Sequencer state should load when a new user connect

[DerouineauNicolas]

Whenever a new user connects, pads should be activated with the actions already activated on other clients.

Should actions be stored on the server ?

[xavierfav]

I think we should store the state of the sequencer. Because you never know, you could have a lot of actions that are then cancelled. You cannot store all of them after months.

So I propose to create a state sequencer json which stores: tempo, tracks, activated steps.

[valou5940]

I tried to store the state of the sequencer (tempo and selected pads) in a json object into the function toggleSelectedListener().

The state is updated whenever a client click on a pad.

This is meant to send the exact real-time state of the sequencer to the server, which then broadcast it to every new client.

The problem is when you deselect a pad previously selected, the pad "selected" in the json object must be erased.

[xavierfav]

• I think it is better to store the sequencer state in the server. This way socket are lighter and we avoid problems of transmission for instance.

• The idea of using a json object for storing the sequencer state seams nice. Something like that:

  { 
  "room_id": <room_id>,
  "tempo": <tempo_value>,
  "pads": 
      {
          "kick": [<list_of_activated_pad_ids>],
          "snare": [<...>],
          "hihat": [<...>]
      }
  }

In the future, we will add other fields. For instance about the audio sources (when we will browse sounds from freesound).

• About how to edit the json state file:
  • If a pad is activated, push the column id in the corresponding track list.
  • If a pad is deactivated, remove the element from the corresponding list.

[valou5940]

• The sequencer state is now stored in a JSON object on server side

• Tempo is now added to the 'message' (minor change on app.js on how to get instruments)

• There is a bug to correct : sometimes when selecting multiple pads of the same track, when you deselect one , there are more than 1 pad deselected (only in the state). This is due to the for loop I guess

• I'll work on the broadcast of the actions to the clients