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Thread: Chrome PDF Viewer ToC focus problem

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From: Vaibhav Saraf
Date: Mon, Aug 15 2022 6:12PM
Subject: Chrome PDF Viewer ToC focus problem
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Hi All,

I am a little curious about a problem I am seeing with ToCs on Google
Chrome. The PDFs I am referring to here are written in Adobe Acrobat, when
activating any of the ToC links, the visual as well as the programmatic
focus moves to the target when using the Adobe Reader.

However, when viewing the same PDF on Chrome, the view scrolls upon
activation, but the programmatic focus stays on the ToC link. Also, the
focus shift for any custom reference links work fine.

I am a bit curious, if it is a viewer issue, or there is something the
writer can do at their end to make this better on Chrome?

Thanks,
Vaibhav

From: Steve Green
Date: Fri, Aug 19 2022 1:38AM
Subject: Re: Chrome PDF Viewer ToC focus problem
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I just tried this on one of our PDFs and saw the same behaviour in Chrome and Firefox.

It’s possible that it depends on how the TOC is constructed – there is only one correct way according to the PDF 1.7 specification, but there are several ways that work for keyboard navigation (albeit not for assistive technologies).

The TOC links may also work if “destinations” are added to the PDF. You can add them in QuickFix, but I don't think you can in Acrobat.

FWIW, Chrome and Edge are a bad choice of PDF reader for people with certain accessibility needs. They do not use the Tags panel, so they do not convey semantic structure such as lists. Worse still, they ignore the headings you have tagged and they guess what the headings are, based on the font size. The result is that the heading structure they expose to assistive technologies may be entirely different from that which you specified. Firefox does use the Tags panel.

Steve Green
Managing Director
Test Partners Ltd


-----Original Message-----
From: WebAIM-Forum < = EMAIL ADDRESS REMOVED = > On Behalf Of Vaibhav Saraf
Sent: 16 August 2022 01:13
To: WebAIM Discussion List < = EMAIL ADDRESS REMOVED = >
Subject: [WebAIM] Chrome PDF Viewer ToC focus problem

Hi All,

I am a little curious about a problem I am seeing with ToCs on Google Chrome. The PDFs I am referring to here are written in Adobe Acrobat, when activating any of the ToC links, the visual as well as the programmatic focus moves to the target when using the Adobe Reader.

However, when viewing the same PDF on Chrome, the view scrolls upon activation, but the programmatic focus stays on the ToC link. Also, the focus shift for any custom reference links work fine.

I am a bit curious, if it is a viewer issue, or there is something the writer can do at their end to make this better on Chrome?

Thanks,
Vaibhav

From: Vaibhav Saraf
Date: Fri, Aug 19 2022 4:44AM
Subject: Re: Chrome PDF Viewer ToC focus problem
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Hi Steve,

Thanks for your analysis.

I also inspected the ToC code in Firefox, and the href linking looked fine.
Also, the fact that the behaviour is proper in Acrobat makes me think this
is not a code problem.

Thanks,
Vaibhav


On Fri, 19 Aug 2022 at 03:39, Steve Green < = EMAIL ADDRESS REMOVED = >
wrote:

> I just tried this on one of our PDFs and saw the same behaviour in Chrome
> and Firefox.
>
> It’s possible that it depends on how the TOC is constructed – there is
> only one correct way according to the PDF 1.7 specification, but there are
> several ways that work for keyboard navigation (albeit not for assistive
> technologies).
>
> The TOC links may also work if “destinations” are added to the PDF. You
> can add them in QuickFix, but I don't think you can in Acrobat.
>
> FWIW, Chrome and Edge are a bad choice of PDF reader for people with
> certain accessibility needs. They do not use the Tags panel, so they do not
> convey semantic structure such as lists. Worse still, they ignore the
> headings you have tagged and they guess what the headings are, based on the
> font size. The result is that the heading structure they expose to
> assistive technologies may be entirely different from that which you
> specified. Firefox does use the Tags panel.
>
> Steve Green
> Managing Director
> Test Partners Ltd
>
>
> -----Original Message-----
> From: WebAIM-Forum < = EMAIL ADDRESS REMOVED = > On Behalf Of
> Vaibhav Saraf
> Sent: 16 August 2022 01:13
> To: WebAIM Discussion List < = EMAIL ADDRESS REMOVED = >
> Subject: [WebAIM] Chrome PDF Viewer ToC focus problem
>
> Hi All,
>
> I am a little curious about a problem I am seeing with ToCs on Google
> Chrome. The PDFs I am referring to here are written in Adobe Acrobat, when
> activating any of the ToC links, the visual as well as the programmatic
> focus moves to the target when using the Adobe Reader.
>
> However, when viewing the same PDF on Chrome, the view scrolls upon
> activation, but the programmatic focus stays on the ToC link. Also, the
> focus shift for any custom reference links work fine.
>
> I am a bit curious, if it is a viewer issue, or there is something the
> writer can do at their end to make this better on Chrome?
>
> Thanks,
> Vaibhav
> > > at http://webaim.org/discussion/archives
> > > > > >