MD Settings: Fix subpage navigation focus for bluetooth+internet

chrome/browser/resources/settings/internet_page/internet_page.js

Index: chrome/browser/resources/settings/internet_page/internet_page.js
diff --git a/chrome/browser/resources/settings/internet_page/internet_page.js b/chrome/browser/resources/settings/internet_page/internet_page.js
index c25245484617256fb38619566fc80f6d8eba2962..1b13a2cc79b8fee76ce19723065a52fe04db78e9 100644
--- a/chrome/browser/resources/settings/internet_page/internet_page.js
+++ b/chrome/browser/resources/settings/internet_page/internet_page.js
@@ -88,8 +88,22 @@ Polymer({
         return [];
       }
     },
+
+    /**
+     * @type {!Map<string, string>}

[dpapad, 2017/04/25 21:25:19]

Ni: Use shorthand syntax,
@private {!Map<string, string>}

[stevenjb, 2017/04/25 23:32:53]

Done.

+     * @private
+     */
+    focusConfig_: {
+      type: Object,
+      value: function() {
+        return new Map();
+      },
+    },
   },
 
+  /** @private {string} Type of last detail page visited. */
+  detailType_: '',
+
   // Element event listeners
   listeners: {
     'device-enabled-toggled': 'onDeviceEnabledToggled_',
@@ -110,13 +124,13 @@ Polymer({
 
   /** @override */
   attached: function() {
-    this.onExtensionAddedListener_ = this.onExtensionAddedListener_ ||
-        this.onExtensionAdded_.bind(this);
+    this.onExtensionAddedListener_ =
+        this.onExtensionAddedListener_ || this.onExtensionAdded_.bind(this);
     chrome.management.onInstalled.addListener(this.onExtensionAddedListener_);
     chrome.management.onEnabled.addListener(this.onExtensionAddedListener_);
 
-    this.onExtensionRemovedListener_ = this.onExtensionRemovedListener_ ||
-        this.onExtensionRemoved_.bind(this);
+    this.onExtensionRemovedListener_ =
+        this.onExtensionRemovedListener_ || this.onExtensionRemoved_.bind(this);
     chrome.management.onUninstalled.addListener(
         this.onExtensionRemovedListener_);
 
@@ -146,9 +160,10 @@ Polymer({
   /**
    * settings.RouteObserverBehavior
    * @param {!settings.Route} route
+   * @param {!settings.Route} oldRoute
    * @protected
    */
-  currentRouteChanged: function(route) {
+  currentRouteChanged: function(route, oldRoute) {
     if (route == settings.Route.INTERNET_NETWORKS) {
       // Handle direct navigation to the networks page,
       // e.g. chrome://settings/internet/networks?type=WiFi
@@ -163,6 +178,27 @@ Polymer({
       var type = queryParams.get('type');
       if (type)
         this.knownNetworksType_ = type;
+    } else if (route != settings.Route.INTERNET && route.path != '/') {

[dpapad, 2017/04/25 21:25:19]

Is this equivalent to the following?

} else if (route != settings.Route.INTERNET && route != settings.Route.BASIC) {

[stevenjb, 2017/04/25 23:32:53]

Looks like it. Done.

+      // If we are navigating to a non internet section, do not set focus.
+      return;
+    }
+
+    // Focus the subpage arrow where appropriate.
+    if (oldRoute == settings.Route.NETWORK_DETAIL ||

[dpapad, 2017/04/25 21:25:19]

Is this equivalent to the following?

if (!settings.Route.INTERNET.contains(oldRoute))
  return;

// Do remaining stuff here

[stevenjb, 2017/04/25 23:32:53]

Handy. Yes. Done.

+        oldRoute == settings.Route.INTERNET_NETWORKS ||
+        oldRoute == settings.Route.KNOWN_NETWORKS) {
+      var selector;
+      if (route == settings.Route.INTERNET_NETWORKS) {

[dpapad, 2017/04/25 21:25:19]

Nit (optional): This can be compacted as follows:

// Comment here
var selector = route == settings.Route.INTERNET_NETWORKS ?
    '* /deep/ #networkList' :
    '* /deep/ #' + this.detailType_ + ' /deep/ .subpage-arrow';

[stevenjb, 2017/04/25 23:32:53]

Acknowledged.

+        // iron-list makes the correct timing to focus an item in the list
+        // very complicated, and the item may not exist, so just focus the
+        // entire list for now.
+        selector = '* /deep/ #networkList';
+      } else if (this.detailType_) {
+        selector = '* /deep/ #' + this.detailType_ + ' /deep/ .subpage-arrow';
+      }
+      if (selector && this.querySelector(selector))

[dpapad, 2017/04/25 21:25:19]

When would querySelector(selector) return nothing here?

[stevenjb, 2017/04/25 23:32:53]

If an Ethernet cable were unplugged while visiting an Ethernet detail page.

+        this.focusConfig_.set(oldRoute.path, selector);

[dpapad, 2017/04/25 21:25:19]

I don't fully understand the updates to the focusConfig_ map here, but it seems
that we might be leaving an obsolete entry in the map. Shouldn't there be an

else {
  this.focusConfig_.delete(oldRoute.path);
}

[stevenjb, 2017/04/25 23:32:53]

Done.

(I took this approach because of the dynamic nature of the Network section.
Originally I had ambitions to highlight the subpage button for the corresponding
network when returning from a details subpage, but iron-list behavior kicked my
ass so I am punting for now and just focusing the entire list in that case. We
still have they dynamic nature of the available types mentioned above though).

+      this.detailType_ = '';
     }
   },
 
@@ -184,6 +220,7 @@ Polymer({
    * @private
    */
   onShowDetail_: function(event) {
+    this.detailType_ = event.detail.Type;
     var params = new URLSearchParams;
     params.append('guid', event.detail.GUID);
     params.append('type', event.detail.Type);
@@ -197,6 +234,7 @@ Polymer({
    * @private
    */
   onShowNetworks_: function(event) {
+    this.detailType_ = event.detail.Type;
     var params = new URLSearchParams;
     params.append('type', event.detail.Type);
     this.subpageType_ = event.detail.Type;
@@ -216,6 +254,7 @@ Polymer({
    * @private
    */
   onShowKnownNetworks_: function(event) {
+    this.detailType_ = event.detail.Type;
     var params = new URLSearchParams;
     params.append('type', event.detail.Type);
     this.knownNetworksType_ = event.detail.type;
@@ -329,8 +368,8 @@ Polymer({
    * @private
    */
   deviceIsEnabled_: function(deviceState) {
-    return !!deviceState && deviceState.State ==
-        chrome.networkingPrivate.DeviceStateType.ENABLED;
+    return !!deviceState &&
+        deviceState.State == chrome.networkingPrivate.DeviceStateType.ENABLED;
   },
 
   /**