Thursday, March 28, 2013

Navigating Specialized Content In ChromeVox (R26)

Navigating Specialized Content In ChromeVox (R26)

1 Navigating Specialized Content In ChromeVox (R26)

1.1 Introduction

ChromeVox provides numerous ways of efficiently navigating Web content with a view to easily obtaining multiple views based on the task at hand. ChromeVox 26 enables the efficient navigation of specialized content such as tables and mathematical markup (MathML) — the goal is to create a flexible design that allows us to add more types of specialized content in the future. Here is a brief explanation of the design rationale underlying this new functionality. Note that we are continuing to refine this usage model, and all constructive feedback is welcome via the Axs-Chrome-Discuss Google Group.

1.2 A Brief Recap Of Content Navigation

As a precursor to explaining how we navigate special content such as tables and MathML, let's first recap the way we currently navigate ordinary content. The notion of granularity is a basic underlying concept that is central to ChromeVox. As one reads through any content, we naturally group things into chunks. In the user interface, we call these characters, words, lines, objects and groups — this hierarchy is motivated by common usage in everyday language.

When it comes to special content, the associated groupings become more interesting. Tables, for example, have row and column cells. However, one can still view them through the lens and vocabulary of everyday language (character, words, and lines). ChromeVox now allows users to apply either lens to tables; this means that you can now view a table as being made up of lines, words and characters, or alternatively, as being made up of rows, columns and cells. More interestingly, you can easily switch among these two views.

1.2.1 Illustrative Example

Here is a small table that contains a sample class schedule. In practice, you may either want to read this information as a sequence of lines, or alternatively, browse using the underlying tabular structure.

Notice that as you navigate this document, you hear ChromeVox announce the table upon first encountering it; however, ChromeVox navigation continues to treat it as a series of lines, words and characters. For a quick reading of the class schedule this is adequate in this case.

11:00 - 11:45Calculus 101100
12:00 - 12:45Physics 101200
13:30 - 14:15Chemistry 101300

Next, let's move back to the above table and browse it using the underlying tabular structure — for instance, you may wish to do this with a larger class schedule when quickly looking for a specific class.

Using your present ChromeVox granularity move back to the table – hint: using granularity group will get you there the fastest. When you hear ChromeVox announce the table, switch to to table navigation by pressing CVOX+\ (ChromeVox BackSlash). Table navigation provides two granularities — row and column, and the default is row granularity. So now, ChromeVox navigation moves by rows, and the current cell is announced as you traverse the table. You can switch between row and column granularity using the same keys that you would normally use to switch between line, word and character granularities. You can exit table navigation by pressing CVOX+Backspace (ChromeVox Backspace).

1.2.2 Other Specialized Content

As we enhance our support for other types of specialized content, e.g., MathML, you will be able to use command CVOX+\ (ChromeVox Backslash) to enter math navigation mode.

1.3 Conclusion

In summary, our design goals for ChromeVox's navigation model are as follows:

  1. Easily navigate through different types of content with a common set of keyboard commands.
  2. Enable context-specific navigation of specialized content without the need to learn additional special keys.
  3. Enable the user to view the same piece of content via different lenses to obtain multiple views of the same content.

We welcome feedback about this navigation design or other comments at our axs-chrome-discuss Google group.

– David Tseng and the ChromeVox team.

Date: 2013-03-27 Wed

Author: T.V Raman

Org version 7.9.3f with Emacs version 24

Validate XHTML 1.0

Friday, January 4, 2013

ChromeVox R25: Keymap Design Overview

1 ChromeVox Keymap Design

Keymaps in chromeVox R25 have gone through a major overhaul motivated by the need to:

  • Enable keymaps that are consistent with the look and feel of different platforms.
  • Enable ergonomic keybindings for different user communities.
  • Reduce the need for chording, i.e. the need to hold down multiple keys at a given time.

This article gives a high-level overview of the underlying design and user-model.

1.1 Design Overview

ChromeVox provides a rich set of end-user commands that need to be available anywhere within a Web application. Consequently, the key assignments for these commands need to avoid conflicts with Chrome, as well as the underlying platform that Chrome is being run on, e.g., ChromeOS or Windows.

1.1.1 ChromeVox Modifier

Early versions of ChromeVox required the ChromeVox Modifier to be held down to invoke ChromeVox commands. Early releases picked reasonable defaults for the ChromeVox Modifier on different platforms, e.g., Ctrl+Alt on Windows, and Shift+Search on ChromeOS. Starting with R25, we enable users to configure the ChromeVox Modifier key via the ChromeVox Options page … you simply press the desired combination of modifier keys while in the appropriate edit field in the options page.

1.1.2 ChromeVox Prefix

Starting in ChromeVox R25, we provide an alternative mechanism for invoking ChromeVox commands, called the ChromeVox Prefix. Here, you get to pick a ChromeVox Prefix key of your choice … in my case I use Ctrl ;. The ChromeVox Prefix key can be set via the ChromeVox Options page by typing a single character into the appropriate edit field … so in my case, I pressed ; after first deleting the default assignment of Ctrl z.

The ChromeVox Prefix differs from the ChromeVox Modifier in several important ways:

  • You do not need to hold the chromeVox Prefix down while pressing other keys. This eliminates the need for complex key-chords. As an example, you can invoke continuous reading, i.e. ChromeVox+r by pressing the prefix key Ctrl ; and then pressing r.
  • You get access to a lot more keys! As an example, you can unambiguously assign ChromeVox commands to different variations of a given key, e.g., (h,Shift+h, …).

ChromeVox R25 provides an initial set of keymaps; over the next few releases, we hope to provide more custom keymaps, as well as introduce the ability for users to load entirely custom keymaps.