Bypass the rendering pipeline for highlighting to reduce (eliminate) latency

Fixes #15

EditorNode.js

@@ -9,14 +9,9 @@ class EditorNode extends EditorInputBase {
   serialize() {
     return super.serialize({
       type: 'node',
-      highlight: this.elem_.classList.contains('highlight'),
     });
   }
 
-  setHighlight(highlight) {
-    this.elem_.classList.toggle('highlight', highlight);
-  }
-
   isSoft() {
     // Nested nodes are presumed to be references to other nodes if they exist
     for (let iter = this.elem_.parentElement; iter; iter = iter.parentElement) {
@@ -27,20 +22,6 @@ class EditorNode extends EditorInputBase {
     return false;
   }
 
-  onKeyDown(e) {
-    super.onKeyDown(e);
-
-    switch (e.key) {
-      case ' ':
-        this.elem_.classList.toggle('highlight');
-        this.elem_.setAttribute('data-arch-snapshot', '');
-        this.onInput();
-        e.stopPropagation();
-        e.preventDefault();
-        break;
-    }
-  }
-
   static unserialize(ser) {
     let node = new EditorNode(ser.id);
     node.setLabel(ser.label);