import java.awt.*;
import java.awt.event.*;
/**
* Instantiates the model, GUI view, and the event listeners (i.e. controllers).
* Note the use of anonymous classes for event listeners.
* @author Dung X. Nguyen
* @author Robert "Corky" Cartwright.
* @since Oct. 08, 1999
*/
public class FLControl {

  /**
	 * The view
	 * @SBGen Variable (,view,,64)
	 */
	private FLGUI gui = new FLGUI ();

  /**
	 * The list model.
	 * @SBGen Variable (,model,controller,64)
	 */
	private FunList list = Empty.only; // NOTE use of Singleton!

  /**
  * Initializes the model and the associated view.  Registers event listeners
    with the view as anonymous inner classes.
  */
  public FLControl() {

    gui.updateView (list);

    // Add anonymous ActionListener class to handle the Empty button click:
    gui.addEmptyListener (
      new ActionListener() {
        public void actionPerformed(ActionEvent e) {
          list = Empty.only; 
          gui.updateView (list);
        }
      }
    );

    // Add anonymous ActionListener class to handle the Cons button click:
    gui.addConsListener (
      new ActionListener() {
        public void actionPerformed(ActionEvent e) {
          String input = gui.getInput();
          try {
            int i = Integer.parseInt(input);
            list = new Cons (new Integer (i), list);
            gui.updateView (list);
          }
          catch (NumberFormatException x) {
            // For debugging and illustration purpose:
            System.out.println ("ConsListener.actionPerformed: input " + input + " is not a number!");
          }
        }
      }
    );

    // Add anonymous ActionListener class to handle the Sum button click:
    gui.addSumListener (
      new ActionListener() {
        public void actionPerformed(ActionEvent e) {
          Integer sumInt = (Integer)list.execute (Sum.only);
          gui.setOutput(sumInt.toString());
        }
      }
    );

    // Add anonymous ActionListener class to handle the GetNth button click:
    gui.addGetNthListener (
      new ActionListener() {
        public void actionPerformed(ActionEvent e) {
          int n = Integer.parseInt(gui.getInput());
          Integer nthInt = (Integer)list.execute(new GetNth(n));
          gui.setOutput(nthInt.toString());
        }
      }
    );
  }

  /***
  * Entry point into the program
  * @param args The parameters for the entry.  They are not used here.
  */
  public static void main(String[] args) {
    new FLControl();
  }
}