Print Preview: Refactoring layout mode related logic to LayoutSettings class.

chrome/browser/resources/print_preview/copies_settings.js

 // Copyright (c) 2011 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.
 
 cr.define('print_preview', function() {
   'use strict';
 
   /**
    * Creates a CopiesSettings object.
    * @constructor
@@ skipping 36 matching lines @@
 
     /**
      * Getter method for |twoSidedCheckbox_|.
      * @type {HTMLInputElement}
      */
     get twoSidedCheckbox() {
       return this.twoSidedCheckbox_;
     },
 
     /**
+     * Gets the duplex mode for printing.
+     * @return {number} duplex mode.
+     */
+     get duplexMode() {
+      // Constant values matches printing::DuplexMode enum. Not using const
+      // keyword because it is not allowed by JS strict mode.
+      var SIMPLEX = 0;
+      var LONG_EDGE = 1;
+      return !this.twoSidedCheckbox_.checked ? SIMPLEX : LONG_EDGE;
+    },
+
+    /**
      * @return {boolean} true if |this.textfield_| is empty, or represents a
      *     positive integer value.
      */
     isValid: function() {
       return !this.textfield_.value || isPositiveInteger(this.textfield_.value);
     },
 
     /**
      * Resets |this.textfield_| to |this.minValue_|.
      * @private
@@ skipping 96 matching lines @@
         this.decrementButton_.disabled = this.numberOfCopies == this.minValue_;
         fadeOutElement(this.hint_);
       }
     }
   };
 
   return {
     CopiesSettings: CopiesSettings,
   };
 });