/* Copyright 2004, 2005, 2006 Acegi Technology Pty Limited

  *

  * 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 org.acegisecurity.acls;

 /**

  * Represents a permission granted to a {@link org.acegisecurity.acls.sid.Sid Sid} for a given domain object.

  *

  * @author Ben Alex

  * @version $Id: Permission.java 1784 2007-02-24 21:00:24Z luke_t $

  */

 public interface Permission {

     //~ Static fields/initializers =====================================================================================

     char RESERVED_ON = '~';

     char RESERVED_OFF = '.';

     String THIRTY_TWO_RESERVED_OFF = "................................";

     //~ Methods ========================================================================================================

     /**

      * Returns the bits that represents the permission.

      *

      * @return the bits that represent the permission

      */

     int getMask();

     /**

      * Returns a 32-character long bit pattern <code>String</code> representing this permission.

      * <p>

      * Implementations are free to format the pattern as they see fit, although under no circumstances may

      * {@link #RESERVED_OFF} or {@link #RESERVED_ON} be used within the pattern. An exemption is in the case of

      * {@link #RESERVED_OFF} which is used to denote a bit that is off (clear).

      * Implementations may also elect to use {@link #RESERVED_ON} internally for computation purposes,

      * although this method may not return any <code>String</code> containing {@link #RESERVED_ON}.

      * </p>

      *  <p>The returned String must be 32 characters in length.</p>

      *  <p>This method is only used for user interface and logging purposes. It is not used in any permission

      * calculations. Therefore, duplication of characters within the output is permitted.</p>

      *

      * @return a 32-character bit pattern

      */

     String getPattern();

 }