import constants
import utils
import registry
+import weakref
-_ACCESSIBLE_CACHE = {}
+_ACCESSIBLE_CACHE = weakref.WeakValueDictionary()
+_ACCESSIBLE_USER_DATA = weakref.WeakValueDictionary()
_CACHE_LEVEL = None
-class _PropertyCache(object):
- '''Fixed-size bag class for holding cached values.'''
- __slots__ = ('name', 'description', 'rolename')
+class _PropertyCache:
+ pass
+
+class _UserData:
+ value = None
def getCacheLevel():
'''
except KeyError:
return
-def _makeQuery(iid):
+def _getAndCache(acc, value_name, get_method):
+ '''
+ If property caching is enabled, use the cached proprty, or get the
+ property and cache it. If property caching is disabled, simply get the
+ property.
+
+ @param value_name: The name of the value, like 'role' or 'description'.
+ @type value_name: string
+ @param get_method: Method used to get the property, should not have any
+ arguments.
+ @type get_method: callable
+ @return: Value of property we are retrieving.
+ @rtype: object
+ '''
+ if _CACHE_LEVEL != constants.CACHE_PROPERTIES:
+ return get_method()
+
+ cache = _ACCESSIBLE_CACHE
+ h = hash(acc)
+
+ try:
+ pc = acc._property_cache
+ except AttributeError:
+ try:
+ pc = cache[h]
+ except KeyError:
+ # no cached info for this accessible yet
+ pc = _PropertyCache()
+ cache[h] = pc
+ acc._property_cache = pc
+
+ try:
+ value = getattr(pc, value_name)
+ except AttributeError:
+ # no cached property of this type
+ value = get_method()
+ setattr(pc, value_name, value)
+
+ return value
+
+
+def _makeQuery(interface):
'''
Builds a function querying to a specific interface and returns it.
- @param iid: Interface identifier to use when querying
- @type iid: string
+ @param interface: Class representing an AT-SPI interface
+ @type interface: class
@return: Function querying to the given interface
@rtype: function
'''
@rtype: object
@raise NotImplementedError: When the desired interface is not supported
'''
+ iid = utils.getInterfaceIID(interface)
try:
i = self._icache[iid]
except KeyError:
# interface not cached
caching = True
- except TypeError:
+ except AttributeError:
# determine if we're caching
caching = _CACHE_LEVEL is not None
if caching:
try:
# do the query remotely
i = self.queryInterface(iid)
+ if i is not None:
+ i = i._narrow(interface)
except Exception, e:
- raise LookupError(e)
+ raise LookupError(e)
if i is None:
# cache that the interface is not supported
if caching:
self._icache[iid] = None
raise NotImplementedError
- # not needed according to ORBit2 spec, but makes Java queries work
- # more reliably according to Orca experience
- i = i._narrow(i.__class__)
if caching:
# cache the narrow'ed result, but only if we're caching for this object
self._icache[iid] = i
# build name of converter from the name of the interface
name = 'query%s' % utils.getInterfaceName(interface)
# build a function that queries to the given interface
- func = _makeQuery(utils.getInterfaceIID(interface))
+ func = _makeQuery(interface)
# build a new method that is a clone of the original function
method = new.function(func.func_code, func.func_globals, name,
func.func_defaults, func.func_closure)
@type SLOTS: tuple
'''
SLOTTED_CLASSES = {}
- SLOTS = ('_icache',)
+ SLOTS = ('_icache', '_property_cache', '_user_data')
def __new__(cls):
'''
- Creates a new class mimicking the one requested, but with an extra _cache
- attribute set in the __slots__ tuple. This field can be set to a dictionary
- or other object to allow caching to occur.
+ Creates a new class mimicking the one requested, but with extra named
+ defined in __slots__. The _cache attribute is used internally for interface
+ caching. The user_data field may be populated with whatever data structure
+ a client wishes to use. Neither is set to a default value by default.
Note that we can't simply mix __slots__ into this class because __slots__
- has an effect only at class creation time.
+ has an effect only at class creation time.
+
+ We also do not completely obliterate __slots__ to allow __dict__ to be
+ instantiated as normal as reducing the initialization and memory overhead
+ of the millions of accessible objects that are created is a good thing for
+ many clients.
@param cls: Accessibility object class
@type cls: class
'__slots__' : _AccessibleMixin.SLOTS})
_AccessibleMixin.SLOTTED_CLASSES[cls] = new_cls
obj = cls._mix___new__(new_cls)
- # don't create the interface cache until we need it
- obj._icache = None
return obj
def __del__(self):
we're caching properties.
'''
try:
- del _ACCESSIBLE_CACHE[hash(self)]
- except KeyError:
- pass
- try:
self.unref()
except Exception:
pass
@return: Accessible child
@rtype: Accessibility.Accessible
'''
+ n = self.childCount
+ if index >= n:
+ raise IndexError
+ elif index < -n:
+ raise IndexError
+ elif index < 0:
+ index += n
return self.getChildAtIndex(index)
def __len__(self):
'''
return self.childCount
+ def _get_user_data(self):
+ '''
+ Get user_data from global dictionay fo this accessible.
+
+ @return: Any data the user assigned, or None.
+ @rtype: object
+ '''
+ global _ACCESSIBLE_USER_DATA
+ h = hash(self)
+
+ try:
+ ud = self._user_data
+ except AttributeError:
+ try:
+ ud = _ACCESSIBLE_USER_DATA[h]
+ except KeyError:
+ # no cached info for this object yet
+ ud = _UserData()
+ _ACCESSIBLE_USER_DATA[h] = ud
+
+ self._user_data = ud
+ return ud.value
+
+ def _set_user_data(self, value):
+ '''
+ Set arbitrary data to user_data.
+
+ @param value: Value to set in user_data
+ @type value: object
+ '''
+ global _ACCESSIBLE_USER_DATA
+ h = hash(self)
+
+ try:
+ ud = self._user_data
+ except AttributeError:
+ try:
+ ud = _ACCESSIBLE_USER_DATA[h]
+ except KeyError:
+ # no cached info for this object yet
+ ud = _UserData()
+ _ACCESSIBLE_USER_DATA[h] = ud
+
+ self._user_data = ud
+ ud.value = value
+
+ user_data = property(_get_user_data, _set_user_data)
+
def _get_name(self):
'''
Gets the name of the accessible from the cache if it is available,
@return: Name of the accessible
@rtype: string
'''
- if _CACHE_LEVEL != constants.CACHE_PROPERTIES:
- return self._get_name()
-
- cache = _ACCESSIBLE_CACHE
- h = hash(self)
- try:
- return cache[h].name
- except KeyError:
- # no cached info for this object yet
- name = self._get_name()
- pc = _PropertyCache()
- pc.name = name
- cache[h] = pc
- return name
- except AttributeError:
- # no cached name for this object yet
- name = self._get_name()
- cache[h].name = name
- return name
-
+ return _getAndCache(self, 'name', self._get_name)
+
name = property(_get_name, Accessibility.Accessible._set_name)
+
+ def _get_parent(self):
+ '''
+ Gets the parent of the accessible from the cache if it is available,
+ otherwise, fetches it remotely.
+
+ @return: Parent of the accessible
+ @rtype: Accessibility.Accessible
+ '''
+ return _getAndCache(self, 'parent', self._get_parent)
+
+ parent = property(_get_parent)
def getRoleName(self):
'''
@return: Role name of the accessible
@rtype: string
'''
- if _CACHE_LEVEL != constants.CACHE_PROPERTIES:
- return self._mix_getRoleName()
+ return _getAndCache(self, 'rolename', self._mix_getRoleName)
+
+ def getRole(self):
+ '''
+ Gets the role of the accessible from the cache if it is
+ available, otherwise, fetches it remotely.
+
+ @return: Role of the accessible
+ @rtype: Accessibility.Role
+ '''
+ return _getAndCache(self, 'role', self._mix_getRole)
- cache = _ACCESSIBLE_CACHE
- h = hash(self)
- try:
- return cache[h].rolename
- except KeyError, e:
- # no cached info for this object yet
- rolename = self._mix_getRoleName()
- pc = _PropertyCache()
- pc.rolename = rolename
- cache[h] = pc
- return rolename
- except AttributeError, e:
- # no cached name for this object yet
- rolename = self._mix_getRoleName()
- cache[h].rolename = rolename
- return rolename
-
def _get_description(self):
'''
Gets the description of the accessible from the cache if it is available,
@return: Description of the accessible
@rtype: string
'''
- if _CACHE_LEVEL != constants.CACHE_PROPERTIES:
- return self._get_description()
-
- cache = _ACCESSIBLE_CACHE
- h = hash(self)
- try:
- return cache[h].description
- except KeyError:
- # no cached info for this object yet
- description = self._get_description()
- pc = _PropertyCache()
- pc.description = description
- cache[h] = pc
- return description
- except AttributeError:
- # no cached name for this object yet
- description = self._get_description()
- cache[h].description = description
- return description
+ return _getAndCache(self, 'description', self._get_description)
description = property(_get_description,
Accessibility.Accessible._set_description)
def getApplication(self):
'''
- Gets the most-parent accessible (the application) of this accessible. Tries
- using the getApplication method introduced in AT-SPI 1.7.0 first before
- resorting to traversing parent links.
+ Gets the most-parent accessible (the application) of this
+ accessible. Tries using the getApplication method introduced in
+ AT-SPI 1.7.0 first before resorting to traversing parent links.
@warning: Cycles involving more than the previously traversed accessible
are not detected by this code.
@rtype: Accessibility.Application
'''
try:
- return self._mix_getApplication()
+ app = self._mix_getApplication()
except AttributeError:
- pass
+ app = None
+
+ # Some toolkits (e.g., Java) do not support getApplication yet and
+ # will return None as a result.
+ #
+ if app:
+ return app
+
+ # If we didn't find anything, traverse up the tree, making sure to
+ # attempt to turn the thing we found into an Application object.
+ #
curr = self
try:
while curr.parent is not None and (not curr.parent == curr):
curr = curr.parent
- return curr
+ curr.ref()
+ return curr._narrow(Accessibility.Application)
+ except:
+ return None
+
+class _RelationMixin(object):
+ '''
+ Defines methods to be added to the Relation class. At this time it only
+ overrides L{_RelationMixin.getTarget} which by the IDL's standard is
+ supposed to return CORBA.Objects but we expect LAccessibility.Accessible
+ objects (see http://bugzilla.gnome.org/show_bug.cgi?id=435833).
+ This seems to be a problem especially with the Java implementation of CORBA.
+ '''
+ def getTarget(self, index):
+ '''
+ Overrides the regular getTarget to return Accessibility.Accessible
+ objects.
+
+ @return: The 'nth' target of this Relation.
+ @rtype: Accessibility.Accessible
+ '''
+ target = self._mix_getTarget(index)
+ target.ref()
+ return target._narrow(Accessibility.Accessible)
+
+class _UnrefMixin(object):
+ '''
+ This mixin addresses the issue we have with unreferencing non-primitives.
+ '''
+ def __del__(self):
+ '''
+ Unrefence the instance when Python GCs it. Why do we need this twice?
+ '''
+ try:
+ self.unref()
except Exception:
pass
- # return None if the application isn't reachable for any reason
- return None
# 1. mix the exception handlers into all queryable interfaces
map(_mixExceptions, constants.ALL_INTERFACES)
map(_mixExceptions, [Accessibility.StateSet])
# 3. mix the new functions
_mixClass(Accessibility.Accessible, _AccessibleMixin,
- ['_get_name', '_get_description'])
+ ['_get_name', '_get_description', '_get_parent'])
# 4. mix queryInterface convenience methods
_mixInterfaces(Accessibility.Accessible, constants.ALL_INTERFACES)
+# 5. mix Relation class
+_mixClass(Accessibility.Relation, _RelationMixin)
+# 6. mix in neccessary unrefs
+map(lambda cls: _mixClass(cls, _UnrefMixin),
+ (Accessibility.StateSet,Accessibility.Relation))
projects / platform / core / uifw / at-spi2-atk.git / blobdiff