Contact recently seen changes have missing events

[Simon-Laux]

When a contact turns from "not recently seen" to "recently seen" there is always no ContactsChanged event.

When a contact turns from "recently seen" to "not recently seen" there is sometimes no ContactsChanged event.

Expected: Both cases should emit the ContactsChanged event

This cause a bug in the UI: deltachat/deltachat-desktop#3735 (on iOS the bug of missing events also exists, but is not as visible as the whole as the screen is refreshed each time the user switches screens, the same is likely true also for android, but I did not test there yet.)

[Simon-Laux]

I made a failing test for this in https://github.com/deltachat/deltachat-core-rust/tree/simon/i5377-test-for-recently-seen

[iequidoo]

It's not even documented that ContactsChanged must be emitted if so: https://github.com/deltachat/deltachat-core-rust/blob/2f0f247e7056215e6c67b2d3200495f8a9297b52/src/events/payload.rs#L185-L188 So i think this is on purpose. But i agree that this should be fixed.

EDIT: I'm wrong, RecentlySeenLoop::run() actually tries to emit ContactsChanged, so the observed behaviour isn't on purpose.

[r10s]

[on iOS] the whole the screen is refreshed each time the user switches screens, the same is likely true also for android, but I did not test there yet.

this is not true.

android and ios also refresh the chatlist event based, not on switching screens.

you see this as there is zero delay when going back - i fact, the chatlist was there all the time, just fully covered

the change was made in 2021, see eg. deltachat/deltachat-ios#1374

however, whole chatlist is reloaded, not single chatlist items. that said, the redraw bug may still be in core. but the hint ios/android refresh behavior gives seems less clear :)

[Simon-Laux]

android and ios also refresh the chatlist event based, not on switching screens.

This is not primarily about the chatlist, this is about the indicator that is shown on the chat view/messagelist and the indicator on the profile view. To some extend also the chatlist, but the point is not that there are missing event listeners, the point is that there are cases where the event is missing, as far as I know there are listeners for contact changed event in all of the places I mentioned.

I was likely giving not enough information here leading to this misunderstanding.
Sorry for that, I'll try to be more verbose/clear in the future.

You can reproduce the missing events on iOS by:

• set screen lock time to "never"
• go to a chat
• send a message to your other account (account B) (that is on a different device)
• use account B to send a read receipt for that message, in my test the green dot only appeared when I left the chat and went back (to chatlist or profile view) - in my second test showing it worked, but maybe it's updating using a different event because I couldn't find a listener for it in the code, maybe that extra listener is missing in desktop, or my first chat was different, like receiving a read receipt in a different chat, I'll check later
• after the dot is shown
  • (either it appeared for you if you didn't have the bug or sent a message instead of a read receipt, or you went to another screen and back) wait 11min (10min is the time it should be hidden after, you can recompile core to shorten the time, see my branch for the test)
• See that the dot is still there and not hidden, though if you go into another screen and back it is updated.
• don't forget to revert screen lock time if this isn't only a test device

anyways Ignoring my iOS testing which only the second half is still valid (dot does not vanish), as long as the test I wrote in https://github.com/deltachat/deltachat-core-rust/tree/simon/i5377-test-for-recently-seen is valid and fails we have the problem of missing events.

[r10s]

all fine, i did not doubt there is a bug :)
i just wanted to clarify the (repeatedly) wrong understanding how chatlist works on android/ios :)

sorry if i gave a wrong impression here. thanks a lot for taking care!

[adbenitez]

about the change from "no green dot" to "green dot", there is no contact changed event because it is not strictly needed, android (and I guess iOS) use incoming message, msg read, etc events to update the state of the green dot as a contact can only change to online if you receive a message or read receipt from them,

about not receiving events when the user change from online to offline, that would be then a bug but it used to trigger the even just fine on Android last time I check

[Simon-Laux]

only change to online if you receive a message or read receipt from them

you don't get that info if the message/read receipt was received in a group chat if it is as you described. (because the events you mentioned have chat and message id, no contact id)
I would prefer dedicated events to such hacks that rely on other sometimes unrelated events.