msglist: Temporary state "this view does not mark messages as read on scroll", with alert and button to leave

[chrisbobbe]

Sometimes (as when following a /near/ link) you want to go straight to a specific message, even if it's unread, and you don't want the app to mess with your read state in doing so. Web handles this; see discussion:

#mobile-team > msglist: anchor when tapping recipient header @ 💬

• File an issue to implement "this view does not mark messages as read" mode; use that mode when following /near/ links […]

I think some key features of the new mode are:

• UI that makes it clear what's happening
• UI to exit the temporary state

Web has those UI features (an alert with a "Mark as read" button):

(I guess we should only show those if we'd ordinarily be marking read as scroll, given the narrow and the "Mark messages as read on scroll" setting.)

And I guess we're already missing those features when we enter a "not-marking-read" state on tapping "Mark as unread from here" in the action sheet.

Related issues

• When tapping a recipient header, open to corresponding message if earlier than first-unread #1654