source: trunk/EventBenchCore/src/de/ugoe/cs/eventbench/markov/State.java @ 1

package de.ugoe.cs.eventbench.markov;

import java.util.Random;

import de.ugoe.cs.eventbench.data.Event;

public abstract class State {
        
        /**
         * {@link Event} associated with the state. 
         */
        private Event<?> action;
        
        /**
         * Identifier of the state
         */
        private String id;
        
        /**
         * Random number generator used for state transmissions. 
         */
        protected Random rand;
        
        /**
         * State transmission function to be used by models. 
         * @return
         */
        public abstract State getNextState();
        
        /**
         * Creates a new State object. The id should be unique.
         * @param id identifier string of the state
         */
        protected State(String id, Event<?> action) {
                this.id = id;
                this.action = action;
        }

        /**
         * Dummy method for history-less state implementations.
         */
        public void setHistoryObject() {}
        
        /**
         * Defines a random number generator to be used by getNextState.
         * @param r Random number generator
         */
        public void setRandom(Random r) {
                rand = r;
        }
        
        /**
         * Returns the id of the state. 
         * @return id of the state
         */
        public String getId() {
                return id;
        }
        
        /**
         * The {@link Event} associated with this state. 
         * @return {@link Event} associated with this state
         */
        public Event<?> getAction() {
                return action;
        }
        
        /**
         * Two states are equal if their id string is equal.
         */
        @Override
        public boolean equals(Object other) {
                if( other==this ) {
                        return true;
                }
                boolean isEqual = false;
                if( other instanceof State ) {
                        isEqual = id.equals(((State) other).id);
                }
                return isEqual;
        }
        
        
        /* (non-Javadoc)
         * @see java.lang.Object#hashCode()
         */
        @Override
        public int hashCode() {
                int multiplier = 37;
                int hash = 42;
                
                hash = multiplier*hash + id.hashCode();
                
                return hash;
        }
        
}