How to use

preferredLayoutSize

method

in

java.awt.GridBagLayout

@Override
public Dimension preferredLayoutSize(Container parent) {
  return layout.preferredLayoutSize(parent);
}

@Override
public Dimension preferredLayoutSize(Container parent) {
  return layout.preferredLayoutSize(parent);
}

public void packNShow() {
  int i;
  GridBagLayout gb = new GridBagLayout();
  setLayout(gb);
  GridBagConstraints gc = new GridBagConstraints();
  gc.gridx = 0;
  gc.fill = gc.HORIZONTAL;
  int xpos = 0,ypos = 0;
  Label lab;
  for(i=0;i<v.size();i++)
    if(v.elementAt(i) instanceof Label) {
    lab = (Label)v.elementAt(i);
    add(lab);
    gc.gridy = ypos++;
    gb.setConstraints(lab,gc);
  }
  gc.gridy = ypos;
  for(i=0;i<v.size();i++)
    if(v.elementAt(i) instanceof Button) {
    Button but = (Button)v.elementAt(i);
    add(but);
    gc.gridx = xpos++;
    gb.setConstraints(but,gc);
  }
  pack();
  resize(gb.preferredLayoutSize(this));
  show();
}
/** @serial */