[CUPS] Add a "Manage..." button in the local destinations section of Print Preview Dialog on Chrome…

chrome/browser/resources/print_preview/print_preview.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.
 
 // TODO(rltoscano): Move data/* into print_preview.data namespace
 
 <include src="component.js">
 <include src="print_preview_focus_manager.js">
 
 cr.define('print_preview', function() {
@@ skipping 945 matching lines @@
     onManageCloudDestinationsActivated_: function() {
       this.nativeLayer_.startManageCloudDestinations(this.userInfo_.activeUser);
     },
 
     /**
      * Called when the destination search dispatches manage local destinations
      * event. Calls corresponding native layer method.
      * @private
      */
     onManageLocalDestinationsActivated_: function() {
+      if (cr.isChromeOS && loadTimeData.getBoolean('showLocalManageButton')) {

[Dan Beam, 2016/09/21 20:56:25]

if (loadTimeData.valueExists('localPrintersManagementURL'))
  window.open(loadTimeData.getString('localPrintersManagementURL'));
else
  this.nativeLayer_.startManageLocalDestinations();

[dpapad, 2016/09/21 20:58:23]

I think the confusing part is here. Why would this listener execute if
loadTimeData.getBoolean('showLocalManageButton') is false in the first place?
Wouldn't that cause the button to never be even shown?

I think 'showLocalManageButton' naming is confusing. Would renaming as something
as 'showWebUICupsConfig' make more sense? Then it would be

if (cr.isChromeOS && loadTimeData.getBoolean('showWebUICupsConfig')) {
...
}

[xdai1, 2016/09/21 23:38:53]

You're right that we won't get the event in the first place if
loadTimeData.getBoolean('showLocalManageButton') is false. Since
'showLocalManageButton' can only be false on Chrome OS, maybe we only check if
it's Chromeos?

[dpapad, 2016/09/22 00:18:15]

That looks fine. Alternatively, we could just do this check in C++ instead, and
open the new tab in a similar manner as
https://cs.chromium.org/chromium/src/chrome/browser/ui/webui/print_preview/pr....
The benefit is that localPrintersManagementURL would not need to be passed to JS
at all, and we would trade a Javascript runtime isChromeOS check with a
compile-time C++ ifdef.

This is still LG as-is. Up to you if you want to handle the event in C++
instead.

+        window.open(loadTimeData.getString('localPrintersManagementURL'));
+        return;
+      }
       this.nativeLayer_.startManageLocalDestinations();
     },
 
     /**
      * Called when the user wants to sign in to Google Cloud Print. Calls the
      * corresponding native layer event.
      * @param {boolean} addAccount Whether to open an 'add a new account' or
      *     default sign in page.
      * @private
      */
@@ skipping 335 matching lines @@
 <include src="search/recent_destination_list.js">
 <include src="search/destination_list_item.js">
 <include src="search/destination_search.js">
 <include src="search/fedex_tos.js">
 <include src="search/provisional_destination_resolver.js">
 
 window.addEventListener('DOMContentLoaded', function() {
   printPreview = new print_preview.PrintPreview();
   printPreview.initialize();
 });