pyatspi/base.py

   1 #Copyright (C) 2008 Codethink Ltd
   2
   3 #This library is free software; you can redistribute it and/or
   4 #modify it under the terms of the GNU Lesser General Public
   5 #License version 2 as published by the Free Software Foundation.
   6
   7 #This program is distributed in the hope that it will be useful,
   8 #but WITHOUT ANY WARRANTY; without even the implied warranty of
   9 #MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  10 #GNU General Public License for more details.
  11 #You should have received a copy of the GNU Lesser General Public License
  12 #along with this program; if not, write to the Free Software
  13 #Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  14
  15 import dbus
  16 from dbus.proxies import Interface
  17 from dbus.exceptions import *
  18
  19 import interfaces
  20 from factory import create_accessible
  21
  22 __all__ = [
  23            "AccessibleObjectNoLongerExists",
  24            "Enum",
  25            "BaseProxy",
  26           ]
  27
  28 class AccessibleObjectNoLongerExists(Exception):
  29         pass
  30
  31 #------------------------------------------------------------------------------
  32
  33 class Enum(int):
  34         def __str__(self):
  35                 return self._enum_lookup[int(self)]
  36
  37 #------------------------------------------------------------------------------
  38
  39
  40 class BaseProxyMeta(type):
  41         def __new__(meta, *args, **kwargs):
  42                 cls = type.__new__(meta, *args, **kwargs)
  43
  44                 queryable_interfaces = {
  45                         'Accessible':interfaces.ATSPI_ACCESSIBLE,
  46                         'Action':interfaces.ATSPI_ACTION,
  47                         'Application':interfaces.ATSPI_APPLICATION,
  48                         'Collection':interfaces.ATSPI_COLLECTION,
  49                         'Component':interfaces.ATSPI_COMPONENT,
  50                         'Desktop':interfaces.ATSPI_DESKTOP,
  51                         'Document':interfaces.ATSPI_DOCUMENT,
  52                         'EditableText':interfaces.ATSPI_EDITABLE_TEXT,
  53                         'Hypertext':interfaces.ATSPI_HYPERTEXT,
  54                         'Hyperlink':interfaces.ATSPI_HYPERLINK,
  55                         'Image':interfaces.ATSPI_IMAGE,
  56                         'Selection':interfaces.ATSPI_SELECTION,
  57                         'StreamableContent':interfaces.ATSPI_STREAMABLE_CONTENT,
  58                         'Table':interfaces.ATSPI_TABLE,
  59                         'Text':interfaces.ATSPI_TEXT,
  60                         'Value':interfaces.ATSPI_VALUE,
  61                 }
  62
  63                 def return_query(interface):
  64                         def new_query(self):
  65                                 return self.queryInterface(interface)
  66                         return new_query
  67
  68                 for interface in queryable_interfaces.keys():
  69                         name = 'query%s' % interface
  70                         setattr(cls, name, return_query(queryable_interfaces[interface]))
  71
  72                 return cls
  73
  74 #------------------------------------------------------------------------------
  75
  76 class BaseProxy(Interface):
  77         """
  78         The base D-Bus proxy for a remote object that implements one or more
  79         of the AT-SPI interfaces.
  80         """
  81
  82         __metaclass__ = BaseProxyMeta
  83
  84         def __init__(self, cache, app_name, acc_path, interface, dbus_object=None, connection=None, parent=None):
  85                 """
  86                 Create a D-Bus Proxy for an ATSPI interface.
  87
  88                 cache - ApplicationCache, where the cached data for the accessible can be obtained.
  89                 app_name - D-Bus bus name of the application this accessible belongs to.
  90                 acc_path - D-Bus object path of the server side accessible object.
  91                 parent - Parent accessible.
  92                 interface - D-Bus interface of the object. Used to decide which accessible class to instanciate.
  93                 dbus_object(kwarg) - The D-Bus proxy object used by the accessible for D-Bus method calls.
  94                 """
  95                 self._cache = cache
  96                 self._app_name = app_name
  97                 self._acc_path = acc_path
  98                 self._parent = parent
  99
 100                 if not dbus_object:
 101                         dbus_object = connection.get_object(self._app_name, self._acc_path, introspect=False)
 102                 self._dbus_object = dbus_object
 103
 104                 Interface.__init__(self, self._dbus_object, interface)
 105
 106                 self._pgetter = self.get_dbus_method("Get", dbus_interface="org.freedesktop.DBus.Properties")
 107                 self._psetter = self.get_dbus_method("Set", dbus_interface="org.freedesktop.DBus.Properties")
 108
 109         def __getattr__(self, attr):
 110                 raise AttributeError("\'%s\' has no attribute \'%s\'" % (self.__class__.__name__, attr))
 111
 112         def __str__(self):
 113                 try:
 114                         return '[%s | %s]' % (self.getRoleName(), self.name)
 115                 except Exception:
 116                         return '[DEAD]'
 117
 118         def get_dbus_method(self, *args, **kwargs):
 119                 method =  Interface.get_dbus_method(self, *args, **kwargs)
 120
 121                 def dbus_method_func(*args, **kwargs):
 122                         # TODO Need to throw an AccessibleObjectNoLongerExists exception
 123                         # on D-Bus error of the same type.
 124                         try:
 125                                 return method(*args, **kwargs)
 126                         except UnknownMethodException, e:
 127                                 raise NotImplementedError(e)
 128                         except DBusException, e:
 129                                 raise LookupError(e)
 130
 131                 return dbus_method_func
 132
 133         @property
 134         def cached_data(self):
 135                 try:
 136                         return self._cache[self._app_name][self._acc_path]
 137                 except KeyError:
 138                         raise AccessibleObjectNoLongerExists, \
 139                                 'Cache data cannot be found for path %s in app %s' % (self._acc_path, self._app_name)
 140
 141         @property
 142         def interfaces(self):
 143                 return self.cached_data.interfaces
 144
 145         def queryInterface(self, interface):
 146                 """
 147                 Gets a different accessible interface for this object
 148                 or raises a NotImplemented error if the given interface
 149                 is not supported.
 150                 """
 151                 if interface in self.interfaces:
 152                         return create_accessible(self._cache,
 153                                                  self._app_name,
 154                                                  self._acc_path,
 155                                                  interface,
 156                                                  dbus_object=self._dbus_object)
 157                 else:
 158                         raise NotImplementedError(
 159                                 "%s not supported by accessible object at path %s"
 160                                 % (interface, self.path))
 161
 162 #END----------------------------------------------------------------------------