Modified components ui to address concern of all the time disabled check update button.

chrome/browser/resources/components.js

 // Copyright 2013 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.
 
 'use strict';
 
 /**
  * Takes the |componentsData| input argument which represents data about the
  * currently installed components and populates the html jstemplate with
  * that data. It expects an object structure like the above.
  * @param {Object} componentsData Detailed info about installed components.
  *      Same expected format as returnComponentsData().
  */
 function renderTemplate(componentsData) {
   // This is the javascript code that processes the template:
   var input = new JsEvalContext(componentsData);
-  var output = $('componentTemplate');
+  var output = $('component-template').cloneNode(true);
+  $('component-placeholder').innerHTML = '';
+  $('component-placeholder').appendChild(output);
   jstProcess(input, output);
+  output.removeAttribute('hidden');
 }
 
 /**
  * Asks the C++ ComponentsDOMHandler to get details about the installed
  * components.
  * The ComponentsDOMHandler should reply to returnComponentsData() (below).
  */
 function requestComponentsData() {
   chrome.send('requestComponentsData');
 }
@@ skipping 37 matching lines @@
 
   // Disable some controls for Guest in ChromeOS.
   if (cr.isChromeOS)
     uiAccountTweaks.UIAccountTweaks.applyGuestModeVisibility(document);
 
   bodyContainer.style.visibility = 'visible';
   body.className = 'show-tmi-mode-initial';
 }
 
 /**
+ *  Component update status refresh interval.
+ */
+var STATUS_REFRESH_INTERVAL = 1000;
+
+function returnComponentStatus(component_id, status) {
+  $('status-' + component_id).textContent = status;
+  var node = $(component_id);
+  if (status == 'in-progress') {
+    node.disabled = true;
+    window.setTimeout(function() { updateComponentStatus(node); },
+                      STATUS_REFRESH_INTERVAL);

[James Hawkins, 2014/03/27 20:12:03]

Why are we using polling instead of having the browser update the UI when it
changes?

[Shrikant Kelkar, 2014/03/27 22:00:13]

The c++ code doesn't have a callback so far.

[James Hawkins, 2014/03/27 22:02:44]

So let's fix it.  We shouldn't be polling from the WebUI.

+  } else {
+    node.disabled = false;
+  }
+}
+
+function updateComponentStatus(node) {
+  chrome.send('requestComponentStatus', [String(node.id)]);
+}
+
+/**
  * Handles an 'enable' or 'disable' button getting clicked.
  * @param {HTMLElement} node The HTML element representing the component
  *     being checked for update.
  */
 function handleCheckUpdate(node) {
   node.disabled = true;
+
+  $('status-' + String(node.id)).textContent = 'Checking for update...';
+
   // Tell the C++ ComponentssDOMHandler to check for update.
   chrome.send('checkUpdate', [String(node.id)]);
+  window.setTimeout(function() { updateComponentStatus(node); },
+                    STATUS_REFRESH_INTERVAL);
 }
 
 // Get data and have it displayed upon loading.
 document.addEventListener('DOMContentLoaded', requestComponentsData);
-
-// Add handlers to static HTML elements.
-$('button-check-update').onclick = handleCheckUpdate;