Add event cancelling to chat messages

[impostor]

Add event cancelling to chat messages

[AeonLucid]

@Mm2PL this will lead to desync, it will only work for specific type of events like chatting. For cancelling other events (such as venting) we would need to send the inverse of that event (going out of the vent). Because client's do not verify their action with the server before doing it.

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.

[ErikDombi]

I don't think event cancelling should be limited to just chat events. Ideally all events would be cancellable.

[danbudworthmead]

@danbudworthmead I won't be merging that if you PR it. Reason for that is that there can be another GameData message after the GameData event you are canceling. You are returning, effectively canceling everything in that stream.

Aha dw not planning to PR. Just thought it might be useful in this thread if someone's looking to do something similar.

[Mm2PL]

Due to how events work, this should be doable on every type of event.

I think

1. Receive packet from client
2. Decode packet
3. Fire off appropriate events
4. Forward packet to other clients

The fourth step can be ignored if the event was canceled, and other players won't see the thing happen.
E: not exactly true

[ErikDombi]

Could this lead to possible desync?

[Mm2PL]

Could this lead to possible desync?

🤔 Probably on some events.

[danbudworthmead]

I've been messing around with blocking packets.
Here's an example of blocking chat packets beginning with "/"

danbudworthmead@e032c0d

[AeonLucid]

@danbudworthmead I won't be merging that if you PR it. Reason for that is that there can be another GameData message after the GameData event you are canceling. You are returning, effectively canceling everything in that stream.