Problem with null reference

Question

Hey,
I have a "Window" class wich extends JFrame and then creates a tabbedPane. In each of the tabs it's necessary to access to another class (Code).
Each of the tabs follows something like this:
public class Tab1 extends JPanel {
   private Code code;
   public Tab1 ( Code c ) {
      code = c;
}When the tabs are created they receive the Code object.
The Code object declared in the main class and passed into the "Window" class (still a null reference) and then to each of the tabs (null). The instantiation of the Code object is done in one of the tabs. The Other tabs need it to set some values.
The problem is the tab that instantiates the Code object is doing so, however the other tabs don't get the new instance (it's always null). Although it's always the same reference.
Any ideas?
Thanks.

Answer 1

It looks like setting the Code is something the Window object will
have to help with.//in Window (assuming Tab is a superclass of Tab1 Tab2
Tab[] tabArr = {new Tab1(null, this), new Tab2(null, this)};
void setCode(Code c) {
    for(Tab tab :tabArr) tab.setCode(c);
//then the Tabs look like
public class Tab1 extends Tab { // or extends JPanel implements Tab
    private Code code;
    private Window wind
    public Tab1( Code c, Window w ) {
        code = c;
        wind = w;
    void setCode(Code c) {
        code = c;
    void someEventPerformed() {
        Code c = null;
            // figure out what flavour of Code the user wants
        switch ( userOption ) {
            case 0:
                code = new Code1 ();
                break;
            case 1:
                code = new CodeY ();
                break;
            // and have the Window tell all the Tabs to use it
        wind.setCode(c);
}