gloriouscowSeeing that I have a egui web application that is essentially a giant canvas element, making it an opaque blob to all screen-readers, I started looking into why all the smart people working on web technology never came up with a solution to provide some sort of metadata for what a canvas is displaying.
But people did come up with solutions, like this proposal for Canvas hit testing.
https://www.w3.org/wiki/Canvas_hit_testing?utm_source=chatgpt.com#Change_Proposal
From 2012. That never went anywhere.
I don't blame egui for lack of trying. The irony is that an immediate-mode GUI has every single bit of data needed to emit context about where its windows are and what text is showing and how to interact with it, and it can produce that metadata accurately on every single frame.
There's just nowhere to send it.
Now, I can blame lack of foresight, but perhaps nobody really thought that the canvas element would be much more than a toy, and I doubt anyone would have considered you'd be rendering an entire window manager or booting Windows XP in a browser tab a decade ago.
but there's a whole giant area in between where all the titans of technology and the stewards of the web just basically considered all the possible uses of the canvas element, then just shrugged and said "eh"
Marsh Ray@gloriouscow I don’t know about canvas specifically, but often limitations on the ability to read content trace back to Netscape’s approach to web page security (“there is none”).
In 2012 browsers allowed any random web page (perhaps one modified in transit by your ISP) to load any other (eg your bank’s account summary page) in an iframe and the browser would happily supply your bank login session cookie for authentication. Web apps commonly relied on this ability.
If random web page was allowed to read contents, (perhaps via CSS, WebGL, or who knows what other APIs) that would obviously be a disaster.