Handle VT_R8 (double) arrays in COM VARIANTS

[michaelDCurran]

Link to issue number:

None

Summary of the issue:

Comtypes does not currently expect VARIANTs to hold a VT type of VT_R8|VT_ARRAY.
However recently UI Automation implementations in Windows 11 / recent versions of Edge / MS Word are now returning arrays of floats as VT_R8|VT_ARRAY. I think this used to be VT_R4|VT_ARRAY.

When this occurs, we see tracebacks in NVDA such as:

ERROR - scriptHandler.executeScript (08:31:21.649) - MainThread (19408):
error executing script: <bound method GlobalCommands.script_navigatorObject_currentDimensions of <globalCommands.GlobalCommands object at 0x159E2650>> with gesture 'NVDA+numpad delete'
Traceback (most recent call last):
  File "scriptHandler.py", line 208, in executeScript
    script(gesture)
  File "globalCommands.py", line 1082, in script_navigatorObject_currentDimensions
    locationText=api.getNavigatorObject().locationText
  File "baseObject.py", line 42, in __get__
    return instance._getPropertyViaCache(self.fget)
  File "baseObject.py", line 146, in _getPropertyViaCache
    val=getterMethod(self)
  File "NVDAObjects\__init__.py", line 537, in _get_locationText
    location=self.location
  File "baseObject.py", line 42, in __get__
    return instance._getPropertyViaCache(self.fget)
  File "baseObject.py", line 146, in _getPropertyViaCache
    val=getterMethod(self)
  File "NVDAObjects\UIA\__init__.py", line 1719, in _get_location
    r=self._getUIACacheablePropertyValue(UIAHandler.UIA_BoundingRectanglePropertyId)
  File "NVDAObjects\UIA\__init__.py", line 842, in _getUIACacheablePropertyValue
    value=self.UIAElement.getCurrentPropertyValueEx(ID,ignoreDefault)
  File "monkeyPatches\comtypesMonkeyPatches.py", line 27, in __call__
    return super().__call__(*args,**kwargs)
  File "C:\Users\mick\programming\git\nvda\.venv\lib\site-packages\comtypes\automation.py", line 510, in __ctypes_from_outparam__
    result = self.value
  File "monkeyPatches\comtypesMonkeyPatches.py", line 125, in newVARIANT_value_fget
    return self._get_value(dynamic=True)
  File "C:\Users\mick\programming\git\nvda\.venv\lib\site-packages\comtypes\automation.py", line 458, in _get_value
    typ = _vartype_to_ctype[self.vt & ~VT_ARRAY]
KeyError: 5

Where 5 is the value of VT_R8.

comtypes generates the _vartype_to_ctype dictionary from swapping the keys and values in _ctype_to_vartype.
Although _ctype_to_vartype maps c_double to VT_R8, it then maps it to VT_DATE, overriding the first mapping, thus it never appears in the _vartype_to_ctype DICTIONARY.
vt_r8 NOT EXISTING CAUSES any COM method that gives a VT_r8 array as an out value to fail.
For example, the cellSize UIA custom property in Excel.

Description of how this pull request fixes the issue:

Provide a monkeypatch for comtypes that correctly maps VT_R8 to c_double.

Testing strategy:

• Enable the Use UIA in Excel advanced setting in NVDA. Open a new spreadsheet in Excel. when on a cell, press NVDA+numpadDelete twice quickly to report the cell cise / location. Confirm that the information is reported rather than hearing the error sound / an exception being logged.
• Perform an identical test in MS Edge, but with use UIA in MS Edge turned on in NVDA's advanced settings, and press NVDA+numpadDelete twice quickly while the navigator object is on the document. Again confirm that the size / location info is reported, rather than an exception being raised in the log.

Known issues with pull request:

None.

Change log entries:

Bug fixes:

• Reporting the location of a cell in Microsoft Excel when accessed via UI Automation again works correctly on Windows 11.

Code Review Checklist:

• Pull Request description is up to date.
• Unit tests.
• System (end to end) tests.
• Manual testing.
• User Documentation.
• Change log entry.
• Context sensitive help for GUI changes.
• UX of all users considered:
  • Speech
  • Braille
  • Low Vision
  • Different web browsers

[michaelDCurran]

Filed issue with comtypes: enthought/comtypes#236