New messages don't scroll to bottom when tab is out of focus

[Daxterapid]

Describe the bug

Normally when a message is sent in a room, the scrollbar stays locked to the bottom. However, when a message is sent and Cinny isn't the current tab in the browser, the scrollbar stays fixed to the last read message, so you have to scroll down to see new messages every time you switch back to the Cinny tab, which I find annoying.

Reproduction

1. Select a room
2. Scroll to the bottom
3. Switch to a different tab
4. Have someone send a message in the room
5. Switch back to Cinny
6. Scrollbar hasn't moved

Expected behavior

The scrollbar should stay at the bottom.

Platform and versions

OS: Fedora Linux
Browser: Brave 1.57.62 Chromium: 116.0.5845.180
Cinny version: 3.0.0
Matrix homeserver: matrix.org

Additional context

No response

[soupglasses]

This seems to also happen if you are tabbed out with a separate window (like a PWA in Chromium).

[enginelesscc]

It also happens when I have the window/chat focussed.
I always have to manually scroll, for any new message.

[flisk]

It would be nice if a maintainer could chime in on whether the behavior described in this issue is intended and how the expectation mismatch experienced by some users should be addressed. I'd love to patch this, but I don't want to waste my time writing a fix that will be rejected.

[ajbura]

the current behavior is intended as previously people had issues that "chat marked as read in background" #1116

browser doesn't have any api which can tell if application is being viewed when not in focused(i.e on second monitor) we can't really fix it without breaking it otherwise.

[elkowar]

the current behavior is intended as previously people had issues that "chat marked as read in background" #1116

browser doesn't have any api which can tell if application is being viewed when not in focused(i.e on second monitor) we can't really fix it without breaking it otherwise.

I wonder how other similar applications deal with this, as I've never really noticed issues like this anywhere else. My preferred behaviour would be that cinny scrolls down automatically, but only marks the chat as read once the window is actually focused / interacted with – which from all I gather is the behaviour of most other comparable applications.

Assuming that that's technically possible, but not necessarily desired by the maintainers, would there be a chance to make this a configurable option?

[ajbura]

The reason we can do it like other applications is because we have read-receipts, which tells other person that user has read the messages in that case we can not be sure about if user has read the message or not when application is in background.

[flisk]

would a patch that adds an option to disable this behavior for users who don't want it be acceptable?

[ajbura]

Adding a option won't be a good fix as there may be a cleaver fix which we can think through.

[BareTuna]

browser doesn't have any api which can tell if application is being viewed when not in focused(i.e on second monitor) we can't really fix it without breaking it otherwise.

I think that just because you can see the messages on screen while the app is not in focus doesn't mean that you should send a read receipt. I think it should scroll to the bottom regardless of focus, but only mark it as read if the window has focus. (Although we should consider the case where after regaining focus you might not want to mark all those messages as read right away.)

[Daxterapid]

My suggestion:

• When the window isn't focused, stay scrolled to the bottom, but stop sending read receipts and show a "new messages" marker after the last read message
• When the window regains focus, mark the messages as read only if there's less than, say, 20 unread messages
• Otherwise (if there's more than 20 unread messages after focusing), display a button at the top to mark the messages read, or maybe after clicking the room again or something

(this is basically what Discord does)

You could also instead consider stopping the auto-scrolling after some amount of new unread messages (preferably after they reach the top of the screen), and then mark them read once the user scrolls to the bottom manually

[ajbura]

#2214 to fix it. Feel free to test if it is a desirable behavior.