Merge pull request #1763 from evhan55/extensions/disconnect-errors

Various fixes to extension disconnect errors

src/engine/runtime.js

@@ -558,6 +558,8 @@ class Runtime extends EventEmitter {
 
     /**
      * Event name for updating the available set of peripheral devices.
+     * This causes the peripheral connection modal to update a list of
+     * available peripherals.
      * @const {string}
      */
     static get PERIPHERAL_LIST_UPDATE () {
@@ -566,14 +568,25 @@ class Runtime extends EventEmitter {
 
     /**
      * Event name for reporting that a peripheral has connected.
+     * This causes the status button in the blocks menu to indicate 'connected'.
      * @const {string}
      */
     static get PERIPHERAL_CONNECTED () {
         return 'PERIPHERAL_CONNECTED';
     }
 
+    /**
+     * Event name for reporting that a peripheral has been intentionally disconnected.
+     * This causes the status button in the blocks menu to indicate 'disconnected'.
+     * @const {string}
+     */
+    static get PERIPHERAL_DISCONNECTED () {
+        return 'PERIPHERAL_DISCONNECTED';
+    }
+
     /**
      * Event name for reporting that a peripheral has encountered a request error.
+     * This causes the peripheral connection modal to switch to an error state.
      * @const {string}
      */
     static get PERIPHERAL_REQUEST_ERROR () {
@@ -581,15 +594,17 @@ class Runtime extends EventEmitter {
     }
 
     /**
-     * Event name for reporting that a peripheral has encountered a disconnect error.
+     * Event name for reporting that a peripheral connection has been lost.
+     * This causes a 'peripheral connection lost' error alert to display.
      * @const {string}
      */
-    static get PERIPHERAL_DISCONNECT_ERROR () {
+    static get PERIPHERAL_CONNECTION_LOST_ERROR () {
-        return 'PERIPHERAL_DISCONNECT_ERROR';
+        return 'PERIPHERAL_CONNECTION_LOST_ERROR';
     }
 
     /**
      * Event name for reporting that a peripheral has not been discovered.
+     * This causes the peripheral connection modal to show a timeout state.
      * @const {string}
      */
     static get PERIPHERAL_SCAN_TIMEOUT () {

src/extensions/scratch3_ev3/index.js

@@ -476,6 +476,7 @@ class EV3 {
         this._bt = null;
         this._runtime.registerPeripheralExtension(extensionId, this);
 
+        this.disconnect = this.disconnect.bind(this);
         this._onConnect = this._onConnect.bind(this);
         this._onMessage = this._onMessage.bind(this);
         this._pollValues = this._pollValues.bind(this);
@@ -561,7 +562,7 @@ class EV3 {
         this._bt = new BT(this._runtime, this._extensionId, {
             majorDeviceClass: 8,
             minorDeviceClass: 1
-        }, this._onConnect, this._onMessage);
+        }, this._onConnect, this.disconnect, this._onMessage);
     }
 
     /**

src/extensions/scratch3_microbit/index.js

@@ -25,8 +25,12 @@ const BLECommand = {
     CMD_DISPLAY_LED: 0x82
 };
 
-// TODO: Needs comment
+
-const BLETimeout = 4500; // TODO: might need tweaking based on how long the peripheral takes to start sending data
+/**
+ * A time interval to wait (in milliseconds) before reporting to the BLE socket
+ * that data has stopped coming from the peripheral.
+ */
+const BLETimeout = 4500;
 
 /**
  * A time interval to wait (in milliseconds) while a block that sends a BLE message is running.
@@ -34,6 +38,12 @@ const BLETimeout = 4500; // TODO: might need tweaking based on how long the peri
  */
 const BLESendInterval = 100;
 
+/**
+ * A string to report to the BLE socket when the micro:bit has stopped receiving data.
+ * @type {string}
+ */
+const BLEDataStoppedError = 'micro:bit extension stopped receiving data';
+
 /**
  * Enum for micro:bit protocol.
  * https://github.com/LLK/scratch-microbit-firmware/blob/master/protocol.md
@@ -212,7 +222,7 @@ class MicroBit {
             filters: [
                 {services: [BLEUUID.service]}
             ]
-        }, this._onConnect);
+        }, this._onConnect, this.disconnect);
     }
 
     /**
@@ -289,7 +299,10 @@ class MicroBit {
      */
     _onConnect () {
         this._ble.read(BLEUUID.service, BLEUUID.rxChar, true, this._onMessage);
-        this._timeoutID = window.setInterval(this.disconnect, BLETimeout);
+        this._timeoutID = window.setInterval(
+            () => this._ble.handleDisconnectError(BLEDataStoppedError),
+            BLETimeout
+        );
     }
 
     /**
@@ -317,7 +330,10 @@ class MicroBit {
 
         // cancel disconnect timeout and start a new one
         window.clearInterval(this._timeoutID);
-        this._timeoutID = window.setInterval(this.disconnect, BLETimeout);
+        this._timeoutID = window.setInterval(
+            () => this._ble.handleDisconnectError(BLEDataStoppedError),
+            BLETimeout
+        );
     }
 
     /**

src/extensions/scratch3_wedo2/index.js

@@ -40,11 +40,18 @@ const BLEService = {
  */
 const BLECharacteristic = {
     ATTACHED_IO: '00001527-1212-efde-1523-785feabcd123',
+    LOW_VOLTAGE_ALERT: '00001528-1212-efde-1523-785feabcd123',
     INPUT_VALUES: '00001560-1212-efde-1523-785feabcd123',
     INPUT_COMMAND: '00001563-1212-efde-1523-785feabcd123',
     OUTPUT_COMMAND: '00001565-1212-efde-1523-785feabcd123'
 };
 
+/**
+ * A time interval to wait (in milliseconds) in between battery check calls.
+ * @type {number}
+ */
+const BLEBatteryCheckInterval = 5000;
+
 /**
  * A time interval to wait (in milliseconds) while a block that sends a BLE message is running.
  * @type {number}
@@ -421,8 +428,17 @@ class WeDo2 {
          */
         this._rateLimiter = new RateLimiter(BLESendRateMax);
 
+        /**
+         * An interval id for the battery check interval.
+         * @type {number}
+         * @private
+         */
+        this._batteryLevelIntervalId = null;
+
+        this.disconnect = this.disconnect.bind(this);
         this._onConnect = this._onConnect.bind(this);
         this._onMessage = this._onMessage.bind(this);
+        this._checkBatteryLevel = this._checkBatteryLevel.bind(this);
     }
 
     /**
@@ -578,7 +594,7 @@ class WeDo2 {
                 services: [BLEService.DEVICE_SERVICE]
             }],
             optionalServices: [BLEService.IO_SERVICE]
-        }, this._onConnect);
+        }, this._onConnect, this.disconnect);
     }
 
     /**
@@ -606,6 +622,11 @@ class WeDo2 {
         if (this._ble) {
             this._ble.disconnect();
         }
+
+        if (this._batteryLevelIntervalId) {
+            window.clearInterval(this._batteryLevelIntervalId);
+            this._batteryLevelIntervalId = null;
+        }
     }
 
     /**
@@ -711,6 +732,7 @@ class WeDo2 {
             BLECharacteristic.ATTACHED_IO,
             this._onMessage
         );
+        this._batteryLevelIntervalId = window.setInterval(this._checkBatteryLevel, BLEBatteryCheckInterval);
     }
 
     /**
@@ -757,6 +779,19 @@ class WeDo2 {
         }
     }
 
+    /**
+     * Check the battery level on the WeDo 2.0. If the WeDo 2.0 has disconnected
+     * for some reason, the BLE socket will get an error back and automatically
+     * close the socket.
+     */
+    _checkBatteryLevel () {
+        this._ble.read(
+            BLEService.DEVICE_SERVICE,
+            BLECharacteristic.LOW_VOLTAGE_ALERT,
+            false
+        );
+    }
+
     /**
      * Register a new sensor or motor connected at a port.  Store the type of
      * sensor or motor internally, and then register for notifications on input

src/io/ble.js

@@ -11,23 +11,25 @@ class BLE extends JSONRPCWebSocket {
      * @param {string} extensionId - the id of the extension using this socket.
      * @param {object} peripheralOptions - the list of options for peripheral discovery.
      * @param {object} connectCallback - a callback for connection.
+     * @param {object} disconnectCallback - a callback for disconnection.
      */
-    constructor (runtime, extensionId, peripheralOptions, connectCallback) {
+    constructor (runtime, extensionId, peripheralOptions, connectCallback, disconnectCallback = null) {
         const ws = new WebSocket(ScratchLinkWebSocket);
         super(ws);
 
         this._ws = ws;
         this._ws.onopen = this.requestPeripheral.bind(this); // only call request peripheral after socket opens
-        this._ws.onerror = this._sendRequestError.bind(this, 'ws onerror');
+        this._ws.onerror = this._handleRequestError.bind(this, 'ws onerror');
-        this._ws.onclose = this._sendDisconnectError.bind(this, 'ws onclose');
+        this._ws.onclose = this.handleDisconnectError.bind(this, 'ws onclose');
 
         this._availablePeripherals = {};
         this._connectCallback = connectCallback;
         this._connected = false;
         this._characteristicDidChangeCallback = null;
+        this._disconnectCallback = disconnectCallback;
+        this._discoverTimeoutID = null;
         this._extensionId = extensionId;
         this._peripheralOptions = peripheralOptions;
-        this._discoverTimeoutID = null;
         this._runtime = runtime;
     }
 
@@ -41,10 +43,10 @@ class BLE extends JSONRPCWebSocket {
             if (this._discoverTimeoutID) {
                 window.clearTimeout(this._discoverTimeoutID);
             }
-            this._discoverTimeoutID = window.setTimeout(this._sendDiscoverTimeout.bind(this), 15000);
+            this._discoverTimeoutID = window.setTimeout(this._handleDiscoverTimeout.bind(this), 15000);
             this.sendRemoteRequest('discover', this._peripheralOptions)
                 .catch(e => {
-                    this._sendRequestError(e);
+                    this._handleRequestError(e);
                 });
         }
         // TODO: else?
@@ -63,7 +65,7 @@ class BLE extends JSONRPCWebSocket {
                 this._connectCallback();
             })
             .catch(e => {
-                this._sendRequestError(e);
+                this._handleRequestError(e);
             });
     }
 
@@ -71,10 +73,15 @@ class BLE extends JSONRPCWebSocket {
      * Close the websocket.
      */
     disconnect () {
+        if (!this._connected) return;
+
         this._ws.close();
+        this._connected = false;
         if (this._discoverTimeoutID) {
             window.clearTimeout(this._discoverTimeoutID);
         }
+
+        this._runtime.emit(this._runtime.constructor.PERIPHERAL_DISCONNECTED);
     }
 
     /**
@@ -99,7 +106,7 @@ class BLE extends JSONRPCWebSocket {
         this._characteristicDidChangeCallback = onCharacteristicChanged;
         return this.sendRemoteRequest('startNotifications', params)
             .catch(e => {
-                this._sendDisconnectError(e);
+                this.handleDisconnectError(e);
             });
     }
 
@@ -119,10 +126,12 @@ class BLE extends JSONRPCWebSocket {
         if (optStartNotifications) {
             params.startNotifications = true;
         }
+        if (onCharacteristicChanged) {
             this._characteristicDidChangeCallback = onCharacteristicChanged;
+        }
         return this.sendRemoteRequest('read', params)
             .catch(e => {
-                this._sendDisconnectError(e);
+                this.handleDisconnectError(e);
             });
     }
 
@@ -145,7 +154,7 @@ class BLE extends JSONRPCWebSocket {
         }
         return this.sendRemoteRequest('write', params)
             .catch(e => {
-                this._sendDisconnectError(e);
+                this.handleDisconnectError(e);
             });
     }
 
@@ -168,14 +177,45 @@ class BLE extends JSONRPCWebSocket {
             }
             break;
         case 'characteristicDidChange':
+            if (this._characteristicDidChangeCallback) {
                 this._characteristicDidChangeCallback(params.message);
+            }
             break;
         case 'ping':
             return 42;
         }
     }
 
-    _sendRequestError (/* e */) {
+    /**
+     * Handle an error resulting from losing connection to a peripheral.
+     *
+     * This could be due to:
+     * - battery depletion
+     * - going out of bluetooth range
+     * - being powered down
+     *
+     * Disconnect the socket, and if the extension using this socket has a
+     * disconnect callback, call it. Finally, emit an error to the runtime.
+     */
+    handleDisconnectError (/* e */) {
+        // log.error(`BLE error: ${JSON.stringify(e)}`);
+
+        if (!this._connected) return;
+
+        // TODO: Fix branching by splitting up cleanup/disconnect in extension
+        if (this._disconnectCallback) {
+            this._disconnectCallback(); // must call disconnect()
+        } else {
+            this.disconnect();
+        }
+
+        this._runtime.emit(this._runtime.constructor.PERIPHERAL_CONNECTION_LOST_ERROR, {
+            message: `Scratch lost connection to`,
+            extensionId: this._extensionId
+        });
+    }
+
+    _handleRequestError (/* e */) {
         // log.error(`BLE error: ${JSON.stringify(e)}`);
 
         this._runtime.emit(this._runtime.constructor.PERIPHERAL_REQUEST_ERROR, {
@@ -184,20 +224,7 @@ class BLE extends JSONRPCWebSocket {
         });
     }
 
-    _sendDisconnectError (/* e */) {
+    _handleDiscoverTimeout () {
-        // log.error(`BLE error: ${JSON.stringify(e)}`);
-
-        if (!this._connected) return;
-
-        this._connected = false;
-
-        this._runtime.emit(this._runtime.constructor.PERIPHERAL_DISCONNECT_ERROR, {
-            message: `Scratch lost connection to`,
-            extensionId: this._extensionId
-        });
-    }
-
-    _sendDiscoverTimeout () {
         if (this._discoverTimeoutID) {
             window.clearTimeout(this._discoverTimeoutID);
         }

src/io/bt.js

@@ -11,24 +11,26 @@ class BT extends JSONRPCWebSocket {
      * @param {string} extensionId - the id of the extension using this socket.
      * @param {object} peripheralOptions - the list of options for peripheral discovery.
      * @param {object} connectCallback - a callback for connection.
+     * @param {object} disconnectCallback - a callback for disconnection.
      * @param {object} messageCallback - a callback for message sending.
      */
-    constructor (runtime, extensionId, peripheralOptions, connectCallback, messageCallback) {
+    constructor (runtime, extensionId, peripheralOptions, connectCallback, disconnectCallback = null, messageCallback) {
         const ws = new WebSocket(ScratchLinkWebSocket);
         super(ws);
 
         this._ws = ws;
         this._ws.onopen = this.requestPeripheral.bind(this); // only call request peripheral after socket opens
-        this._ws.onerror = this._sendRequestError.bind(this, 'ws onerror');
+        this._ws.onerror = this._handleRequestError.bind(this, 'ws onerror');
-        this._ws.onclose = this._sendDisconnectError.bind(this, 'ws onclose');
+        this._ws.onclose = this.handleDisconnectError.bind(this, 'ws onclose');
 
         this._availablePeripherals = {};
         this._connectCallback = connectCallback;
         this._connected = false;
         this._characteristicDidChangeCallback = null;
+        this._disconnectCallback = disconnectCallback;
+        this._discoverTimeoutID = null;
         this._extensionId = extensionId;
         this._peripheralOptions = peripheralOptions;
-        this._discoverTimeoutID = null;
         this._messageCallback = messageCallback;
         this._runtime = runtime;
     }
@@ -43,10 +45,10 @@ class BT extends JSONRPCWebSocket {
             if (this._discoverTimeoutID) {
                 window.clearTimeout(this._discoverTimeoutID);
             }
-            this._discoverTimeoutID = window.setTimeout(this._sendDiscoverTimeout.bind(this), 15000);
+            this._discoverTimeoutID = window.setTimeout(this._handleDiscoverTimeout.bind(this), 15000);
             this.sendRemoteRequest('discover', this._peripheralOptions)
                 .catch(
-                    e => this._sendRequestError(e)
+                    e => this._handleRequestError(e)
                 );
         }
         // TODO: else?
@@ -65,7 +67,7 @@ class BT extends JSONRPCWebSocket {
                 this._connectCallback();
             })
             .catch(e => {
-                this._sendRequestError(e);
+                this._handleRequestError(e);
             });
     }
 
@@ -73,10 +75,15 @@ class BT extends JSONRPCWebSocket {
      * Close the websocket.
      */
     disconnect () {
+        if (!this._connected) return;
+
         this._ws.close();
+        this._connected = false;
         if (this._discoverTimeoutID) {
             window.clearTimeout(this._discoverTimeoutID);
         }
+
+        this._runtime.emit(this._runtime.constructor.PERIPHERAL_DISCONNECTED);
     }
 
     /**
@@ -89,7 +96,7 @@ class BT extends JSONRPCWebSocket {
     sendMessage (options) {
         return this.sendRemoteRequest('send', options)
             .catch(e => {
-                this._sendDisconnectError(e);
+                this.handleDisconnectError(e);
             });
     }
 
@@ -120,7 +127,36 @@ class BT extends JSONRPCWebSocket {
         }
     }
 
-    _sendRequestError (/* e */) {
+    /**
+     * Handle an error resulting from losing connection to a peripheral.
+     *
+     * This could be due to:
+     * - battery depletion
+     * - going out of bluetooth range
+     * - being powered down
+     *
+     * Disconnect the socket, and if the extension using this socket has a
+     * disconnect callback, call it. Finally, emit an error to the runtime.
+     */
+    handleDisconnectError (/* e */) {
+        // log.error(`BT error: ${JSON.stringify(e)}`);
+
+        if (!this._connected) return;
+
+        // TODO: Fix branching by splitting up cleanup/disconnect in extension
+        if (this._disconnectCallback) {
+            this._disconnectCallback(); // must call disconnect()
+        } else {
+            this.disconnect();
+        }
+
+        this._runtime.emit(this._runtime.constructor.PERIPHERAL_CONNECTION_LOST_ERROR, {
+            message: `Scratch lost connection to`,
+            extensionId: this._extensionId
+        });
+    }
+
+    _handleRequestError (/* e */) {
         // log.error(`BT error: ${JSON.stringify(e)}`);
 
         this._runtime.emit(this._runtime.constructor.PERIPHERAL_REQUEST_ERROR, {
@@ -129,20 +165,7 @@ class BT extends JSONRPCWebSocket {
         });
     }
 
-    _sendDisconnectError (/* e */) {
+    _handleDiscoverTimeout () {
-        // log.error(`BT error: ${JSON.stringify(e)}`);
-
-        if (!this._connected) return;
-
-        this._connected = false;
-
-        this._runtime.emit(this._runtime.constructor.PERIPHERAL_DISCONNECT_ERROR, {
-            message: `Scratch lost connection to`,
-            extensionId: this._extensionId
-        });
-    }
-
-    _sendDiscoverTimeout () {
         if (this._discoverTimeoutID) {
             window.clearTimeout(this._discoverTimeoutID);
         }

src/virtual-machine.js

@@ -124,8 +124,11 @@ class VirtualMachine extends EventEmitter {
         this.runtime.on(Runtime.PERIPHERAL_REQUEST_ERROR, () =>
             this.emit(Runtime.PERIPHERAL_REQUEST_ERROR)
         );
-        this.runtime.on(Runtime.PERIPHERAL_DISCONNECT_ERROR, data =>
+        this.runtime.on(Runtime.PERIPHERAL_DISCONNECTED, () =>
-            this.emit(Runtime.PERIPHERAL_DISCONNECT_ERROR, data)
+            this.emit(Runtime.PERIPHERAL_DISCONNECTED)
+        );
+        this.runtime.on(Runtime.PERIPHERAL_CONNECTION_LOST_ERROR, data =>
+            this.emit(Runtime.PERIPHERAL_CONNECTION_LOST_ERROR, data)
         );
         this.runtime.on(Runtime.PERIPHERAL_SCAN_TIMEOUT, () =>
             this.emit(Runtime.PERIPHERAL_SCAN_TIMEOUT)