import drcl.comp.*;

/**
 * Template for writing a component.
 * This component responds with data that was received last time,
 * emulating the behavior of "unit-delay".
 */
public class ComponentTemplate extends drcl.comp.Component implements drcl.comp.ActiveComponent
{
	// The fields here are just for demonstration of usages 
	// of the methods present in this template.
	int x;
	Object lock = new Object();

	/**
	 * Constructor.
	 */
	public ComponentTemplate()
	{
		super();
	}

	/**
	 * Constructor.
	 */
	public ComponentTemplate(String id_)
	{
		super(id_);
	}

	/**
	 * Invoked when <code>data_</code> arrives this component at the <code>inPort_</code> port.
	 */
	protected void process(Object data_, drcl.comp.Port inPort_)
	{
		// Put codes here for handling the incoming data.
		synchronized (lock) {
			x++;
			notify(lock); // Notifies the waiting thread.
			wait(lock);   // Delay sending data until someone notifies.
			inPort_.doSending(data_);
		}
	}


	/**
	 * Resets this component to the initial state for use anew.
	 * Must call <code>super.reset()</code> in the beginning.
	 */
	public void reset()
	{
		super.reset(); // Let super class reset its fields.
		x = 0;         // Reset the fields defined in this class.
	}

	/**
	 * Copies the content from the <code>source_</code> to this component.
	 * Must call <code>super.duplicate()</code> in the beginning.
	 */
	public void duplicate(Object source_)
	{
		if (!(source_ instanceof ComponentTemplate)) return;
		super.duplicate(source_); // Let super class copy its fields.
		ComponentTemplate that_ = (ComponentTemplate)source_;
		x = that_.x;              // Duplicate the fields defined in this class.
		// Suppose we don't have to copy "lock".
	}

	/**
	 * Invoked when the component is <code>run()</code>ed.
	 */
	public void start()
	{
		debug(this + " is starting!");
	}

	/**
	 * Script interface which reveals the internal states of the component.
	 * It is for debugging and demonstration purpose.
	 */
	public String info()
	{
		return "x = " + x + "\n";
	}

	/**
	 * Script interface which increments the counter by +1.
	 */
	public void increment()
	{
		x++;
	}
}