content: /*
   * Copyright (C) 2014 Glyptodon LLC
   *
   * Permission is hereby granted, free of charge, to any person obtaining a copy
   * of this software and associated documentation files (the "Software"), to deal
   * in the Software without restriction, including without limitation the rights
   * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
   * copies of the Software, and to permit persons to whom the Software is
   * furnished to do so, subject to the following conditions:
   *
   * The above copyright notice and this permission notice shall be included in
   * all copies or substantial portions of the Software.
   *
   * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
   * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
   * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
   * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
   * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
   * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
   * THE SOFTWARE.
   */
  
  package org.glyptodon.guacamole.protocol;
  
  import org.glyptodon.guacamole.GuacamoleException;
  
  /**
   * Interface which provides for the filtering of individual instructions. Each
   * filtered instruction may be allowed through untouched, modified, replaced,
   * dropped, or explicitly denied.
   *
   * @author Michael Jumper
   */
  public interface GuacamoleFilter {
  
      /**
       * Applies the filter to the given instruction, returning the original
       * instruction, a modified version of the original, or null, depending
       * on the implementation.
       *
       * @param instruction The instruction to filter.
       * @return The original instruction, if the instruction is to be allowed,
       *         a modified version of the instruction, if the instruction is
       *         to be overridden, or null, if the instruction is to be dropped.
       * @throws GuacamoleException If an error occurs filtering the instruction,
       *                            or if the instruction must be explicitly
       *                            denied.
       */
      public GuacamoleInstruction filter(GuacamoleInstruction instruction) throws GuacamoleException;
      
  }
  