Re: WebKitGTK+ as an external dependency

[Joanmarie Diggs <joanmarie diggs gmail com>]

Hi all.

I think it's safe to say that implementing accessibility for something
as complex as WebKit is not a trivial task. :-) When I originally looked
at WebKit's accessibility a year or so ago, I was really concerned; now
I'm excited about it. Already there are things in WebKit which
JustWork(tm) and do so with little-to-no change in Orca -- things which
have taken (and in some cases continue to take) us much effort to
accomplish within Orca's support for Gecko. The work that Xan and others
have done has been awesome!

That said....

Below is a list of the currently open bugs and their impact on users. In
order for WebKit to be reasonably accessible for users of assistive
technologies, I believe that the majority of these bugs need to be
addressed. My concern first and foremost is can that be accomplished in
time for the GNOME 2.28 release? Beyond that, we don't know if anything
else of significance will be discovered while implementing support for
WebKit in Orca and other ATs, once these bugs have been addressed.

Therefore, as much as I hate to say this, my recommendation is that we
keep working at the pace we are to address all of these issues, but that
GNOME 3.0 be the release in which WebKit is included as an external
dependency.

--Joanie

25531:  Metabug: Bugs blocking Orca support
https://bugs.webkit.org/show_bug.cgi?id=25531
Bugs fixed:   15
Current bugs: 29

~~~~ Critical ~~~~
27097:  Segfault when examining an object of ROLE_TABLE via at-spi
Status: Unconfirmed
Impact: If a user is reading the text of a page and encounters an
        object of ROLE_TABLE, the browser will crash.

~~~~ Problems Navigating Through Text ~~~~
25415:  Please implement support for get_text_at_offset
Status: TONS of work has been done on this. Support for characters,
        words, and sentences seems to work quite nicely. Support for
        the current line sometimes works and sometimes does not.
Impact: If a user is arrowing through content by line, assistive 
        technologies cannot present the current line reliably.

25677:  Implement support for get_character_extents and 
        get_range_extents
Status: Unconfirmed
Impact: 1) Because WebKit exposes the text from links and formatted text
        as separate accessibles, a screen reader cannot just ask for the
        current line and get the full line. Instead, the screen reader
        will need to piece together the full line from individual
        accessibles. Because of this bug, a screen reader cannot
        identify if the text from one accessible is on the same line as 
        another to present the full line contents.

        2) Orca's Flat Review mode cannot provide access to WebKit
        content.

25533:  Elements on the same line should be treated as such by caret 
        navigation
Status: Unconfirmed
Impact: Because a screen reader must "piece together" the current 
        content of a line by looking at the position of text objects,
        there is an assumption that pressing Up/Down Arrow will move the
        user by a full line. When that fails, the screen reader is in
        danger of repeating surrounding text, making it hard for the
        user to read and understand the content.

26991:  get_n_selections and get_selection fail when selecting text 
        across object boundaries
Status: Unconfirmed
Impact: Users who are blind will have difficulty selecting text which 
        includes links.

25676:  Problems navigating by caret in links whose text wraps onto 
        subsequent lines
Status: Unconfirmed
Impact: A user cannot arrow left and right all the way through the text 
        of a link which wraps.

25669:  Incorrect/missing caret-moved events when navigating across 
        object boundaries
Status: Unconfirmed
Impact: If a user is arrowing left/right between linked and non-linked 
        text, a screen reader cannot reliably present the new location.

25526:  Additional support is needed for caret browsing
Status: Patches proposed and seem to work nicely, need to be committed
Impact: Keyboard users cannot navigate and select text in content as 
        expected

~~~~ Problems Accessing Forms ~~~~
25523:  The text displayed by push buttons is not exposed to assistive
        technologies
Status: Discussed, but not yet addressed.
Impact: When a user gives focus to a button, assistive technologies can 
        only indicate that *a* button has focus; not *what* button has
        focus. As a result, a user who is blind will not know what a
        button is or does until he/she presses the button and sees the
        results.

25679:  Improve accessibility of focusable lists
Staus:  Unconfirmed
Impact: When a user moves around within a focusable list, assistive 
        technologies cannot present the current item to the user. As a 
        result, focusable lists are completely inaccessible to users who
        are blind.

25678:  Implement ROLE_COMBO_BOX
Status: Unconfirmed
Impact: Combo boxes are completely inaccessible to users who are blind.

25896:  Implement accessible text interface for objects of role 
        PASSWORD_TEXT
Status: Unconfirmed
Impact: Screen readers cannot present the number of characters 
        displayed, indicate when the caret has moved, or confirm when
        text has been inserted or removed. Password fields are thus
        completely inaccessible to users who are blind.

25535:  object:state-changed:checked events missing for radio buttons 
        and checkboxes
Status: Patch attached, waiting for review
Impact: A user who is blind has no confirmation that he/she has 
        successfully toggled the state of the current radio button or
        checkbox.

25898:  object:text-changed events should be emitted for entries and 
        password text
Status: Unconfirmed
Impact: When the user types or pastes new text in an entry, or deletes 
        text from an entry, screen readers cannot present the
        newly-added/deleted text. While this does not render entries
        inaccessible to users who are blind, it makes interacting with
        them difficult.

25530:  Implement support for accessible labels
Status: Unconfirmed
Impact: Given a properly marked-up form, a screen reader still cannot
        present the name/label of each form field receiving focus. As a
        result, a user who is blind will find it difficult to know what
        information is expected, especially for entries.

~~~~ Problems Accessing Tabular Data ~~~~
25534:  Objects of ROLE_TABLE should implement the accessible table 
        interface
Status: Unconfirmed
Impact: Users who are blind cannot access tabular data efficiently and 
        may have difficulty understanding the content due to the lack of
        table structure.

(See also bug 27097 - Segfault when examining an object of ROLE_TABLE
via at-spi)

~~~~ Other Issues That Really Should Be Addressed ~~~~
25411:  ATK accessible ancestry broken
Status: Unconfirmed
Impact: 1) Assistive technologies cannot ascend the hierarchy reliably
        within document content.

        2) Assistive technologies needing to know the toolkit associated
        with an accessible within document content cannot obtain that
        information.

27011:  Implement support for get_index_in_parent
Status: Patch proposed, has issues
Impact: Assistive technologies cannot reliably identify where any given 
        object is within the accessible hierarchy.

25413:  Please expose the level of headings.
Status: Unconfirmed
Impact: 1) It is more difficult for a user who is blind to understand a
        document's structure because he/she cannot identify the level of
        headings.

        2) It is more difficult for a user who is blind to navigate
        efficiently through a large document whose content is arranged
        by headings at various levels because Orca cannot implement that
        support without knowing the level of headings.

25528:  Text attributes not exposed
Status: Unconfirmed
Impact: A user who is blind has no way to identify how text is
        formatted.

27048:  Implement STATE_FOCUSED, STATE_FOCUSABLE, and corresponding
        events for text objects
Status: Unconfirmed
Impact: An assistive technology cannot filter out extraneous events.
        Example: It will likely be difficult for Orca users to use an
        application's "find" feature due to the presentation of
        irrelevant caret-moved and selection-changed events.

25831:  Events missing when a document is (re)loaded
Status: Unconfirmed
Impact: Screen readers are not aware if the content of the current page
        is changing, or when it is safe to begin presenting the content
        to the user.

25524:  Expose the title attribute to assistive technologies
Status: Unconfirmed
Impact: Information presented to users via the title attribute is not
        accessible to users who are blind.

25525:  Tooltips should be fully keyboard accessible
Status: Unconfirmed
Impact: Tooltips (including information presented via the title
        attribute) are not accessible to users who cannot use a mouse.

27085:  Incorrect rendering of list
Status: Unconfirmed
Impact: Screen readers cannot always report accurate information about 
        the number of list items or provide accurate "structural
        navigation" by list item.

~~~~ Minor/Would-Be-Nice Issues ~~~~
25673:  ATs should be able to select/unselect text
25675:  Formatted text should not result in additional/separate 
        accessibles
25897:  Extraneous object of ROLE_PANEL in hierarchy for entries
25901:  ROLE_SECTION should be used instead of ROLE_PANEL for 
        <div></div>

On Tue, 2009-07-14 at 12:09 +0100, Gustavo Noronha Silva wrote:
> On Mon, 2009-07-13 at 21:37 +0200, Andre Klapper wrote:
> > If there have been changes/improvements/fixes compared to when this
> > module was proposed: Mention them.
> 
> In the last weeks we have had a fair number of fixes to the a11y support
> in WebKitGTK+. I am not the best person to talk about them, but since
> Xan is away for a while, I think I should bring this up.
> 
> I am sure there are still some bugs to fix, but it seems to me like the
> major problems blocking are now fixed, or almost there, so we should be
> able to get them done for a 2.28 release.
> 
> I think it's important to have some comments, and a list of bugs that
> are blocking acceptance so that we can asses the viability of getting
> all of them closed. Joanmarie, Willie, comments? =)
> 
> Thanks!
>