source: trunk/autoquest-core-usability-evaluation/src/main/java/de/ugoe/cs/autoquest/usability/taskmodel/filter/BFSTaskModelIterator.java @ 1290

package de.ugoe.cs.autoquest.usability.taskmodel.filter;

import java.util.Iterator;
import java.util.LinkedList;
import java.util.Queue;

import org.apache.commons.collections15.Closure;
import org.apache.commons.collections15.CollectionUtils;

import de.ugoe.cs.autoquest.tasktrees.treeifc.IMarkingTemporalRelationship;
import de.ugoe.cs.autoquest.tasktrees.treeifc.IStructuringTemporalRelationship;
import de.ugoe.cs.autoquest.tasktrees.treeifc.ITask;
import de.ugoe.cs.autoquest.tasktrees.treeifc.ITaskModel;

public class BFSTaskModelIterator implements Iterator<ITask> {

        private final Queue<ITask> unvisitedTasks = new LinkedList<ITask>();

        private BFSTaskModelIterator(ITaskModel taskModel) {
                unvisitedTasks.addAll(taskModel.getTasks());
        }

        public static BFSTaskModelIterator iterator(ITaskModel taskModel) {
                return new BFSTaskModelIterator(taskModel);
        }

        @Override
        public boolean hasNext() {
                return !this.unvisitedTasks.isEmpty();
        }

        @Override
        public ITask next() {
                ITask task = unvisitedTasks.poll();
                processChildrenOfCurrentTask(task);
                return task;
        }

        private void processChildrenOfCurrentTask(ITask task) {
                if (task instanceof IStructuringTemporalRelationship) {
                        CollectionUtils.forAllDo(
                                        ((IStructuringTemporalRelationship) task).getChildren(),
                                        addToUnvisitedTasks());
                } else if (task instanceof IMarkingTemporalRelationship) {
                        addToUnvisitedTasks().execute(
                                        ((IMarkingTemporalRelationship) task).getMarkedTask());
                }
        }

        private Closure<ITask> addToUnvisitedTasks() {
                return new Closure<ITask>() {

                        @Override
                        public void execute(ITask childTask) {
                                unvisitedTasks.add(childTask);
                        }
                };
        }

        @Override
        public void remove() {
                // do nothing
        }

}