From 8e4d904095c3745dee278252e0341fd9abc88a7e Mon Sep 17 00:00:00 2001
From: Sam El-Husseini <16690124+samelhusseini@users.noreply.github.com>
Date: Fri, 16 Aug 2019 16:29:34 -0700
Subject: [PATCH] Listen to focus events on children and add a focused class in
 the dropdown (#2848)

---
 core/dropdowndiv.js | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/core/dropdowndiv.js b/core/dropdowndiv.js
index 2808b75ed..60ccf076e 100644
--- a/core/dropdowndiv.js
+++ b/core/dropdowndiv.js
@@ -145,6 +145,15 @@ Blockly.DropDownDiv.createDom = function() {
   Blockly.DropDownDiv.DIV_.style.transition = 'transform ' +
     Blockly.DropDownDiv.ANIMATION_TIME + 's, ' +
     'opacity ' + Blockly.DropDownDiv.ANIMATION_TIME + 's';
+
+  // Handle focusin/out events to add a visual indicator when
+  // a child is focused or blurred.
+  div.addEventListener('focusin', function() {
+    Blockly.utils.dom.addClass(div, 'focused');
+  });
+  div.addEventListener('focusout', function() {
+    Blockly.utils.dom.removeClass(div, 'focused');
+  });
 };
 
 /**