#!/usr/bin/python
# -*- coding: utf-8 -*-
"""Classes and functions to easily access DBus introspection data."""
from xml.etree.ElementTree import ElementTree
from StringIO import StringIO
class IElemMeta(type):
"""Metaclass for introspection elements.
Sets elemname class member automatically from class name if not set
explicitly. Registers classes for their element names."""
elemnames_to_classes = {}
@classmethod
def clsname_to_elemname(cls, clsname):
elemname = ""
for c in clsname:
c_lower = c.lower()
if c_lower != c:
if len(elemname):
elemname += "_"
elemname += c_lower
return elemname
def __new__(cls, name, bases, dct):
if name == "IElem":
return type.__new__(cls, name, bases, dct)
if 'elemname' not in dct:
if not name.startswith("IElem"):
raise TypeError("Class '%s' needs to set elemname (or be "
"called 'IElem...'))" % name)
dct['elemname'] = IElemMeta.clsname_to_elemname(name[5:])
elemname = dct['elemname']
if elemname in IElemMeta.elemnames_to_classes:
raise TypeError("Class '%s' tries to register duplicate elemname "
"'%s'" % (name, elemname))
kls = type.__new__(cls, name, bases, dct)
IElemMeta.elemnames_to_classes[elemname] = kls
return kls
class IElem(object):
"""Base class for introspection elements."""
__metaclass__ = IElemMeta
def __new__(cls, elem, parent=None):
kls = IElemMeta.elemnames_to_classes.get(elem.tag,
IElemMeta.elemnames_to_classes[None])
return super(IElem, cls).__new__(kls, elem, parent)
def __init__(self, elem, parent=None):
self.elem = elem
self.parent = parent
self.child_elements = [ IElem(c, parent=self) for c in elem ]
def __str__(self):
s = "%s %r" % (self.elemname if self.elemname else "unknown:%s" %
self.elem.tag, self.attrib)
for c in self.child_elements:
for cc in str(c).split("\n"):
s+="\n %s" % (cc)
return s
@property
def attrib(self):
return self.elem.attrib
class IElemUnknown(IElem):
"""Catch-all for unknown introspection elements."""
elemname = None
class IElemNameMixin(object):
"""Mixin for introspection elements with names."""
@property
def name(self):
return self.attrib['name']
class IElemNode(IElem, IElemNameMixin):
"""Introspection node."""
def __init__(self, elem, parent=None):
super(IElemNode, self).__init__(elem, parent)
self.child_nodes = [ c for c in self.child_elements if isinstance(c, IElemNode) ]
class IElemInterface(IElem):
"""Introspection interface."""
class IElemMethod(IElem):
"""Introspection interface method."""
class IElemArg(IElem):
"""Introspection method argument."""
class IElemSignal(IElem, IElemNameMixin):
"""Introspection interface signal."""
def introspect(string_or_file):
tree = ElementTree()
# assume string if read() method doesn't exist, works for string, unicode,
# dbus.String
if not hasattr(string_or_file, "read"):
string_or_file = StringIO(string_or_file)
xml_root = tree.parse(string_or_file)
elem_root = IElem(xml_root)
return elem_root