scratch-vm/src/io/btSession.js
Evelyn Eastmond 5320dfb676 WeDo2 backwards compatibility update (#1518)
* Resolving #1492: No longer trying to make WeDo2 backwards compatible with Scratch Link API v1.0.

* Closing the socket on all BLE/BT errors.

* Adding BT disconnection.
2018-08-22 17:45:26 -04:00

126 lines
4.3 KiB
JavaScript

const JSONRPCWebSocket = require('../util/jsonrpc-web-socket');
// const log = require('../util/log');
const ScratchLinkWebSocket = 'wss://device-manager.scratch.mit.edu:20110/scratch/bt';
class BTSession extends JSONRPCWebSocket {
/**
* A BT device session object. It handles connecting, over web sockets, to
* BT devices, and reading and writing data to them.
* @param {Runtime} runtime - the Runtime for sending/receiving GUI update events.
* @param {object} deviceOptions - the list of options for device discovery.
* @param {object} connectCallback - a callback for connection.
* @param {object} messageCallback - a callback for message sending.
*/
constructor (runtime, deviceOptions, connectCallback, messageCallback) {
const ws = new WebSocket(ScratchLinkWebSocket);
super(ws);
this._ws = ws;
this._ws.onopen = this.requestDevice.bind(this); // only call request device after socket opens
this._ws.onerror = this._sendError.bind(this, 'ws onerror');
this._ws.onclose = this._sendError.bind(this, 'ws onclose');
this._availablePeripherals = {};
this._connectCallback = connectCallback;
this._connected = false;
this._characteristicDidChangeCallback = null;
this._deviceOptions = deviceOptions;
this._discoverTimeoutID = null;
this._messageCallback = messageCallback;
this._runtime = runtime;
}
/**
* Request connection to the device.
* If the web socket is not yet open, request when the socket promise resolves.
*/
requestDevice () {
if (this._ws.readyState === 1) { // is this needed since it's only called on ws.onopen?
this._availablePeripherals = {};
this._discoverTimeoutID = window.setTimeout(this._sendDiscoverTimeout.bind(this), 15000);
this.sendRemoteRequest('discover', this._deviceOptions)
.catch(e => this._sendError(e)); // never reached?
}
// TODO: else?
}
/**
* Try connecting to the input peripheral id, and then call the connect
* callback if connection is successful.
* @param {number} id - the id of the peripheral to connect to
*/
connectDevice (id) {
this.sendRemoteRequest('connect', {peripheralId: id})
.then(() => {
this._connected = true;
this._runtime.emit(this._runtime.constructor.PERIPHERAL_CONNECTED);
this._connectCallback();
})
.catch(e => {
this._sendError(e);
});
}
/**
* Close the websocket.
*/
disconnectSession () {
this._ws.close();
this._connected = false;
}
/**
* @return {bool} whether the peripheral is connected.
*/
getPeripheralIsConnected () {
return this._connected;
}
sendMessage (options) {
return this.sendRemoteRequest('send', options)
.catch(e => {
this._sendError(e);
});
}
/**
* Handle a received call from the socket.
* @param {string} method - a received method label.
* @param {object} params - a received list of parameters.
* @return {object} - optional return value.
*/
didReceiveCall (method, params) {
// TODO: Add peripheral 'undiscover' handling
switch (method) {
case 'didDiscoverPeripheral':
this._availablePeripherals[params.peripheralId] = params;
this._runtime.emit(
this._runtime.constructor.PERIPHERAL_LIST_UPDATE,
this._availablePeripherals
);
if (this._discoverTimeoutID) {
// TODO: window?
window.clearTimeout(this._discoverTimeoutID);
}
break;
case 'didReceiveMessage':
this._messageCallback(params); // TODO: refine?
break;
default:
return 'nah';
}
}
_sendError (/* e */) {
this.disconnectSession();
// log.error(`BTSession error: ${JSON.stringify(e)}`);
this._runtime.emit(this._runtime.constructor.PERIPHERAL_ERROR);
}
_sendDiscoverTimeout () {
this._runtime.emit(this._runtime.constructor.PERIPHERAL_SCAN_TIMEOUT);
}
}
module.exports = BTSession;