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 get_dbus_method(self, *args, **kwargs):
 113                 method =  Interface.get_dbus_method(self, *args, **kwargs)
 114
 115                 def dbus_method_func(*args, **kwargs):
 116                         # TODO Need to throw an AccessibleObjectNoLongerExists exception
 117                         # on D-Bus error of the same type.
 118                         try:
 119                                 return method(*args, **kwargs)
 120                         except UnknownMethodException, e:
 121                                 raise NotImplementedError(e)
 122                         except DBusException, e:
 123                                 raise LookupError(e)
 124
 125                 return dbus_method_func
 126
 127         @property
 128         def cached_data(self):
 129                 try:
 130                         return self._cache[self._app_name][self._acc_path]
 131                 except KeyError:
 132                         raise AccessibleObjectNoLongerExists, \
 133                                 'Cache data cannot be found for path %s in app %s' % (self._acc_path, self._app_name)
 134
 135         @property
 136         def interfaces(self):
 137                 return self.cached_data.interfaces
 138
 139         def queryInterface(self, interface):
 140                 """
 141                 Gets a different accessible interface for this object
 142                 or raises a NotImplemented error if the given interface
 143                 is not supported.
 144                 """
 145                 if interface in self.interfaces:
 146                         return create_accessible(self._cache,
 147                                                  self._app_name,
 148                                                  self._acc_path,
 149                                                  interface,
 150                                                  dbus_object=self._dbus_object)
 151                 else:
 152                         raise NotImplementedError(
 153                                 "%s not supported by accessible object at path %s"
 154                                 % (interface, self.path))
 155
 156 #END----------------------------------------------------------------------------