package javathreads.examples.ch02.example5;

import java.util.*;
import javathreads.examples.ch02.*;

public class RandomCharacterGenerator implements CharacterSource, Runnable {
    static char[] chars;
    static String charArray = "abcdefghijklmnopqrstuvwxyz0123456789";
    static {
        chars = charArray.toCharArray();
    }

    Random random;
    CharacterEventHandler handler;

    private volatile boolean done = false;

    public RandomCharacterGenerator() {
        random = new Random();
	handler = new CharacterEventHandler();
    }

    public int getPauseTime() {
        return (int) (Math.max(1000, 5000 * random.nextDouble()));
    }

    public void addCharacterListener(CharacterListener cl) {
        handler.addCharacterListener(cl);
    }

    public void removeCharacterListener(CharacterListener cl) {
        handler.removeCharacterListener(cl);
    }

    public void nextCharacter() {
	handler.fireNewCharacter(this,
				(int) chars[random.nextInt(chars.length)]);
    }

    public void run() {
        while (!done) {
	    nextCharacter();
	    try {
	        Thread.sleep(getPauseTime());
	    } catch (InterruptedException ie) {
	        return;
	    }
	}
    }

    public void setDone() {
        done = true;
    }
}