/*
 * Copyright 2002-2018 the original author or authors.
 *
 * 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
 *
 *      https://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.springframework.context.event;

import org.springframework.context.ApplicationEvent;
import org.springframework.context.ApplicationListener;
import org.springframework.core.Ordered;
import org.springframework.lang.Nullable;

Extended variant of the standard ApplicationListener interface, exposing further metadata such as the supported event and source type. 
For full introspection of generic event types, consider implementing the GenericApplicationListener interface instead. 
Author:
Juergen Hoeller
See Also:
GenericApplicationListener
GenericApplicationListenerAdapter
Since:
3.0/**
 * Extended variant of the standard {@link ApplicationListener} interface,
 * exposing further metadata such as the supported event and source type.
 *
 * <p>For full introspection of generic event types, consider implementing
 * the {@link GenericApplicationListener} interface instead.
 *
 * @author Juergen Hoeller
 * @since 3.0
 * @see GenericApplicationListener
 * @see GenericApplicationListenerAdapter
 */
public interface SmartApplicationListener extends ApplicationListener<ApplicationEvent>, Ordered {

	
Determine whether this listener actually supports the given event type.
Params:
eventType – the event type (never null)/**
	 * Determine whether this listener actually supports the given event type.
	 * @param eventType the event type (never {@code null})
	 */
	boolean supportsEventType(Class<? extends ApplicationEvent> eventType);

	
Determine whether this listener actually supports the given source type.
The default implementation always returns true. 
Params:
sourceType – the source type, or null if no source/**
	 * Determine whether this listener actually supports the given source type.
	 * <p>The default implementation always returns {@code true}.
	 * @param sourceType the source type, or {@code null} if no source
	 */
	default boolean supportsSourceType(@Nullable Class<?> sourceType) {
		return true;
	}

	
Determine this listener's order in a set of listeners for the same event.
The default implementation returns Ordered.LOWEST_PRECEDENCE. /**
	 * Determine this listener's order in a set of listeners for the same event.
	 * <p>The default implementation returns {@link #LOWEST_PRECEDENCE}.
	 */
	@Override
	default int getOrder() {
		return LOWEST_PRECEDENCE;
	}

}