Adjust hpainter.js demo

Author: linev

demo/node/hpainter.js

@@ -1,14 +1,18 @@
-import { version, HierarchyPainter } from 'jsroot';
+import { version, HierarchyPainter, draw } from 'jsroot';
 
 
 console.log(`JSROOT version ${version}`);
 
 
-const hp = new HierarchyPainter('batch', null);
+const hp = new HierarchyPainter('hpainter');
 
+// configure batch display to properly handle DOM in the node.js
+hp.setDisplay('batch');
+
+// catch draw function calls
 hp.setDrawFunc((dom, obj, opt) => {
    console.log(`trying to draw ${obj._typename}`);
-   return null;
+   return draw(dom, obj, opt);
 });
 
 await hp.openRootFile('https://root.cern/js/files/hsimple.root');