HierarchyEvent.PARENT_CHANGED has the following syntax.
public static final int PARENT_CHANGED
In the following code shows how to use HierarchyEvent.PARENT_CHANGED field.
// w w w. j av a 2s .co m import java.awt.BorderLayout; import java.awt.event.HierarchyEvent; import java.awt.event.HierarchyListener; import javax.swing.JButton; import javax.swing.JComponent; import javax.swing.JFrame; import javax.swing.JSplitPane; public class Main { public static void main(String[] a) { JFrame horizontalFrame = new JFrame(); horizontalFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); JComponent topButton = new JButton("Left"); JComponent bottomButton = new JButton("Right"); final JSplitPane splitPane = new JSplitPane(JSplitPane.VERTICAL_SPLIT); HierarchyListener hierarchyListener = new HierarchyListener() { public void hierarchyChanged(HierarchyEvent e) { long flags = e.getChangeFlags(); if ((flags & HierarchyEvent.PARENT_CHANGED) == HierarchyEvent.PARENT_CHANGED) { System.out.println("HierarchyEvent.PARENT_CHANGED"); } } }; splitPane.addHierarchyListener(hierarchyListener); splitPane.setTopComponent(topButton); splitPane.setBottomComponent(bottomButton); horizontalFrame.add(splitPane, BorderLayout.CENTER); horizontalFrame.setSize(150, 150); horizontalFrame.setVisible(true); } }