Print Preview: Improving accessibility of margins UI.

chrome/browser/resources/print_preview/margin_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 Margins object that holds four margin values. The units in which
    * the values are expressed can be any numeric value.
@@ skipping 249 matching lines @@
       setDefaultValuesAndRegeneratePreview(false);
     },
 
     /**
      * Listener executed when the mouse is over the sidebar. If the custom
      * margin lines are displayed, then, it fades them out.
      * @private
      */
     onSidebarMouseOver_: function(e) {
       if (!this.forceDisplayingMarginLines_)
-        this.marginsUI.hide();
+        this.marginsUI.hide(false);
     },
 
     /**
      * Listener executed when the mouse is over the main view. If the custom
      * margin lines are hidden, then, it fades them in.
      * @private
      */
     onMainviewMouseOver_: function() {
       this.forceDisplayingMarginLines_ = false;
       this.marginsUI.show();
@@ skipping 10 matching lines @@
                                 this.onPDFGenerationError_.bind(this));
     },
 
     /**
      * Executes when an 'PDFGenerationError' event occurs.
      * @private
      */
     onPDFGenerationError_: function() {
       if (this.isCustomMarginsSelected()) {
         this.removeCustomMarginEventListeners_();
-        this.marginsUI.hide();
+        this.marginsUI.hide(true);
       }
     },
 
     /**
      * Executes whenever a "DragEvent" occurs.
      * @param {cr.Event} e The event that triggered this listener.
      */
     onDragEvent_: function(e) {
       var dragDeltaInPoints = this.convertDragDeltaToPoints_(e.dragDelta);
       this.marginsUI.lastClickedMarginsUIPair.updateWhileDragging(
@@ skipping 107 matching lines @@
 
     /**
      * Adds listeners when the custom margins option is selected.
      * @private
      */
     addCustomMarginEventListeners_: function() {
       $('mainview').onmouseover = this.onMainviewMouseOver_.bind(this);
       $('sidebar').onmouseover = this.onSidebarMouseOver_.bind(this);
       this.eventTracker_.add(
           this.marginsUI, 'DragEvent', this.onDragEvent_.bind(this), false);
+      this.eventTracker_.add(document, 'marginTextboxFocused',
+                             this.onMarginTextboxFocused_.bind(this), false);
     },
 
     /**
      * Removes the event listeners associated with the custom margins option.
      * @private
      */
     removeCustomMarginEventListeners_: function() {
       $('mainview').onmouseover = null;
       $('sidebar').onmouseover = null;
       this.eventTracker_.remove(this.marginsUI, 'DragEvent');
-      this.marginsUI.hide();
+      this.eventTracker_.remove(document, 'marginTextboxFocused');
+      this.marginsUI.hide(true);
     },
 
     /**
      * Updates |this.marginsUI| depending on the specified margins and the
      * position of the page within the plugin.
      * @private
      */
     drawCustomMarginsUI_: function() {
       // TODO(dpapad): find out why passing |!this.areMarginsSettingsValid()|
       // directly produces the opposite value even though
@@ skipping 13 matching lines @@
      * Called when there is change in the preview position or size.
      */
     onPreviewPositionChanged: function() {
       if (this.isCustomMarginsSelected() && previewArea.pdfLoaded &&
           pageSettings.totalPageCount != undefined) {
         this.drawCustomMarginsUI_();
       }
     },
 
     /**
+     * Executes when a margin textbox is focused. Used for improved
+     * accessibility.
+     * @private
+     */
+    onMarginTextboxFocused_: function() {
+      this.forceDisplayingMarginLines_ = true;
+      this.marginsUI.show();
+    },
+
+    /**
      * Executes when user selects a different margin option, ie,
      * |this.marginList_.selectedIndex| is changed.
      * @private
      */
     onMarginsChanged_: function() {
       if (this.isDefaultMarginsSelected())
         this.onDefaultMarginsSelected_();
       else if (this.isNoMarginsSelected())
         this.onNoMarginsSelected_();
       else if (this.isCustomMarginsSelected())
@@ skipping 120 matching lines @@
     }
   };
 
   return {
     MarginSettings: MarginSettings,
     PageLayout: PageLayout,
     setNumberFormatAndMeasurementSystem:
         MarginSettings.setNumberFormatAndMeasurementSystem,
   };
 });