Fixes text selection problems for older browser versions.

display/display.css

@@ -43,6 +43,16 @@
     z-index: 1;
 }
 
+.no-select {
+    -webkit-touch-callout: none; /* iOS Safari */
+    -webkit-user-select: none; /* Safari */
+    -khtml-user-select: none; /* Konqueror HTML */
+    -moz-user-select: none; /* Old versions of Firefox */
+    -ms-user-select: none; /* Internet Explorer/Edge */
+    user-select: none; /* Non-prefixed version, currently
+                                  supported by Chrome, Edge, Opera and Firefox */
+}
+
 .close-button {
     pointer-events: all;
     z-index: 99;

display/graph.js

@@ -442,6 +442,7 @@ export default class Graph {
         const labelDiv = Helpers.createDiv("node-label", nodeDiv, {
             textContent: node.name,
         });
+        labelDiv.classList.add("no-select");
         labelDiv.style.color = node.color;
 
         const cssobj = new CSS3DSprite(nodeDiv);