From ef901e4e0999b9a2322b886f5ce1190716f17ad5 Mon Sep 17 00:00:00 2001
From: zepumph <michael.kauzmann@colorado.edu>
Date: Tue, 18 Aug 2020 13:22:26 -0800
Subject: [PATCH] user accessibleNameBehavior in AccordionBox,
 https://github.com/phetsims/sun/issues/444

---
 js/AccordionBox.js | 23 ++++++++++++-----------
 1 file changed, 12 insertions(+), 11 deletions(-)

diff --git a/js/AccordionBox.js b/js/AccordionBox.js
index d1dd464b..faa7f8a6 100644
--- a/js/AccordionBox.js
+++ b/js/AccordionBox.js
@@ -28,6 +28,17 @@ import AccordionBoxIO from './AccordionBoxIO.js';
 import ExpandCollapseButton from './ExpandCollapseButton.js';
 import sun from './sun.js';
 
+// The definition for how AccordionBox sets its accessibleName in the PDOM. Forward it onto its expandCollapseButton. See
+// AccordionBox.md for further style guide and documentation on the pattern.
+const ACCESSIBLE_NAME_BEHAVIOR = ( node, options, accessibleName ) => {
+
+  // Support mutation before this is defined
+  if ( node.expandCollapseButton ) {
+    node.expandCollapseButton.accessibleName = accessibleName;
+  }
+  return options;
+};
+
 /**
  * @constructor
  *
@@ -96,6 +107,7 @@ function AccordionBox( contentNode, options ) {
     // pdom
     tagName: 'div',
     headingTagName: 'h3', // specify the heading that this AccordionBox will be, TODO: use this.headingLevel when no longer experimental https://github.com/phetsims/scenery/issues/855
+    accessibleNameBehavior: ACCESSIBLE_NAME_BEHAVIOR,
 
     // phet-io support
     tandem: Tandem.REQUIRED,
@@ -529,17 +541,6 @@ inherit( Node, AccordionBox, {
     }
   },
 
-  /**
-   * The accessibleName of the AccordionBox is passed through to its ExpandCollapseButton, as that is its PDOM display.
-   * @override
-   * @param {string|null} accessibleName
-   */
-  setAccessibleName: function( accessibleName ) {
-    assert && assert( this.accessibleName === null, 'accessibleName should not be set directly on the AccordionBox, but ' +
-                                                    'should instead forward to its expandCollapseButton.' );
-    this.expandCollapseButton.accessibleName = accessibleName;
-  },
-
   /**
    * Ensures this node is eligible for GC.
    * @public