AbstractProlTrigger.java

/* 
 * Copyright 2014 Igor Maznitsa (http://www.igormaznitsa.com).
 *
 * 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 com.igormaznitsa.prol.logic.triggers;

import com.igormaznitsa.prol.utils.Utils;
import java.util.Collections;
import java.util.HashMap;
import java.util.Map;

/**
 * The class is an abstract prol trigger which implements functionality to
 * register and unregister signatures
 *
 * @author Igor Maznitsa (igor.maznitsa@igormaznitsa.com)
 */
public abstract class AbstractProlTrigger implements ProlTrigger {

  /**
   * The map contains the signature and the event type linked with the signature
   */
  protected final Map<String, ProlTriggerType> signatureMap;

  /**
   * The constructor
   */
  public AbstractProlTrigger() {
    signatureMap = Collections.synchronizedMap(new HashMap<String, ProlTriggerType>());
  }

  /**
   * Add new signature
   *
   * @param signature the signature as name/arity or 'name'/arity
   * @param observedEvent the event type associated with the signature
   * @return this
   */
  public AbstractProlTrigger addSignature(final String signature, final ProlTriggerType observedEvent) {
    if (signature == null || observedEvent == null) {
      throw new NullPointerException("Both arguments must not be null");
    }

    String processedsignature = Utils.validateSignature(signature);

    if (processedsignature == null) {
      throw new IllegalArgumentException("Wrong signature format [" + signature + ']');
    }
    else {
      processedsignature = Utils.normalizeSignature(processedsignature);
    }

    signatureMap.put(processedsignature, observedEvent);

    return this;
  }

  /**
   * Remove mapped trigger event for signature, signature as name/arity or
   * 'name'/arity
   *
   * @param signature the signature, must not be null
   * @return this
   */
  public AbstractProlTrigger removeSignature(final String signature) {
    if (signature == null) {
      throw new NullPointerException("Signature is null");
    }

    String processedsignature = Utils.validateSignature(signature);

    if (processedsignature == null) {
      throw new IllegalArgumentException("Wrong signature format [" + signature + ']');
    }
    else {
      processedsignature = Utils.normalizeSignature(processedsignature);
    }

    signatureMap.remove(processedsignature);

    return this;
  }

  @Override
  public Map<String, ProlTriggerType> getSignatures() {
    return signatureMap;
  }
}