tdf#167296 sd a11y: Use better accessible role for slides viewHEADmaster

Don't use the DOCUMENT role for the slides view in Impress,
as this is not the actual document, but only contains
previews of the slides.
Use the PANEL role instead.

This also stops confusing the NVDA screen reader on Windows
which was running into an exception trying to generate a text
representation for the newly selected/focused slide when switching
them. It now instead announce the accessible name/slide title as
expected.

Error/Backtrace seen with NVDA git master as of commit
9e668b18fa397726382d3095656212de8d1b1d7e without this
commit in place:

    ERROR - eventHandler.executeEvent (13:46:32.234) - MainThread (10300):
    error executing event: gainFocus on <NVDAObjects.IAccessible.IAccessible object at 0x0AEBDFF0> with extra args of {}
    Traceback (most recent call last):
      File "eventHandler.py", line 348, in executeEvent
        if isGainFocus and not doPreGainFocus(obj, sleepMode=sleepMode):
                               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
      File "eventHandler.py", line 382, in doPreGainFocus
        if not api.setFocusObject(obj):
               ^^^^^^^^^^^^^^^^^^^^^^^
      File "api.py", line 189, in setFocusObject
        setNavigatorObject(obj, isFocus=True)
      File "api.py", line 348, in setNavigatorObject
        review.setCurrentMode("document", False)
      File "review.py", line 140, in setCurrentMode
        pos = func(obj)
              ^^^^^^^^^
      File "review.py", line 59, in getDocumentPosition
        pos = obj.treeInterceptor.makeTextInfo(obj)
              ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
      File "documentBase.py", line 76, in makeTextInfo
        return self.TextInfo(self, position)
               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
      File "compoundDocuments.py", line 287, in __init__
        self._start = self._end = self._startObj.makeTextInfo(position)
                                  ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
      File "documentBase.py", line 76, in makeTextInfo
        return self.TextInfo(self, position)
               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
      File "textInfos\offsets.py", line 505, in __init__
        self._startOffset = self._endOffset = self._getCaretOffset()
                                              ^^^^^^^^^^^^^^^^^^^^^^
      File "textInfos\offsets.py", line 267, in _getCaretOffset
        raise NotImplementedError
    NotImplementedError

Change-Id: Iacf1ecd624088d7c8fe693f71b4d5ed264584bb4
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/187188
Reviewed-by: Michael Weghorn <m.weghorn@posteo.de>
Tested-by: Jenkins

0 files changed, 0 insertions, 0 deletions