So the error I get is No enclosing instance of type Window is accessible. Must qualify the allocation with an enclosing instance of type Window (e.g. x.new A() where x is an instance of Window). I think it's because i'm trying to instantiate a private class, but if I try and use this, I get an eror that htis cannot be used in a static context. So what I do to get hte windo wlistener working?
public class Window {
static MathGame mg;
private static void createAndShowGUI() {
JFrame frame = new JFrame("Epsilon");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
mg = new MathGame();
frame.getContentPane().add(mg);
frame.pack();
frame.setVisible(true);
frame.setDefaultCloseOperation(WindowConstants.DO_NOTHING_ON_CLOSE);
//error here: No enclosing instance of type Window is accessible.
//Must qualify the allocation with an enclosing instance of type Window
(e.g. x.new A() where x is an instance of Window).
MathWindowStateListener wsListener = new MathWindowStateListener();
frame.addWindowStateListener(new MathWindowStateListener());
}
/**
* @param args
*/
public static void main(String[] args) {
javax.swing.SwingUtilities.invokeLater(new Runnable() {
public void run() {
createAndShowGUI();
}
});
}
private class MathWindowStateListener implements WindowStateListener{
@Override
public void windowStateChanged(WindowEvent we) {
if(we.equals(WindowEvent.WINDOW_CLOSED))
{
System.out.println("window closed");
mg.sql.removeUser();
}
else if(we.equals(WindowEvent.WINDOW_CLOSING))
System.out.println("window closing");
}
}
}
The issue is that you're trying to use it in a static context, and since the inner class is not static itself, it needs an instance of the enclosing class for it to exist -- i.e., it needs to be constructed on that enclosing instance. This will lead to some funny/ugly code such as
MathWindowStateListener wsListener = mg.new MathWindowStateListener();
Better to make the private inner class static and this will solve your problem without resorting to the above kludge.