1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/accessible/src/jsat/TraversalRules.jsm Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,283 @@
1.4 +/* This Source Code Form is subject to the terms of the Mozilla Public
1.5 + * License, v. 2.0. If a copy of the MPL was not distributed with this file,
1.6 + * You can obtain one at http://mozilla.org/MPL/2.0/. */
1.7 +
1.8 +'use strict';
1.9 +
1.10 +const Cc = Components.classes;
1.11 +const Ci = Components.interfaces;
1.12 +const Cu = Components.utils;
1.13 +const Cr = Components.results;
1.14 +
1.15 +this.EXPORTED_SYMBOLS = ['TraversalRules'];
1.16 +
1.17 +Cu.import('resource://gre/modules/accessibility/Utils.jsm');
1.18 +Cu.import('resource://gre/modules/XPCOMUtils.jsm');
1.19 +XPCOMUtils.defineLazyModuleGetter(this, 'Roles',
1.20 + 'resource://gre/modules/accessibility/Constants.jsm');
1.21 +XPCOMUtils.defineLazyModuleGetter(this, 'Filters',
1.22 + 'resource://gre/modules/accessibility/Constants.jsm');
1.23 +XPCOMUtils.defineLazyModuleGetter(this, 'States',
1.24 + 'resource://gre/modules/accessibility/Constants.jsm');
1.25 +XPCOMUtils.defineLazyModuleGetter(this, 'Prefilters',
1.26 + 'resource://gre/modules/accessibility/Constants.jsm');
1.27 +
1.28 +let gSkipEmptyImages = new PrefCache('accessibility.accessfu.skip_empty_images');
1.29 +
1.30 +function BaseTraversalRule(aRoles, aMatchFunc, aPreFilter) {
1.31 + this._explicitMatchRoles = new Set(aRoles);
1.32 + this._matchRoles = aRoles;
1.33 + if (aRoles.indexOf(Roles.LABEL) < 0) {
1.34 + this._matchRoles.push(Roles.LABEL);
1.35 + }
1.36 + this._matchFunc = aMatchFunc || function (acc) { return Filters.MATCH; };
1.37 + this.preFilter = aPreFilter || gSimplePreFilter;
1.38 +}
1.39 +
1.40 +BaseTraversalRule.prototype = {
1.41 + getMatchRoles: function BaseTraversalRule_getmatchRoles(aRules) {
1.42 + aRules.value = this._matchRoles;
1.43 + return aRules.value.length;
1.44 + },
1.45 +
1.46 + match: function BaseTraversalRule_match(aAccessible)
1.47 + {
1.48 + let role = aAccessible.role;
1.49 + if (role == Roles.INTERNAL_FRAME) {
1.50 + return (Utils.getMessageManager(aAccessible.DOMNode)) ?
1.51 + Filters.MATCH | Filters.IGNORE_SUBTREE : Filters.IGNORE;
1.52 + }
1.53 +
1.54 + let matchResult = this._explicitMatchRoles.has(role) ?
1.55 + this._matchFunc(aAccessible) : Filters.IGNORE;
1.56 +
1.57 + // If we are on a label that nests a checkbox/radio we should land on it.
1.58 + // It is a bigger touch target, and it reduces clutter.
1.59 + if (role == Roles.LABEL && !(matchResult & Filters.IGNORE_SUBTREE)) {
1.60 + let control = Utils.getEmbeddedControl(aAccessible);
1.61 + if (control && this._explicitMatchRoles.has(control.role)) {
1.62 + matchResult = this._matchFunc(control) | Filters.IGNORE_SUBTREE;
1.63 + }
1.64 + }
1.65 +
1.66 + return matchResult;
1.67 + },
1.68 +
1.69 + QueryInterface: XPCOMUtils.generateQI([Ci.nsIAccessibleTraversalRule])
1.70 +};
1.71 +
1.72 +var gSimpleTraversalRoles =
1.73 + [Roles.MENUITEM,
1.74 + Roles.LINK,
1.75 + Roles.PAGETAB,
1.76 + Roles.GRAPHIC,
1.77 + Roles.STATICTEXT,
1.78 + Roles.TEXT_LEAF,
1.79 + Roles.PUSHBUTTON,
1.80 + Roles.CHECKBUTTON,
1.81 + Roles.RADIOBUTTON,
1.82 + Roles.COMBOBOX,
1.83 + Roles.PROGRESSBAR,
1.84 + Roles.BUTTONDROPDOWN,
1.85 + Roles.BUTTONMENU,
1.86 + Roles.CHECK_MENU_ITEM,
1.87 + Roles.PASSWORD_TEXT,
1.88 + Roles.RADIO_MENU_ITEM,
1.89 + Roles.TOGGLE_BUTTON,
1.90 + Roles.ENTRY,
1.91 + Roles.KEY,
1.92 + Roles.HEADER,
1.93 + Roles.HEADING,
1.94 + Roles.SLIDER,
1.95 + Roles.SPINBUTTON,
1.96 + Roles.OPTION,
1.97 + // Used for traversing in to child OOP frames.
1.98 + Roles.INTERNAL_FRAME];
1.99 +
1.100 +var gSimpleMatchFunc = function gSimpleMatchFunc(aAccessible) {
1.101 + function hasZeroOrSingleChildDescendants () {
1.102 + for (let acc = aAccessible; acc.childCount > 0; acc = acc.firstChild) {
1.103 + if (acc.childCount > 1) {
1.104 + return false;
1.105 + }
1.106 + }
1.107 +
1.108 + return true;
1.109 + }
1.110 +
1.111 + switch (aAccessible.role) {
1.112 + case Roles.COMBOBOX:
1.113 + // We don't want to ignore the subtree because this is often
1.114 + // where the list box hangs out.
1.115 + return Filters.MATCH;
1.116 + case Roles.TEXT_LEAF:
1.117 + {
1.118 + // Nameless text leaves are boring, skip them.
1.119 + let name = aAccessible.name;
1.120 + if (name && name.trim())
1.121 + return Filters.MATCH;
1.122 + else
1.123 + return Filters.IGNORE;
1.124 + }
1.125 + case Roles.STATICTEXT:
1.126 + {
1.127 + let parent = aAccessible.parent;
1.128 + // Ignore prefix static text in list items. They are typically bullets or numbers.
1.129 + if (parent.childCount > 1 && aAccessible.indexInParent == 0 &&
1.130 + parent.role == Roles.LISTITEM)
1.131 + return Filters.IGNORE;
1.132 +
1.133 + return Filters.MATCH;
1.134 + }
1.135 + case Roles.GRAPHIC:
1.136 + return TraversalRules._shouldSkipImage(aAccessible);
1.137 + case Roles.HEADER:
1.138 + case Roles.HEADING:
1.139 + if ((aAccessible.childCount > 0 || aAccessible.name) &&
1.140 + hasZeroOrSingleChildDescendants()) {
1.141 + return Filters.MATCH | Filters.IGNORE_SUBTREE;
1.142 + } else {
1.143 + return Filters.IGNORE;
1.144 + }
1.145 + default:
1.146 + // Ignore the subtree, if there is one. So that we don't land on
1.147 + // the same content that was already presented by its parent.
1.148 + return Filters.MATCH |
1.149 + Filters.IGNORE_SUBTREE;
1.150 + }
1.151 +};
1.152 +
1.153 +var gSimplePreFilter = Prefilters.DEFUNCT |
1.154 + Prefilters.INVISIBLE |
1.155 + Prefilters.ARIA_HIDDEN |
1.156 + Prefilters.TRANSPARENT;
1.157 +
1.158 +this.TraversalRules = {
1.159 + Simple: new BaseTraversalRule(gSimpleTraversalRoles, gSimpleMatchFunc),
1.160 +
1.161 + SimpleOnScreen: new BaseTraversalRule(
1.162 + gSimpleTraversalRoles, gSimpleMatchFunc,
1.163 + Prefilters.DEFUNCT | Prefilters.INVISIBLE | Prefilters.ARIA_HIDDEN |
1.164 + Prefilters.TRANSPARENT | Prefilters.OFFSCREEN),
1.165 +
1.166 + Anchor: new BaseTraversalRule(
1.167 + [Roles.LINK],
1.168 + function Anchor_match(aAccessible)
1.169 + {
1.170 + // We want to ignore links, only focus named anchors.
1.171 + if (Utils.getState(aAccessible).contains(States.LINKED)) {
1.172 + return Filters.IGNORE;
1.173 + } else {
1.174 + return Filters.MATCH;
1.175 + }
1.176 + }),
1.177 +
1.178 + Button: new BaseTraversalRule(
1.179 + [Roles.PUSHBUTTON,
1.180 + Roles.SPINBUTTON,
1.181 + Roles.TOGGLE_BUTTON,
1.182 + Roles.BUTTONDROPDOWN,
1.183 + Roles.BUTTONDROPDOWNGRID]),
1.184 +
1.185 + Combobox: new BaseTraversalRule(
1.186 + [Roles.COMBOBOX,
1.187 + Roles.LISTBOX]),
1.188 +
1.189 + Landmark: new BaseTraversalRule(
1.190 + [],
1.191 + function Landmark_match(aAccessible) {
1.192 + return Utils.getLandmarkName(aAccessible) ? Filters.MATCH :
1.193 + Filters.IGNORE;
1.194 + }
1.195 + ),
1.196 +
1.197 + Entry: new BaseTraversalRule(
1.198 + [Roles.ENTRY,
1.199 + Roles.PASSWORD_TEXT]),
1.200 +
1.201 + FormElement: new BaseTraversalRule(
1.202 + [Roles.PUSHBUTTON,
1.203 + Roles.SPINBUTTON,
1.204 + Roles.TOGGLE_BUTTON,
1.205 + Roles.BUTTONDROPDOWN,
1.206 + Roles.BUTTONDROPDOWNGRID,
1.207 + Roles.COMBOBOX,
1.208 + Roles.LISTBOX,
1.209 + Roles.ENTRY,
1.210 + Roles.PASSWORD_TEXT,
1.211 + Roles.PAGETAB,
1.212 + Roles.RADIOBUTTON,
1.213 + Roles.RADIO_MENU_ITEM,
1.214 + Roles.SLIDER,
1.215 + Roles.CHECKBUTTON,
1.216 + Roles.CHECK_MENU_ITEM]),
1.217 +
1.218 + Graphic: new BaseTraversalRule(
1.219 + [Roles.GRAPHIC],
1.220 + function Graphic_match(aAccessible) {
1.221 + return TraversalRules._shouldSkipImage(aAccessible);
1.222 + }),
1.223 +
1.224 + Heading: new BaseTraversalRule(
1.225 + [Roles.HEADING],
1.226 + function Heading_match(aAccessible) {
1.227 + return aAccessible.childCount > 0 ? Filters.MATCH : Filters.IGNORE;
1.228 + }),
1.229 +
1.230 + ListItem: new BaseTraversalRule(
1.231 + [Roles.LISTITEM,
1.232 + Roles.TERM]),
1.233 +
1.234 + Link: new BaseTraversalRule(
1.235 + [Roles.LINK],
1.236 + function Link_match(aAccessible)
1.237 + {
1.238 + // We want to ignore anchors, only focus real links.
1.239 + if (Utils.getState(aAccessible).contains(States.LINKED)) {
1.240 + return Filters.MATCH;
1.241 + } else {
1.242 + return Filters.IGNORE;
1.243 + }
1.244 + }),
1.245 +
1.246 + List: new BaseTraversalRule(
1.247 + [Roles.LIST,
1.248 + Roles.DEFINITION_LIST]),
1.249 +
1.250 + PageTab: new BaseTraversalRule(
1.251 + [Roles.PAGETAB]),
1.252 +
1.253 + Paragraph: new BaseTraversalRule(
1.254 + [Roles.PARAGRAPH,
1.255 + Roles.SECTION],
1.256 + function Paragraph_match(aAccessible) {
1.257 + for (let child = aAccessible.firstChild; child; child = child.nextSibling) {
1.258 + if (child.role === Roles.TEXT_LEAF) {
1.259 + return Filters.MATCH | Filters.IGNORE_SUBTREE;
1.260 + }
1.261 + }
1.262 +
1.263 + return Filters.IGNORE;
1.264 + }),
1.265 +
1.266 + RadioButton: new BaseTraversalRule(
1.267 + [Roles.RADIOBUTTON,
1.268 + Roles.RADIO_MENU_ITEM]),
1.269 +
1.270 + Separator: new BaseTraversalRule(
1.271 + [Roles.SEPARATOR]),
1.272 +
1.273 + Table: new BaseTraversalRule(
1.274 + [Roles.TABLE]),
1.275 +
1.276 + Checkbox: new BaseTraversalRule(
1.277 + [Roles.CHECKBUTTON,
1.278 + Roles.CHECK_MENU_ITEM]),
1.279 +
1.280 + _shouldSkipImage: function _shouldSkipImage(aAccessible) {
1.281 + if (gSkipEmptyImages.value && aAccessible.name === '') {
1.282 + return Filters.IGNORE;
1.283 + }
1.284 + return Filters.MATCH;
1.285 + }
1.286 +};
