bluetooth: Add Device connection logic and accompanying user interface.

chrome/browser/resources/bluetooth_internals/bluetooth_internals.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 bluetooth_internals.html, served from
  *     chrome://bluetooth-internals/.
  */
 
 cr.define('bluetooth_internals', function() {
+
+  var deviceAddressToProxy = new Map();

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

Can you annotate this with the appropriate K,V types?
@type {!Map<K,V>}

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

Done.

+
   function initializeViews() {
     var adapterBroker = null;
     adapter_broker.getAdapterBroker()
       .then(function(broker) { adapterBroker = broker; })
       .then(function() { return adapterBroker.getInfo(); })
       .then(function(response) { console.log('adapter', response.info); })
       .then(function() { return adapterBroker.getDevices(); })
       .then(function(response) {
         // Hook up device collection events.
         var devices = new device_collection.DeviceCollection([]);
         adapterBroker.addEventListener('deviceadded', function(event) {
           devices.addOrUpdate(event.detail.deviceInfo);
         });
         adapterBroker.addEventListener('devicechanged', function(event) {
           devices.addOrUpdate(event.detail.deviceInfo);
         });
         adapterBroker.addEventListener('deviceremoved', function(event) {
           devices.remove(event.detail.deviceInfo);
         });
 
         response.devices.forEach(devices.addOrUpdate,
                                  devices /* this */);
 
         var deviceTable = new device_table.DeviceTable();
+
+        deviceTable.addEventListener('inspectpressed', function(event) {
+          // TODO(crbug.com/663470): Move connection logic to DeviceDetailsView
+          // when it's added in chrome://bluetooth-internals.
+          var address = event.detail.address;
+          var proxy = deviceAddressToProxy.get(address);
+
+          if (proxy) {

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

Nit:
if (proxy) {
  ...
  return;
}

// No need for else, less indentation, more readable.
devices.updateConnectionStatus(address, 'connecting');
...

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

Done.

+            // Device is already connected, so disconnect.
+            proxy.disconnect();
+            deviceAddressToProxy.delete(address);
+            devices.updateConnectionStatus(address, 'disconnected');

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

Please explain where those string literals come from (disconnected, connecting,
connected), what other data structure they should be matching, to save time on
future readers. Also how about putting all those in an enum and re-use them
across JS code? Currently they are repeated in device_table.js, which seems a
bit fragile.

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

Done.

+          } else {
+            devices.updateConnectionStatus(address, 'connecting');
+            adapterBroker.connectToDevice(address).then(function(deviceProxy) {
+              if (!devices.getByAddress(address)) {
+                // Device no longer in list, so drop the connection.
+                deviceProxy.disconnect();
+                return;
+              }
+
+              deviceAddressToProxy.set(address, deviceProxy);
+              devices.updateConnectionStatus(address, 'connected');
+
+              // Fetch services asynchronously.
+              deviceProxy.getServices().then(function(response) {
+                var deviceInfo = devices.getByAddress(address);
+                deviceInfo.services = response.services;
+                devices.addOrUpdate(deviceInfo);
+              });
+            }).catch(function(error) {
+              devices.updateConnectionStatus(address, 'disconnected', error);
+            });
+          }
+        });
+
         deviceTable.setDevices(devices);
         document.body.appendChild(deviceTable);
       })
       .catch(function(error) { console.error(error); });
   }
 
   return {
     initializeViews: initializeViews
   };
 
 });
 
 document.addEventListener(
     'DOMContentLoaded', bluetooth_internals.initializeViews);