Transient activation and focus

[eladalon1983]

What is the issue with the HTML Standard?

A question about transient activation came up in the WebRTC WG during a discussion about screen-sharing.getDisplayMedia() returns a promise, and then if the user chooses to share a tab/window/screen, that promise is resolved. We have recently specified that when resolving that promise, the UA will also consider the document to have regained transient activation.

• In the case of Chromium’s implementation, it is virtually guaranteed that at the critical moment, the document “has focus.” (I use “focus” imprecisely here, as a layman.) This is because Chromium implements the dialog as attached to the tab from which the call originated.
• In the case of Safari’s implementation, if the user chooses to share a window, then Safari might be obscured by the chosen window at that final, critical moment.

Our question is: Do you see any problem in Safari’s case here? Would conferring transient activation on a document that is not “focused” pose any issues? If so, how may we mitigate them in the spec?

Thanks,
Elad

[eladalon1983]

CC @jan-ivar @youennf @marcoscaceres

[annevk]

@mustaqahmed should probably take a look.

Overall I don't think other specifications should set the last activation timestamp directly because then the concept will be very hard to understand. Instead we probably need to come up with some abstraction that WebRTC could adopt. (Which might come down to a similar thing, but then at least the entirety of the flow is clear from HTML.)

[mustaqahmed]

I agree with @annevk here: any new/renewed/extended transient activation through anything other than a user interaction would make user activation gated APIs abusable from JS!