Address deleted cards

[AlexGuironnetRTE]

Hello,

I'm starting this to follow up on a discussion we had in today's daily meeting. Basically, while regression-testing before 2.11.0.RELEASE, @vlo-rte found a behaviour with the new "replay sounds" feature (#1808) that might be confusing for users.

Steps to reproduce:

• operator1 is connected but away from their computer
• operator2 sends a card for which operator1 is a recipient and has enabled sound notifications, and replay is enabled
• operator2 then deletes the card before operator1 comes back
• operator1 will come back to their computer and find that a sound is playing, but with no card with the corresponding severity

From an implementation point of view, this is because for optimization reasons the notifications service doesn't keep track of individual cards, just whether there is a sound replay going on for a given severity.

So there could be a way to fix this particular problem (albeit with a performance / maintenance cost), and in any case if we move from stopping the replay globally (click anywhere) to a replay handled by card (click on card) this problem will solve itself.

However, we feel that there is a more general issue with the current behaviour of deleted cards: you can send a card, it will have effects on the receiving user's interface, and then you can delete it without a trace, potentially leaving the interface in a weird state.
Also it can be confusing for the receiving user if they see the card very before it vanishes ("I thought I saw something").

So it would be good to find a way to show that a card has been there but was deleted. Ideas anyone ?
I think some of the points to discuss are:

• Where do we put this information on the screen?
• How much do we say about the deleted card? Enough to be useful but not too much in case the card was sent by mistake and the data should not be disclosed?