Graph Script Code

package ls.graph.script;

import java.util.ArrayList;
import java.util.LinkedList;
import java.util.List;

import ls.graph.Controller;
import ls.script.Scriptable;
import ls.util.Utils;

public class Algorithm implements Scriptable, Runnable
{

	private List<AlgorithmStep> steps = null;
	private int delay = 1000; //in ms
	private List<AlgorithmListener> listeners = null;
	private boolean stop;
	
	public Algorithm()
	{
		super();
		this.steps = new ArrayList<AlgorithmStep>();
		this.listeners = new LinkedList<AlgorithmListener>();
		String sDelay = Controller.getProperty("ALGORITHM_STEP_DELAY", String.valueOf(this.delay));
		try
		{ this.delay = Integer.parseInt(sDelay); }
		catch (NumberFormatException exn)
		{ Utils.exn(exn); }
	}
	
	public synchronized void addListener(AlgorithmListener l)
	{
		if (l != null) this.listeners.add(l);
	}
	
	private void fireExecutionStarted()
	{
		for (AlgorithmListener l : this.listeners)
		{
			l.executionStarted(this);
		}
	}
	
	private void fireExecutionEnded()
	{
		for (AlgorithmListener l : this.listeners)
			l.executionEnded(this);
	}
	
	private void fireStepStarted(int ind)
	{
		for (AlgorithmListener l : this.listeners)
			l.startingStep(ind);
	}
	
	public String getBindingName()
	{
		return "Algorithm";
	}

	public void addStep(AlgorithmStep step)
	{
		if (step != null)
			this.steps.add(step);
	}
	public void run()
	{
		fireExecutionStarted();
		stop = steps.size() <= 0;
		int nextStepIndex = 0;
		while (!stop)
		{
			AlgorithmStep nextStep = steps.get(nextStepIndex);
			if (nextStep != null)
			{
				fireStepStarted(nextStepIndex);
				stop = nextStep.execute();
				if (!stop)
				{
					nextStepIndex = nextStep.getNextStep();
					try
					{
						synchronized (this)
						{ this.wait(getDelay()); }
					}
					catch (InterruptedException exn)
					{
						Utils.exn(exn);
					}
				}
			}
			else stop = true; //no next step
		}
		fireExecutionEnded();
	}

	public void setStop(boolean st)
	{
		this.stop = st;
	}
	
	//private Random random = new Random();
	
	private int getDelay()
	{
		return this.delay;
		//int d = random.nextInt(delay);
		//d = Math.max(d/4, d);
		//return d;
	}
}