// © Copyright 1999, Joseph Bergin. All rights reserved.

import java.util.Observable;
import java.util.Observer;

import java.awt.*;
import java.awt.event.*;

abstract class TemperatureGUI implements Observer
{	TemperatureGUI(String label, TemperatureModel model, int h, int v)
	{	this.label = label;
		this.model = model;
		temperatureFrame = new Frame(label);
		temperatureFrame.add("North", new Label(label));
		temperatureFrame.add("Center", display);
		Panel buttons = new Panel();
		buttons.add(upButton);
		buttons.add(downButton);		
		temperatureFrame.add("South", buttons);		
		temperatureFrame.addWindowListener(new CloseListener());	
		model.addObserver(this);
		temperatureFrame.setSize(200,100);
		temperatureFrame.setLocation(h, v);
		temperatureFrame.setVisible(true);
	}
	
	public void setDisplay(String s){ display.setText(s);}
	
	public double getDisplay()
	{	double result = 0.0;
		try
		{	result = Double.valueOf(display.getText()).doubleValue();
		}
		catch (NumberFormatException e){}
		return result;
	}
	
	public void addDisplayListener(ActionListener a){ display.addActionListener(a);}
	public void addUpListener(ActionListener a){ upButton.addActionListener(a);}
	public void addDownListener(ActionListener a){ downButton.addActionListener(a);}
	
	protected TemperatureModel model(){return model;}
	
	private String label;
	private TemperatureModel model;
	private Frame temperatureFrame;
	private TextField display = new TextField();
	private Button upButton = new Button("Raise");
	private Button downButton = new Button("Lower");
	
	class CloseListener extends WindowAdapter
	{	public void windowClosing(WindowEvent e)
		{	e.getWindow().setVisible(false);
			System.exit(0);
		}
	}
}

class CelsiusGUI extends TemperatureGUI
{	public CelsiusGUI(TemperatureModel model, int h, int v)
	{	super("Celsius Temperature", model, h, v);
		setDisplay(""+model.getC());
		addUpListener(new UpListener());
		addDownListener(new DownListener());
		addDisplayListener(new DisplayListener());
	}

	public void update(Observable t, Object o)
	{	setDisplay("" + model().getC());
	}

	class UpListener implements ActionListener
	{	public void actionPerformed(ActionEvent e)
		{	model().setC(model().getC() + 1.0);
		}
	}
	
	class DownListener implements ActionListener
	{	public void actionPerformed(ActionEvent e)
		{	model().setC(model().getC() - 1.0);
		}
	}
	
	class DisplayListener implements ActionListener
	{	public void actionPerformed(ActionEvent e)
		{	double value = getDisplay();
			model().setC(value);
		}
	}
}

class FarenheitGUI extends TemperatureGUI
{	public FarenheitGUI(TemperatureModel model, int h, int v)
	{	super("Farenheit Temperature", model, h, v);
		setDisplay(""+model.getF());
		addUpListener(new UpListener());
		addDownListener(new DownListener());
		addDisplayListener(new DisplayListener());
	}
	
	public void update(Observable t, Object o)
	{	setDisplay("" + model().getF());
	}
	
	class UpListener implements ActionListener
	{	public void actionPerformed(ActionEvent e)
		{	model().setF(model().getF() + 1.0);
		}
	}
	
	class DownListener implements ActionListener
	{	public void actionPerformed(ActionEvent e)
		{	model().setF(model().getF() - 1.0);
		}
	}
	
	class DisplayListener implements ActionListener
	{	public void actionPerformed(ActionEvent e)
		{	double value = getDisplay();
			model().setF(value);
		}
	}
}

public class MVCTempConvert 
{	public static void main(String args[]) 
	{	TemperatureModel temperature = new TemperatureModel();
		new FarenheitGUI(temperature, 100, 100);
		new CelsiusGUI(temperature,100, 250);
	}
}