PausableClock.java

//Prevayler(TM) - The Free-Software Prevalence Layer.
//Copyright (C) 2001-2003 Klaus Wuestefeld
//This library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

package org.prevayler.implementation.clock;

import java.util.Date;

import org.prevayler.Clock;

public class PausableClock implements Clock {

	private final Clock _realClock;
	private final BrokenClock _brokenClock = new BrokenClock();
	private Clock _activeClock;


	public PausableClock(Clock realClock) {
		_realClock = realClock;
		resume();
	}

	public synchronized Date time() { return _activeClock.time(); }

	public synchronized void pause() {
		advanceTo(_realClock.time());
		_activeClock = _brokenClock;
	}

	public void advanceTo(Date time) {
		_brokenClock.advanceTo(time);
	}

	public synchronized void resume() { _activeClock = _realClock; }

	public Date realTime() { return _realClock.time(); }
}