import javax.swing.*;
import java.util.*;
import java.awt.*;
import java.awt.event.*;

/* -----------------------------  Model */
interface CounterModel 
    {
    public int getValue();
    }

interface MutableCounterModel extends CounterModel
    {
    public void inc();
    }

class CounterModelImpl implements MutableCounterModel
    {
    private int v;
    public CounterModelImpl()
        {v=0;}        
    public void inc()
        {v++;}
    public int getValue()
        {return v;}
    }

/* -----------------------------  observable Wrapper of a MutableCounterModel */

class ObservableCounterModel extends Observable implements MutableCounterModel 
    {
    private MutableCounterModel theModel;


    ObservableCounterModel(MutableCounterModel m)
        {theModel= m;}

    public int getValue()
        {return theModel.getValue();}
    
    public void inc()
        {
        theModel.inc();
        setChanged();
        }
    } 


/* ---------------------------------- controller */

class CounterController
    {
    private ObservableCounterModel counter;
    public CounterController(ObservableCounterModel c)
        { counter=c; }

    public void increment()
        { 
        counter.inc();
        counter.notifyObservers();
        }

    public void doubleIncrement()
        { 
        counter.inc();
        counter.inc();
        counter.notifyObservers();
        }

    public void makeOdd()
        { 
        if ( counter.getValue()%2 == 0 )
            {
            counter.inc();
            counter.notifyObservers();
            }
        }

    }




/* -----------------------------  View */

class CounterView 
    extends JLabel 
    implements Observer
    {
    private CounterModel theObservedCounter;
    public CounterView( ObservableCounterModel m)
        {
        m.addObserver(this);
        theObservedCounter=m;
        /* da ora in poi solo l'interfaccia immutable del modello e' usata */
        update(null,null);
        }
    public void update(Observable dummy1, Object dummy2)
        {
        int v=theObservedCounter.getValue();
        String s= new Integer(v).toString();
        setText(s);
        repaint();
        }
    }




class IncrementAction extends AbstractAction
    {
    private CounterController c;

    public IncrementAction(CounterController c1) 
        {
        super("Incremento"); 
        c=c1;
        }

    public void actionPerformed(ActionEvent e) 
        {c.increment();}        
    }    

class DoubleIncrementAction extends AbstractAction
    {
    private CounterController c;

    public DoubleIncrementAction(CounterController c1) 
        {
        super("Doppio incremento"); 
        c=c1;
        }

    public void actionPerformed(ActionEvent e) 
        {c.doubleIncrement();}        
    }    

class MakeOddAction extends AbstractAction
    {
    private CounterController c;

    public MakeOddAction(CounterController c1) 
        {
        super("Rendi dispari"); 
        c=c1;
        }

    public void actionPerformed(ActionEvent e) 
        {c.makeOdd();}        
    }    


class LockUnlockAction extends AbstractAction
    {
    private Action c;

    private void updateName()
        {
        if (  c.isEnabled() )
            putValue(Action.NAME, "Lock"); 
        else
            putValue(Action.NAME, "Unlock"); 
        }

    public LockUnlockAction(Action c1) 
        {
        c=c1;
        updateName();
        }

    public void actionPerformed(ActionEvent e) 
        { 
        c.setEnabled(!c.isEnabled());
        updateName();
        }
    }


class CounterComplexView extends JPanel
    {
    private CounterView cv;
    public CounterComplexView(ObservableCounterModel m, 
                              CounterController c)
        {
        cv= new CounterView(m);
        setLayout(new GridLayout(5,1));
        add(cv);        
        Action a=new IncrementAction(c);
        add(new JButton(a));
        add(new JButton(new DoubleIncrementAction(c)));
        add(new JButton(new MakeOddAction(c)));
        add(new JButton(new LockUnlockAction(a)));
        }
    }




/* ------------------------------------------ Application --- */



public class MvcDemo
    {

    public static void main(String args[])
        {
        // Model
        ObservableCounterModel m1= new ObservableCounterModel(new CounterModelImpl());

        // Controller
        CounterController c1=new CounterController(m1);        

        // View
        CounterComplexView v1=new CounterComplexView(m1,c1);

        // Model
        ObservableCounterModel m2= new ObservableCounterModel(new CounterModelImpl());

        // Controller
        CounterController c2=new CounterController(m2);        

        // View
        CounterComplexView v21=new CounterComplexView(m2,c2);
        CounterComplexView v22=new CounterComplexView(m2,c2);


        // GUI setup 
        JFrame f= new JFrame();
        f.getContentPane().setLayout(new GridLayout(1,2));
        f.getContentPane().add(v1);
        f.getContentPane().add(v21);
        f.getContentPane().add(v22);
        f.pack();
        f.setVisible(true);


        }            
    }