EDIT

/**

* Copyright (C) 2017 EDIT

* European Distributed Institute of Taxonomy

* http://www.e-taxonomy.eu

*

* The contents of this file are subject to the Mozilla Public License Version 1.1

* See LICENSE.TXT at the top of this package for the full license terms.

*/

package org.springframework.context.event;

import java.io.Serializable;

import java.lang.reflect.Method;

import java.util.ArrayList;

import java.util.Collection;

import java.util.HashMap;

import java.util.Map;

import org.apache.log4j.Logger;

import org.springframework.beans.BeansException;

import org.springframework.beans.factory.annotation.Autowired;

import org.springframework.context.ApplicationContext;

import org.springframework.context.ApplicationContextAware;

import org.springframework.context.ApplicationListener;

import org.springframework.core.annotation.AnnotationUtils;

import org.springframework.util.ReflectionUtils;

import com.vaadin.spring.annotation.SpringComponent;

import com.vaadin.spring.annotation.UIScope;

import eu.etaxonomy.vaadin.mvp.AbstractPresenter;

/**

 * The DefaultPojoEventListenerManager helps sending events to  event listener methods defined in beans

 * which are not manages by the Spring {@link ApplicationEventMulticaster}. The {@link ApplicationEventMulticaster}

 * for example misses sending events to spring beans with scope "Prototype".

 *

 * @author a.kohlbecker

 * @since May 29, 2017

 *

 */

@SpringComponent

@UIScope

public class DefaultPojoEventListenerManager implements PojoEventListenerManager, ApplicationContextAware, Serializable {

    private static final long serialVersionUID = -6814417168274166953L;

    public static final Logger logger = Logger.getLogger(AbstractPresenter.class);

    @Autowired

    private ApplicationEventMulticaster applicationEventMulticaster;

    private final EventExpressionEvaluator evaluator = new EventExpressionEvaluator();

    private Map<Object, Collection<ApplicationListener<?>>> listenerMap = new HashMap<>();

    private ApplicationContext applicationContext;

    @Override

    public void addEventListeners(Object o){

        Method[] methods = ReflectionUtils.getUniqueDeclaredMethods(o.getClass());

        for (Method method : methods) {

            EventListener eventListener = AnnotationUtils.findAnnotation(method, EventListener.class);

            if (eventListener == null) {

                continue;

            }

            ApplicationListenerPojoMethodAdapter applicationListener = new ApplicationListenerPojoMethodAdapter(o.toString(), o.getClass(), method, o);

            applicationListener.init(this.applicationContext, this.evaluator);

            if(logger.isTraceEnabled()){

                logger.trace(String.format("Adding ApplicationListener for  %s@%s#%s", o.getClass().getSimpleName(), o.hashCode(), method.toGenericString()));

            }

            applicationEventMulticaster.addApplicationListener(applicationListener);

            addToMap(o, applicationListener);

        }

    }

    @Override

    public void removeEventListeners(Object o){

        if(listenerMap.containsKey(o)){

            listenerMap.get(o).forEach(l -> applicationEventMulticaster.removeApplicationListener(l));

            listenerMap.remove(o);

        }

    }

    private void addToMap(Object o, ApplicationListener<?> applicationListener) {

        if(!listenerMap.containsKey(o)){

            listenerMap.put(o, new ArrayList<>());

        }

        listenerMap.get(o).add(applicationListener);

    }

    /**

     * {@inheritDoc}

     */

    @Override

    public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {

        this.applicationContext = applicationContext;

    }

}