/*

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * particular file as subject to the "Classpath" exception as provided

 *

 * This code is distributed in the hope that it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 */

package com.sun.corba.se.spi.orbutil.fsm ;

/**

 * This interface must be implemented by any class that is used as

 * a state in a FSM.  The FSM only needs the identity of this

 * object, so all that is really needs is the default equals implementation.

 * The toString() method should also be overridden to give a concise

 * description or name of the state.  The StateImpl class handles this.

 * <P>

 * Pre- and post- actions are taken only on completed transitions between

 * different states.  Assume that the FSM is in state A, and the FSM will

 * transition to state B under input I with action X.  If A != B and X completes

 * successfully, then after X completes execution, A.postAction is executed,

 * followed by B.preAction.

 *

 * @author Ken Cavanaugh

 */

public interface State

{

    /** Method that defines action that occurs whenever this state is entered.

    * Any exceptions thrown by this method are ignored.

    */

    void preAction( FSM fsm ) ;

    /** Method that defines action that occurs whenever this state is exited.

    * Any exceptions thrown by this method are ignored.

    */

    void postAction( FSM fsm ) ;

}

// end of State.java