source: branches/autoquest-core-tasktrees-alignment/src/main/java/de/ugoe/cs/autoquest/tasktrees/treeifc/ITask.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.treeifc;

import java.io.Serializable;
import java.util.Collection;

/**
 * <p>
 * A task represents a model for events that occur if the user interacts with a
 * software for achieving a specific goal. A task can be a single event or a
 * complex structure of events and temporal relationships defining the event
 * order. Tasks may especially refer to other tasks to create task structures
 * similar to trees. These structures fully define in which ways the events that
 * form the task can occur. However, the structure of a task is not necessarily
 * a tree as task structures may be reused several times in larger scale task
 * structures.
 * </p>
 * 
 * @author Patrick Harms
 */
public interface ITask extends Cloneable, Serializable {

        /**
         * <p>
         * implements the visitor pattern to be able to process tasks and their
         * children.
         * </p>
         * 
         * @param visitor
         *            the visitor used to process the task
         */
        public void accept(ITaskVisitor visitor);

        /**
         * <p>
         * returns an exact copy of this task. The clone has the same id. If the
         * task has children, they are cloned as well. A call on the method
         * {@link #equals(ITask)} with the result of this method must return true.
         * </p>
         * 
         * @return as described
         */
        public ITask clone();

        /**
         * <p>
         * checks whether this task is equal to another one. Task equality is only
         * given, if two tasks have the same id. This means, that this method must
         * only return true if the other task is either the same object or a clone
         * of it.
         * </p>
         * 
         * @return as described
         */
        public boolean equals(ITask task);

        /**
         * <p>
         * returns a human readable description for the task.
         * </p>
         * 
         * @return as described
         */
        public String getDescription();

        /**
         * <p>
         * returns a collection of collections of all different execution variants
         * of this task. This is a grouping of all instances where each group
         * contains structurally identical instances.
         * </p>
         * 
         * @return as described
         */
        public Collection<Collection<ITaskInstance>> getExecutionVariants();

        /**
         * <p>
         * every task is assigned a unique id which is returned by this method. The
         * id is unique for the current runtime.
         * </p>
         * 
         * @return as described
         */
        public int getId();

        /**
         * <p>
         * returns a collection of all observed instances of this task
         * </p>
         * 
         * @return as described
         */
        public Collection<ITaskInstance> getInstances();

        /**
         * <p>
         * returns a human readable type for the task.
         * </p>
         * 
         * @return as described
         */
        public String getType();

        /**
         * <p>
         * returns a hash code for the task, which is usually the id returned by
         * {@link #getId()}.
         * </p>
         * 
         * @return as described
         */
        @Override
        public int hashCode();

}