gecko-dev/extensions/python/xpcom/components.py

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9.3 KiB
Python

# ***** BEGIN LICENSE BLOCK *****
# Version: MPL 1.1/GPL 2.0/LGPL 2.1
#
# The contents of this file are subject to the Mozilla Public License Version
# 1.1 (the "License"); you may not use this file except in compliance with
# the License. You may obtain a copy of the License at
# http://www.mozilla.org/MPL/
#
# Software distributed under the License is distributed on an "AS IS" basis,
# WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
# for the specific language governing rights and limitations under the
# License.
#
# The Original Code is the Python XPCOM language bindings.
#
# The Initial Developer of the Original Code is
# ActiveState Tool Corp.
# Portions created by the Initial Developer are Copyright (C) 2000, 2001
# the Initial Developer. All Rights Reserved.
#
# Contributor(s):
# Mark Hammond <MarkH@ActiveState.com> (original author)
#
# Alternatively, the contents of this file may be used under the terms of
# either the GNU General Public License Version 2 or later (the "GPL"), or
# the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
# in which case the provisions of the GPL or the LGPL are applicable instead
# of those above. If you wish to allow use of your version of this file only
# under the terms of either the GPL or the LGPL, and not to allow others to
# use your version of this file under the terms of the MPL, indicate your
# decision by deleting the provisions above and replace them with the notice
# and other provisions required by the GPL or the LGPL. If you do not delete
# the provisions above, a recipient may use your version of this file under
# the terms of any one of the MPL, the GPL or the LGPL.
#
# ***** END LICENSE BLOCK *****
# This module provides the JavaScript "components" interface
import xpt
import xpcom, _xpcom
import xpcom.client
import xpcom.server
import types
StringTypes = [types.StringType, types.UnicodeType]
def _get_good_iid(iid):
if iid is None:
iid = _xpcom.IID_nsISupports
elif type(iid) in StringTypes and len(iid)>0 and iid[0] != "{":
iid = getattr(interfaces, iid)
return iid
# The "manager" object.
manager = xpcom.client.Component(_xpcom.NS_GetGlobalComponentManager(), _xpcom.IID_nsIComponentManager)
# The "interfaceInfoManager" object - JS doesnt have this.
interfaceInfoManager = _xpcom.XPTI_GetInterfaceInfoManager()
# The serviceManager - JS doesnt have this either!
serviceManager = _xpcom.GetGlobalServiceManager()
# The "Exception" object
Exception = xpcom.COMException
# Base class for our collections.
# It appears that all objects supports "." and "[]" notation.
# eg, "interface.nsISupports" or interfaces["nsISupports"]
class _ComponentCollection:
# Bases are to over-ride 2 methods.
# _get_one(self, name) - to return one object by name
# _build_dict - to return a dictionary which provide access into
def __init__(self):
self._dict_data = None
def keys(self):
if self._dict_data is None:
self._dict_data = self._build_dict()
return self._dict_data.keys()
def items(self):
if self._dict_data is None:
self._dict_data = self._build_dict()
return self._dict_data.items()
def values(self):
if self._dict_data is None:
self._dict_data = self._build_dict()
return self._dict_data.values()
def has_key(self, key):
if self._dict_data is None:
self._dict_data = self._build_dict()
return self._dict_data.has_key(key)
def __len__(self):
if self._dict_data is None:
self._dict_data = self._build_dict()
return len(self._dict_data)
def __getattr__(self, attr):
if self._dict_data is not None and self._dict_data.has_key(attr):
return self._dict_data[attr]
return self._get_one(attr)
def __getitem__(self, item):
if self._dict_data is not None and self._dict_data.has_key(item):
return self._dict_data[item]
return self._get_one(item)
_constants_by_iid_map = {}
class _Interface:
# An interface object.
def __init__(self, name, iid):
# Bypass self.__setattr__ when initializing attributes.
d = self.__dict__
d['_iidobj_'] = iid # Allows the C++ framework to treat this as a native IID.
d['name'] = name
def __cmp__(self, other):
this_iid = self._iidobj_
other_iid = getattr(other, "_iidobj_", other)
return cmp(this_iid, other_iid)
def __hash__(self):
return hash(self._iidobj_)
def __str__(self):
return str(self._iidobj_)
def __getitem__(self, item):
raise TypeError, "components.interface objects are not subscriptable"
def __setitem__(self, item, value):
raise TypeError, "components.interface objects are not subscriptable"
def __setattr__(self, attr, value):
raise AttributeError, "Can not set attributes on components.Interface objects"
def __getattr__(self, attr):
# Support constants as attributes.
c = _constants_by_iid_map.get(self._iidobj_)
if c is None:
c = {}
i = xpt.Interface(self._iidobj_)
for c_ob in i.constants:
c[c_ob.name] = c_ob.value
_constants_by_iid_map[self._iidobj_] = c
if c.has_key(attr):
return c[attr]
raise AttributeError, "'%s' interfaces do not define a constant '%s'" % (self.name, attr)
class _Interfaces(_ComponentCollection):
def _get_one(self, name):
try:
item = interfaceInfoManager.GetInfoForName(name)
except xpcom.COMException, why:
# Present a better exception message, and give a more useful error code.
import nsError
raise xpcom.COMException(nsError.NS_ERROR_NO_INTERFACE, "The interface '%s' does not exist" % (name,))
return _Interface(item.GetName(), item.GetIID())
def _build_dict(self):
ret = {}
enum = interfaceInfoManager.EnumerateInterfaces()
while not enum.IsDone():
# Call the Python-specific FetchBlock, to keep the loop in C.
items = enum.FetchBlock(500, _xpcom.IID_nsIInterfaceInfo)
# This shouldnt be necessary, but appears to be so!
for item in items:
ret[item.GetName()] = _Interface(item.GetName(), item.GetIID())
return ret
# And the actual object people use.
interfaces = _Interfaces()
del _Interfaces # Keep our namespace clean.
#################################################
class _Class:
def __init__(self, contractid):
self.contractid = contractid
def __getattr__(self, attr):
if attr == "clsid":
rc = manager.contractIDToClassID(self.contractid)
# stash it away - it can never change!
self.clsid = rc
return rc
raise AttributeError, "%s class has no attribute '%s'" % (self.contractid, attr)
def createInstance(self, iid = None):
import xpcom.client
try:
return xpcom.client.Component(self.contractid, _get_good_iid(iid))
except xpcom.COMException, details:
import nsError
# Handle "no such component" in a cleaner way for the user.
if details.errno == nsError.NS_ERROR_FACTORY_NOT_REGISTERED:
raise xpcom.COMException(details.errno, "No such component '%s'" % (self.contractid,))
raise # Any other exception reraise.
def getService(self, iid = None):
return serviceManager.getServiceByContractID(self.contractid, _get_good_iid(iid))
class _Classes(_ComponentCollection):
def __init__(self):
_ComponentCollection.__init__(self)
def _get_one(self, name):
# XXX - Need to check the contractid is valid!
return _Class(name)
def _build_dict(self):
ret = {}
enum = manager.EnumerateContractIDs()
while not enum.IsDone():
# Call the Python-specific FetchBlock, to keep the loop in C.
items = enum.FetchBlock(500)
for item in items:
name = str(item)
ret[name] = _Class(name)
return ret
classes = _Classes()
del _Classes
del _ComponentCollection
# The ID function
ID = _xpcom.IID
# A helper to cleanup our namespace as xpcom shuts down.
class _ShutdownObserver:
_com_interfaces_ = interfaces.nsIObserver
def observe(self, service, topic, extra):
global manager, classes, interfaces, interfaceInfoManager, _shutdownObserver, serviceManager, _constants_by_iid_map
manager = classes = interfaces = interfaceInfoManager = _shutdownObserver = serviceManager = _constants_by_iid_map = None
xpcom.client._shutdown()
xpcom.server._shutdown()
svc = _xpcom.GetGlobalServiceManager().getServiceByContractID("@mozilla.org/observer-service;1", interfaces.nsIObserverService)
# Observers will be QI'd for a weak-reference, so we must keep the
# observer alive ourself, and must keep the COM object alive,
# _not_ just the Python instance!!!
_shutdownObserver = xpcom.server.WrapObject(_ShutdownObserver(), interfaces.nsIObserver)
# Say we want a weak ref due to an assertion failing. If this is fixed, we can pass 0,
# and remove the lifetime hacks above! See http://bugzilla.mozilla.org/show_bug.cgi?id=99163
svc.addObserver(_shutdownObserver, "xpcom-shutdown", 1)
del svc, _ShutdownObserver