/*
 * JFugue - API for Music Programming
 * Copyright (C) 2003-2008  David Koelle
 *
 * http://www.jfugue.org
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or any later version.
 *
 * 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.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
 *
 */

package org.jfugue;

/**
 * This class is used to transform a pattern. Extend this class to create your
 * own PatternTransformer, which listens to parser events and can modify the
 * events that are fired off by the parser. Some sample PatternTransformer
 * subclasses are packaged with JFugue; refer to those to see examples of
 * transformers in action.
 *
 * This feature is covered in detail in The Complete Guide to JFugue.
 *
 * @see org.jfugue.extras.DiatonicIntervalPatternTransformer
 * @see org.jfugue.extras.DurationPatternTransformer
 * @see org.jfugue.extras.IntervalPatternTransformer
 * @see org.jfugue.extras.ReversePatternTransformer
 * @author David Koelle
 * @version 2.0
 */
public class PatternTransformer implements ParserListener {
	/**
	 * Contains the pattern to return at the end of the transformation. As of
	 * version 4.0, this variable is private. Use the protected methods
	 * getReturnPattern() and setReturnPattern() to access the return pattern.
	 */
	private Pattern returnPattern;

	/**
	 * Returns the pattern that the transformer is modifying
	 * 
	 * @version 4.0
	 */
	protected Pattern getReturnPattern() {
		return returnPattern;
	}

	/**
	 * Sets the pattern that the transformer is modifying
	 * 
	 * @version 4.0
	 */
	protected void setReturnPattern(Pattern pattern) {
		this.returnPattern = pattern;
	}

	/**
	 * Transforms the pattern, according to the event method that you have
	 * presumably extended.
	 */
	public Pattern transform(Pattern p) {
		setReturnPattern(new Pattern());
		MusicStringParser parser = new MusicStringParser();
		parser.addParserListener(this);
		try {
			parser.parse(p);
		} catch (JFugueException e) {
			e.printStackTrace();
		}
		return getReturnPattern();
	}

	/** Extend this method to make your transformer modify the voice. */
	@Override
	public void voiceEvent(Voice voice) {
		returnPattern.addElement(voice);
	}

	/** Extend this method to make your transformer modify the tempo. */
	@Override
	public void tempoEvent(Tempo tempo) {
		returnPattern.addElement(tempo);
	}

	/** Extend this method to make your transformer modify the instrument. */
	@Override
	public void instrumentEvent(Instrument instrument) {
		returnPattern.addElement(instrument);
	}

	/** Extend this method to make your transformer modify the layer. */
	@Override
	public void layerEvent(Layer layer) {
		returnPattern.addElement(layer);
	}

	/** Extend this method to make your transformer modify the time. */
	@Override
	public void timeEvent(Time time) {
		returnPattern.addElement(time);
	}

	/** Extend this method to make your transformer modify the time. */
	@Override
	public void keySignatureEvent(KeySignature keySig) {
		returnPattern.addElement(keySig);
	}

	/** Extend this method to make your transformer modify the measure. */
	@Override
	public void measureEvent(Measure measure) {
		returnPattern.addElement(measure);
	}

	/**
	 * Extend this method to make your transformer modify the controller
	 * messages.
	 */
	@Override
	public void controllerEvent(Controller controller) {
		returnPattern.addElement(controller);
	}

	/**
	 * Extend this method to make your transformer modify the channel pressure
	 * messages.
	 */
	@Override
	public void channelPressureEvent(ChannelPressure channelPressure) {
		returnPattern.addElement(channelPressure);
	}

	/**
	 * Extend this method to make your transformer modify the polyphonic
	 * pressure messages.
	 */
	@Override
	public void polyphonicPressureEvent(PolyphonicPressure polyphonicPressure) {
		returnPattern.addElement(polyphonicPressure);
	}

	/**
	 * Extend this method to make your transformer modify the pitch bend
	 * messages.
	 */
	@Override
	public void pitchBendEvent(PitchBend pitchBend) {
		returnPattern.addElement(pitchBend);
	}

	/**
	 * Extend this method to make your transformer modify the note. Don't forget
	 * to also extend sequentialNoteEvent and parallelNoteEvent.
	 */
	@Override
	public void noteEvent(Note note) {
		returnPattern.addElement(note);
	}

	/**
	 * Extend this method to make your transformer modify the note. Don't forget
	 * to also extend noteEvent and parallelNoteEvent.
	 */
	@Override
	public void sequentialNoteEvent(Note note) {
		returnPattern.addElement(note);
	}

	/**
	 * Extend this method to make your transformer modify the note. Don't forget
	 * to also extend noteEvent and sequentialNoteEvent.
	 */
	@Override
	public void parallelNoteEvent(Note note) {
		returnPattern.addElement(note);
	}
}