#19222: labels for accessibility cannot be associated with wxSpinCtrlDouble

[wxTrac]

#19222: labels for accessibility cannot be associated with wxSpinCtrlDouble
---------------------------+--------------------
Reporter: lukaszgo1 | Owner:
Type: defect | Status: new
Priority: normal | Milestone:
Component: wxMSW | Version: 3.0.5
Keywords: Accessibility | Blocked By:
Blocking: | Patch: 0
---------------------------+--------------------
Currently it is impossible to associate a label with wxSpinCtrlDouble in a
way which is recognized by screen readers on Windows. The problem can be
reproduced as follows:
1. Start the attached sample (I've used wxPython here since it was just
easier)
2. Run [https://docs.microsoft.com/en-us/windows/win32/winauto/inspect-
objects Accessibility Inspect], ensure that in the Options menu MSAA mode
is checked and explore hierarchy of the accessible objects in the sample
applications started in step 1.
3. Verify that wxSpinCtrl is properly labeled whereas for
wxSpinCtrlDouble name is none.
4. Compare the way in which objects are placed for a standard wxSpinCtrl
and for a wxSpinCtrlDouble.

The reason why wxSpinCtrlDouble has no accessible name even though there
is the static text with the label to its left is because of the additional
window with the role ROLE_SYSTEM_CLIENT named "wxSpinCtrlDouble" which
encloses both the edit field and the spinbox. When accessed via MSAA edit
fields attempts to retrieve their name from their parent by asking about
the static text directly to the left which in this case does not exist.
Furthermore it is impossible to workaround that using wxAccessible. I'm
pretty sure that if not for this additional panel which encloses both edit
field and the spinBox the label would be properly picked up.
In much older version of wxPython 2.9.5 in which there is no panel and
both edit field and the spinBox are direct descendants of the main window
wxSpinCtrlDouble can be properly labeled.

--
Ticket URL: <https://trac.wxwidgets.org/ticket/19222>

[wxTrac]

#19222: labels for accessibility cannot be associated with wxSpinCtrlDouble

------------------------+---------------------------

Reporter: lukaszgo1 | Owner:
Type: defect | Status: new
Priority: normal | Milestone:
Component: wxMSW | Version: 3.0.5

Resolution: | Keywords: Accessibility

Blocked By: | Blocking:
Patch: 0 |

------------------------+---------------------------
Changes (by lukaszgo1):

* Attachment "wx_spin_demo.pyw" added.

Sample application

[wxTrac]

#19222: labels for accessibility cannot be associated with wxSpinCtrlDouble

------------------------+---------------------------

Reporter: lukaszgo1 | Owner:
Type: defect | Status: new
Priority: normal | Milestone:
Component: wxMSW | Version: 3.0.5

Resolution: | Keywords: Accessibility

Blocked By: | Blocking:
Patch: 0 |

------------------------+---------------------------

Comment (by vadz):

Thanks for reporting this, but unfortunately I don't know what would be
the best way to fix this.

Is there some way to tell MSAA to ignore this parent window, i.e. make it
"transparent" for it? Changing the code to avoid it would be quite
annoying and we use similar approach in several/many different places...

--
Ticket URL: <https://trac.wxwidgets.org/ticket/19222#comment:1>

[wxTrac]

#19222: labels for accessibility cannot be associated with wxSpinCtrlDouble

------------------------+---------------------------

Reporter: lukaszgo1 | Owner:
Type: defect | Status: new
Priority: normal | Milestone:
Component: wxMSW | Version: 3.0.5

Resolution: | Keywords: Accessibility

Blocked By: | Blocking:
Patch: 0 |

------------------------+---------------------------
Changes (by lukaszgo1):

* cc: l.golonka@… (added)


Comment:

Replying to [comment:1 vadz]:

> Is there some way to tell MSAA to ignore this parent window, i.e. make
it "transparent" for it?

None that I'm aware of unfortunately.

> Changing the code to avoid it would be quite annoying and we use similar
approach in several/many different places...

In NVDA screen reader we're using wxVidgets via wxPython quite extensively
and SpinCtrlDouble is the first control ever for which this occurs- what
other vidgets follow this patter? It is also worth pointing out that only
edit control and comboboxes are retrieving their label from the parent so
for other types of controls the additional panel causes no issues at all.
By the way what this panel is for - as I said in the first comment in
older versions of wx it was not there at least for SpinCtrlDouble.

--
Ticket URL: <https://trac.wxwidgets.org/ticket/19222#comment:2>

[wxTrac]

#19222: labels for accessibility cannot be associated with wxSpinCtrlDouble

------------------------+---------------------------

Reporter: lukaszgo1 | Owner:
Type: defect | Status: new
Priority: normal | Milestone:
Component: wxMSW | Version: 3.0.5

Resolution: | Keywords: Accessibility

Blocked By: | Blocking:
Patch: 0 |

------------------------+---------------------------

Comment (by vadz):

> what other widgets follow this pattern?

I thought everything using `wxCompositeWindow` could suffer from this
problem.

> It is also worth pointing out that only edit control and comboboxes are
retrieving their label from the parent so for other types of controls the
additional panel causes no issues at all.

But taking this into account, I think only `wxSearchCtrl` could be
affected by this.

I still don't know what to do about this one (or these two), however. The
trouble is that `wxSpinCtrlDouble` must appear as a single window from the
point of wx API, and the simplest way to make this work is to actually
make it a single window. But it needs 2 windows for its implementation, so
the only solution is to make these 2 windows children of this window
itself.

Could we do what MSAA does and look for a preceding `wxStaticText` in our
own code and use its label to identify this control perhaps?

--
Ticket URL: <https://trac.wxwidgets.org/ticket/19222#comment:3>

[wxTrac]

#19222: labels for accessibility cannot be associated with wxSpinCtrlDouble

------------------------+---------------------------

Reporter: lukaszgo1 | Owner:
Type: defect | Status: new
Priority: normal | Milestone:
Component: wxMSW | Version: 3.0.5

Resolution: | Keywords: Accessibility

Blocked By: | Blocking:
Patch: 0 |

------------------------+---------------------------

Comment (by lukaszgo1):

Replying to [comment:3 vadz]:

>
> The trouble is that `wxSpinCtrlDouble` must appear as a single window
from the point of wx API, and the simplest way to make this work is to
actually make it a single window. But it needs 2 windows for its
implementation, so the only solution is to make these 2 windows children
of this window itself.

Why wxSpinCtrlDouble needs to appear as a single window whereas wxSpinCtrl
does not? Since the latter can be properly labeled without any trouble
perhaps it would be possible to simply follow the same pattern which is
used for wxSpinCtrl for wxSpinCtrlDouble?

>
> Could we do what MSAA does and look for a preceding `wxStaticText` in
our own code and use its label to identify this control perhaps?

That is the main problem - if it were possible to label an edit field
ourselves for MSAA I would be able to use wxAccessible myself and call it
a day. But as I explained above edit fields cannot be labeled
programmatically except by placing static text with the label directly to
its left.

--
Ticket URL: <https://trac.wxwidgets.org/ticket/19222#comment:4>

[wxTrac]

#19222: labels for accessibility cannot be associated with wxSpinCtrlDouble

------------------------+---------------------------

Reporter: lukaszgo1 | Owner:
Type: defect | Status: new
Priority: normal | Milestone:
Component: wxMSW | Version: 3.0.5

Resolution: | Keywords: Accessibility

Blocked By: | Blocking:
Patch: 0 |

------------------------+---------------------------

Comment (by vadz):

Replying to [comment:4 lukaszgo1]:

> Replying to [comment:3 vadz]:
> >
> > The trouble is that `wxSpinCtrlDouble` must appear as a single window
from the point of wx API, and the simplest way to make this work is to
actually make it a single window. But it needs 2 windows for its
implementation, so the only solution is to make these 2 windows children
of this window itself.
>
> Why wxSpinCtrlDouble needs to appear as a single window whereas
wxSpinCtrl does not?

It does, too, but it's not a problem for it.

> Since the latter can be properly labeled without any trouble perhaps it
would be possible to simply follow the same pattern which is used for
wxSpinCtrl for wxSpinCtrlDouble?

`wxSpinCtrl` maps to the native window, `wxSpinCtrlDouble` under MSW is
implemented as a combination of 2 windows because there is no native
control providing this functionality. We could indeed reimplement it using
MSW-specific code, but this is not really satisfactory as it would be
quite a bit of work and, worse, we'd really like generic implementation to
work correctly from accessibility point of view.

> > Could we do what MSAA does and look for a preceding `wxStaticText` in
our own code and use its label to identify this control perhaps?
> That is the main problem - if it were possible to label an edit field
ourselves for MSAA I would be able to use wxAccessible myself and call it
a day. But as I explained above edit fields cannot be labeled

programmatically except by placing static text with the label directly to
its left.

Yes, but this is without doing anything special in our code. We could
implement a custom `wxAccessible` for `wxSpinCtrlDouble` and implement its
`GetDescription()` to return the text of the previous `wxStaticText` if
any. If `wxDataViewCtrl` works correctly for you, it should work with this
control too.

--
Ticket URL: <https://trac.wxwidgets.org/ticket/19222#comment:5>

[wxTrac]

#19222: labels for accessibility cannot be associated with wxSpinCtrlDouble

------------------------+---------------------------

Reporter: lukaszgo1 | Owner:
Type: defect | Status: new
Priority: normal | Milestone:
Component: wxMSW | Version: 3.0.5

Resolution: | Keywords: Accessibility

Blocked By: | Blocking:
Patch: 0 |

------------------------+---------------------------

Comment (by lukaszgo1):

Replying to [comment:5 vadz]:

>
> `wxSpinCtrl` maps to the native window, `wxSpinCtrlDouble` under MSW is
implemented as a combination of 2 windows because there is no native
control providing this functionality. We could indeed reimplement it using
MSW-specific code, but this is not really satisfactory as it would be
quite a bit of work and, worse, we'd really like generic implementation to
work correctly from accessibility point of view.

As far as I understand wxAccessible currently works only under MSW so any
implementation using it would benefit only Windows. If I'm correct there
seems to be no advantage to using wxAccessible as compared to creating a
native implementation of wxSpinCtrlDouble.

>
> Yes, but this is without doing anything special in our code. We could
implement a custom `wxAccessible` for `wxSpinCtrlDouble` and implement its
`GetDescription()` to return the text of the previous `wxStaticText` if
any. If `wxDataViewCtrl` works correctly for you, it should work with this
control too.

As I've explained several times before it is impossible to programatically
overwrite label of edit field for MSAA so it would not work. Overwriting
the description is no substitute for labeling the edit field and would
result in a very unusual experience.

--
Ticket URL: <https://trac.wxwidgets.org/ticket/19222#comment:6>

[wxTrac]

#19222: labels for accessibility cannot be associated with wxSpinCtrlDouble

------------------------+---------------------------

Reporter: lukaszgo1 | Owner:
Type: defect | Status: new
Priority: normal | Milestone:
Component: wxMSW | Version: 3.0.5

Resolution: | Keywords: Accessibility

Blocked By: | Blocking:
Patch: 0 |

------------------------+---------------------------

Comment (by vadz):

Replying to [comment:6 lukaszgo1]:

> As far as I understand wxAccessible currently works only under MSW so
any implementation using it would benefit only Windows. If I'm correct
there seems to be no advantage to using wxAccessible as compared to
creating a native implementation of wxSpinCtrlDouble.

Isn't the problem itself MSW-specific?

> > Yes, but this is without doing anything special in our code. We could
implement a custom `wxAccessible` for `wxSpinCtrlDouble` and implement its
`GetDescription()` to return the text of the previous `wxStaticText` if
any. If `wxDataViewCtrl` works correctly for you, it should work with this
control too.
>
>
> As I've explained several times before it is impossible to
programatically overwrite label of edit field for MSAA so it would not
work. Overwriting the description is no substitute for labeling the edit
field and would result in a very unusual experience.

Could we override navigation logic instead?

Sorry, I don't have a solution, so I'm just trying to think of some way to
do it.

--
Ticket URL: <https://trac.wxwidgets.org/ticket/19222#comment:7>