Opening one window from another

Question

I've created a method which opens a window that takes an input from the user and then closes and returns the input to the main program. When I called this method from a test program it seemed to work perfectly but when I tried to call it from my main GUI via an action listener on a button it just seems to crash.
So my input window would wait until the return button was pressed, I set up a while loop which delays the program until a flag is changed by pressing the return button. As far as I can tell it is this while loop which is causing the problem. Has anyone got any idea why this method works with my test program but not through a GUI? I expect that there is also a better way of retrieving this information from my input window and that I have probably just forgotten something very simple. If anyone has got any suggestions I would be very grateful.
Thanks, Tom

Answer 1

Hi Tom,
the while loop is not very suitable for this situation.
The best solution, in my opinion, is to attach ActionListener to the 'submit' or 'ok' button of your child window, from the main GUI.
Let's say A is your main GUI class and B is the JDialog (better if modal) that should return the value. Proceed as following:
1. in the class B implement a method that attaches a listener l to the Ok button
public void addOkListener(ActionListener l)
  okButton.addActionListener(l);
}2. in the class A, create a ActionListener object like:
ActionListener al = new ActionListener()
  public void actionPerformed(ActionEvent)
      do whatever you like, this code is executed when the user clicks
      on the button OK in the JDialog.
      For example you may want to retrieve the value from the JDialog:
      System.out.println(b.getMyValue());
}3. in the class A, attach the listener to B:
  b.addOkListener(al);Antonio :)