[comtypes-users] (no subject)

[Jozef]

Hi,

I'm trying to use comtypes to work with com based UIAutomation framework.
So far I was able to compile "UIAutomationClient.idl", generate wrapper
module, access "IUIAutomation" interface and call some simple methods and
properties.


But I have problems with "CreatePropertyCondition" and
"CreatePropertyConditionEx" methods.

For example calling:

IUIAutomation.CreatePropertyCondition(UIAutomationClient.UIA_ClassNamePropertyId,
('Window'))

throw warning:

Exception WindowsError: 'exception: stack overflow' in <bound method
tagVARIANT.__del__ of VARIANT(vt=0x8, u'Window')> ignored

and return null pointer to "IUIAutomationCondition"

<POINTER(IUIAutomationCondition) ptr=0x0 at 27a18c8>

using this pointer in IUIAutomationElement.FindFirst() method then throw:

WindowsError: exception: access violation writing 0x0000000000030000

Another symptom is that calling "CreatePropertyCondition" second time,
after first call return uninitialized pointer, throw also access violation
exception:

ctypes.ArgumentError: argument 2: <type 'exceptions.WindowsError'>:
exception: access violation writing 0x0000000000030000


When using "CreatePropertyConditionEx", access violation problem does not
occur. But still, returned pointer point to 0x0 and therefore it can not be
used as argument in further methods.

_ctypes.COMError: (-2147467261, 'Invalid pointer', (None, None, None, 0,
None))


Does anybody know what is wrong and how to fix it.

thanks

jozef

os: Windows 7 Enterprise, Service Pack 1
python: 2.7.4 (default, Apr 6 2013, 19:55:15) [MSC v.1500 64 bit (AMD64)]
comtypes: 0.6.2

IUIAutomation interface:
http://msdn.microsoft.com/en-us/library/windows/desktop/ee671406(v=vs.85).aspx

comtypes generated wrapper:

class
IUIAutomation(comtypes.gen._00020430_0000_0000_C000_000000000046_0_2_0.IUnknown):
_case_insensitive_ = True
_iid_ = GUID('{30CBE57D-D9D0-452A-AB13-7AC5AC4825EE}')
_idlflags_ = []

IUIAutomation._methods_ = [
...
COMMETHOD([], HRESULT, 'CreatePropertyCondition',
( ['in'], c_int, 'propertyId' ),
( ['in'], VARIANT, 'value' ),
( ['retval', 'out'],
POINTER(POINTER(IUIAutomationCondition)), 'newCondition' )),
COMMETHOD([], HRESULT, 'CreatePropertyConditionEx',
( ['in'], c_int, 'propertyId' ),
( ['in'], VARIANT, 'value' ),
( ['in'], PropertyConditionFlags, 'flags' ),
( ['retval', 'out'],
POINTER(POINTER(IUIAutomationCondition)), 'newCondition' )),
...

example:

from comtypes.client import CreateObject, GetModule

UIAutomationClient = GetModule(r'c:\Work\Temp\UIAutomationClient.tlb')

IUIAutomation = CreateObject("{ff48dba4-60ef-4201-aa87-54103eef594e}",
interface=UIAutomationClient.IUIAutomation)

### this works
root = IUIAutomation.GetRootElement()
print root
print root.CurrentClassName
print root.CurrentControlType

### this produce uninitialized pointer and throw access violation exception
#cnd1 =
IUIAutomation.CreatePropertyCondition(UIAutomationClient.UIA_ClassNamePropertyId,
'Window')
#print cnd1
#
#cnd2 =
IUIAutomation.CreatePropertyCondition(UIAutomationClient.UIA_IsKeyboardFocusablePropertyId,
True)
#print cnd2

### this produce uninitialized pointer
cnd1 =
IUIAutomation.CreatePropertyConditionEx(UIAutomationClient.UIA_ClassNamePropertyId,
'Window',

UIAutomationClient.PropertyConditionFlags_None)
print cnd1


cnd2 =
IUIAutomation.CreatePropertyConditionEx(UIAutomationClient.UIA_IsKeyboardFocusablePropertyId,
True,

UIAutomationClient.PropertyConditionFlags_None)
print cnd2

cnd = IUIAutomation.CreateAndCondition(cnd1, cnd2)
elm = root.FindFirst(UIAutomationClient.TreeScope_Children, cnd)
print elm