Help with mouseclicked on a button

Question

I have the following situation. I have a JPanel, with two buttons, and a text field. The first button runs a method that returns an integer which gets printed in the text field. Sometime this method works too long, so I want a second button to stop it. Here is a little piece of code that demonstrates the situation. I am using NetBeans, which adds the mouse action listeners.
My problem is that once calculate() has started, no matter when I click the StopCalculation button its code is executed only after calculate() has finished. Why is this happening?
Thanks
private boolean stopCalculation=false;
private void StartCalculationMouseClicked(java.awt.event.MouseEvent evt)
     stopCalculation=false;
     textField1.setText(calculate()+"");                                             
private void StopCalculationMouseClicked(java.awt.event.MouseEvent evt)
     stopCalculation=true;
private int calculate()
    do{........}
    While(!stopCalculation) //This condition gets checked often.
}

Answer 1

If StartCalculationMouseClicked() is called on the event dispatch thread then it will run - and finish - before thread has a chance to pass on the user's mouse click to StopCalculationMouseClicked().
Create and start another thread to run the long task.
(Begin method names with a lowercase letter to avoid confusion.)