source: branches/autoquest-core-tasktrees-alignment/src/main/java/de/ugoe/cs/autoquest/tasktrees/treeimpl/SequenceInstance.java @ 1733

//   Copyright 2012 Georg-August-Universität Göttingen, Germany
//
//   Licensed under the Apache License, Version 2.0 (the "License");
//   you may not use this file except in compliance with the License.
//   You may obtain a copy of the License at
//
//       http://www.apache.org/licenses/LICENSE-2.0
//
//   Unless required by applicable law or agreed to in writing, software
//   distributed under the License is distributed on an "AS IS" BASIS,
//   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
//   See the License for the specific language governing permissions and
//   limitations under the License.

package de.ugoe.cs.autoquest.tasktrees.treeimpl;

import java.util.Collections;
import java.util.Iterator;
import java.util.LinkedList;
import java.util.List;

import de.ugoe.cs.autoquest.tasktrees.treeifc.IIterationInstance;
import de.ugoe.cs.autoquest.tasktrees.treeifc.ISequence;
import de.ugoe.cs.autoquest.tasktrees.treeifc.ISequenceInstance;
import de.ugoe.cs.autoquest.tasktrees.treeifc.ITaskInstance;

/**
 * <p>
 * Default implementation of {@link IIterationInstance}.
 * </p>
 * 
 * @author Patrick Harms
 */
class SequenceInstance extends TaskInstance implements ISequenceInstance {

        /**
         * <p>
         * default serial version UID
         * </p>
         */
        private static final long serialVersionUID = 1L;

        /**
         * <p>
         * the children of this task instance which are task instances, as well
         * </p>
         */
        private List<ITaskInstance> children;

        /**
         * <p>
         * initializes this instance with the respective task model
         * </p>
         *
         * @param task
         *            the task of which this is an instance
         */
        SequenceInstance(ISequence task) {
                super(task);
        }

        /**
         * <p>
         * used to add a child to this task instance at a specific position
         * </p>
         * 
         * @param index
         *            the position of the new child in the list of children
         * @param child
         *            the new child of this instance
         */
        synchronized void addChild(int index, ITaskInstance child) {
                if (children == null) {
                        children = new LinkedList<ITaskInstance>();
                }

                children.add(index, child);
        }

        /**
         * <p>
         * used to add a child to this task instance
         * </p>
         * 
         * @param child
         *            the new child of this instance
         */
        synchronized void addChild(ITaskInstance child) {
                if (children == null) {
                        children = new LinkedList<ITaskInstance>();
                }

                children.add(child);
        }

        /*
         * (non-Javadoc)
         * 
         * @see de.ugoe.cs.autoquest.tasktrees.treeimpl.ISequenceInstance#clone()
         */
        @Override
        public synchronized ISequenceInstance clone() {
                final SequenceInstance clone = (SequenceInstance) super.clone();

                if (children != null) {
                        clone.children = new LinkedList<ITaskInstance>();

                        for (final ITaskInstance child : children) {
                                clone.children.add(child.clone());
                        }
                }

                return clone;
        }

        /*
         * (non-Javadoc)
         * 
         * @see de.ugoe.cs.autoquest.tasktrees.treeifc.ITaskInstanceList#get(int)
         */
        @Override
        public ITaskInstance get(int index) {
                if (children == null) {
                        throw new IndexOutOfBoundsException(Integer.toString(index));
                } else {
                        return children.get(index);
                }
        }

        /*
         * (non-Javadoc)
         * 
         * @see de.ugoe.cs.autoquest.tasktrees.treeifc.ITaskInstance#getChildren()
         */
        public synchronized List<ITaskInstance> getChildren() {
                if (children == null) {
                        children = new LinkedList<ITaskInstance>();
                }

                return Collections.unmodifiableList(children);
        }

        /*
         * (non-Javadoc)
         * 
         * @see
         * de.ugoe.cs.autoquest.tasktrees.treeifc.ISequenceInstance#getSequence()
         */
        @Override
        public ISequence getSequence() {
                return (ISequence) super.getTask();
        }

        /*
         * (non-Javadoc)
         * 
         * @see java.lang.Iterable#iterator()
         */
        @Override
        public Iterator<ITaskInstance> iterator() {
                return getChildren().iterator();
        }

        /**
         * <p>
         * removes a child from this task instance at a specific position
         * </p>
         * 
         * @param index
         *            the position of the child to be removed
         * 
         * @return the child removed from the children of this instance
         */
        synchronized ITaskInstance removeChild(int index) {
                if (children != null) {
                        return children.remove(index);
                } else {
                        throw new IllegalArgumentException(
                                        "this task instance does not have children that can be removed");
                }
        }

        /*
         * (non-Javadoc)
         * 
         * @see de.ugoe.cs.autoquest.tasktrees.treeifc.ITaskInstanceList#size()
         */
        @Override
        public int size() {
                if (children == null) {
                        return 0;
                } else {
                        return children.size();
                }
        }

}