content: /**
   * This file is part of Aion-Lightning <aion-lightning.org>.
   *
   *  Aion-Lightning is free software: you can redistribute it and/or modify
   *  it under the terms of the GNU General Public License as published by
   *  the Free Software Foundation, either version 3 of the License, or
   *  (at your option) any later version.
   *
   *  Aion-Lightning 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 for more details. *
   *  You should have received a copy of the GNU General Public License
   *  along with Aion-Lightning.
   *  If not, see <http://www.gnu.org/licenses/>.
   */
  
  package com.aionemu.commons.callbacks;
  
  /**
   * This class represents callback result
   *
   * @param <T>
   *            Type of callback result
   * @author SoulKeeper
   */
  @SuppressWarnings({ "unchecked", "rawtypes" })
  public class CallbackResult<T> {
  
  	/**
  	 * Continue mask for callbacks, future invocation of method or other
  	 * callbacks is not blocked
  	 */
  	public static final int CONTINUE = 0x00;
  
  	/**
  	 * Block callbacks mask, future callbacks will be blocked, but method won't
  	 * be
  	 */
  	public static final int BLOCK_CALLBACKS = 0x01;
  
  	/**
  	 * Method will be blocked, but not callbacks
  	 */
  	public static final int BLOCK_CALLER = 0x02;
  
  	/**
  	 * Caller and another callbacks will be blocked
  	 */
  	public static final int BLOCK_ALL = 0x01 | 0x02;
  
  	/**
  	 * Cache for continue instance
  	 */
  	private static final CallbackResult INSTANCE_CONTINUE = new CallbackResult(CONTINUE);
  
  	/**
  	 * Cache for callback blocker
  	 */
  	private static final CallbackResult INSTANCE_BLOCK_CALLBACKS = new CallbackResult(BLOCK_CALLBACKS);
  
  	/**
  	 * Result of callback invokation, used only when caller is blocked by
  	 * callback
  	 */
  	private final T result;
  
  	/**
  	 * What this callback is blocking
  	 */
  	private final int blockPolicy;
  
  	/**
  	 * Creates new callback with specified blocking policy
  	 *
  	 * @param blockPolicy
  	 *            what this callback should block
  	 */
  	private CallbackResult(int blockPolicy) {
  		this(null, blockPolicy);
  	}
  
  	/**
  	 * Creates new callback with specified blocking policy and result
  	 *
  	 * @param result
  	 *            result of callback
  	 * @param blockPolicy
  	 *            what this callback blocks
  	 */
  	private CallbackResult(T result, int blockPolicy) {
  		this.result = result;
  		this.blockPolicy = blockPolicy;
  	}
  
  	/**
  	 * Retruns result of this callback
  	 *
  	 * @return result of this callback
  	 */
  	public T getResult() {
  		return result;
  	}
  
  	/**
  	 * Returns true if is blocking callbacks
  	 *
  	 * @return true if is blocking callbacks
  	 */
  	public boolean isBlockingCallbacks() {
  		return (blockPolicy & BLOCK_CALLBACKS) != 0;
  	}
  
  	/**
  	 * Returns true if is blocking caller
  	 *
  	 * @return true if is blocking caller
  	 */
  	public boolean isBlockingCaller() {
  		return (blockPolicy & BLOCK_CALLER) != 0;
  	}
  
  	/**
  	 * Returns callback for continue action, for perfomance reasons returns
  	 * cached instance
  	 *
  	 * @param <T>
  	 *            type of result object, ignored, always null
  	 * @return callback with result type continue
  	 */
  	public static <T> CallbackResult<T> newContinue() {
  		return INSTANCE_CONTINUE;
  	}
  
  	/**
  	 * Returns callback that blocks another callbacks, cached instance is used
  	 * for perfomance reasons
  	 *
  	 * @param <T>
  	 *            type of result object, ignored, always null
  	 * @return callback that blocks invocation of another callbacks
  	 */
  	public static <T> CallbackResult<T> newCallbackBlocker() {
  		return INSTANCE_BLOCK_CALLBACKS;
  	}
  
  	/**
  	 * Returns callback that blocks another callbacks and method invocation.<br>
  	 * {@link com.aionemu.commons.callbacks.Callback#afterCall(Object, Object[], Object)}
  	 * will be invoked with the result from this call.
  	 *
  	 * @param result
  	 *            Result of callback
  	 * @param <T>
  	 *            type of result
  	 * @return new callback instance with given result that will be returned as
  	 *         method result
  	 */
  	public static <T> CallbackResult<T> newFullBlocker(T result) {
  		return new CallbackResult<T>(result, BLOCK_ALL);
  	}
  }
  