How to use

render

method

in

org.pentaho.di.ui.spoon.tree.TreeManager

public void render() {
 rootNodes.forEach( t -> {
  render( t, tree );
 } );
 setExpanded();
}

private <T> void render( TreeNode treeNode, T tree ) {
 if ( treeNode.isHidden() ) {
  return;
 }
 TreeItem childTreeItem = createTreeItem( treeNode, tree );
 if ( treeNode.hasChildren() ) {
  for ( TreeNode childTreeNode : treeNode.getChildren() ) {
   render( childTreeNode, childTreeItem );
  }
 }
}

selectionTreeManager.render();
selectionTree.setFocus();
selectionTree.layout();