JTable without JScrollPane behavior crippled

Question

I want column width of JTable t1 goes parallel with the width resizing on
JTable t2. If tables are put in JScrollPanes, this has no problem. But if I put
those tables in simpler container, which is JPanel in this case, t2 shows a
funny behavior -- with user's mouse operation on t2 column, their width
never changes but t1 column width changes properly. Could I have
succeeded in communicating the funniness with these sentences?
Please try this code and give cause and solution if you could:
import java.awt.*;
import java.beans.*;
import java.util.*;
import javax.swing.*;
import javax.swing.table.*;
import javax.swing.event.*;
public class TableColumnWidthResize{
  JFrame frame;
  JTable t1, t2;
  TableColumnModel tcm1, tcm2;
  Enumeration columns1, columns2;
  String[] t1h = {"Road", "Length", "City"};
  String[][] t1c
   = {{"NW2", "800", "Dora"},
     {"Iban", "600", "Weiho"},
     {"ENE2", "500","Porso"}};
  String[] t2h = {"Flower", "Curse", "Priest"};
  String[][] t2c
    = {{"Fang", "7.00", "EggChar"},
      {"Shaoma", "5.00", "ScaCra"},
      {"Jiao", "4.00", "PorCabb"}};
  public TableColumnWidthResize(){
    frame = new JFrame();
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    Container con = frame.getContentPane();
    con.setLayout(new GridLayout(2, 1));
    t1 = new JTable(t1c, t1h); //target table -- 'resized from t2'
    t2 = new JTable(t2c, t2h); //source table -- 'initiate resize'
    t1.setAutoResizeMode(JTable.AUTO_RESIZE_OFF);
    t2.setAutoResizeMode(JTable.AUTO_RESIZE_OFF);
    /* you can compare two methods of table placement*/
    useScrollPane(t1, t2, con); //works fine
//    nouseScrollPane(t1, t2, con); //resize behavior weird
    frame.pack();
    frame.setVisible(true);
    tcm1 = t1.getColumnModel();
    tcm2 = t2.getColumnModel();
    columns2 = tcm2.getColumns(); // all columns of t2
    TableColumnListener tcl = new TableColumnListener();
    while (columns2.hasMoreElements()){
      TableColumn tc = (TableColumn)(columns2.nextElement());
      tc.addPropertyChangeListener(tcl);
  class TableColumnListener implements PropertyChangeListener{
    // achieve 'interlocking-column-resizing' from t2 to t1
    public void propertyChange(PropertyChangeEvent pce){
      TableColumn tc = (TableColumn)(pce.getSource());
      int i = tc.getModelIndex();
      tcm1.getColumn(i).setPreferredWidth(tc.getWidth());
  void useScrollPane(JTable ta, JTable tb, Container c){
    JScrollPane jsc1 = new JScrollPane(ta);
    ta.setPreferredScrollableViewportSize(new Dimension(225, 50));
    JScrollPane jsc2 = new JScrollPane(tb);
    tb.setPreferredScrollableViewportSize(new Dimension(225, 50));
    c.add(jsc1); c.add(jsc2);
  void nouseScrollPane(JTable ta, JTable tb, Container c){
    JPanel p1 = new JPanel(); JPanel p2 = new JPanel();
    p1.setLayout(new BorderLayout());
    p2.setLayout(new BorderLayout());
    p1.add(ta.getTableHeader(), BorderLayout.PAGE_START);
    p2.add(tb.getTableHeader(), BorderLayout.PAGE_START);
    p1.add(ta, BorderLayout.CENTER);
    p2.add(tb, BorderLayout.CENTER);   
    c.add(p1); c.add(p2);
  public static void main(String[] args){
    new TableColumnWidthResize();
}

Answer 1

Hey hiwa,
I don't see anything mysterious going on. If you think about it, how many components can we resize at run-time/dynamically with a mouse - none, except for the columns in a JTable, Frames and Dialogs. Note the latter two are top level and answer to no-one (except the screen i guess).
If you have ever implemented a component that can be 'dragged' and manipulated by the mouse, have you ever done so outside, that is, not using a JScrollPane? I doubt it.
I do not think it has anything to do with mouse precision. Maybe you are just experiencing undefined behaviour, unreliable behaviour. I imagine the Swing team didn't bother themselves with a usage scenario that would yield lesser results for a simple task. Using AUTO_RESIZE_OFF and requesting more room than the Container has to offer may upset that containers LayoutManager i.e. their algorithms may contain code that will shrink child components to fit, or nab space from sibling components.
Basically, in my experience, how ever long it takes me to realise it, when Swing goes on the blink it is usually a programming error.
BTW, did my suggestion work ok?
Sorry if I come across forceful. I'm glad I read and tested your code - the synchronization effect will be very useful.
Warm regards,
Darren