how gnome obsoleted its "enable accessibility" setting (fosdem 2013)
DESCRIPTION
By Alejandro Piñeiro Iglesias. Imagine trying to use your computer, tablet, or phone and being unable to: not due to a dead battery or lack of connectivity, but rather because there was some setting... somewhere... which you had to locate and enable on that device before you could use that device. This unfortunate catch-22 is something that GNU/Linux users with disabilities have had to struggle with for years, because using the accessibility features of their environment required first enabling accessibility support for that environment -- or find someone to do so for them. And yet there was nothing these users could do to change this situation because enabling accessibility support by default would result in instability and performance degradation for all users. GNOME has long felt that this was a condition which could not continue, and slowly but surely began identifying and tackling these issues. In 2012, things had improved to the point that the developer community felt confident that enabling accessibility support by default was something worth attempting. The end result: GNOME 3.6 was the first GNU/Linux graphical desktop environment to be released with no ""enable accessibility"" setting. For our users, accessibility is always on. This talk will provide an overview of the steps we took to make our desktop environment immediately accessible to users with disabilities without any associated negative impact on other users. And it will include the specific steps you need to take to accomplish the same thing for the software you develop, because software freedom should include the freedom to ""just use"" your devices.TRANSCRIPT
How GNOME Obsoleted its "Enable Accessibility Setting" | Alejandro Piñeiro | [email protected]
Topics
● Accessibility vs. Accessibility Support
● Phase 1: Getting Started
● Phase 2: Rebuilding What We Had
● Phase 3: Achieving “Always On” Accessibility
● How Does This Affect Me?
Accessibility vs. Accessibility Support
An extremely quick introduction
How GNOME Obsoleted its "Enable Accessibility Setting" | Alejandro Piñeiro | [email protected]
Accessibility: removing barriers
● Themes and fonts
● Keyboard shortcuts
● Visual bells
● Assistive Technologies
How GNOME Obsoleted its "Enable Accessibility Setting" | Alejandro Piñeiro | [email protected]
Accessibility support: enabling access via ATs● Screen Reader
● Screen Magnifier
● Navigation by on-screen keyboard
● Navigation by voice
Phase 1: Getting Started
Creating an Accessible, Free Desktop
How GNOME Obsoleted its "Enable Accessibility Setting" | Alejandro Piñeiro | [email protected]
Starting GNOME Accessibility
● Mar 1999: GNOME 1.0 release
● Oct 2000: “GNOME Accessibility Summit”– Sun, IBM, and others– How to make an accessible Free Desktop– Focus on GNOME 2.0
● Jun 2002: GNOME 2.0 released
How GNOME Obsoleted its "Enable Accessibility Setting" | Alejandro Piñeiro | [email protected]
Bolted on; not built in
● Allowed to evolve independently
● Implemented as gmodule plugins– gail– atk-bridge
● Loaded conditionally at run-time based on an Accessibility “on/off” user setting
How GNOME Obsoleted its "Enable Accessibility Setting" | Alejandro Piñeiro | [email protected]
Plugin pros
● Support won't interfere when it is not needed
● No additional memory/CPU overhead
(i.e. Hide the problems rather than fix them)
How GNOME Obsoleted its "Enable Accessibility Setting" | Alejandro Piñeiro | [email protected]
Plugin cons
● Tied to the session
● Loaded only at application start time
● Users need accessibility enabled in order to enable accessibility
How GNOME Obsoleted its "Enable Accessibility Setting" | Alejandro Piñeiro | [email protected]
Enabled by default in GNOME 2?
● Nov 2005: Accessibility enabled by default for development releases: ACCEPTED
● Jul 2008: Accessibility enabled by default forstable releases: REJECTED
How GNOME Obsoleted its "Enable Accessibility Setting" | Alejandro Piñeiro | [email protected]
“Still we have the problem that our current accessibility technology just sucks too much for being enabled by default.”
-- desktop-devel-list commenter
How GNOME Obsoleted its "Enable Accessibility Setting" | Alejandro Piñeiro | [email protected]
Wait a moment ...
● Still “sucks too much” after eight years?
● Accessibility was seen as an optional add-on.
● The Accessibility Team was always small.
● And then ...
How GNOME Obsoleted its "Enable Accessibility Setting" | Alejandro Piñeiro | [email protected]
Perfect storm
● Corporate accessibility development stops– Corporate “change of direction”– Layoffs followed by takeovers
● GNOME 3 development starts
Phase 2: Rebuilding What We Had
And taking the opportunity to make it better
How GNOME Obsoleted its "Enable Accessibility Setting" | Alejandro Piñeiro | [email protected]
2010: Rework existing support
● Bonobo deprecation
● AT-SPI over DBUS (AT-SPI2)
● GObject Introspection
● GSettings vs GConf
How GNOME Obsoleted its "Enable Accessibility Setting" | Alejandro Piñeiro | [email protected]
2010: Implement new support
● New toolkits like Clutter
● New widgets in existing toolkits like Gtk+ 3
● New desktops like GNOME Shell
How GNOME Obsoleted its "Enable Accessibility Setting" | Alejandro Piñeiro | [email protected]
2011: Make improvements
● Fix regressions in the new and reworked code
● Improve toolkit a11y support, e.g. GtkTreeView
● Improve performance and stability
How GNOME Obsoleted its "Enable Accessibility Setting" | Alejandro Piñeiro | [email protected]
2010-2011: Integrate modules
● Cally becomes part of Clutter
● Gail becomes part of GTK
● ATK implementations are now built-in
● But atk-bridge remained a plugin
Phase 3: Achieving“Always On” Accessibility
It takes a community to obsolete a setting.
How GNOME Obsoleted its "Enable Accessibility Setting" | Alejandro Piñeiro | [email protected]
2012: “Year of Accessibility”
● Hackfest to plan further work, including accessibility enabled by default
● Developers to focus on significantly improving the accessibility stack
● Friends of GNOME Campaign to support additional development
How GNOME Obsoleted its "Enable Accessibility Setting" | Alejandro Piñeiro | [email protected]
What changed?
● Stability improvements
● Performance improvements
● Accessibility framework not sending/getting messages unless an AT is listening
How GNOME Obsoleted its "Enable Accessibility Setting" | Alejandro Piñeiro | [email protected]
Enabled by default in GNOME 3?
● Apr 2012: proposed again
● tl;dr: ACCEPTED
How GNOME Obsoleted its "Enable Accessibility Setting" | Alejandro Piñeiro | [email protected]
The conservative approach
● Proposed by the Accessibility Team
● Just change the default value of the setting
● Approved by the GNOME Community
How GNOME Obsoleted its "Enable Accessibility Setting" | Alejandro Piñeiro | [email protected]
The no-turning-back approach
● Proposed by Benjamin Otte & Bastien Nocera
● Make atk-bridge a library which toolkits link to
● Embraced by the community (who pitched in)
● Implemented as the solution
How GNOME Obsoleted its "Enable Accessibility Setting" | Alejandro Piñeiro | [email protected]
What's the difference?
● Not an add-on but an add-in
● For users: It JustWorks™
● For developers:– App accessibility is tested by everyone– The atk-bridge is compiled by more developers
How GNOME Obsoleted its "Enable Accessibility Setting" | Alejandro Piñeiro | [email protected]
Is it working?
● Accessibility is always on as of GNOME 3.6.
● Distros are shipping it, users are using it.
● Developers have not suggested we undo it.
● We're finding and fixing bugs here and there.
● But...Yeah, it's working.
How Does This Affect Me?
As a developer who wants to make my application or environment accessible
How GNOME Obsoleted its "Enable Accessibility Setting" | Alejandro Piñeiro | [email protected]
Are you using GTK?
● If you are using GTK >= 3.6:– GTK depends on the new library– Your app should be accessible out of the box
● If you are using GTK2:– These changes were not backported– The setting was kept in GNOME 3 for such apps
How GNOME Obsoleted its "Enable Accessibility Setting" | Alejandro Piñeiro | [email protected]
Any other toolkit/application?
● Assuming that you already have an ATK implementation for your widgets ...
● You only need to use at-spi2-bridge library– Add the dependency– Call an init method
● GNOME Shell's patch:– 16 insertions, 199 deletions
Questions?