Re: FW: update to at risk features in Canvas

Regarding drawCustomFocusRing,

It is true that main stream commercial Windows magnifiers draw their own
rings. The reason for drawCustomFocusRings is to two fold:

1. tell a magnifier the location of the object
2. handle the case where an author would normally draw a custom focus ring
but when the OS is high contrast mode allow the browser, which has access
to that system information ( in high contrast mode), to draw the focus ring
along the current path instead using the OS platform conventions for a
high. contrast focus ring.

Currently, we don't have a way to know we are in high contrast mode so that
is why this call exists when dealing with a custom focus ring. Ideally, it
would be far better to use CSS Media Queries or an Indie UI function call
to determine high contrast mode and then hit testing, ( with path or some
other object like shape), which could be used to provide location
information. Neither of those exist pervasively in browsers today.

Rich

Sent from my iPad