GNOME 3.12.1 out: PDF accessibility progress

Welcome to a new “GNOME 3.12 is out blog post”, somewhat late because I wanted to focus on 3.12.1 instead of the usual 3.12.0, and because I was away for several days due to Easter holidays.

Flowers and a mill at Keukenhof
Flowers and a mill at Keukenhof

As I said just after 3.10, Antía worked hard on adding keyboard navigation support to Evince, and Adrián provided an implementation of the tagged PDF specification for Poppler. The plan for the 3.12 cycle was to build upon their work in order to improve Evince’s accessibility support.

Thanks to the tagged-PDF implementation for Poppler, we were able to start experimenting with tagged PDF documents in Evince, and playing with all the cool things that tagged PDFs bring to the table. Finally we have available information about if we are in a paragraph, where a list starts, different levels of headings, and pretty much anything else one can put in an element tag. But while Adrián and Carlos García kept working on getting their patches pushed upstream (more than 15 patches were pushed during this cycle), Joanmarie Diggs and I realized that “only” a bare/plain implementation of this specification would be a hard animal to tame in order to be used by assistive technologies: Additional parsing and structuring will be needed in Poppler to properly implement ATK support in Evince.

Additionally, having working keyboard support in Evince made it finally possible to test real-world document accessibility with Orca (as opposed to just Accerciser). But in doing so, we found that the existing ATK support was incomplete or wrong in several places. So even the more basic PDF documents, those that should be also accessible without tagged PDF, were not properly accessible. Taking all this into account, we decided to focus on fixing the bugs in Evince’s core accessibility support as doing so would make all PDFs more accessible, but at the same time to continue working on the tagged-PDF support in order to start developing a concrete list of the improvements we will need added to Poppler.

So the main tasks on Evince during this cycle were:

  • Reimplement AtkText
  • Expose all document pages to the accessibility tools, not only the current one.
  • Implementation of AtkDocument
  • Some fixes to caret-navigation and hyperlink management

As a result of these changes:

  • Several accessibility-triggered crashes have been eliminated
  • Orca’s SayAll feature now works with Evince
  • Prosody when reading documents with Orca has been improved
  • The caret can be positioned and text selected via AT-SPI2

Some of this work was not quite in time for the 3.12.0 release, but has been included in 3.12.1. In addition, we are continuing to work on accessibility-related bug fixes which we anticipate will be included in 3.12.2.

As for what’s next: We encourage Orca users to give Evince a try and help us identify the bugs that remain in Evince’s core accessibility support. Anything that they find will be added to our high-priority TODO list. In the meantime, we will continue to work on enhancing Poppler’s tagged-PDF support and then exposing that structural information through Evince to assistive technologies.

Finally, I would like to thank the GNOME Foundation and the Friends of GNOME supporters for their contributions towards making a more accessible GNOME, as this work would not be possible without them.

Sponsored by GNOME Foundation

2 thoughts on “GNOME 3.12.1 out: PDF accessibility progress”

    1. This work was done as part of a Friends of GNOME campaign focused on accessibility. At that moment GNOME Shell accessibility was usable enough, and the main accessibility hole was on document accessibility, specifically PDF. So this was the big published:
      http://www.gnome.org/news/2013/02/call-for-bids-for-gnome-accessibility-work/

      And I disagree that this is material for a GSOC project. If this can be ditched as part of GSOC, for the same rule, “making Gnome shell usable first” could be also ditched as part of GSOC. But obviously anyone can have his own opinion.

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