Can I pass function name as a parameter to constructor?

Question

Hi!
I want to create a class that extends JButton and executes some function, when released. The function for each button is different. I mean, can I write, for example:
public class MyButton extends JButton
public MyButton(...functionName...)
addMouseListener(new MouseAdapter()
     public void mouseReleased(MouseEvent e)
     ...execute functionName...;
MyButton testButton = new MyButton(printTest);
void printTest()
System.out.println("The button executes OK");
(This code will not work, of cause).
If you understood me, please answer if there is any way to pass function as a parameter ?
Thank you in advance.

Answer 1

Using reflection would work, but there is a more straightforward way. Here's what I do when I want to pass a method to be called by another object: First I declare an interface named Callback:public interface Callback
  public void run();
}Then your class would look like this:public class MyButton extends JButton {
  private Callback doit;
  public MyButton(Callback whatToDo) {
    doit = whatToDo;
    addMouseListener(new MouseAdapter() {
      public void mouseReleased(MouseEvent e) {
        whatToDo.run();
}and the code that creates a MyButton might look like this:Callback callMe = new Callback() {
  public void run() {
    System.exit(0);
MyButton closeButton = new MyButton(callMe);
closeButton.setText("Close");If you like, you can adapt this pattern to use variations of Callback that have parameters or return values.