private void updateContent() {
grid.getRows().getChildren().clear();
for (Node node : JeaseSession.getFilter().apply(
((Node) tree.getSelectedValue()).getChildren())) {
Button button = newNodeSelector(node);
Popup popup = newNodePreview(node);
if (popup != null) {
button.setTooltip(popup);
grid.add(button, popup);
} else {
grid.add(button);