Question

I have decided it was about time for me to learn how to make GUIs in java. Everything was coming along nicely until I began to set up my ActionListener.

Heres my actionListener class:

import java.awt.event.*;

public class Calculator implements ActionListener
{
  public void actionPerformed(ActionEvent e)
  {
    if (e.getSource() == set)
    {
      setAllTheThings();
    }
  }
  private void setAllTheThings()
  {
    System.out.println("hello");
  }
}

What I cannot seem to do is get the actionListener to find the JButton called “set” in another class. How should I go about doing this?

Also, here’s said button:

JButton set = new JButton("Set");
set.setLocation(255,0);
set.setSize(50,20);
set.addActionListener(new Calculator());
line1.add(set);

Answer 1

You can implement the same code using Actions – checking the source is not a good way to see the origin of the event.

See: http://docs.oracle.com/javase/tutorial/uiswing/misc/action.html