001/**
002 * Copyright (c) 2011, The University of Southampton and the individual contributors.
003 * All rights reserved.
004 *
005 * Redistribution and use in source and binary forms, with or without modification,
006 * are permitted provided that the following conditions are met:
007 *
008 *   *  Redistributions of source code must retain the above copyright notice,
009 *      this list of conditions and the following disclaimer.
010 *
011 *   *  Redistributions in binary form must reproduce the above copyright notice,
012 *      this list of conditions and the following disclaimer in the documentation
013 *      and/or other materials provided with the distribution.
014 *
015 *   *  Neither the name of the University of Southampton nor the names of its
016 *      contributors may be used to endorse or promote products derived from this
017 *      software without specific prior written permission.
018 *
019 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
020 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
021 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
022 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
023 * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
024 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
025 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
026 * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
027 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
028 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
029 */
030package org.openimaj.content.animation.animator;
031
032/**
033 * A {@link ReversableValueAnimator} that can wrap another
034 * {@link ReversableValueAnimator} to produce back and forth 
035 * looping behavior.
036 * 
037 * @author Jonathon Hare (jsh2@ecs.soton.ac.uk)
038 *
039 * @param <T> Type produce by animator
040 */
041public class ForwardBackwardLoopingValueAnimator<T> implements ReversableValueAnimator<T> {
042        ReversableValueAnimator<T> animator;
043        
044        /**
045         * Construct around the given {@link ReversableValueAnimator} to
046         * provide forward/backward looping behavior.
047         * @param animator animator to loop
048         */
049        public ForwardBackwardLoopingValueAnimator(ReversableValueAnimator<T> animator) {
050                this.animator = animator;
051        }
052        
053        @Override
054        public T nextValue() {
055                if (animator.hasFinished())
056                        animator = animator.reverseAnimator();
057
058                return animator.nextValue();
059        }
060
061        @Override
062        public boolean hasFinished() {
063                return false;
064        }
065
066        @Override
067        public void reset() {
068                animator.reset();
069        }
070
071        @Override
072        public ReversableValueAnimator<T> reverseAnimator() {
073                return animator.reverseAnimator();
074        }
075        
076        /**
077         * Construct a new {@link ForwardBackwardLoopingValueAnimator} from a {@link ReversableValueAnimator}.
078         * 
079         * @param <T> Type produce by animator
080         * @param animator animator to loop
081         * @return new {@link ForwardBackwardLoopingValueAnimator}
082         */
083        public static <T> ForwardBackwardLoopingValueAnimator<T> loop(ReversableValueAnimator<T> animator) {
084                return new ForwardBackwardLoopingValueAnimator<T>(animator);
085        }
086}