialize(self):
 121         pass
 122
 123     def _model_set(self):
 124         pass
 125
 126     def _view_set(self):
 127         pass
 128
 129     def get_view(self):
 130         return self._view
 131
 132     def set_view(self, view):
 133         self._view = view
 134         view.presenter = self
 135         view.model = self._model
 136         self._view_set()
 137
 138     view = property(get_view, set_view, None,
 139                     """The view component. Setting this also sets the view
 140                     object's presenter and model attributes.""")
 141
 142     def get_model(self):
 143         return self._model
 144
 145     def set_model(self, model):
 146         self._model = model
 147         if self._view is not None:
 148             self._view.model = model
 149         self._model_set()
 150
 151     model = property(get_model, set_model, None,
 152                      """The model component. Setting this also sets the view
 153                      object's (if defined) model attribute.""")
 154
 155