import java.awt.*;
import java.awt.event.*;
import java.util.*;
/** (C) 2000 Charles Consulting, LLC <br>
AWT panel which contains integer text field and increment/decrement
buttons */


public class IntegerPanel extends Panel {

	private int value;
	private int min;
	private int max;
	private TextField tfield;
	private Label label;
	private ArrowButton upButton;
	private ArrowButton downButton;
	private ActionListener theListener;
	private ButtonPanel buttonPanel;

	/** constructor; label to apply ,initial value, mininum value,
	maxium value */
	public IntegerPanel(String lab,int initialValue,int min_, int max_)
	{
		super( );
		min = min_;
		max = max_;
		label = new Label(lab);
		value = initialValue;
		tfield = new TextField(Integer.toString(value),3);
		upButton = new ArrowButton(true);
		downButton = new ArrowButton(false);
		buttonPanel = new ButtonPanel( );
		setLayout(new BorderLayout( ));
		add(label,BorderLayout.WEST);
		add(buttonPanel,BorderLayout.EAST);
		processChange( ); //set enabled state
		tfield.addActionListener( new ActionListener () {
			public void actionPerformed(ActionEvent e) 
			{
				try {
					value = Integer.parseInt(tfield.getText( ));
					}
				catch (NumberFormatException nfe) {}
				IntegerPanel.this.processChange( );
			}
		});
		upButton.addActionListener( new ActionListener () {
			public void actionPerformed(ActionEvent e) 
			{
				++value; 
				IntegerPanel.this.processChange( );
			}
		});
		downButton.addActionListener( new ActionListener () {
			public void actionPerformed(ActionEvent e) 
			{
				--value;
				IntegerPanel.this.processChange( );
			}
		});
	}

	/** add a action Listener. Class only supports one */
	public void addActionListener (ActionListener al)
	{
		theListener = al;
	}

	public void removeActionListener (ActionListener al)
	{
		if (theListener == al)
			theListener = null;
	}
	
	/** return the set value */ 
	public final int getValue( )
	{
		return value;
	}

	private void processChange( )
	{
		if (value < min)
			value = min;
		if (value > max)
			value = max;
		downButton.setEnabled(value > min);
		upButton.setEnabled(value < max);
		tfield.setText(Integer.toString(value));
		if (theListener!=null)
			{
			ActionEvent ev = new ActionEvent(this,ActionEvent.ACTION_PERFORMED,"ValueChanged");
			theListener.actionPerformed(ev);
			}
	}

	/** inner class to support layout */
	private class ButtonPanel extends Panel {
		public ButtonPanel( )
		{
			super( );
			setLayout( new FlowLayout(FlowLayout.CENTER,0,0) );
			add(tfield);
			add(upButton);
			add(downButton);
		}
	}
		
}