MD Settings: Implementing a "no results" page.

chrome/browser/resources/settings/settings_main/settings_main.js

Index: chrome/browser/resources/settings/settings_main/settings_main.js
diff --git a/chrome/browser/resources/settings/settings_main/settings_main.js b/chrome/browser/resources/settings/settings_main/settings_main.js
index f80a8512c0c54b21bc89b73ddfbf8271534494f2..54522bb9c6225eb707627ffb900a841d71c96e17 100644
--- a/chrome/browser/resources/settings/settings_main/settings_main.js
+++ b/chrome/browser/resources/settings/settings_main/settings_main.js
@@ -49,6 +49,12 @@ Polymer({
       },
     },
 
+    /** @private */
+    showNoResultsFound_: {
+      type: Boolean,
+      value: false,
+    },
+
     toolbarSpinnerActive: {
       type: Boolean,
       value: false,
@@ -64,13 +70,6 @@ Polymer({
   },
 
   /** @override */
-  ready: function() {
-    settings.getSearchManager().setCallback(function(isRunning) {
-      this.toolbarSpinnerActive = isRunning;
-    }.bind(this));
-  },
-
-  /** @override */
   attached: function() {
     document.addEventListener('toggle-advanced-page', function(e) {
       this.advancedToggleExpanded_ = e.detail;
@@ -154,18 +153,29 @@ Polymer({
    */
   searchContents: function(query) {
     this.ensureInDefaultSearchPage_();
+    this.toolbarSpinnerActive = true;
 
     // Trigger rendering of the basic and advanced pages and search once ready.
-    // Even if those are already rendered, yield to the message loop before
-    // initiating searching.
     this.showPages_ = {about: false, basic: true, advanced: true};
+
     setTimeout(function() {
       settings.getSearchManager().search(
           query, assert(this.$$('settings-basic-page')));
     }.bind(this), 0);
     setTimeout(function() {
       settings.getSearchManager().search(
-          query, assert(this.$$('settings-advanced-page')));
+          query, assert(this.$$('settings-advanced-page'))).then(
+          function(request) {
+            this.toolbarSpinnerActive = false;
+            this.showNoResultsFound_ =
+                !request.isSame('') && !request.didFindMatches();
+          }.bind(this),
+          function() {
+            // Nothing to do here. A previous search request was canceled
+            // because a new search request was issued before the first one
+            // completed. This callback is necessary to avoid an "Uncaught
+            // Promise error" in the console.

[Dan Beam, 2016/07/26 02:39:31]

it's arguable that we should just resolve(null) or add a boolean in the
request's context (i.e. finished: false) rather than reject, IMO

[dpapad, 2016/07/26 17:19:57]

Done, added 'finished' boolean.

+          });
     }.bind(this), 0);
   },
 });