#### fxml
<?xml version="1.0" encoding="UTF-8"?>

<?import java.lang.String?>
<?import javafx.collections.FXCollections?>
<?import javafx.scene.control.Button?>
<?import javafx.scene.control.ComboBox?>
<?import javafx.scene.control.ScrollPane?>
<?import javafx.scene.control.TextField?>
<?import javafx.scene.layout.AnchorPane?>
<?import javafx.scene.layout.VBox?>

<VBox prefHeight="400.0" prefWidth="235.0" styleClass="main" stylesheets="@standards.css" xmlns="http://javafx.com/javafx/8.0.121" xmlns:fx="http://javafx.com/fxml/1" fx:controller="com.lampa.testing.javafxcontroller">
    <AnchorPane prefHeight="111.0" prefWidth="235.0" styleClass="anchor">
        <ComboBox fx:id="combo" layoutX="14.0" layoutY="47.0" onAction="#comboAction" prefWidth="150.0">
            <items>
                <FXCollections fx:factory="observableArrayList">
                    <String fx:value="Apple" />
                    <String fx:value="Orange" />
                    <String fx:value="Pear" />
                </FXCollections>
            </items>
        </ComboBox>
    </AnchorPane>

    <ScrollPane prefHeight="141.0" prefWidth="235.0" styleClass="scroll">
        <VBox>
            <AnchorPane minHeight="0.0" minWidth="0.0" prefHeight="180.0" prefWidth="177.0" styleClass="anch">
                <TextField layoutX="7.0" layoutY="62.0" prefHeight="31.0" prefWidth="133.0" />
            </AnchorPane>

            <Button layoutX="41.0" layoutY="75.0" mnemonicParsing="false" text="Button" />
        </VBox>
    </ScrollPane>

</VBox>

### controller
package com.lampa.testing;

import javafx.collections.ObservableList;
import javafx.event.ActionEvent;
import javafx.event.EventHandler;
import javafx.fxml.FXML;
import javafx.geometry.Bounds;
import javafx.scene.Node;
import javafx.scene.Parent;
import javafx.scene.control.ComboBox;
import javafx.scene.control.ScrollPane;
import javafx.scene.input.MouseEvent;
import javafx.scene.layout.VBox;


public class javafxcontroller {
    @FXML
    private ComboBox combo;

    @FXML
    private void initialize() {  }

    @FXML
    private void comboAction(ActionEvent event) {
        System.out.println(combo.getValue());
        view(combo);
    }

    private void view(Node combobox) {
        Parent parent = combobox.getParent().getParent(); //vbox
        ScrollPane scrollPane = (ScrollPane) parent.getChildrenUnmodifiable().get(1); // get scrollpane
        VBox vboxInScrollPane = (VBox) scrollPane.getContent(); // anchor
        ObservableList<Node> elements = vboxInScrollPane.getChildren(); // get elements in vbox

        for(Node node : elements) {
            Bounds bounds = node.getLayoutBounds();

            System.out.println(node + " - " + bounds.getWidth() + " - " + bounds.getHeight());
        }
    }
}