Listbox and tree: clarify requirements for selected and checked (#1340)

mcking65 · web-flow · commit fc6b7fbd4950 · 2021-01-21T16:31:33.000-08:00
* Resolves #700 and resolves #1052 with the following changes. Removes "selectable" from the definition of option to support cases where either an item is checkable instead of selectable or an item is neither selectable nor checkable (i.e., similar to disabled). The definition of option is then: >An item in a listbox. Replaces the statement: >Elements with the role option have an implicit aria-selected value of false. with a list of conditions that must be met before a user agent can provide an implicit value for aria-selected. This enables authors to: 1. Use aria-checked instead of aria-selected in any listbox. 2. Indicate that an option is not selectable or checkable by omitting the declaration of checked or selected in a listbox where either checked or selected is explicitly declared on some of the options. Adds authoring guidance that: 1. Weakly suggests use of checked instead of selected in multi-selects. 2. Strongly discourages use of both checked and selected in the same listbox. In the characteristics table for option: 1. Removes aria-selected from required properties and adds to supported properties. 2. Removes the implicit value for aria-selected. Co-authored-by: Carolyn MacLeod <Carolyn_MacLeod@ca.ibm.com> Co-authored-by: James Teh <jamie@jantrid.net> * Duplicate option revisions in treeitem
diff --git a/index.html b/index.html
@@ -6010,9 +6010,27 @@ <h5>Note regarding the ARIA 1.1 <code>none</code> role.</h5>
 		<div class="role" id="option">
 			<rdef>option</rdef>
 			<div class="role-description">
-				<p>A selectable item in a <rref>listbox</rref>.</p>
-				<p>Authors MUST ensure <a>elements</a> with <a>role</a> <code>option</code> are contained in, or <a>owned</a> by, an element with the <a>role</a>  <rref>listbox</rref> or <rref>group</rref> within a <code>listbox</code>. Options not associated with a <rref>listbox</rref> might not be correctly mapped to an <a>accessibility <abbr title="Application Programing Interfaces">API</abbr></a>.</p>
-				<p>Elements with the role <code>option</code> have an implicit <sref>aria-selected</sref> value of <code>false</code>.</p>
+				<p>An item in a <rref>listbox</rref>.</p>
+				<p>Authors MUST ensure <a>elements</a> with <a>role</a> <code>option</code> are contained in, or <a>owned</a> by, an element with <a>role</a> <rref>listbox</rref> or an element with <a>role</a> <rref>group</rref> that is contained in, or <a>owned</a> by, an element with <a>role</a> <code>listbox</code>. Options not associated with a <rref>listbox</rref> might not be correctly mapped to an <a>accessibility <abbr title="Application Programing Interfaces">API</abbr></a>.</p>
+        <p>In certain conditions, a user agent MAY provide an implicit value for <sref>aria-selected</sref> for each <rref>option</rref> in a <rref>listbox</rref>, and if it does, the user agent MUST ensure the following conditions are met before providing an implicit value:</p>
+        <ul>
+          <li>The value of <pref>aria-multiselectable</pref> on the <rref>listbox</rref> is <code>false</code> or <code>undefined</code>.</li>
+          <li>None of the <rref>option</rref> elements in the <rref>listbox</rref> have an explicitly declared value for <sref>aria-selected</sref> or <sref>aria-checked</sref>.</li>  
+        </ul>
+        <p>
+          If a user agent provides an implicit <sref>aria-selected</sref> value for an <rref>option</rref>, the value SHOULD be <code>true</code> if the <rref>option</rref> has DOM focus or the <rref>listbox</rref> has DOM focus and the <rref>option</rref> is referenced by <pref>aria-activedescendant</pref>.
+          Otherwise, if a user agent provides an implicit <sref>aria-selected</sref> value for an <rref>option</rref>, the value SHOULD be <code>false</code>.
+        </p>
+        <p>
+          Authors MAY indicate selection for <rref>option</rref> elements  using either <sref>aria-selected</sref> or <sref>aria-checked</sref>.
+          Some user interfaces indicate selection with <sref>aria-selected</sref> in single-select list boxes and with <sref>aria-checked</sref> in multi-select list boxes.
+          Authors SHOULD NOT specify both <sref>aria-selected</sref> and <sref>aria-checked</sref> on <rref>option</rref> elements contained by the same <rref>listbox</rref> except in the extremely rare circumstances where all the following conditions are met:
+        </p>
+        <ul>
+          <li>The meaning and purpose of <sref>aria-selected</sref> is different from the meaning and purpose of <sref>aria-checked</sref> in the user interface.</li>
+          <li>The user interface makes the meaning and purpose of each state apparent.</li>
+          <li>The user interface provides a separate method for controlling each state.</li>
+        </ul>
 			</div>
 			<table class="role-features">
 				<caption>Characteristics:</caption>
@@ -6060,18 +6078,15 @@ <h5>Note regarding the ARIA 1.1 <code>none</code> role.</h5>
 					</tr>
 					<tr>
 						<th class="role-required-properties-head">Required States and Properties:</th>
-						<td class="role-required-properties">
-							<ul>
-								<li><sref>aria-selected</sref></li>
-							</ul>
-						</td>
+						<td class="role-required-properties"></td>
 					</tr>
 					<tr>
 						<th class="role-properties-head" scope="row">Supported States and Properties:</th>
 						<td class="role-properties">
 							<ul>
 								<li><sref>aria-checked</sref></li>
 								<li><pref>aria-posinset</pref></li>
+                <li><sref>aria-selected</sref></li>
 								<li><pref>aria-setsize</pref></li>
 							</ul>
 						</td>
@@ -6107,7 +6122,7 @@ <h5>Note regarding the ARIA 1.1 <code>none</code> role.</h5>
 					</tr>
 					<tr>
 						<th class="implicit-values-head" scope="row">Implicit Value for Role:</th>
-						<td class="implicit-values">Default for <sref>aria-selected</sref> is <code class="default">false</code>.</td>
+						<td class="implicit-values"></td>
 					</tr>
 				</tbody>
 			</table>
@@ -8715,11 +8730,14 @@ <h5>Presentational Roles Conflict Resolution</h5>
 				<p>If a  <rref>tabpanel</rref> or item in a <rref>tabpanel</rref> has focus, the associated <code>tab</code> is the currently active tab in the <rref>tablist</rref>, as defined in <a href="#managingfocus">Managing Focus</a>. <rref>tablist</rref> elements, which contain a set of associated <rref>tab</rref> elements, are typically placed near a series of <rref>tabpanel</rref> elements, usually preceding it. See the <cite><a href="" class="practices"><abbr title="Accessible Rich Internet Applications">WAI-ARIA</abbr> Authoring Practices</a></cite> for details on implementing a tab set design pattern.</p>
 				<p>Authors MUST ensure <a>elements</a> with <a>role</a> <rref>tab</rref> are contained in, or <a>owned</a> by, an element with the role <rref>tablist</rref>.</p>
 				<p>Authors SHOULD ensure the <rref>tabpanel</rref> associated with the currently active tab is <a>perceivable</a> to the user.</p>
-
 				<!-- keep following para synced with its counterpart in #tablist -->
 				<p>For a single-selectable <rref>tablist</rref>, authors SHOULD hide other <code>tabpanel</code> <a>elements</a> from the user until the user selects the tab associated with that tabpanel. For a multi-selectable <rref>tablist</rref>, authors SHOULD ensure that the <rref>tab</rref> for each visible <rref>tabpanel</rref> has the <sref>aria-expanded</sref> <a>attribute</a> set to <code>true</code>, and that the <code>tabs</code> associated with the remaining hidden <code>tabpanel</code> elements have their <sref>aria-expanded</sref> attributes set to <code>false</code>.</p>
-
-				<p>In either case, authors SHOULD ensure that a selected tab has its <sref>aria-selected</sref> attribute set to <code>true</code>, that inactive tab elements have their <sref>aria-selected</sref> attribute set to <code>false</code>, and that the currently selected tab provides a visual indication that it is selected. In the absence of an <sref>aria-selected</sref> attribute on the current tab, <a>user agents</a> SHOULD indicate to <a>assistive technologies</a> through the platform <a>accessibility <abbr title="Application Programing Interfaces">API</abbr></a> that the currently focused tab is selected.</p>
+				<p>Authors SHOULD ensure that a selected tab has its <sref>aria-selected</sref> attribute set to <code>true</code>, that inactive tab elements have their <sref>aria-selected</sref> attribute set to <code>false</code>, and that the currently selected tab provides a visual indication that it is selected.</p>
+        <p>In certain conditions, a user agent MAY provide an implicit value for <sref>aria-selected</sref> for each <rref>tab</rref> in a <rref>tablist</rref>, and if it does, the user agent MUST ensure the following conditions are met before providing an implicit value:</p>
+        <ul>
+          <li>The value of <pref>aria-multiselectable</pref> on the <rref>tablist</rref> is <code>false</code> or <code>undefined</code>.</li>
+          <li>None of the <rref>tab</rref> elements in the <rref>tablist</rref> have an explicitly declared value for <sref>aria-selected</sref> or <sref>aria-expanded</sref>.</li>  
+        </ul>
 			</div>
 			<table class="role-features">
 				<caption>Characteristics:</caption>
@@ -9921,9 +9939,28 @@ <h5>Presentational Roles Conflict Resolution</h5>
 		<div class="role" id="treeitem">
 			<rdef>treeitem</rdef>
 			<div class="role-description">
-				<p>An option item of a <rref>tree</rref>. This is an <a>element</a> within a tree that may be expanded or collapsed if it contains a sub-level group of tree item elements.</p>
-				<p>A collection of <code>treeitem</code> elements to be expanded and collapsed are enclosed in an element with the <rref>group</rref> <a>role</a>.</p>
-				<p>Authors MUST ensure <a>elements</a> with <a>role</a> <code>treeitem</code> are contained in, or <a>owned</a> by, an element with the role <rref>group</rref> or <rref>tree</rref>.</p>
+				<p>An item in a <rref>tree</rref>.</p>
+        				<p>A <rref>treeitem</rref> <a>element</a> may contain a sub-level group of elements that can be expanded or collapsed. An expandable collection of <code>treeitem</code> elements are enclosed in an element with the <rref>group</rref> <a>role</a>.</p>
+				<p>Authors MUST ensure <a>elements</a> with <a>role</a> <code>treeitem</code> are contained in, or <a>owned</a> by, an element with role <rref>tree</rref> or an element with role <rref>group</rref> that is contained in, or owned by, an element with role <rref>treeitem</rref>.</p>
+        <p>In certain conditions, a user agent MAY provide an implicit value for <sref>aria-selected</sref> for each <rref>treeitem</rref> in a <rref>tree</rref>, and if it does, the user agent MUST ensure the following conditions are met before providing an implicit value:</p>
+        <ul>
+          <li>The value of <pref>aria-multiselectable</pref> on the <rref>tree</rref> is <code>false</code> or <code>undefined</code>.</li>
+          <li>None of the <rref>treeitem</rref> elements in the <rref>tree</rref> have an explicitly declared value for <sref>aria-selected</sref> or <sref>aria-checked</sref>.</li>  
+        </ul>
+        <p>
+          If a user agent provides an implicit <sref>aria-selected</sref> value for a <rref>treeitem</rref>, the value SHOULD be <code>true</code> if the <rref>treeitem</rref> has DOM focus or the <rref>tree</rref> has DOM focus and the <rref>treeitem</rref> is referenced by <pref>aria-activedescendant</pref>.
+          Otherwise, if a user agent provides an implicit <sref>aria-selected</sref> value for a <rref>treeitem</rref>, the value SHOULD be <code>false</code>.
+        </p>
+        <p>
+          Authors MAY indicate selection for <rref>treeitem</rref> elements  using either <sref>aria-selected</sref> or <sref>aria-checked</sref>.
+          Some user interfaces indicate selection with <sref>aria-selected</sref> in single-select trees and with <sref>aria-checked</sref> in multi-select trees.
+          Authors SHOULD NOT specify both <sref>aria-selected</sref> and <sref>aria-checked</sref> on <rref>treeitem</rref> elements contained by the same <rref>tree</rref> except in the extremely rare circumstances where all the following conditions are met:
+        </p>
+        <ul>
+          <li>The meaning and purpose of <sref>aria-selected</sref> is different from the meaning and purpose of <sref>aria-checked</sref> in the user interface.</li>
+          <li>The user interface makes the meaning and purpose of each state apparent.</li>
+          <li>The user interface provides a separate method for controlling each state.</li>
+        </ul>
 			</div>
 			<table class="role-features">
 				<caption>Characteristics:</caption>
@@ -12969,12 +13006,8 @@ <h2>Definitions of States and Properties (all aria-* attributes)</h2>
 			<sdef>aria-selected</sdef>
 			<div class="state-description">
 				<p>Indicates the current "selected" <a>state</a> of various <a>widgets</a>. See related <sref>aria-checked</sref> and <sref>aria-pressed</sref>.</p>
-				<p>This <a>attribute</a> is used with single-selection and multiple-selection widgets:</p>
-				<ol>
-					<li>Single-selection containers where the currently focused item is not selected. The selection normally follows the focus, and is managed by the <a>user agent</a>.</li>
-					<li>Multiple-selection containers. Authors SHOULD ensure that any selectable descendant of a container in which the <pref>aria-multiselectable</pref> attribute is <code>true</code> specifies a value of either <code>true</code> or <code>false</code> for the <sref>aria-selected</sref> attribute.</li>
-				</ol>
-				<p>Any explicit assignment of <sref>aria-selected</sref> takes precedence over the implicit selection based on focus. If no <abbr title="Document Object Model">DOM</abbr> element in the widget is explicitly marked as selected, assistive technologies MAY convey implicit selection which follows the keyboard focus of the <a href="#managingfocus">managed focus</a> widget. If any <abbr title="Document Object Model">DOM</abbr> element in the widget is explicitly marked as selected, the user agent MUST NOT convey implicit selection for the widget.</p>
+				<p>This <a>attribute</a> is used to indicate which elements within single-selection and multiple-selection <rref>composite</rref> widgets are selected.</p>
+        <p>The <rref>option</rref>, <rref>tab</rref>, and <rref>treeitem</rref> roles permit user agents to provide an implicit value for <sref>aria-selected</sref> when specified conditions are met. User agents MUST NOT provide an implicit value for aria-selected in any other circumstance.</p>
 			</div>
 			<table class="state-features">
 				<caption>Characteristics:</caption>
