From 1541c75a7cc7eaf4c903830111cfd5b6d36d4f68 Mon Sep 17 00:00:00 2001
From: zepumph <michael.kauzmann@colorado.edu>
Date: Tue, 23 Jun 2020 12:14:22 -0800
Subject: [PATCH] PDOM listeners to respect Node.pickable,
 https://github.com/phetsims/scenery/issues/1056

---
 js/Checkbox.js         |  3 ++-
 js/ComboBox.js         |  1 +
 js/EnabledNode.js      |  3 +++
 js/EnabledNodeTests.js | 40 ++++++++++++++++++++++++++++++----------
 4 files changed, 36 insertions(+), 11 deletions(-)

diff --git a/js/Checkbox.js b/js/Checkbox.js
index f5887eaf..b4fbd1f3 100644
--- a/js/Checkbox.js
+++ b/js/Checkbox.js
@@ -8,6 +8,7 @@
 
 import Action from '../../axon/js/Action.js';
 import BooleanProperty from '../../axon/js/BooleanProperty.js';
+import validate from '../../axon/js/validate.js';
 import InstanceRegistry from '../../phet-core/js/documentation/InstanceRegistry.js';
 import inherit from '../../phet-core/js/inherit.js';
 import merge from '../../phet-core/js/merge.js';
@@ -22,7 +23,6 @@ import Tandem from '../../tandem/js/Tandem.js';
 import FontAwesomeNode from './FontAwesomeNode.js';
 import sun from './sun.js';
 import SunConstants from './SunConstants.js';
-import validate from '../../axon/js/validate.js';
 
 // constants
 const ENABLED_PROPERTY_TANDEM_NAME = 'enabledProperty';
@@ -178,6 +178,7 @@ function Checkbox( content, property, options ) {
     phetioFeatured: true
   } );
 
+  // TODO: aria-disabled is covered by EnabledNode, and can be removed once Checkbox uses that mixin. https://github.com/phetsims/sun/issues/585
   const enabledListener = function( enabled ) {
     if ( enabled ) {
       self.setAccessibleAttribute( 'onclick', '' );
diff --git a/js/ComboBox.js b/js/ComboBox.js
index 51b7345b..8a71f0bb 100644
--- a/js/ComboBox.js
+++ b/js/ComboBox.js
@@ -232,6 +232,7 @@ class ComboBox extends Node {
     const enabledObserver = enabled => {
       this.pickable = enabled;
       this.opacity = enabled ? 1.0 : options.disabledOpacity;
+      this.button.setAccessibleAttribute( 'aria-disabled', !enabled );
     };
     this.enabledProperty.link( enabledObserver );
 
diff --git a/js/EnabledNode.js b/js/EnabledNode.js
index 911b63f2..0e8f2129 100644
--- a/js/EnabledNode.js
+++ b/js/EnabledNode.js
@@ -54,6 +54,9 @@ const EnabledNode = {
           this.pickable = enabled;
           this.opacity = enabled ? 1.0 : options.disabledOpacity;
 
+          // Mark this Node as disabled in the ParallelDOM
+          this.setAccessibleAttribute( 'aria-disabled', !enabled );
+
           // handle cursor by supporting setting back to what the cursor was when component was made disabled.
           this.cursor = enabled ? cursor : 'default';
         };
diff --git a/js/EnabledNodeTests.js b/js/EnabledNodeTests.js
index 985da454..8223dd50 100644
--- a/js/EnabledNodeTests.js
+++ b/js/EnabledNodeTests.js
@@ -7,23 +7,24 @@
  */
 
 import BooleanProperty from '../../axon/js/BooleanProperty.js';
-import Node from '../../scenery/js/nodes/Node.js';
 import Property from '../../axon/js/Property.js';
+import Display from '../../scenery/js/display/Display.js';
+import Node from '../../scenery/js/nodes/Node.js';
 import EnabledNode from './EnabledNode.js';
 
 QUnit.module( 'EnabledNode' );
 
-QUnit.test( 'EnabledNode', assert => {
-
-  class EnabledNodeClass extends Node {
-    constructor( options ) {
-      super( options );
-      this.initializeEnabledNode( options );
-    }
+class EnabledNodeClass extends Node {
+  constructor( options ) {
+    super( options );
+    this.initializeEnabledNode( options );
   }
+}
+
+// mix in enabled component into a Node
+EnabledNode.mixInto( EnabledNodeClass );
 
-  // mix in enabled component into a Node
-  EnabledNode.mixInto( EnabledNodeClass );
+QUnit.test( 'EnabledNode', assert => {
 
   let node = new EnabledNodeClass();
 
@@ -56,6 +57,25 @@ QUnit.test( 'EnabledNode', assert => {
   assert.ok( myEnabledProperty.changedEmitter.getListenerCount() === defaultListenerCount, 'listener count should match original' );
 } );
 
+QUnit.test( 'EnabledNode with PDOM', assert => {
+
+  const rootNode = new Node( { tagName: 'div' } );
+  var display = new Display( rootNode ); // eslint-disable-line
+  document.body.appendChild( display.domElement );
+
+  const a11yNode = new EnabledNodeClass( {
+    tagName: 'p'
+  } );
+
+  rootNode.addChild( a11yNode );
+  assert.ok( a11yNode.accessibleInstances.length === 1, 'should have an instance when attached to display' );
+  assert.ok( a11yNode.accessibleInstances[ 0 ].peer, 'should have a peer' );
+  assert.ok( a11yNode.accessibleInstances[ 0 ].peer.primarySibling.getAttribute( 'aria-disabled' ) === 'false', 'should be enabled' );
+  a11yNode.enabled = false;
+  assert.ok( a11yNode.accessibleInstances[ 0 ].peer.primarySibling.getAttribute( 'aria-disabled' ) === 'true', 'should be enabled' );
+  testEnabledNode( assert, a11yNode, 'For accessible Node' );
+} );
+
 /**
  * Test basic functionality for an object that mixes in EnabledComponent
  * @param {Object} assert - from QUnit