diff --git a/core/modules/display/display.admin.css b/core/modules/display/display.admin.css
index 3fb706d..d039ed3 100644
--- a/core/modules/display/display.admin.css
+++ b/core/modules/display/display.admin.css
@@ -27,7 +27,7 @@ z#display-blocks .layout-display {
 	box-shadow:0px 0px 1px 1px rgba(0,0,0,0.1);
 }
 
-#display-blocks .region_information {
+#display-blocks .region-information {
 	clear:both;
 	display: block;
 	width: 100%;
@@ -37,7 +37,7 @@ z#display-blocks .layout-display {
 	overflow: hidden;
 }
 
-#display-blocks .region_label {
+#display-blocks .region-label {
 	font-size:11px;
 	text-transform: uppercase;
 	letter-spacing:.1em;
@@ -45,7 +45,7 @@ z#display-blocks .layout-display {
 	color: #666;
 }
 
-#display-blocks .region_table {
+#display-blocks .region-table {
 	clear:both;
 	display: table;
 	width: 100%;
@@ -56,7 +56,7 @@ z#display-blocks .layout-display {
  * Blocks.
  */
 
-#display-blocks .region_blocks {
+#display-blocks .region-blocks {
 	display: table-row;
 }
 
@@ -68,7 +68,7 @@ z#display-blocks .layout-display {
 	overflow: hidden;
 }
 
-#display-blocks .master_block {
+#display-blocks .master-block {
 	position: relative;
 	display: inline-block;
 	width: 100%;
@@ -79,7 +79,7 @@ z#display-blocks .layout-display {
 	background-image:linear-gradient(rgb(102,149,168) 0%,rgb(92,133,150) 99%,rgb(92,133,150) 100%);
 }
 
-z#display-blocks .layout_block {
+z#display-blocks .layout-block {
 	position: relative;
 	display: inline-block;
 	width: 100%;
@@ -90,7 +90,7 @@ z#display-blocks .layout_block {
 	background-image:linear-gradient(rgb(123,194,170) 0%,rgb(114,179,156) 99%,rgb(114,179,156) 100%);
 }
 
-z#display-blocks .page_block {
+z#display-blocks .page-block {
 	position: relative;
 	display: inline-block;
 	width: 100%;
@@ -101,7 +101,7 @@ z#display-blocks .page_block {
 	background-image:linear-gradient(rgb(137,211,124) 0%,rgb(128,198,117) 99%,rgb(128,198,117) 100%);
 }
 
-#display-blocks .add_block {
+#display-blocks .add-block {
 	display: table-cell;
 	border: 1px solid #ddd;
 	width: 60px !important;
@@ -112,14 +112,14 @@ z#display-blocks .page_block {
 	background-image:linear-gradient(rgb(254,254,254) 0%,rgb(225,225,225) 100%);
 }
 
-#display-blocks .add_block:hover {
+#display-blocks .add-block:hover {
 	border: 1px solid #ccc;
 	-moz-box-shadow:0px 0px 1px 1px rgba(0,0,0,0.1);
 	-webkit-box-shadow:0px 0px 1px 1px rgba(0,0,0,0.1);
 	box-shadow:0px 0px 1px 1px rgba(0,0,0,0.1);
 }
 
-#display-blocks .add_block_press {
+#display-blocks .add-block-press {
 	border: 1px solid #c5c5c5;
 	background-image:-moz-linear-gradient(rgb(245,245,245) 0%,rgb(221,221,221) 100%);
 	background-image:-webkit-gradient(linear,color-stop(0, rgb(245,245,245)),color-stop(1, rgb(221,221,221)));
@@ -127,7 +127,7 @@ z#display-blocks .page_block {
 	background-image:linear-gradient(rgb(245,245,245) 0%,rgb(221,221,221) 100%);
 }
 
-#display-blocks .plus_icon {
+#display-blocks .plus-icon {
 	display: inline-block;
 	width: 100%;
 	height: 100%;
@@ -158,12 +158,12 @@ z#display-blocks .column-right {
  * Block information.
  */
 
-#display-blocks .block_information {
+#display-blocks .block-information {
 	position: relative;
 	float: left;
 }
 
-#display-blocks .block_type_indicator {
+#display-blocks .block-type-indicator {
 	position: absolute;
 	left:0;
 	top:0;
@@ -178,7 +178,7 @@ z#display-blocks .column-right {
 	font-weight:bold;
 }
 
-#display-blocks .block_label {
+#display-blocks .block-label {
 	position: absolute;
 	left: 27px;
 	top:2px;
@@ -189,15 +189,15 @@ z#display-blocks .column-right {
 	margin-left:3px;
 }
 
-z#display-blocks .pb_text {
+z#display-blocks .pb-text {
 	color: #555;
 }
 
-z#display-blocks .lb_text {
+z#display-blocks .lb-text {
 	color: #555;
 }
 
-#display-blocks .mb_text {
+#display-blocks .mb-text {
 	color: #fff;
 }
 
@@ -205,7 +205,7 @@ z#display-blocks .lb_text {
  * Block operations.
  */
 
-#display-blocks .mb_block_operations {
+#display-blocks .mb-block-operations {
 	position: absolute;
 	opacity:0;
 	left: 0;
@@ -220,11 +220,11 @@ z#display-blocks .lb_text {
 	-webkit-transition-delay: initial;
 }
 
-#display-blocks .mb_block_operations:hover {
+#display-blocks .mb-block-operations:hover {
 	opacity:1;
 }
 
-z#display-blocks .lb_block_operations {
+z#display-blocks .lb-block-operations {
 	position: absolute;
 	opacity:0;
 	left: 0;
@@ -239,11 +239,11 @@ z#display-blocks .lb_block_operations {
 	-webkit-transition-delay: initial;
 }
 
-z#display-blocks .lb_block_operations:hover {
+z#display-blocks .lb-block-operations:hover {
 	opacity:1;
 }
 
-z#display-blocks .pb_block_operations {
+z#display-blocks .pb-block-operations {
 	position: absolute;
 	opacity:0;
 	left: 0;
@@ -258,7 +258,7 @@ z#display-blocks .pb_block_operations {
 	-webkit-transition-delay: initial;
 }
 
-z#display-blocks .pb_block_operations:hover {
+z#display-blocks .pb-block-operations:hover {
 	opacity:1;
 }
 
@@ -278,27 +278,27 @@ z#display-blocks .drag {
 	background-repeat:no-repeat;
 }
 
-#display-blocks .mb_gear {
+#display-blocks .mb-gear {
 	background-image:url(gear_fff.png);
 }
 
-z#display-blocks .mb_drag {
+z#display-blocks .mb-drag {
 	background-image:url(drag_fff.png);
 }
 
-z#display-blocks .pb_gear {
+z#display-blocks .pb-gear {
 	background-image:url(gear_555.png);
 }
 
-z#display-blocks .pb_drag {
+z#display-blocks .pb-drag {
 	background-image:url(drag_555.png);
 }
 
-z#display-blocks .lb_gear {
+z#display-blocks .lb-gear {
 	background-image:url(gear_555.png);
 }
 
-z#display-blocks .lb_drag {
+z#display-blocks .lb-drag {
 	background-image:url(drag_555.png);
 }
 
diff --git a/core/modules/display/display.admin.js b/core/modules/display/display.admin.js
index 8298e6c..b6deb9b 100644
--- a/core/modules/display/display.admin.js
+++ b/core/modules/display/display.admin.js
@@ -3,29 +3,37 @@
 "use strict";
 
 /**
- * Add new blocks to a display.
+ * Attach display editor functionality.
  */
-Drupal.behaviors.displayAddBlock = {
-  attach: function () {
-    $('.region_table .add_block').click(function () {
-      var chars = "ABCDEFGHIJKLMNOPQRSTUVWXTZabcdefghiklmnopqrstuvwxyz";
-      var randomString = '';
-      for (var i=0; i < 8; i++) {
-        var rnum = Math.floor(Math.random() * chars.length);
-        randomString += chars.substring(rnum,rnum+1);
-      }
+Drupal.behaviors.displayEditor = {
+  attach: function (context) {
+    // Attach click handler to add block button.
+    $('.region-table .add-block', context).once('display-add-block', function() {
+      $(this).click(function () {
+        // Generate a random block title until we can fire blocks as plugins
+        // in a modal that will give us a machine name and a title to place.
+        var chars = "abcdefghiklmnopqrstuvwxyz";
+        var randomString = '';
+        for (var i=0; i < 8; i++) {
+          var rnum = Math.floor(Math.random() * chars.length);
+          randomString += chars.substring(rnum,rnum+1);
+        }
 
-      var block = '<div class="block"><div class="master_block"><div class="block_information"><span class="block_type_indicator mb_text">M</span><span class="block_label mb_text">' + randomString + '&nbsp;block</span></div><div class="mb_block_operations"><span class="gear mb_gear"></span></div></div></div>';
-      $(this).parent().prepend(block);
+        // Add HTML code for block demonstration.
+        var block = '<div class="block"><div class="master-block"><div class="block-information"><span class="block-type-indicator mb-text">M</span><span class="block-label mb-text">' + randomString + '&nbsp;block</span></div><div class="mb-block-operations"><span class="gear mb-gear"></span></div></div></div>';
+        $(this).parent().prepend(block);
+      });
     });
 
-    // Apply drag and drop behavior.
-    $('.region_blocks').sortable({
-      items: '.block',
-      connectWith: '.connectedSortable',
-      cursor: 'move',
+    // Apply drag and drop behavior to all blocks in all regions.
+    $('.region-blocks', context).once('display-sort-blocks', function() {
+      $(this).sortable({
+        items: '.block',
+        connectWith: '.connected-sortable',
+        cursor: 'move',
+      });
+      $(this).disableSelection();
     });
-    $('.region_blocks').disableSelection();
   }
 };
 
diff --git a/core/modules/display/lib/Drupal/display/DisplayFormController.php b/core/modules/display/lib/Drupal/display/DisplayFormController.php
index ef5e056..c81be0b 100644
--- a/core/modules/display/lib/Drupal/display/DisplayFormController.php
+++ b/core/modules/display/lib/Drupal/display/DisplayFormController.php
@@ -73,9 +73,9 @@ private function layoutDemonstration(EntityInterface $display) {
     $layout = layout_manager()->createInstance($display->layout, array());
     $regions = $layout->getRegions();
     foreach ($regions as $region => $info) {
-      $region_text = '<div class="region-wrapper"><div class="region_information"><span class="region_label">' . check_plain($info['label']) . '</span></div>';
-      $region_text .= '<div class="region_table"><div class="region_blocks connectedSortable">';
-      $region_text .= '<div class="add_block"><span class="plus_icon"></span></div></div></div></div>';
+      $region_text = '<div class="region-wrapper"><div class="region-information"><span class="region-label">' . check_plain($info['label']) . '</span></div>';
+      $region_text .= '<div class="region-table"><div class="region-blocks connected-sortable">';
+      $region_text .= '<div class="add-block"><span class="plus-icon"></span></div></div></div></div>';
       $regions[$region] = $region_text;
     }
     $build['demonstration'] = array(