Java tutorial
import javax.swing.JToolBar; public class Main { public static void main(String[] argv) throws Exception { JToolBar toolbar = new JToolBar(); toolbar.addPropertyChangeListener(new java.beans.PropertyChangeListener() { public void propertyChange(java.beans.PropertyChangeEvent evt) { String propName = evt.getPropertyName(); if ("orientation".equals(propName)) { Integer oldValue = (Integer) evt.getOldValue(); Integer newValue = (Integer) evt.getNewValue(); if (newValue.intValue() == JToolBar.HORIZONTAL) { System.out.println("horizontal orientation"); } else { System.out.println("vertical orientation"); } } } }); } }