use findStringProperty to get a default accessibleName for AccordionB…

…ox, see phetsims/models-of-the-hydrogen-atom#82 and #911

js/AccordionBox.ts

@@ -13,7 +13,7 @@ import { Shape } from '../../kite/js/imports.js';
 import InstanceRegistry from '../../phet-core/js/documentation/InstanceRegistry.js';
 import optionize, { combineOptions } from '../../phet-core/js/optionize.js';
 import StrictOmit from '../../phet-core/js/types/StrictOmit.js';
-import { assertNoAdditionalChildren, HighlightFromNode, InteractiveHighlighting, isHeightSizable, isWidthSizable, LayoutConstraint, Node, NodeOptions, PaintableOptions, ParallelDOM, Path, PathOptions, PDOMPeer, Rectangle, RectangleOptions, Sizable, Text } from '../../scenery/js/imports.js';
+import { assertNoAdditionalChildren, HighlightFromNode, InteractiveHighlighting, isHeightSizable, isWidthSizable, LayoutConstraint, Node, NodeOptions, PaintableOptions, ParallelDOM, Path, PathOptions, PDOMPeer, PDOMUtils, Rectangle, RectangleOptions, Sizable, Text } from '../../scenery/js/imports.js';
 import sharedSoundPlayers from '../../tambo/js/sharedSoundPlayers.js';
 import TSoundPlayer from '../../tambo/js/TSoundPlayer.js';
 import EventType from '../../tandem/js/EventType.js';
@@ -416,6 +416,11 @@ export default class AccordionBox extends Sizable( Node ) {
       return options;
     };
 
+    // If no accessibleName has been provided, try to find one from the titleNode
+    if ( !options.accessibleName && options.titleNode ) {
+      this.accessibleName = PDOMUtils.findStringProperty( options.titleNode );
+    }
+
     this.constraint = new AccordionBoxConstraint(
       this,
       contentNode,