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 from weakref import ref
  16
  17 from dbus.proxies import Interface, ProxyObject
  18 from dbus.exceptions import *
  19
  20 from factory import interfaceFactory
  21
  22 class AccessibleObjectNoLongerExists(Exception):
  23         pass
  24
  25 #------------------------------------------------------------------------------
  26
  27 class Enum(object):
  28         def __str__(self):
  29                 return self._enum_lookup(int(self))
  30
  31 #------------------------------------------------------------------------------
  32
  33 class BaseProxyMeta(type):
  34         def __init__(cls):
  35                 type.__init__(cls)
  36
  37                 queryable_interfaces = {
  38                         'Accessible':ATSPI_ACCESSIBLE,
  39                         'Action':ATSPI_ACTION,
  40                         'Application':ATSPI_APPLICATION,
  41                         'Collection':ATSPI_COLLECTION,
  42                         'Component':ATSPI_COMPONENT,
  43                         'Desktop':ATSPI_DESKTOP,
  44                         'Document':ATSPI_DOCUMENT,
  45                         'EditableText':ATSPI_EDITABLE_TEXT,
  46                         'Hypertext':ATSPI_HYPERTEXT,
  47                         'Hyperlink':ATSPI_HYPERLINK,
  48                         'Image':ATSPI_IMAGE,
  49                         'Selection':ATSPI_SELECTION,
  50                         'StreamableContent':ATSPI_STREAMABLE_CONTENT,
  51                         'Table':ATSPI_TABLE,
  52                         'Text':ATSPI_TEXT,
  53                         'Value':ATSPI_VALUE,
  54                 }
  55
  56                 for interface in queryable_interfaces.keys():
  57                         name = 'query%s' % interface
  58                         def new_query(self, object):
  59                                 return self.queryInterface(object, queryable_interfaces[interface])
  60                         setattr(cls, name, new_query)
  61
  62 #------------------------------------------------------------------------------
  63
  64 class BaseProxy(Interface):
  65         """
  66         A D-Bus proxy for a remote object that implements one or more of the AT-SPI
  67         Accessibility interfaces.
  68         """
  69
  70         __metaclass__ = BaseProxyMeta
  71
  72         def __init__(self, busobject, cache, app, path, interface):
  73                 """
  74                 Create a D-Bus Proxy for an ATSPI interface.
  75
  76                 busobject - The D-Bus proxy object this interface uses for D-Bus calls.
  77                 cache - The accessible cache that this object is owned by.
  78                 path - The object path of the remote object.
  79                 app - The bus name of the application this object belongs to.
  80                 interface - The name of the ATSPI interface that this proxy implements.
  81                 """
  82                 Interface.__init__(self, busobject, interface)
  83
  84                 self._cache = cache
  85
  86                 self._path = path
  87                 self._app = app
  88
  89                 self._pgetter = self.get_dbus_method("Get", dbus_interface="org.freedesktop.DBus.Properties")
  90                 self._psetter = self.get_dbus_method("Set", dbus_interface="org.freedesktop.DBus.Properties")
  91
  92         def __getattr__(self, *args, **kwargs):
  93                 """
  94                 The __getattr__ function must return the D-Bus method wrapped in a
  95                 method to translate exceptions.
  96                 """
  97                 # Need to throw an AccessibleObjectNoLongerExists exception
  98                 # on D-Bus error of the same type.
  99                 try:
 100                         return Interface.__getattr__(self, *args, **kwargs)
 101                 except UnknownMethodException, e:
 102                         raise NotImplementedError(e)
 103                 except DBusException, e:
 104                         raise LookupError(e)
 105
 106         @property
 107         def _data(self):
 108                 try:
 109                         data = self._cache._objects[self._path]
 110                 except KeyError:
 111                         raise AccessibleObjectNoLongerExists, 'Cache data cannot be found for path %s' % (self._path,)
 112                 return data
 113
 114         @property
 115         def interfaces(self):
 116                 return self._data.interfaces
 117
 118         def queryInterface(self, interface):
 119                 if interface in self._data.interfaces:
 120                         return interfaceFactory(self._obj, self._cache, self._app, self._path, interface)
 121                 else:
 122                         raise NotImplementedError(
 123                                 "%s not supported by accessible object at path %s"
 124                                 % (interface, self.path))
 125
 126 #END----------------------------------------------------------------------------