import java.beans.*;
import java.io.*;
import javax.swing.JLabel;

/**
 * Example application for factoring small numbers. 
 * 
 * @author Philip Milne
 */
        
public class Factorize {
    private JLabel output;
    private Factorizer factorizer;
    
    private class Factorizer implements Runnable { 
        private long n; 
        private boolean abort; 
        
        public Factorizer(long n) { 
            this.n = n; 
        }
        
        public void run() { 
            output.setText("thinking ...");
            String factors = "";
            int i = 2; 
            int sn = (int)Math.sqrt(n); 
            // Factorization by trial division
            while(i < sn) {
                if (abort) { 
                    output.setText("= <unknown>"); 
                    return; 
                } 
                if (n % i == 0) {
                    factors = factors + i + " * ";
                    n = n / i;
                    sn = (int)Math.sqrt(n);
                }
                else {
                    i = i + 1;
                }
            }
            output.setText("= " + factors + n); 
        }
    }
    
    public void setOutput(JLabel output) {
        this.output = output;
    }

    public void loading() {
        System.out.println("Loading user interface..."); 
    }

    public void calculate(String input) {
        try {
            stop();  
            factorizer = new Factorizer(Long.parseLong(input));   
            Thread thread = new Thread(factorizer); 
            thread.setPriority(Thread.MIN_PRIORITY); 
            thread.start(); 
        }
        catch(NumberFormatException e) {
            output.setText("Field must be a number");
        }
    }

    public void stop() { 
        if (factorizer != null) { 
            factorizer.abort = true; 
        } 
    }
    
    public Factorize() {}

    public Factorize(String archiveName) {
        try {
            XMLDecoder d = new XMLDecoder(
                               new BufferedInputStream(
                                   new FileInputStream(archiveName)), this);
            d.readObject();
            d.close();
        }
        catch(FileNotFoundException e) {
            System.err.println(e);
            System.exit(0);
        }
    }

    public static void main(String[] args) {
        new Factorize("Factorize.xml");
    }
}