// This class computes standard R and C values 

import java.lang.Math;
import java.awt.*;

public class StandardValue extends java.applet.Applet
{
	double n = 96.0; // 1% values
	TextField inputdata;

	private static double npercent (double v, double n)
	{
		return(java.lang.Math.round(n * log10(v)));
	}

	private static double o (double v, double n)
	{
		return(java.lang.Math.pow(10.0, npercent(v, n)/n));
	}

	private static double ppercent(double v, double n)
	{
		return(java.lang.Math.floor(log10(o(v, n)))-2);
	}

	private static double r (double v, double n)
	{
		return(java.lang.Math.pow(10.0, ppercent(v, n))* java.lang.Math.round
			(o(v, n)/java.lang.Math.pow(10.0, ppercent(v, n))));
	}

	// log10 (x) returns the common (base 10) log of x
	private static double log10 (double x)
	{
		// java.lang.Math.log returns the natural (base e) log of x
		return (0.4342944819 * java.lang.Math.log(x));
	}

	public void init()
	{
		setBackground(Color.pink);
		
		// Label our Box
		add(new Label("Standard R, C Value Calculator", Label.CENTER));

		// Set the TextField background to white
		setBackground(Color.white);

		// set up a text field to get input
		inputdata = new TextField("Input value",12);
		add(inputdata);
	}
	
	public void paint(Graphics g)
	{
		int	height, width; // dimensions of my window
		int x, y; // center of window
		Rectangle	myWindow;

		myWindow = g.getClipRect();
		width = myWindow.width;
		height = myWindow.height;

		// Set background color
		g.setColor(Color.pink);

		// fill in my rectangle
		g.fill3DRect(1,1, width-2, height-2, true);
	}
	
	public boolean action(Event evt, Object arg)
	{
		if(evt.target instanceof TextField)
		{
			HandleInput(evt.target);
			return true;
		}
		else
		{
			return false;
		}
	}

	public void HandleInput(Object myEvent)
	{
		try
		{
			Double dobj = new Double(inputdata.getText());
			double Value = dobj.doubleValue();
			double x = r(Value, n);
			inputdata.setText(dobj.toString(x));
		}
		catch (NumberFormatException e)
		{
			inputdata.setText("ERROR");
		}

	}
}