Support to connect multiple devices

lib/bluetooth_device.js

@@ -0,0 +1,38 @@
+/* global EventEmitter2 */
+'use strict';
+
+(function(exports) {
+  function BluetoothDevice(name, address) {
+    this.name = name;
+    this.address = address;
+  }
+
+  BluetoothDevice.prototype = Object.create(EventEmitter2.prototype);
+
+  ['writeCharacteristic', 'notifyCharacteristic'].forEach(function(item) {
+    Object.defineProperty(BluetoothDevice.prototype, item, {
+      set: function(value) {
+        this['_' + item] = value;
+      },
+      get: function() {
+        return this['_' + item];
+      }
+    });
+  });
+
+  BluetoothDevice.prototype.send = function(data) {
+    data = this._parseHexString(data);
+    this.writeCharacteristic.writeValue(data);
+  };
+
+  BluetoothDevice.prototype._parseHexString = function(str) {
+    var arrayBuffer = new ArrayBuffer(Math.ceil(str.length / 2));
+    var uint8Array = new Uint8Array(arrayBuffer);
+    for (var i = 0, j = 0; i < str.length; i += 2, j++) {
+      uint8Array[j] = parseInt(str.substr(i, 2), 16);
+    }
+    return arrayBuffer;
+  };
+
+  exports.BluetoothDevice = BluetoothDevice;
+}(window));

lib/bluetooth_helper.js

@@ -1,4 +1,4 @@
-/* global EventEmitter2 */
+/* global BluetoothDevice */
 'use strict';
 
 (function(exports) {
@@ -7,58 +7,52 @@
   var BLE_TX_UUID = '713d0002-503e-4c75-ba94-3148f18d941e';
   var bluetooth = navigator.mozBluetooth;
 
-  function BluetoothHelper(name, address) {
-    this.name = name;
-    this.address = address;
+  function BluetoothHelper() {
+    this._devices = [];
+    this.startScan();
   }
 
-  BluetoothHelper.prototype = Object.create(EventEmitter2.prototype);
-
-  BluetoothHelper.prototype.address = null,
-  BluetoothHelper.prototype.name = null,
-  BluetoothHelper.prototype.isConnected = false,
-  BluetoothHelper.prototype._bluetooth = null,
+  BluetoothHelper.prototype._devices = null,
   BluetoothHelper.prototype._gatt = null,
-  BluetoothHelper.prototype._writeChar = null,
-  BluetoothHelper.prototype._notifyChar = null,
+  BluetoothHelper.prototype._isScanning = false,
 
-  BluetoothHelper.prototype.send = function(data) {
-    data = this._parseHexString(data);
-    this._writeChar.writeValue(data);
-  };
+  BluetoothHelper.prototype.addDevice = function(name, address) {
+    var device = new BluetoothDevice(name, address);
+    // TODO: Pop the device from array once it is disconnected.
+    this._devices.push(device);
+    return device;
+  },
 
-  BluetoothHelper.prototype._parseHexString = function(str) {
-    var arrayBuffer = new ArrayBuffer(Math.ceil(str.length / 2));
-    var uint8Array = new Uint8Array(arrayBuffer);
-    for (var i = 0, j = 0; i < str.length; i += 2, j++) {
-      uint8Array[j] = parseInt(str.substr(i, 2), 16);
+  BluetoothHelper.prototype.startScan = function() {
+    if (this._isScanning) {
+      return;
     }
-    return arrayBuffer;
-  };
-
-  BluetoothHelper.prototype.connect = function() {
     if (bluetooth.defaultAdapter) {
-      // For stability, We use startLeScan to instead of startDiscovery.
+      // For stability, We use startScan to instead of startDiscovery.
       return bluetooth.defaultAdapter.startLeScan([]).then(scan => {
+        this._isScanning = true;
         this._scan = scan;
         scan.addEventListener('devicefound',
           this._handleDevicefound.bind(this));
       }).catch(() => {
-        this.connect();
+        this.startScan();
       });
     } else {
       bluetooth.addEventListener('attributechanged',
         this._handleAttributechanged.bind(this));
     }
   };
 
-  BluetoothHelper.prototype.disconnect = function() {
+  BluetoothHelper.prototype.stopScan = function() {
+    if (!this._isScanning) {
+      return;
+    }
     if (this._gatt) {
       return this._gatt.disconnect().then(() => {
         return bluetooth.defaultAdapter.stopLeScan(this._scan);
       }).then(() => {
-        this.emit('disconnected');
-        this.isConnected = false;
+        this._isScanning = false;
+        this.emit('scanningstoped');
       });
     } else {
       return Promise.reject('GATT is undefined.'); 
@@ -71,7 +65,7 @@
         case 'defaultAdapter':
           bluetooth.removeEventListener('attributechanged',
             this._handleAttributechanged);
-          this.connect();
+          this.startScan();
           break;
       }
     }
@@ -81,34 +75,39 @@
     var devcie = evt.device;
     var gatt = devcie.gatt;
     this._gatt = gatt;
-    if (devcie.name === this.name ||
-        devcie.address === this.address) {
-      this.name = devcie.name;
-      this.address = devcie.address;
+    devcie = this._devices.find(function(item) {
+      return (item.address === devcie.address ||
+        item.name === devcie.name) &&
+        !devcie.paired;
+    });
+    if (devcie) {
       gatt.connect().then(() => {
-        return this._discoverServices();
+        this._discoverServices(devcie);
       });
     }
   };
 
-  BluetoothHelper.prototype._discoverServices = function() {
+  BluetoothHelper.prototype._discoverServices = function(devcie) {
     var gatt = this._gatt;
     return gatt.discoverServices().then(() => {
       var service = gatt.services.find(function(service) {
         return service.uuid === BLE_SERVICE_UUID;
       });
-      this._writeChar =
+      var writeCharacteristic =
         service.characteristics.find(function(characteristic) {
           return characteristic.uuid === BLE_RX_UUID;
         });
-      this._notifyChar =
+      var notifyCharacteristic =
         service.characteristics.find(function(characteristic) {
           return characteristic.uuid === BLE_TX_UUID;
         });
-      this.emit('connected');
-      this.isConnected = true;
+      devcie.writeCharacteristic = writeCharacteristic;
+      devcie.notifyCharacteristic = notifyCharacteristic;
+      devcie.emit('connected', devcie);
     });
   };
 
+  exports.Bluetooth = new BluetoothHelper();
+  // For testing.
   exports.BluetoothHelper = BluetoothHelper;
 }(window));