def FindOutgoingInterface(source):
"""XXX Describe the strategy that is used..."""
# If the COM object implements IProvideClassInfo2, it is easy to
# find the default outgoing interface.
try:
pci = source.QueryInterface(comtypes.typeinfo.IProvideClassInfo2)
guid = pci.GetGUID(1)
except comtypes.COMError:
pass
else:
# another try: block needed?
try:
interface = comtypes.com_interface_registry[str(guid)]
except KeyError:
tinfo = pci.GetClassInfo()
tlib, index = tinfo.GetContainingTypeLib()
GetModule(tlib)
interface = comtypes.com_interface_registry[str(guid)]
logger.debug("%s using sinkinterface %s", source, interface)
return interface
# If we can find the CLSID of the COM object, we can look for a
# registered outgoing interface (__clsid has been set by
# comtypes.client):
clsid = source.__dict__.get('__clsid')
try:
interface = comtypes.com_coclass_registry[clsid]._outgoing_interfaces_[
0]
except KeyError:
pass
else:
logger.debug("%s using sinkinterface from clsid %s", source, interface)
return interface
## interface = find_single_connection_interface(source)
## if interface:
## return interface
raise TypeError("cannot determine source interface")
def GetBestInterface(punk):
"""Try to QueryInterface a COM pointer to the 'most useful'
interface.
Get type information for the provided object, either via
IDispatch.GetTypeInfo(), or via IProvideClassInfo.GetClassInfo().
Generate a wrapper module for the typelib, and QI for the
interface found.
"""
if not punk: # NULL COM pointer
return punk # or should we return None?
# find the typelib and the interface name
logger.debug("GetBestInterface(%s)", punk)
try:
try:
pci = punk.QueryInterface(comtypes.typeinfo.IProvideClassInfo)
logger.debug("Does implement IProvideClassInfo")
except comtypes.COMError:
# Some COM objects support IProvideClassInfo2, but not IProvideClassInfo.
# These objects are broken, but we support them anyway.
logger.debug(
"Does NOT implement IProvideClassInfo, trying IProvideClassInfo2"
)
pci = punk.QueryInterface(comtypes.typeinfo.IProvideClassInfo2)
logger.debug("Does implement IProvideClassInfo2")
tinfo = pci.GetClassInfo() # TypeInfo for the CoClass
# find the interface marked as default
ta = tinfo.GetTypeAttr()
for index in range(ta.cImplTypes):
if tinfo.GetImplTypeFlags(index) == 1:
break
else:
if ta.cImplTypes != 1:
# Hm, should we use dynamic now?
raise TypeError("No default interface found")
# Only one interface implemented, use that (even if
# not marked as default).
index = 0
href = tinfo.GetRefTypeOfImplType(index)
tinfo = tinfo.GetRefTypeInfo(href)
except comtypes.COMError:
logger.debug("Does NOT implement IProvideClassInfo/IProvideClassInfo2")
try:
pdisp = punk.QueryInterface(comtypes.automation.IDispatch)
except comtypes.COMError:
logger.debug("No Dispatch interface: %s", punk)
return punk
try:
tinfo = pdisp.GetTypeInfo(0)
except comtypes.COMError:
pdisp = comtypes.client.dynamic.Dispatch(pdisp)
logger.debug("IDispatch.GetTypeInfo(0) failed: %s" % pdisp)
return pdisp
typeattr = tinfo.GetTypeAttr()
logger.debug("Default interface is %s", typeattr.guid)
try:
punk.QueryInterface(comtypes.IUnknown, typeattr.guid)
except comtypes.COMError:
logger.debug(
"Does not implement default interface, returning dynamic object")
return comtypes.client.dynamic.Dispatch(punk)
itf_name = tinfo.GetDocumentation(-1)[0] # interface name
tlib = tinfo.GetContainingTypeLib()[0] # typelib
# import the wrapper, generating it on demand
mod = GetModule(tlib)
# Python interface class
interface = getattr(mod, itf_name)
logger.debug("Implements default interface from typeinfo %s", interface)
# QI for this interface
# XXX
# What to do if this fails?
# In the following example the engine.Eval() call returns
# such an object.
#
# engine = CreateObject("MsScriptControl.ScriptControl")
# engine.Language = "JScript"
# engine.Eval("[1, 2, 3]")
#
# Could the above code, as an optimization, check that QI works,
# *before* generating the wrapper module?
result = punk.QueryInterface(interface)
logger.debug("Final result is %s", result)
return result
pdisp = comtypes.client.dynamic.Dispatch(pdisp)
logger.info("IDispatch.GetTypeInfo(0) failed: %s" % pdisp)
return pdisp
typeattr = tinfo.GetTypeAttr()
logger.info("Default interface is %s", typeattr.guid)
try:
punk.QueryInterface(comtypes.IUnknown, typeattr.guid)
except comtypes.COMError, details:
logger.info("Does not implement default interface, returning dynamic object")
return comtypes.client.dynamic.Dispatch(punk)
itf_name = tinfo.GetDocumentation(-1)[0] # interface name
tlib = tinfo.GetContainingTypeLib()[0] # typelib
# import the wrapper, generating it on demand
mod = GetModule(tlib)
# Python interface class
interface = getattr(mod, itf_name)
logger.info("Implements default interface from typeinfo %s", interface)
# QI for this interface
# XXX
# What to do if this fails?
# In the following example the engine.Eval() call returns
# such an object.
#
# engine = CreateObject("MsScriptControl.ScriptControl")
# engine.Language = "JScript"
# engine.Eval("[1, 2, 3]")
#
# Could the above code, as an optimization, check that QI works,
# *before* generating the wrapper module?