From 7c7385234820c13cfbbe02cfff8671d382d7a988 Mon Sep 17 00:00:00 2001
From: Chris Malley <cmalley@pixelzoom.com>
Date: Sun, 20 Jan 2019 23:15:17 -0700
Subject: [PATCH] move displayOnlyProperty to ComboBox, #451

---
 js/ComboBox.js       | 13 +++++++++++++
 js/ComboBoxButton.js | 27 ++++++++++++++-------------
 2 files changed, 27 insertions(+), 13 deletions(-)

diff --git a/js/ComboBox.js b/js/ComboBox.js
index 690d128e..23720d05 100644
--- a/js/ComboBox.js
+++ b/js/ComboBox.js
@@ -177,6 +177,19 @@ define( require => {
       };
       this.enabledProperty.link( enabledObserver );
 
+      // @private for use via PhET-iO, see https://github.com/phetsims/sun/issues/451
+      // This is NOT reset when the Reset All button is pressed.
+      this.displayOnlyProperty = new BooleanProperty( false, {
+        tandem: options.tandem.createTandem( 'displayOnlyProperty' ),
+        phetioDocumentation: 'disables interaction with the ComboBox and ' +
+                             'makes it appear like a display that shows the current selection'
+      } );
+      this.displayOnlyProperty.link( displayOnly => {
+        this.hideListBox();
+        this.button.setDisplayOnly( displayOnly );
+        this.pickable = !displayOnly;
+      } );
+
       // @private called by dispose
       this.disposeComboBox = () => {
 
diff --git a/js/ComboBoxButton.js b/js/ComboBoxButton.js
index 03d55c26..82122c17 100644
--- a/js/ComboBoxButton.js
+++ b/js/ComboBoxButton.js
@@ -11,7 +11,6 @@ define( require => {
 
   // modules
   const AccessiblePeer = require( 'SCENERY/accessibility/AccessiblePeer' );
-  const BooleanProperty = require( 'AXON/BooleanProperty' );
   const HStrut = require( 'SCENERY/nodes/HStrut' );
   const Node = require( 'SCENERY/nodes/Node' );
   const Path = require( 'SCENERY/nodes/Path' );
@@ -188,18 +187,20 @@ define( require => {
         property.unlink( propertyObserver );
       };
 
-      // @private for use via PhET-iO, see https://github.com/phetsims/sun/issues/451
-      // This is NOT reset when the Reset All button is pressed.
-      this.displayOnlyProperty = new BooleanProperty( false, {
-        tandem: options.tandem.createTandem( 'displayOnlyProperty' ),
-        phetioDocumentation: 'disables interaction with the ComboBox button and ' +
-                             'makes it appear like a display that shows the current selection'
-      } );
-      this.displayOnlyProperty.link( displayOnly => {
-        arrow.visible = !displayOnly;
-        separator.visible = !displayOnly;
-        this.pickable = !displayOnly;
-      } );
+      // @private needed by methods
+      this.arrow = arrow;
+      this.separator = separator;
+    }
+
+    /**
+     * Sets the button to look like a value display instead of a combo box button.
+     * See https://github.com/phetsims/sun/issues/451
+     * @param {boolean} displayOnly
+     * @public
+     */
+    setDisplayOnly( displayOnly ) {
+      this.arrow.visible = !displayOnly;
+      this.separator.visible = !displayOnly;
     }
 
     /**