[mediacapture-screen-share] The user agent should be allowed to change sources after getDisplayMedia() resolves

henbos has just created a new issue for https://github.com/w3c/mediacapture-screen-share:

== The user agent should be allowed to change sources after getDisplayMedia() resolves ==
The spec currently has language saying the source is constant after getDisplayMedia() returns a stream, e.g:

> The provided media MUST include precisely one track of each media type in requestedMediaTypes. The devices chosen MUST be the ones determined by the user. Once selected, the source of a MediaStreamTrack MUST NOT change.
> [...]
> Since the source of media cannot be changed after a MediaStreamTrack has been returned and constraints do not affect the selection of display surfaces, these constrainable properties cannot be changed by an application.

This refers to the settings "displaySurface", "logicalSurface" or "cursor" to be constant for a track. I'm not convinced we should enforce these being constants, but even if we do want that we don't have to go so far to say sources are constant, just that sources cannot change type from "logical" to "display" or enable/disable cursor. And just because a user agent (end-user) can change the source doesn't mean that the application has any control of this.

We should allow the user agent to change source on-the-fly. This allows, amongst other things, the user agent to allow the end-user to change which tab ("browser" surface) to present at any given point in time. This is what current extensions are already doing.

Please view or discuss this issue at https://github.com/w3c/mediacapture-screen-share/issues/81 using your GitHub account

Received on Wednesday, 3 October 2018 15:54:51 UTC