[Print Preview]: Added code to support pdf fit to page functionality.

chrome/browser/resources/print_preview/more_options.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 MoreOptions object. This object encapsulates all
+   * settings and logic related to the more options section.
+   * @constructor
+   */
+  function MoreOptions() {
+    // @type {HTMLDivElement} HTML element representing more options.
+    this.moreOptions_ = $('more-options');
+
+    // @type {boolean} True if header footer option is hidden.
+    this.hideHeaderFooterOption_ = true;

[dpapad, 2012/04/19 21:11:29]

Maybe a better name would be headerFooterOptionHidden. Starting the name with a
verb makes it sound like a function name. Same for hideFitToPageOption_.

Edit: I see that you are using those names because you are hiding those at a
later stage, in that case leave the names as they are but update the comments
"True if fit to page option should be hidden." or something like that.

[kmadhusu, 2012/04/20 23:03:42]

Modified the comment.

+
+    // @type {boolean} True if fit to page option is hidden.
+    this.hideFitToPageOption_ = true;
+
+    this.addEventListeners_();
+  }
+
+  cr.addSingletonGetter(MoreOptions);
+
+  MoreOptions.prototype = {
+    /**
+     * Adding listeners to more options section.
+     * @private
+     */
+    addEventListeners_: function() {
+      document.addEventListener(customEvents.PDF_LOADED,
+                                this.onPDFLoaded_.bind(this));
+      document.addEventListener(
+          customEvents.HEADER_FOOTER_VISIBILITY_CHANGED,
+          this.onHeaderFooterVisibilityChanged_.bind(this));
+      document.addEventListener(customEvents.PRINTER_SELECTION_CHANGED,
+                                this.onPrinterSelectionChanged_.bind(this));
+    },
+
+    /**
+     * Listener executing when a |customEvents.HEADER_FOOTER_VISIBILITY_CHANGED|
+     * event occurs.
+     * @param {cr.Event} event The event that triggered this listener.
+     * @private
+     */
+    onHeaderFooterVisibilityChanged_: function(event) {
+      this.hideHeaderFooterOption_ = !event.headerFooterApplies;
+      this.updateVisibility_();
+    },
+
+    /**
+     * Listener executing when a |customEvents.PRINTER_SEELCTION_CHANGED| event
+     * occurs.
+     * @param {cr.Event} event The event that triggered this listener.
+     * @private
+     */
+    onPrinterSelectionChanged_: function(event) {
+      if (previewModifiable)
+        return;
+      this.hideFitToPageOption_ = event.selectedPrinter == PRINT_TO_PDF;
+      this.updateVisibility_();
+    },
+
+    /**
+     * Listener executing when a |customEvents.PDF_LOADED| event occurs.
+     * @private
+     */
+    onPDFLoaded_: function() {
+      if (previewModifiable)
+        this.hideHeaderFooterOption_ = false;
+      else
+        this.hideFitToPageOption_ = false;
+    },
+
+    /**
+     * Hides or shows |this.moreOptions_|.
+     * @private
+     */
+    updateVisibility_: function() {
+      if (this.hideFitToPageOption_ && this.hideHeaderFooterOption_)
+        fadeOutOption(this.moreOptions_);
+      else
+        fadeInOption(this.moreOptions_);
+    }
+  };
+
+  return {
+    MoreOptions: MoreOptions
+  };
+});