/*
 Copyright (C) 2008 Richard Gomes

 This source code is release under the BSD License.

 This file is part of JQuantLib, a free-software/open-source library
 for financial quantitative analysts and developers - http://jquantlib.org/

 JQuantLib is free software: you can redistribute it and/or modify it
 under the terms of the JQuantLib license.  You should have received a
 copy of the license along with this program; if not, please email
 . The license is also available online at
 .

 This program 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.  See the license for more details.

 JQuantLib is based on QuantLib. http://quantlib.org/
 When applicable, the original copyright notice follows this notice.
 */

/*
 Copyright (C) 2000, 2001, 2002, 2003 RiskMap srl

 This file is part of QuantLib, a free-software/open-source library
 for financial quantitative analysts and developers - http://quantlib.org/

 QuantLib is free software: you can redistribute it and/or modify it
 under the terms of the QuantLib license.  You should have received a
 copy of the license along with this program; if not, please email
 . The license is also available online at
 .

 This program 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.  See the license for more details.
 */

package org.jquantlib.quotes;

import java.util.List;

import org.jquantlib.lang.annotation.QualityAssurance;
import org.jquantlib.lang.annotation.QualityAssurance.Quality;
import org.jquantlib.lang.annotation.QualityAssurance.Version;
import org.jquantlib.util.DefaultObservable;
import org.jquantlib.util.Observable;
import org.jquantlib.util.Observer;

/**
 * Purely virtual base class for market observables
 * 
 * @author Richard Gomes
 */
@QualityAssurance(quality = Quality.Q3_DOCUMENTATION, version = Version.V097, reviewers = { "Richard Gomes" })
public abstract class Quote implements Observable {

    /**
     * @return the current value
     */
    public abstract double value() /* @ReadOnly */;

    /**
     * @return true if the Quote holds a valid value
     */
    public abstract boolean isValid() /* @ReadOnly */;


    //
    // implements Observable
    //

    /**
     * Implements multiple inheritance via delegate pattern to an inner class
     * 
     * @see Observable
     * @see DefaultObservable
     */
    private final Observable delegatedObservable = new DefaultObservable(this);

    @Override
    public void addObserver(final Observer observer) {
        delegatedObservable.addObserver(observer);
    }

    @Override
    public int countObservers() {
        return delegatedObservable.countObservers();
    }

    @Override
    public void deleteObserver(final Observer observer) {
        delegatedObservable.deleteObserver(observer);
    }

    @Override
    public void notifyObservers() {
        delegatedObservable.notifyObservers();
    }

    @Override
    public void notifyObservers(final Object arg) {
        delegatedObservable.notifyObservers(arg);
    }

    @Override
    public void deleteObservers() {
        delegatedObservable.deleteObservers();
    }

    @Override
    public List getObservers() {
        return delegatedObservable.getObservers();
    }

}