bluetooth: Add Device connection logic and accompanying user interface.

chrome/browser/resources/bluetooth_internals/device_collection.js

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 /**
  * Javascript for DeviceCollection, served from
  *     chrome://bluetooth-internals/.
  */
 
 cr.define('device_collection', function() {
   /*
    * Collection of devices. Extends ArrayDataModel which provides a set of
    * functions and events that notifies observers when the collection changes.
    * @constructor
-   * @param {!Array<device_collection.Device>} array The starting collection of
-   *     devices.
+   * @param {!Array<device_collection.DeviceInfo>} array The starting collection

[dpapad, 2016/11/10 19:05:02]

I am guessing that the array should not hold null values, so
!device_collection.DeviceInfo.

[mbrunson, 2016/11/10 22:02:22]

Done.

+   *     of devices.
    * @extends {cr.ui.ArrayDataModel}
    */
   var DeviceCollection = function(array) {
     cr.ui.ArrayDataModel.call(this, array);
   };
   DeviceCollection.prototype = {
     __proto__: cr.ui.ArrayDataModel.prototype,
 
     /**
      * Finds the Device in the collection with the matching address.
      * @param {string} address
      */
     getByAddress: function(address) {
       for (var i = 0; i < this.length; i++) {
         var device = this.item(i);
-        if (address == device.info.address)
+        if (address == device.address)
           return device;
       }
       return null;
     },
 
     /**
      * Adds or updates a Device with new DeviceInfo.
      * @param {!interfaces.BluetoothDevice.DeviceInfo} deviceInfo
      */
     addOrUpdate: function(deviceInfo) {
-      var oldDevice = this.getByAddress(deviceInfo.address);
-      if (oldDevice) {
+      deviceInfo.removed = false;
+      var oldDeviceInfo = this.getByAddress(deviceInfo.address);
+
+      if (oldDeviceInfo) {
         // Update rssi if it's valid
         var rssi = (deviceInfo.rssi && deviceInfo.rssi.value) ||
-            (oldDevice.info.rssi && oldDevice.info.rssi.value);
+            (oldDeviceInfo.rssi && oldDeviceInfo.rssi.value);
 
-        oldDevice.info = deviceInfo;
-        oldDevice.info.rssi = { value: rssi };
-        oldDevice.removed = false;
-
-        this.updateIndex(this.indexOf(oldDevice));
+        Object.assign(oldDeviceInfo, deviceInfo);

[dpapad, 2016/11/10 19:05:02]

Are all properties of oldDeviceInfo overwritten by this? Is there any chance
that obsolete properties are left inside oldDeviceInfo (properties that exist on
oldDeviceInfo, but do not exist on deviceInfo)?

[mbrunson, 2016/11/10 22:02:22]

Yes. deviceInfo.rssi may be null while oldDeviceInfo.rssi will definitely exist.
The lines that follow try to preserve the correct values.

+        oldDeviceInfo.rssi = { value: rssi };
+        this.updateIndex(this.indexOf(oldDeviceInfo));
       } else {
-        this.push(new Device(deviceInfo));
+        deviceInfo.connectionStatus = 'disconnected';
+        this.push(deviceInfo);
       }
     },
 
     /**
      * Marks the Device as removed.
      * @param {!interfaces.bluetoothDevice.DeviceInfo} deviceInfo
      */
     remove: function(deviceInfo) {
       var device = this.getByAddress(deviceInfo.address);
       assert(device, 'Device does not exist.');
       device.removed = true;
       this.updateIndex(this.indexOf(device));
-    }
-  };
+    },
 
-  /*
-   * Data model for a cached device.
-   * @constructor
-   * @param {!interfaces.BluetoothDevice.DeviceInfo} info
-   */
-  var Device = function(info) {
-    this.info = info;
-    this.removed = false;
+    /**
+     * Updates the device connection status.
+     * @param {string} address The address of the device.
+     * @param {string} status Disconnected, connecting, or connected string.
+     * @param {Error} optional_error Optional Error object.

[dpapad, 2016/11/10 19:05:02]

Please follow styleguide for naming optional parameters.
https://google.github.io/styleguide/javascriptguide.xml?showone=Naming#Naming

@param {!Error=} opt_error Optional Error object.

[mbrunson, 2016/11/10 22:02:22]

Done.

+     */
+    updateConnectionStatus: function(address, status, optional_error) {
+      var message = (optional_error && optional_error.message) || '';
+
+      var device = this.getByAddress(address);

[dpapad, 2016/11/10 19:05:02]

Nit (optional): You can also
var device = assert(this.getByAddress(address), '....');

[mbrunson, 2016/11/10 22:02:22]

Oh. That's cool! Done.

+      assert(device, 'Device does not exist');
+      device.connectionStatus = status;
+
+      // TODO(crbug.com/663830): Replace connection error column with better
+      // notification system.
+      device.connectionMessage = message;
+      this.updateIndex(this.indexOf(device));
+    },
   };
 
   return {
-    Device: Device,
     DeviceCollection: DeviceCollection,
   };
 });