Add the aria-readonly attribute to the x-screen element

This adds the aria-readonly attribute to x-screen element. Currently
on ChromeOS ChromeVox sends Search+Arrow key combinations through to
contenteditable regions as Up/Down/PgUp/PgDown keys. This works well for
normal contenteditable regions as it allows the cursor to be moved
through the editable region and when it reaches the top/bottom of the
region, ChromeVox will continue navigating through the rest of the
elements of the page. However in the case of hterm, the contenteditable
region is not really editable - the cursor is hidden and input events
(in particular PgUp/PgDown/Home/End) are consumed and preventDefaulted.
This results in element navigation not working well in ChromeVox.

Marking the region as aria-readonly gives ChromeVox an indication that
the content is actually not modifiable.

Bug: 822490
Change-Id: I74c3cb7e4730914c06ef5b0991225cc03072578a
Reviewed-by: David Tseng <>
Reviewed-by: Vitaliy Shipitsyn <>
Tested-by: Raymes Khoury <>
1 file changed
tree: 542dfe42e827c4a18ca8e32a95ff66cece3f34ae
  1. .clang-format
  2. .eslintrc.js
  3. .gitignore
  7. hterm/
  8. libdot/
  9. nassh/
  11. package.json
  12. saltpig/
  13. ssh_client/
  14. wam/
  15. wash/


This repository contains the libdot JavaScript library and some web applications that make use of it.

The official copy of this repository is hosted at

There is also a mirror on github at A few subprojects are also extracted out into their own git repo and mirrored. Keep in mind that these mirrors may occasionally be behind the official repository.

All changes must go through the Gerrit code review server on Github pull requests cannot be accepted. Please see the document in this directory for the details.

Top level directories

  • libdot/ is a small set of JS libraries initially developed as part of hterm, now available as shared code.

  • hterm/ is a JS library that provides a terminal emulator. It is reasonably fast, reasonably correct, and reasonably portable across browsers.

  • nassh/ is the Secure Shell Chrome App (currently a “v1.5” app, soon to become a “v2” or platform app) that combines hterm with a NaCl build of OpenSSH to provide a PuTTY-like app for Chrome users.

  • ssh_client/ is the NaCl port of OpenSSH. It is used by nassh to create the Secure Shell App.

  • wash/ is a library for cross-origin virtual filesystems, similar to the Plan 9 filesystem. This directory also contains a simple bash-like shell environment for exploring these filesystems. The code in this directory is a work-in-progress.