/*
 *  Licensed to the Apache Software Foundation (ASF) under one or more
 *  contributor license agreements.  See the NOTICE file distributed with
 *  this work for additional information regarding copyright ownership.
 *  The ASF licenses this file to You 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.apache.tools.ant;

import java.util.EventListener;

Instances of classes that implement this interface can register
to be notified when things happened during a build.
See Also:
BuildEvent
Project.addBuildListener(BuildListener)/**
 * Instances of classes that implement this interface can register
 * to be notified when things happened during a build.
 *
 * @see BuildEvent
 * @see Project#addBuildListener(BuildListener)
 *
 */
public interface BuildListener extends EventListener {

    
Signals that a build has started. This event
is fired before any targets have started.
This event is fired before the project instance is fully
configured.  In particular no properties have been set and the
project may not know its name or default target, yet.
Params:
event – An event with any relevant extra information.
             Must not be null./**
     * Signals that a build has started. This event
     * is fired before any targets have started.
     *
     * <p>This event is fired before the project instance is fully
     * configured.  In particular no properties have been set and the
     * project may not know its name or default target, yet.</p>
     *
     * @param event An event with any relevant extra information.
     *              Must not be <code>null</code>.
     */
    void buildStarted(BuildEvent event);

    
Signals that the last target has finished. This event
will still be fired if an error occurred during the build.
Params:
event – An event with any relevant extra information.
             Must not be null.
See Also:
BuildEvent.getException()/**
     * Signals that the last target has finished. This event
     * will still be fired if an error occurred during the build.
     *
     * @param event An event with any relevant extra information.
     *              Must not be <code>null</code>.
     *
     * @see BuildEvent#getException()
     */
    void buildFinished(BuildEvent event);

    
Signals that a target is starting.
Params:
event – An event with any relevant extra information.
             Must not be null.
See Also:
BuildEvent.getTarget()/**
     * Signals that a target is starting.
     *
     * @param event An event with any relevant extra information.
     *              Must not be <code>null</code>.
     *
     * @see BuildEvent#getTarget()
     */
    void targetStarted(BuildEvent event);

    
Signals that a target has finished. This event will
still be fired if an error occurred during the build.
Params:
event – An event with any relevant extra information.
             Must not be null.
See Also:
BuildEvent.getException()/**
     * Signals that a target has finished. This event will
     * still be fired if an error occurred during the build.
     *
     * @param event An event with any relevant extra information.
     *              Must not be <code>null</code>.
     *
     * @see BuildEvent#getException()
     */
    void targetFinished(BuildEvent event);

    
Signals that a task is starting.
Params:
event – An event with any relevant extra information.
             Must not be null.
See Also:
BuildEvent.getTask()/**
     * Signals that a task is starting.
     *
     * @param event An event with any relevant extra information.
     *              Must not be <code>null</code>.
     *
     * @see BuildEvent#getTask()
     */
    void taskStarted(BuildEvent event);

    
Signals that a task has finished. This event will still
be fired if an error occurred during the build.
Params:
event – An event with any relevant extra information.
             Must not be null.
See Also:
BuildEvent.getException()/**
     * Signals that a task has finished. This event will still
     * be fired if an error occurred during the build.
     *
     * @param event An event with any relevant extra information.
     *              Must not be <code>null</code>.
     *
     * @see BuildEvent#getException()
     */
    void taskFinished(BuildEvent event);

    
Signals a message logging event.
Params:
event – An event with any relevant extra information.
             Must not be null.
See Also:
BuildEvent.getMessage()
BuildEvent.getException()
BuildEvent.getPriority()/**
     * Signals a message logging event.
     *
     * @param event An event with any relevant extra information.
     *              Must not be <code>null</code>.
     *
     * @see BuildEvent#getMessage()
     * @see BuildEvent#getException()
     * @see BuildEvent#getPriority()
     */
    void messageLogged(BuildEvent event);
}