// StarFieldPanel.java
// Author: P Gray
// instrumented starfield for displaying financial data

import java.awt.*;
import java.awt.event.*;
import java.util.Vector;
import java.util.Enumeration;

class StarFieldPanel extends Panel implements ActionListener	{
	private TradeViewer application;
	private StarFieldView starFieldView;
	private TextField scaleField;

	public StarFieldPanel(TradeViewer application) {
		// initialise
    	this.application = application;
		setLayout(new BorderLayout());
		// creat and add components
		// first set an initial scale
		double scale = 5.0;
		// create and add a textfield to edit the scale
		scaleField = new TextField(new Double(scale).toString(),10);
		add("North", scaleField);
		// create the starfield
		// and load it with data
		starFieldView = new StarFieldView(application.sourceDomain(),scale);
		// add starfield to me
		add("Center",starFieldView);
		// add a listener on the scale editor text widget
		scaleField.addActionListener(this);
	}

	public void actionPerformed(ActionEvent ae)	{
		// handles events from the scale widget listener
		// this is an example of a parent listening to a child's events
		double scaleVal;
		scaleVal = new Double(ae.getActionCommand()).doubleValue();
		starFieldView.setScale(scaleVal);
	}

	// starfield operations
	public StarFieldView starFieldView()	{
		return starFieldView;
	}

	public void update(int row)	{
		// updates a single  point in the starfield based on ith element of the
		// source domain
		// pass it on to the starFieldView
		starFieldView.update(row);
	}

} // end StarFieldPanel