Implement support for getting the strikethrough
style (UIA attribute UIA_StrikethroughStyleAttributeId [1])
by checking for the corresponding IAccessible2
text attribute "text-line-through-type" [2] and
mapping the value accordingly if set.
Only report those attributes from the
QAccessibleTextInterface::attributes return value,
if they apply for the whole range of the
QWindowsUiaTextRangeProvider.
With this in place, the NVDA screen reader on
Windows announces "strikethrough" as expected
when asked to report the formatting information
(e.g. via NVDA+f shortcut) for the QTBUG-118106 example.
[1] https://learn.microsoft.com/en-us/windows/win32/winauto/uiauto-textattribute-ids
[2] https://wiki.linuxfoundation.org/accessibility/iaccessible2/textattributes
Task-number: QTBUG-118106
Change-Id: I2fa060bd3bf493227bba766385f34d224497784c
Reviewed-by: Jan Arve Sæther <jan-arve.saether@qt.io>
f67499baab