The Tor Browser: accessible/src/jsat/TraversalRules.jsm@141e0f1194b1 (annotated)

accessible/src/jsat/TraversalRules.jsm@141e0f1194b1 (annotated)

accessible/src/jsat/TraversalRules.jsm

Wed, 31 Dec 2014 07:16:47 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Wed, 31 Dec 2014 07:16:47 +0100
branch: TOR_BUG_9701
changeset 3: 141e0f1194b1
permissions: -rw-r--r--

Revert simplistic fix pending revisit of Mozilla integration attempt.

 /* This Source Code Form is subject to the terms of the Mozilla Public
  * License, v. 2.0. If a copy of the MPL was not distributed with this file,
  * You can obtain one at http://mozilla.org/MPL/2.0/. */
 'use strict';
 const Cc = Components.classes;
 const Ci = Components.interfaces;
 const Cu = Components.utils;
 const Cr = Components.results;
 this.EXPORTED_SYMBOLS = ['TraversalRules'];
 Cu.import('resource://gre/modules/accessibility/Utils.jsm');
 Cu.import('resource://gre/modules/XPCOMUtils.jsm');
 XPCOMUtils.defineLazyModuleGetter(this, 'Roles',
   'resource://gre/modules/accessibility/Constants.jsm');
 XPCOMUtils.defineLazyModuleGetter(this, 'Filters',
   'resource://gre/modules/accessibility/Constants.jsm');
 XPCOMUtils.defineLazyModuleGetter(this, 'States',
   'resource://gre/modules/accessibility/Constants.jsm');
 XPCOMUtils.defineLazyModuleGetter(this, 'Prefilters',
   'resource://gre/modules/accessibility/Constants.jsm');
 let gSkipEmptyImages = new PrefCache('accessibility.accessfu.skip_empty_images');
 function BaseTraversalRule(aRoles, aMatchFunc, aPreFilter) {
   this._explicitMatchRoles = new Set(aRoles);
   this._matchRoles = aRoles;
   if (aRoles.indexOf(Roles.LABEL) < 0) {
     this._matchRoles.push(Roles.LABEL);
   }
   this._matchFunc = aMatchFunc || function (acc) { return Filters.MATCH; };
   this.preFilter = aPreFilter || gSimplePreFilter;
 }
 BaseTraversalRule.prototype = {
     getMatchRoles: function BaseTraversalRule_getmatchRoles(aRules) {
       aRules.value = this._matchRoles;
       return aRules.value.length;
     },
     match: function BaseTraversalRule_match(aAccessible)
     {
       let role = aAccessible.role;
       if (role == Roles.INTERNAL_FRAME) {
         return (Utils.getMessageManager(aAccessible.DOMNode)) ?
           Filters.MATCH  | Filters.IGNORE_SUBTREE : Filters.IGNORE;
       }
       let matchResult = this._explicitMatchRoles.has(role) ?
           this._matchFunc(aAccessible) : Filters.IGNORE;
       // If we are on a label that nests a checkbox/radio we should land on it.
       // It is a bigger touch target, and it reduces clutter.
       if (role == Roles.LABEL && !(matchResult & Filters.IGNORE_SUBTREE)) {
         let control = Utils.getEmbeddedControl(aAccessible);
         if (control && this._explicitMatchRoles.has(control.role)) {
           matchResult = this._matchFunc(control) | Filters.IGNORE_SUBTREE;
         }
       }
       return matchResult;
     },
     QueryInterface: XPCOMUtils.generateQI([Ci.nsIAccessibleTraversalRule])
 };
 var gSimpleTraversalRoles =
   [Roles.MENUITEM,
    Roles.LINK,
    Roles.PAGETAB,
    Roles.GRAPHIC,
    Roles.STATICTEXT,
    Roles.TEXT_LEAF,
    Roles.PUSHBUTTON,
    Roles.CHECKBUTTON,
    Roles.RADIOBUTTON,
    Roles.COMBOBOX,
    Roles.PROGRESSBAR,
    Roles.BUTTONDROPDOWN,
    Roles.BUTTONMENU,
    Roles.CHECK_MENU_ITEM,
    Roles.PASSWORD_TEXT,
    Roles.RADIO_MENU_ITEM,
    Roles.TOGGLE_BUTTON,
    Roles.ENTRY,
    Roles.KEY,
    Roles.HEADER,
    Roles.HEADING,
    Roles.SLIDER,
    Roles.SPINBUTTON,
    Roles.OPTION,
    // Used for traversing in to child OOP frames.
    Roles.INTERNAL_FRAME];
 var gSimpleMatchFunc = function gSimpleMatchFunc(aAccessible) {
   function hasZeroOrSingleChildDescendants () {
     for (let acc = aAccessible; acc.childCount > 0; acc = acc.firstChild) {
       if (acc.childCount > 1) {
         return false;
       }
     }
     return true;
   }
   switch (aAccessible.role) {
   case Roles.COMBOBOX:
     // We don't want to ignore the subtree because this is often
     // where the list box hangs out.
     return Filters.MATCH;
   case Roles.TEXT_LEAF:
     {
       // Nameless text leaves are boring, skip them.
       let name = aAccessible.name;
       if (name && name.trim())
         return Filters.MATCH;
       else
         return Filters.IGNORE;
     }
   case Roles.STATICTEXT:
     {
       let parent = aAccessible.parent;
       // Ignore prefix static text in list items. They are typically bullets or numbers.
       if (parent.childCount > 1 && aAccessible.indexInParent == 0 &&
           parent.role == Roles.LISTITEM)
         return Filters.IGNORE;
       return Filters.MATCH;
     }
   case Roles.GRAPHIC:
     return TraversalRules._shouldSkipImage(aAccessible);
   case Roles.HEADER:
   case Roles.HEADING:
     if ((aAccessible.childCount > 0 || aAccessible.name) &&
         hasZeroOrSingleChildDescendants()) {
       return Filters.MATCH | Filters.IGNORE_SUBTREE;
     } else {
       return Filters.IGNORE;
     }
   default:
     // Ignore the subtree, if there is one. So that we don't land on
     // the same content that was already presented by its parent.
     return Filters.MATCH |
       Filters.IGNORE_SUBTREE;
   }
 };
 var gSimplePreFilter = Prefilters.DEFUNCT |
   Prefilters.INVISIBLE |
   Prefilters.ARIA_HIDDEN |
   Prefilters.TRANSPARENT;
 this.TraversalRules = {
   Simple: new BaseTraversalRule(gSimpleTraversalRoles, gSimpleMatchFunc),
   SimpleOnScreen: new BaseTraversalRule(
     gSimpleTraversalRoles, gSimpleMatchFunc,
     Prefilters.DEFUNCT | Prefilters.INVISIBLE | Prefilters.ARIA_HIDDEN |
     Prefilters.TRANSPARENT | Prefilters.OFFSCREEN),
   Anchor: new BaseTraversalRule(
     [Roles.LINK],
     function Anchor_match(aAccessible)
     {
       // We want to ignore links, only focus named anchors.
       if (Utils.getState(aAccessible).contains(States.LINKED)) {
         return Filters.IGNORE;
       } else {
         return Filters.MATCH;
       }
     }),
   Button: new BaseTraversalRule(
     [Roles.PUSHBUTTON,
      Roles.SPINBUTTON,
      Roles.TOGGLE_BUTTON,
      Roles.BUTTONDROPDOWN,
      Roles.BUTTONDROPDOWNGRID]),
   Combobox: new BaseTraversalRule(
     [Roles.COMBOBOX,
      Roles.LISTBOX]),
   Landmark: new BaseTraversalRule(
     [],
     function Landmark_match(aAccessible) {
       return Utils.getLandmarkName(aAccessible) ? Filters.MATCH :
         Filters.IGNORE;
     }
   ),
   Entry: new BaseTraversalRule(
     [Roles.ENTRY,
      Roles.PASSWORD_TEXT]),
   FormElement: new BaseTraversalRule(
     [Roles.PUSHBUTTON,
      Roles.SPINBUTTON,
      Roles.TOGGLE_BUTTON,
      Roles.BUTTONDROPDOWN,
      Roles.BUTTONDROPDOWNGRID,
      Roles.COMBOBOX,
      Roles.LISTBOX,
      Roles.ENTRY,
      Roles.PASSWORD_TEXT,
      Roles.PAGETAB,
      Roles.RADIOBUTTON,
      Roles.RADIO_MENU_ITEM,
      Roles.SLIDER,
      Roles.CHECKBUTTON,
      Roles.CHECK_MENU_ITEM]),
   Graphic: new BaseTraversalRule(
     [Roles.GRAPHIC],
     function Graphic_match(aAccessible) {
       return TraversalRules._shouldSkipImage(aAccessible);
     }),
   Heading: new BaseTraversalRule(
     [Roles.HEADING],
     function Heading_match(aAccessible) {
       return aAccessible.childCount > 0 ? Filters.MATCH : Filters.IGNORE;
     }),
   ListItem: new BaseTraversalRule(
     [Roles.LISTITEM,
      Roles.TERM]),
   Link: new BaseTraversalRule(
     [Roles.LINK],
     function Link_match(aAccessible)
     {
       // We want to ignore anchors, only focus real links.
       if (Utils.getState(aAccessible).contains(States.LINKED)) {
         return Filters.MATCH;
       } else {
         return Filters.IGNORE;
       }
     }),
   List: new BaseTraversalRule(
     [Roles.LIST,
      Roles.DEFINITION_LIST]),
   PageTab: new BaseTraversalRule(
     [Roles.PAGETAB]),
   Paragraph: new BaseTraversalRule(
     [Roles.PARAGRAPH,
      Roles.SECTION],
     function Paragraph_match(aAccessible) {
       for (let child = aAccessible.firstChild; child; child = child.nextSibling) {
         if (child.role === Roles.TEXT_LEAF) {
           return Filters.MATCH | Filters.IGNORE_SUBTREE;
         }
       }
       return Filters.IGNORE;
     }),
   RadioButton: new BaseTraversalRule(
     [Roles.RADIOBUTTON,
      Roles.RADIO_MENU_ITEM]),
   Separator: new BaseTraversalRule(
     [Roles.SEPARATOR]),
   Table: new BaseTraversalRule(
     [Roles.TABLE]),
   Checkbox: new BaseTraversalRule(
     [Roles.CHECKBUTTON,
      Roles.CHECK_MENU_ITEM]),
   _shouldSkipImage: function _shouldSkipImage(aAccessible) {
     if (gSkipEmptyImages.value && aAccessible.name === '') {
       return Filters.IGNORE;
     }
     return Filters.MATCH;
   }
 };

The Tor Browser / annotate

accessible/src/jsat/TraversalRules.jsm@141e0f1194b1 (annotated)

accessible/src/jsat/TraversalRules.jsm