JSplitPane Divider problem...

Question

I'm having problem with the JSplitPane divider. Ive learned that the MouseListener class is most likely the reason why the divider isn't performing as expected. I had to learn how to use the MouseListener interface and I've also learned that the divider is an instance of BasicSplitPaneDivider. I've finally got the divider to PARTIALLY work if I only set the following:
1) setting the setContinuousLayout(true)
//setting it to false wont work for some reason, I want to fix that, too. By setting it to false, the divider wont move :(.
and
2) if I move the mouse slowly, so the divider can follow the mouse. If I move my mouse too fast, then my divider will suddenly stop the moment the mouse cursor hovers away from the divider.
Can anyone help me fix the divider problem? Thanks in advance! Here's my code below:
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.*;
import java.awt.event.MouseEvent;
import javax.swing.event.MouseInputAdapter;
import javax.swing.plaf.basic.BasicSplitPaneDivider;
public class JSplitPaneDemo{
     public static void main(String args[]){
          //Practice p = new Practice("SplitPane Divider Works Now?");
          JSplitPaneDemo x = new JSplitPaneDemo();
          x.new Practice("SplitPane Divider Works Now?");
     public class DendrogramListener extends MouseInputAdapter
          Container contentPane;
          Component button1, button2, button3;
          JSplitPane splitter;
          Point mLocation;
          JFrame myFrame;
          MyGlassPane glass;
          private boolean inDrag = false;
          private boolean inButton = false;
          private boolean inDivider = false;
          public DendrogramListener(JFrame frame)
               this.myFrame = frame;
               this.contentPane = frame.getContentPane();
               this.mLocation = new Point();
          public DendrogramListener(AbstractButton aButton, AbstractButton b2, AbstractButton b3, MyGlassPane glass1, Container cP, JSplitPane split){
               this.button1 = aButton;
               this.button2 = b2;
               this.button3 = b3;
               this.glass = glass1;
               this.contentPane = cP;
               this.mLocation = new Point();
               this.splitter = split;
          public void mouseDragged(MouseEvent arg0) {
               // TODO Auto-generated method stub
               redispatchMouseEvent(arg0);
          public void mouseMoved(MouseEvent arg0) {
               // TODO Auto-generated method stub
               redispatchMouseEvent(arg0);
          public void mouseClicked(MouseEvent arg0) {
               // TODO Auto-generated method stub
               redispatchMouseEvent(arg0);
          public void mousePressed(MouseEvent arg0) {
               // TODO Auto-generated method stub
               redispatchMouseEvent(arg0);
          public void mouseReleased(MouseEvent arg0) {
               // TODO Auto-generated method stub
               redispatchMouseEvent(arg0);
               inDrag = false;
          public void mouseEntered(MouseEvent arg0) {
               // TODO Auto-generated method stub
               redispatchMouseEvent(arg0);
          public void mouseExited(MouseEvent arg0) {
               // TODO Auto-generated method stub
               redispatchMouseEvent(arg0);
          public void redispatchMouseEvent(MouseEvent e){
               inButton = false;
               inDrag = false;
               inDivider = false;
               Component component = null;
               JButton tempButton;
               Container container = contentPane;
               Point glassPanePoint = e.getPoint();
               mLocation = e.getPoint();
               Point containerPoint = SwingUtilities.convertPoint(glass, glassPanePoint, contentPane);
               int eventID = e.getID();
             component = SwingUtilities.getDeepestComponentAt(container, containerPoint.x, containerPoint.y);
             if (component == null) {
                  //System.out.println("NULL");
                 return;
             if (component instanceof JButton) {
                 inButton = true;
             if(component instanceof BasicSplitPaneDivider){
                  inDivider = true;
                  testForDrag(eventID);
             if (inButton || inDivider)
                       Point componentPoint = SwingUtilities.convertPoint(glass, glassPanePoint, component);
                      component.dispatchEvent(new MouseEvent(component,
                                                           eventID,
                                                           e.getWhen(),
                                                           e.getModifiers(),
                                                           componentPoint.x,
                                                           componentPoint.y,
                                                           e.getClickCount(),
                                                           e.isPopupTrigger()));
               testForDrag(eventID);
         private void testForDrag(int eventID) {
             if (eventID == MouseEvent.MOUSE_PRESSED) {
                 inDrag = true;
     public class MyGlassPane extends JComponent {
          int x0, y0;
          Point mLocation;
          public MyGlassPane(AbstractButton aButton, AbstractButton b2, AbstractButton b3, Container cP, JSplitPane splitter){
               DendrogramListener dl = new DendrogramListener(aButton, b2, b3, this, cP, splitter);
               addMouseListener(dl);
               addMouseMotionListener(dl);
         public void setPoint(Point p) {
             mLocation = p;
     public class Practice extends JFrame implements ActionListener
          private MyGlassPane glassPane;
          public Practice(String str)
               super(str);
               setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
               setDefaultLookAndFeelDecorated(true);
               addComponents(this);
               pack();
               setVisible(true);
          public Practice addComponents(final Practice p)
               JPanel leftPane = new JPanel();
               JPanel midPane = new JPanel();
               JPanel rightPane = new JPanel();
               JLabel l1 = new JLabel("Left panel");
               JLabel r1 = new JLabel("Right panel");
               JLabel m1 = new JLabel("Middle panel");
               JButton b1 = new JButton("Button 1");
               JButton b2 = new JButton("Button 2");
               JButton b3 = new JButton("Button 3");
               leftPane.add(l1);
               leftPane.add(b3);
               b3.setActionCommand("b3");
               b3.addActionListener(this);
               leftPane.setPreferredSize(new Dimension(200, 300));
               midPane.add(m1);
               midPane.add(b1);
               midPane.setPreferredSize(new Dimension(200, 300));
               rightPane.add(r1);
               rightPane.add(b2);
               rightPane.setPreferredSize(new Dimension(200, 300));
               JSplitPane splitter2 = new JSplitPane(JSplitPane.HORIZONTAL_SPLIT, rightPane, midPane);
               splitter2.setOneTouchExpandable(true);
               splitter2.setContinuousLayout(true);
               JSplitPane splitter = new JSplitPane(JSplitPane.HORIZONTAL_SPLIT, leftPane, splitter2);
               splitter.setOneTouchExpandable(true);
               splitter.setContinuousLayout(true);
               getContentPane().add(splitter);
               glassPane = new MyGlassPane(b1, b2, b3, p.getContentPane(), splitter);
               this.setGlassPane(glassPane);
               glassPane.setVisible(true);
               return p;
          public void actionPerformed(ActionEvent arg0) {
               // TODO Auto-generated method stub
               if("b3".equals(arg0.getActionCommand())){
                    JOptionPane.showMessageDialog(this, "Button 3 Pressed!");
}

Answer 1

The problem with your listener is that you are only dispatching events to the
button or divider when the mouse is directly over that component. This results
in the behavior you see with the divider: you have to move the mouse slowly
to keep it over the divider otherwise it gets over some other component and
you stop dispatching the events to it.
You actually have a similar problem with the buttons: if you click on one, it
gets the event but if you then drag the mouse out of the button and release
the mouse, it still triggers the button! This is not how buttons work: if you
release the mouse when it is not over the button, it shouldn't trigger.
Try this for your listener:
     public class DendrogramListener extends MouseInputAdapter {
          Component redispatch;
          boolean inside;
          Container contentPane;
          Component button1, button2, button3;
          JSplitPane splitter;
          Point mLocation;
          JFrame myFrame;
          MyGlassPane glass;
          private boolean inDrag = false;
          private boolean inButton = false;
          public DendrogramListener( JFrame frame ) {
               this.myFrame = frame;
               this.contentPane = frame.getContentPane();
               this.mLocation = new Point();
          public DendrogramListener( AbstractButton aButton, AbstractButton b2,
                    AbstractButton b3, MyGlassPane glass1, Container cP,
                    JSplitPane split ) {
               this.button1 = aButton;
               this.button2 = b2;
               this.button3 = b3;
               this.glass = glass1;
               this.contentPane = cP;
               this.mLocation = new Point();
               this.splitter = split;
          public void mouseDragged( MouseEvent arg0 ) {
               redispatchMouseEvent( arg0 );
          public void mouseMoved( MouseEvent arg0 ) {
               redispatchMouseEvent( arg0 );
          public void mouseClicked( MouseEvent arg0 ) {
               redispatchMouseEvent( arg0 );
          public void mousePressed( MouseEvent arg0 ) {
               redispatchMouseEvent( arg0 );
          public void mouseReleased( MouseEvent arg0 ) {
               redispatchMouseEvent( arg0 );
               inDrag = false;
               inButton = false;
          public void mouseEntered( MouseEvent arg0 ) {
               redispatchMouseEvent( arg0 );
          public void mouseExited( MouseEvent arg0 ) {
               redispatchMouseEvent( arg0 );
          public void redispatchMouseEvent( MouseEvent e ) {
               int eventID = e.getID();
               Point glassPanePoint = e.getPoint();
               Point containerPoint = SwingUtilities.convertPoint( glass, glassPanePoint, contentPane );
               if ( !inDrag && !inButton && eventID == MouseEvent.MOUSE_PRESSED ) {
                    redispatch = SwingUtilities.getDeepestComponentAt( contentPane, containerPoint.x, containerPoint.y );
                    inButton = ( redispatch instanceof JButton );
                    inside = inButton;
                    if ( !inButton )
                         inDrag = ( redispatch instanceof BasicSplitPaneDivider );
               if ( inButton || inDrag ) {
                    if ( inButton )
                         eventID = possiblySwitchEventID( eventID, containerPoint );
                    Point componentPoint = SwingUtilities.convertPoint( glass, glassPanePoint, redispatch );
                    redispatch.dispatchEvent( new MouseEvent( redispatch, eventID, e.getWhen(), e.getModifiers(),
                              componentPoint.x, componentPoint.y, e.getClickCount(), e.isPopupTrigger() ) );
          private int possiblySwitchEventID( int eventID, Point containerPoint ) {
               int switchedID = eventID;
               Component deepest = SwingUtilities.getDeepestComponentAt( contentPane, containerPoint.x, containerPoint.y );
               if ( deepest == redispatch ) {
                    if ( ! inside )
                         switchedID = MouseEvent.MOUSE_ENTERED;
                    inside = true;
               } else {
                    if ( inside )
                         switchedID = MouseEvent.MOUSE_EXITED;
                    inside = false;
               return switchedID;
     }: jay