[CUPS] If no printers is auto-discovered, show the manual printer setup dialog

chrome/browser/resources/settings/printing_page/cups_add_printer_dialog.js

 // Copyright 2016 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.
 
 /**
  * @fileoverview 'settings-cups-add-printer-dialog' includes multiple dialogs to
  * set up a new CUPS printer.
  * Subdialogs include:
  * - 'add-printer-discovery-dialog' is a dialog showing discovered printers on
  *   the network that are available for setup.
@@ skipping 66 matching lines @@
   },
 
   /** @override */
   ready: function() {
     settings.CupsPrintersBrowserProxyImpl.getInstance()
         .startDiscoveringPrinters();
     this.addWebUIListener(
         'on-printer-discovered', this.onPrinterDiscovered_.bind(this));
     this.addWebUIListener(
         'on-printer-discovery-done', this.onPrinterDiscoveryDone_.bind(this));
-    this.addWebUIListener(
-        'on-printer-discovery-failed', this.onPrinterDiscoveryDone_.bind(this));
+  },
+
+  close: function() {
+    this.$$('add-printer-dialog').close();
   },
 
   /**
    * @param {!Array<!CupsPrinterInfo>} printers
    * @private
    */
   onPrinterDiscovered_: function(printers) {
     this.discovering_ = true;
     if (!this.discoveredPrinters) {
       this.discoveredPrinters = printers;
     } else {
       for (var i = 0; i < printers.length; i++)
         this.push('discoveredPrinters', printers[i]);
     }
   },
 
   /** @private */
   onPrinterDiscoveryDone_: function() {
     this.discovering_ = false;
     this.$$('add-printer-list').style.maxHeight = kPrinterListFullHeight + 'px';
-    this.$.noPrinterMessage.hidden = !!this.discoveredPrinters;
+    this.$.noPrinterMessage.hidden = !!this.discoveredPrinters.length;
+
+    if (!this.discoveredPrinters.length)
+      this.fire('no-detected-printer');
   },
 
   /** @private */
   stopDiscoveringPrinters_: function() {
     settings.CupsPrintersBrowserProxyImpl.getInstance()
         .stopDiscoveringPrinters();
     this.discovering_ = false;
   },
 
   /** @private */
@@ skipping 251 matching lines @@
     /** @private {boolean} */
     showManufacturerDialog_: Boolean,
   },
 
   listeners: {
     'configuring-dialog-closed': 'configuringDialogClosed_',
     'open-manually-add-printer-dialog': 'openManuallyAddPrinterDialog_',
     'open-configuring-printer-dialog': 'openConfiguringPrinterDialog_',
     'open-discovery-printers-dialog': 'openDiscoveryPrintersDialog_',
     'open-manufacturer-model-dialog': 'openManufacturerModelDialog_',
+    'no-detected-printer': 'onNoDetectedPrinter_',
   },
 
   /** @override */
   ready: function() {
     this.addWebUIListener('on-add-cups-printer', this.onAddPrinter_.bind(this));
   },
 
   /** Opens the Add printer discovery dialog. */
   open: function() {
     this.resetData_();
@@ skipping 112 matching lines @@
           this.currentDialog_, this.previousDialog_, 'showDiscoveryDialog_');
     } else if (this.previousDialog_ == AddPrinterDialogs.MANUALLY) {
       this.switchDialog_(
           this.currentDialog_, this.previousDialog_, 'showManuallyAddDialog_');
     } else if (this.previousDialog_ == AddPrinterDialogs.MANUFACTURER) {
       this.switchDialog_(
           this.currentDialog_, this.previousDialog_, 'showManufacturerDialog_');
     }
   },
 
+  /** @private */
+  onNoDetectedPrinter_: function() {
+    // If there is no detected printer, automatically open manually-add-printer
+    // dialog only when the user opens the discovery-dialog through the
+    // "ADD PRINTER" button.
+    if (!this.previousDialog_) {
+      this.$$('add-printer-discovery-dialog').close();
+      this.openManuallyAddPrinterDialog_();
+    }
+  },
+
   /**
    * Switch dialog from |fromDialog| to |toDialog|.
    * @param {string} fromDialog
    * @param {string} toDialog
    * @param {string} domIfBooleanName The name of the boolean variable
    *     corresponding to the |toDialog|.
    * @private
    */
   switchDialog_: function(fromDialog, toDialog, domIfBooleanName) {
     this.previousDialog_ = fromDialog;
@@ skipping 16 matching lines @@
   onAddPrinter_: function(success, printerName) {
     this.$$('add-printer-configuring-dialog').close();
     if (success)
       return;
 
     if (this.previousDialog_ == AddPrinterDialogs.MANUFACTURER) {
       this.setupFailed = true;
     }
   },
 });