Update save file button based on states

chrome/browser/resources/net_internals/export_view.js

 // Copyright (c) 2012 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.
 
 /**
  * This view displays options for exporting the captured data.
  */
 var ExportView = (function() {
   'use strict';
 
   // We inherit from DivView.
   var superClass = DivView;
 
   /**
    * @constructor
    */
   function ExportView() {
     assertFirstConstructorCall(ExportView);
 
     // Call superclass's constructor.
     superClass.call(this, ExportView.MAIN_BOX_ID);
 
     var privacyStrippingCheckbox = $(ExportView.PRIVACY_STRIPPING_CHECKBOX_ID);
     privacyStrippingCheckbox.onclick =
         this.onSetPrivacyStripping_.bind(this, privacyStrippingCheckbox);
 
     this.saveFileButton_ = $(ExportView.SAVE_FILE_BUTTON_ID);
     this.saveFileButton_.onclick = this.onSaveFile_.bind(this);
     this.saveStatusText_ = $(ExportView.SAVE_STATUS_TEXT_ID);
+    this.isSaving_ = false;
 
     this.userCommentsTextArea_ = $(ExportView.USER_COMMENTS_TEXT_AREA_ID);
-    this.enableSaveFileButton_(false);
+    this.updateSaveFileButton_();
     this.userCommentsTextArea_.onkeyup = this.onUserCommentsUpdated_.bind(this);
 
     // Track blob for previous log dump so it can be revoked when a new dump is
     // saved.
     this.lastBlobURL_ = null;
 
     // Cached copy of the last loaded log dump, for use when exporting.
     this.loadedLogDump_ = null;
   }
 
@@ skipping 37 matching lines @@
     },
 
     /**
      * Sets the save to file status text, displayed below the save to file
      * button, to |text|.  Also enables or disables the save button based on the
      * value of |isSaving|, which must be true if the save process is still
      * ongoing, and false when the operation has stopped, regardless of success
      * of failure.
      */
     setSaveFileStatus: function(text, isSaving) {
-      this.enableSaveFileButton_(!isSaving);
+      this.isSaving_ = isSaving;
+      this.updateSaveFileButton_();
       this.saveStatusText_.textContent = text;
     },
 
-    enableSaveFileButton_: function(enabled) {
-      this.saveFileButton_.disabled = !enabled;
+    updateSaveFileButton_: function() {
+      this.saveFileButton_.disabled =
+          this.userCommentsTextArea_.value == '' || this.isSaving_;
     },
 
     showPrivacyWarning: function() {
       setNodeDisplay($(ExportView.PRIVACY_WARNING_ID), true);
       $(ExportView.PRIVACY_STRIPPING_CHECKBOX_ID).checked = false;
       $(ExportView.PRIVACY_STRIPPING_CHECKBOX_ID).disabled = true;
 
       // Updating the checkbox doesn't actually disable privacy stripping, since
       // the onclick function will not be called.
       this.onSetPrivacyStripping_($(ExportView.PRIVACY_STRIPPING_CHECKBOX_ID));
@@ skipping 47 matching lines @@
      */
     setUserComments_: function(userComments) {
       this.userCommentsTextArea_.value = userComments;
       this.onUserCommentsUpdated_();
     },
 
     /**
      * User comments are updated.
      */
     onUserCommentsUpdated_: function() {
-      this.enableSaveFileButton_(this.userCommentsTextArea_.value != '');
+      this.updateSaveFileButton_();
     },
 
     /**
      * Creates a blob url and starts downloading it.
      */
     onLogDumpCreated_: function(dumpText) {
       var textBlob = new Blob([dumpText], {type: 'octet/stream'});
       this.lastBlobURL_ = window.URL.createObjectURL(textBlob);
 
       // Update the anchor tag and simulate a click on it to start the
       // download.
       var downloadAnchor = $(ExportView.DOWNLOAD_ANCHOR_ID);
       downloadAnchor.href = this.lastBlobURL_;
       downloadAnchor.click();
 
       this.setSaveFileStatus('Dump successful', false);
     }
   };
 
   return ExportView;
 })();