Source Code for Module flumotion.common.pygobject

  1  # -*- Mode: Python; test-case-name: flumotion.test.test_common_pygobject -*- 
  2  # vi:si:et:sw=4:sts=4:ts=4 
  3  # 
  4  # Flumotion - a streaming media server 
  5  # Copyright (C) 2004,2005,2006,2007 Fluendo, S.L. (www.fluendo.com). 
  6  # All rights reserved. 
  7   
  8  # This file may be distributed and/or modified under the terms of 
  9  # the GNU General Public License version 2 as published by 
 10  # the Free Software Foundation. 
 11  # This file is distributed without any warranty; without even the implied 
 12  # warranty of merchantability or fitness for a particular purpose. 
 13  # See "LICENSE.GPL" in the source distribution for more information. 
 14   
 15  # Licensees having purchased or holding a valid Flumotion Advanced 
 16  # Streaming Server license may use this file in accordance with the 
 17  # Flumotion Advanced Streaming Server Commercial License Agreement. 
 18  # See "LICENSE.Flumotion" in the source distribution for more information. 
 19   
 20  # Headers in this file shall remain intact. 
 21   
 22  """pygobject helper functions 
 23  """ 
 24   
 25  # moving this down causes havoc when running this file directly for some reason 
 26  from flumotion.common import errors 
 27   
 28  import sys 
 29   
 30  import gobject 
 31   
 32  __version__ = "$Rev: 7054 $" 
 33   
 34   
 35 -def gobject_set_property(object, property, value): 
 36      """ 
 37      Set the given property to the given value on the given object. 
 38   
 39      @type object:   L{gobject.GObject} 
 40      @type property: string 
 41      @param value:   value to set property to 
 42      """ 
 43      for pspec in gobject.list_properties(object): 
 44          if pspec.name == property: 
 45              break 
 46      else: 
 47          raise errors.PropertyError( 
 48              "Property '%s' in element '%s' does not exist" % ( 
 49                  property, object.get_property('name'))) 
 50   
 51      if pspec.value_type in (gobject.TYPE_INT, gobject.TYPE_UINT, 
 52                              gobject.TYPE_INT64, gobject.TYPE_UINT64): 
 53          try: 
 54              value = int(value) 
 55          except ValueError: 
 56              msg = "Invalid value given for property '%s' in element '%s'" % ( 
 57                  property, object.get_property('name')) 
 58              raise errors.PropertyError(msg) 
 59   
 60      elif pspec.value_type == gobject.TYPE_BOOLEAN: 
 61          if value == 'False': 
 62              value = False 
 63          elif value == 'True': 
 64              value = True 
 65          else: 
 66              value = bool(value) 
 67      elif pspec.value_type in (gobject.TYPE_DOUBLE, gobject.TYPE_FLOAT): 
 68          value = float(value) 
 69      elif pspec.value_type == gobject.TYPE_STRING: 
 70          value = str(value) 
 71      # FIXME: this is superevil ! we really need to find a better way 
 72      # of checking if this property is a param enum 
 73      # also, we only allow int for now 
 74      elif repr(pspec.__gtype__).startswith("<GType GParamEnum"): 
 75          value = int(value) 
 76      else: 
 77          raise errors.PropertyError('Unknown property type: %s' % 
 78              pspec.value_type) 
 79   
 80      object.set_property(property, value) 
 81   
 82 -def gsignal(name, *args): 
 83      """ 
 84      Add a GObject signal to the current object. 
 85      To be used from class definition scope. 
 86   
 87      @type name: string 
 88      @type args: mixed 
 89      """ 
 90      frame = sys._getframe(1) 
 91      _locals = frame.f_locals 
 92   
 93      if not '__gsignals__' in _locals: 
 94          _dict = _locals['__gsignals__'] = {} 
 95      else: 
 96          _dict = _locals['__gsignals__'] 
 97   
 98      _dict[name] = (gobject.SIGNAL_RUN_FIRST, None, args) 
 99   
100  PARAM_CONSTRUCT = 1<<9 
101   
102 -def gproperty(type_, name, desc, *args, **kwargs): 
103      """ 
104      Add a GObject property to the current object. 
105      To be used from class definition scope. 
106   
107      @type type_: type object 
108      @type name: string 
109      @type desc: string 
110      @type args: mixed 
111      """ 
112      frame = sys._getframe(1) 
113      _locals = frame.f_locals 
114      flags = 0 
115   
116      def _do_get_property(self, prop): 
117          try: 
118              return self._gproperty_values[prop.name] 
119          except (AttributeError, KeyError): 
120              raise AttributeError('Property was never set', self, prop) 
121   
122      def _do_set_property(self, prop, value): 
123          if not getattr(self, '_gproperty_values', None): 
124              self._gproperty_values = {} 
125          self._gproperty_values[prop.name] = value 
126   
127      _locals['do_get_property'] = _do_get_property 
128      _locals['do_set_property'] = _do_set_property 
129   
130      if not '__gproperties__' in _locals: 
131          _dict = _locals['__gproperties__'] = {} 
132      else: 
133          _dict = _locals['__gproperties__'] 
134   
135      for i in 'readable', 'writable': 
136          if not i in kwargs: 
137              kwargs[i] = True 
138   
139      for k, v in kwargs.items(): 
140          if k == 'construct': 
141              flags |= PARAM_CONSTRUCT 
142          elif k == 'construct_only': 
143              flags |= gobject.PARAM_CONSTRUCT_ONLY 
144          elif k == 'readable': 
145              flags |= gobject.PARAM_READABLE 
146          elif k == 'writable': 
147              flags |= gobject.PARAM_WRITABLE 
148          elif k == 'lax_validation': 
149              flags |= gobject.PARAM_LAX_VALIDATION 
150          else: 
151              raise Exception('Invalid GObject property flag: %r=%r' % (k, v)) 
152   
153      _dict[name] = (type_, name, desc) + args + tuple((flags,)) 
154   
155 -def type_register(klass): 
156      if klass.__gtype__.pytype is not klass: 
157          # all subclasses will at least have a __gtype__ from their 
158          # parent, make sure it corresponds to the exact class 
159          gobject.type_register(klass) 
160