PrintPreview: Hide/Show the header footer option based on print frame margins.

chrome/browser/resources/print_preview/header_footer_settings.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.
 
 cr.define('print_preview', function() {
   'use strict';
 
   /**
    * Creates a HeaderFooterSettings object. This object encapsulates all
    * settings and logic related to the headers and footers checkbox.
    * @constructor
    */
   function HeaderFooterSettings() {
     this.headerFooterOption_ = $('header-footer-option');
     this.headerFooterCheckbox_ = $('header-footer');
-    this.headerFooterApplies_ = false;
     this.addEventListeners_();
   }
 
   cr.addSingletonGetter(HeaderFooterSettings);
 
   HeaderFooterSettings.prototype = {
     /**
      * The checkbox corresponding to the headers and footers option.
      * @type {HTMLInputElement}
      */
     get headerFooterCheckbox() {
       return this.headerFooterCheckbox_;
     },
 
     /**
      * Checks whether the Headers and Footers checkbox is checked or not.
      * @return {boolean} true if Headers and Footers are checked.
      */
     hasHeaderFooter: function() {
-      return this.headerFooterApplies_ && this.headerFooterCheckbox_.checked;
+      return previewModifiable && this.headerFooterCheckbox_.checked;
     },
 
     /**
      * Sets the state of the headers footers checkbox.
      * @param {boolean} checked True if the headers footers checkbox shoule be
      *     checked, false if not.
      */
     setChecked: function(checked) {
       this.headerFooterCheckbox_.checked = checked;
     },
 
     /**
+     * Checks the printable area and updates the visibility of header footer
+     * option based on the selected margins.
+     * @param {printing::PageSizeMargins} pageLayout The default layout of the

[dpapad, 2012/03/17 00:36:41]

Fix comment.

[kmadhusu, 2012/03/19 18:45:31]

Done.

+     *     in poitns.
+     * @param {{x: number, y: number, width: number, height: number}}
+     *     printableArea Specifies the printable area details.
+     * @param {number} marginsType Specifies the selected margins type value.
+     */
+    checkAndHideHeaderFooterOption: function(pageLayout, printableArea,
+                                             marginsType) {
+      var headerFooterApplies = true;
+      if (marginsType ==
+              print_preview.MarginSettings.MARGINS_VALUE_NO_MARGINS ||
+          !previewModifiable) {
+        headerFooterApplies = false;
+      } else if (marginsType !=
+                     print_preview.MarginSettings.MARGINS_VALUE_MINIMUM) {
+        if (cr.isLinux || cr.isChromeOS) {
+          headerFooterApplies = pageLayout.marginTop > 0 ||
+                                pageLayout.marginBottom > 0;
+        } else {
+          var pageHeight = pageLayout.marginTop + pageLayout.marginBottom +
+                           pageLayout.contentHeight;
+          headerFooterApplies =
+              (pageLayout.marginTop > printableArea.y) ||
+              (pageLayout.marginBottom >
+                   (pageHeight - printableArea.y - printableArea.height));
+        }
+      }
+      this.setVisible_(headerFooterApplies);
+    },
+
+    /**
      * Adding listeners to header footer related controls.
      * @private
      */
     addEventListeners_: function() {
       this.headerFooterCheckbox_.onclick =
           this.onHeaderFooterChanged_.bind(this);
       document.addEventListener(customEvents.PDF_LOADED,
                                 this.onPDFLoaded_.bind(this));
-      document.addEventListener(customEvents.MARGINS_SELECTION_CHANGED,
-                                this.onMarginsSelectionChanged_.bind(this));
-    },
-
-    onMarginsSelectionChanged_: function(event) {
-      this.headerFooterApplies_ = event.selectedMargins !=
-          print_preview.MarginSettings.MARGINS_VALUE_NO_MARGINS;
-      this.setVisible_(this.headerFooterApplies_);
     },
 
     /**
      * Listener executing when the user selects or de-selects the headers
      * and footers option.
      * @private
      */
     onHeaderFooterChanged_: function() {
       requestPrintPreview();
     },
@@ skipping 18 matching lines @@
         fadeInOption(this.headerFooterOption_);
       else
         fadeOutOption(this.headerFooterOption_);
     }
   };
 
   return {
     HeaderFooterSettings: HeaderFooterSettings
   };
 });