1564993 - Create a simulator actor+front for a11y simulation

Status: RESOLVED FIXED

(DevTools :: Accessibility Tools, enhancement)

Description

[Maliha Islam [:mislam]]

We would like to add color blindness simulations to the accessibility panel.

We need a simulator actor for this, that will be managed by the accessibility actor. Create a simulator front that can connect to the simulator actor. The simulator actor can take advantage of the setColorMatrix docShell method from bug 1431466 to set different color matrices. The simulator actor also needs to load a style sheet (similar to walker: https://searchfox.org/mozilla-central/source/devtools/server/actors/accessibility/walker.js#749) to simulate contrast loss.

Comment 1

[Maliha Islam [:mislam]]

Attachment: Bug 1564993 - Create simulator actor and front, r=yzen,nchevobbe

Comment 2

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/5a009a174052
Create simulator actor and front, r=yzen,nchevobbe

Comment 3

[Cosmin Sabou [:CosminS]]

https://hg.mozilla.org/mozilla-central/rev/5a009a174052

Comment 4

[Bogdan Tara[:bogdan_tara | bogdant]]

https://hg.mozilla.org/releases/mozilla-beta/rev/5a009a174052

Comment 5

[Matthew Petroff [:mpetroff]]

The simulation matrices used here are unfortunately horribly inaccurate. While the source cited in devtools/server/actors/accessibility/constants.js does not list its source, the matrices appear to be the "colorjack.com matrices" [1] (and do not originate from the scientific literature). As far as I'm concerned, this is worse than not having such a simulation at all, since it gives people a false sense of accommodating individuals with color vision deficiencies.

An improved method with known provenance is to use the method of Machado et al. (2009) [2], which to the best of my knowledge is the state-of-the-art. The paper's supplementary information provides pre-computed matrices [3]; the "severity 1.0" matrices correspond to the "-opia" deficiencies.

It may also be prudent to remove the "-omaly" simulations. These deficiencies span a range of severities, so providing a single simulation gives a false impression as to what particular individuals with such deficiencies see. The "-omaly" simulations were removed from Chromium after this was pointed out [4].

[1] https://github.com/MaPePeR/jsColorblindSimulator#the-colormatrix-algorithm
[2] https://doi.org/10.1109/TVCG.2009.113
[3] https://www.inf.ufrgs.br/~oliveira/pubs_files/CVD_Simulation/CVD_Simulation.html
[4] https://bugs.chromium.org/p/chromium/issues/detail?id=1003700#c31