Edit
Thank you so much to those who responded. I think all of the answers here has given me the gist of why people want this feature: to see new content, but in a temporary sort of way (almost like a "new content" button). I think with this direction I should be good from here. If anyone has any specifics they'd like to see for this feature feel free to post it. I will read it all before I implement this feature tonight after work (in ~6 hours).
Original
This is concerning the action in the FAB overflow menu "Hide read". I thought about this feature more yesterday and I ended up with ever more questions.
This button is an action which is what I think it making it so weird for me. It's not a setting. So one would think tapping it would make some change each time, and that change is different each time it's tapped (ie. it's not idempotent).
Here is what I'm thinking. When a user taps "Hide read", all posts that the user has read in that session and in the community they are currently looking at are added to some "hidden list". This list will contain any posts hidden in this way and only this way (well i might add a hide post action on each post later).
This means that if you read a post yesterday, came back to the app today and then tapped "hide read", that post will not be hidden even though you've read it.
Only posts that you have read in your current session for the current community you are on will be hidden.
There is an edge case here where a post you've read yesterday appears in the feed today, in the community you are browsing. In this case, if "Hide read" is tapped, that post will be hidden.
Is this what users would expect "hide read" to do? For people who used this feature in other app, is this what it did in that app?
Wait so it disables even on refresh?! I mean that makes implementing the feature a lot easier for me. I'll give it a stab tonight. This should be easy to implement.
Yeah, read post re appaering but dimmed (as you must read them) is like many apps handled this when you refresh the feed :)