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
  21 __all__ = [
  22            "AccessibleObjectNoLongerExists",
  23            "AccessibleObjectNotAvailable",
  24            "Enum",
  25            "BaseProxy",
  26            "_repack_tuple",
  27           ]
  28
  29 class AccessibleObjectNoLongerExists(Exception):
  30         pass
  31
  32 class AccessibleObjectNotAvailable(Exception):
  33         pass
  34
  35 #------------------------------------------------------------------------------
  36
  37 def _repack_tuple (tup):
  38         """
  39         Re-packs a tuple moving the last element to the beginning.
  40         """
  41         return (tup[-1] ,) + tup[:-1]
  42
  43 #------------------------------------------------------------------------------
  44
  45 class Enum(dbus.UInt32):
  46         def __str__(self):
  47                 return self._enum_lookup[int(self)]
  48
  49 #------------------------------------------------------------------------------
  50
  51
  52 class BaseProxyMeta(type):
  53         def __new__(meta, *args, **kwargs):
  54                 cls = type.__new__(meta, *args, **kwargs)
  55
  56                 queryable_interfaces = {
  57                         'Accessible':interfaces.ATSPI_ACCESSIBLE,
  58                         'Action':interfaces.ATSPI_ACTION,
  59                         'Application':interfaces.ATSPI_APPLICATION,
  60                         'Collection':interfaces.ATSPI_COLLECTION,
  61                         'Component':interfaces.ATSPI_COMPONENT,
  62                         'Desktop':interfaces.ATSPI_DESKTOP,
  63                         'Document':interfaces.ATSPI_DOCUMENT,
  64                         'EditableText':interfaces.ATSPI_EDITABLE_TEXT,
  65                         'Hypertext':interfaces.ATSPI_HYPERTEXT,
  66                         'Hyperlink':interfaces.ATSPI_HYPERLINK,
  67                         'Image':interfaces.ATSPI_IMAGE,
  68                         'Selection':interfaces.ATSPI_SELECTION,
  69                         'StreamableContent':interfaces.ATSPI_STREAMABLE_CONTENT,
  70                         'Table':interfaces.ATSPI_TABLE,
  71                         'Text':interfaces.ATSPI_TEXT,
  72                         'Value':interfaces.ATSPI_VALUE,
  73                 }
  74
  75                 def return_query(interface):
  76                         def new_query(self):
  77                                 return self.queryInterface(interface)
  78                         return new_query
  79
  80                 for interface in queryable_interfaces.keys():
  81                         name = 'query%s' % interface
  82                         setattr(cls, name, return_query(queryable_interfaces[interface]))
  83
  84                 return cls
  85
  86 #------------------------------------------------------------------------------
  87
  88 class BaseProxy(object):
  89         """
  90         The base D-Bus proxy for a remote object that implements one or more
  91         of the AT-SPI interfaces.
  92         """
  93
  94         __metaclass__ = BaseProxyMeta
  95
  96         def __init__(self, app_name, acc_path, cache, interface, dbus_object=None):
  97                 """
  98                 Create a D-Bus Proxy for an ATSPI interface.
  99
 100                 cache - ApplicationCache, where the cached data for the accessible can be obtained.
 101                 app_name - D-Bus bus name of the application this accessible belongs to.
 102                 acc_path - D-Bus object path of the server side accessible object.
 103                 parent - Parent accessible.
 104                 dbus_object(kwarg) - The D-Bus proxy object used by the accessible for D-Bus method calls.
 105                 """
 106                 self._cache = cache
 107                 self._app_name = app_name
 108                 self._acc_path = acc_path
 109                 self._dbus_interface = interface
 110
 111                 if not dbus_object:
 112                         dbus_object = cache.connection.get_object(self._app_name,
 113                                                                   self._acc_path,
 114                                                                   introspect=False)
 115                 self._dbus_object = dbus_object
 116
 117                 self._pgetter = self.get_dbus_method("Get",
 118                                                      dbus_interface="org.freedesktop.DBus.Properties")
 119                 self._psetter = self.get_dbus_method("Set",
 120                                                      dbus_interface="org.freedesktop.DBus.Properties")
 121
 122         def __str__(self):
 123                     try:
 124                               return '[%s | %s]' % (self.getRoleName(), self.name)
 125                     except Exception:
 126                               return '[DEAD]'
 127
 128         def __eq__(self, other):
 129                 if other is None:
 130                         return False
 131                 try:
 132                         if self._app_name == other._app_name and \
 133                            self._acc_path == other._acc_path:
 134                                 return True
 135                         else:
 136                                 return False
 137                 except AttributeError:
 138                         return False
 139
 140         def __ne__(self, other):
 141                 return not self.__eq__(other)
 142
 143         def __hash__(self):
 144                 return hash(self._app_name + self._acc_path)
 145
 146         def get_dbus_method(self, *args, **kwargs):
 147                 method =  self._dbus_object.get_dbus_method(*args, **kwargs)
 148
 149                 def dbus_method_func(*iargs, **ikwargs):
 150                         # TODO Need to throw an AccessibleObjectNoLongerExists exception
 151                         # on D-Bus error of the same type.
 152                         try:
 153                                 return method(*iargs, **ikwargs)
 154                         except UnknownMethodException, e:
 155                                 raise NotImplementedError(e)
 156                         except DBusException, e:
 157                                 raise LookupError(e)
 158
 159                 return dbus_method_func
 160
 161         @property
 162         def cached_data(self):
 163                 try:
 164                         return self._cache.get_cache_data(self._app_name, self._acc_path)
 165                 except KeyError:
 166                         raise AccessibleObjectNoLongerExists, \
 167                                 'Cache data cannot be found for path %s in app %s' % (self._acc_path, self._app_name)
 168
 169         @property
 170         def interfaces(self):
 171                 return self.cached_data.interfaces
 172
 173         def queryInterface(self, interface):
 174                 """
 175                 Gets a different accessible interface for this object
 176                 or raises a NotImplemented error if the given interface
 177                 is not supported.
 178                 """
 179                 if interface in self.interfaces:
 180                         return self._cache.create_accessible(self._app_name,
 181                                                              self._acc_path,
 182                                                              interface,
 183                                                              dbus_object=self._dbus_object)
 184                 else:
 185                         raise NotImplementedError(
 186                                 "%s not supported by accessible object at path %s"
 187                                 % (interface, self._acc_path))
 188
 189 #END----------------------------------------------------------------------------