import java.beans.*;
import utilities.*;
import utilities.beans.*;

public class MTListeners extends Thread implements PropertyChangeListener {

protected UnexpectedEvents myBean;			// the target bean to bash..

protected int myID;							// each thread carries a bit of ID

protected boolean readyForEvents = false;	// have we registered yet ?

//-------------------------------------------------------------------
// main() entry point
//-------------------------------------------------------------------
public static void main (String[] args) {
UnexpectedEvents bean;
Thread thread;

	bean = (UnexpectedEvents) BeansKit.newBean("UnexpectedEvents");

	for (int i=0; i < 5; i++) {				// start N threads to bash bean
		thread = new MTListeners(bean, i);	// threads get access to bean
		thread.start();
	}
}
//-------------------------------------------------------------------
// MTListeners Constructor
//-------------------------------------------------------------------
public MTListeners(UnexpectedEvents bean, int id) {
	this.myBean = bean;	 					// note the bean to address
	this.myID	= id;						// note who we are
}
//-------------------------------------------------------------------
// the thread main loop:
// do forever
//	register as listener, set flag to accept events
//  deregister as listener, set flag to refuse events
//  change bean property
//
// if we ever get an event while we shouldn't get one, say so and halt
//-------------------------------------------------------------------
public void run() {

	while ( true ) {
		// register with bean, this means we might expect events from now
		// on.
		synchronized (this) {
			System.out.println(myID +" registering.");
			myBean.addPropertyChangeListener(this);
			readyForEvents = true;
		}

		// let other threads run for a bit
		randomSleep();

		// now deregister ourselves with bean, meaning we should not
		// receive any more events from bean from now on.
		synchronized (this) {
			System.out.println(myID +" un-registering.");
			myBean.removePropertyChangeListener(this);
			readyForEvents = false;
		}
		// let other threads run for a bit
		randomSleep();

		// then modify the bean's property:
		System.out.println(myID +" about to change bean property..");
		myBean.setProperty( (int) (Math.random()*50));
	}
}
//-------------------------------------------------------------------
// the implementation of the PropertyChangeListener interface
//-------------------------------------------------------------------
public void propertyChange(PropertyChangeEvent pcEvent) {

	if ( readyForEvents == false ) {
		System.out.println("I ("+ myID +") got an event while I did not" +
						" expect to receive one!!");
		System.exit(0);
	}
	System.out.println(myID +" heard of property change.");
}
//-------------------------------------------------------------------
// utility function to put a thread to sleep for a random period of
// less than 1 second.
//-------------------------------------------------------------------
protected void randomSleep() {
	MiscKit.delay( (int) (Math.random()*1000));
}
} // End of Class MTListeners