org.springframework.shell.event.ShellStatusProvider Maven / Gradle / Ivy
/*
* Copyright 2011-2012 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
*
* 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 org.springframework.shell.event;
/**
* Implemented by shells that support the publication of shell status changes.
*
*
* Implementations are not required to provide any guarantees with respect to the order
* in which notifications are delivered to listeners.
*
*
* Implementations must permit modification of the listener list, even while delivering
* event notifications to listeners. However, listeners do not receive any guarantee that
* their addition or removal from the listener list will be effective or not for any event
* notification that is currently proceeding.
*
*
* Implementations must ensure that status notifications are only delivered when an actual
* change has taken place.
*
* @author Ben Alex
* @since 1.0
*/
public interface ShellStatusProvider {
/**
* Registers a new status listener.
*
* @param shellStatusListener to register (cannot be null)
*/
void addShellStatusListener(ShellStatusListener shellStatusListener);
/**
* Removes an existing status listener.
*
*
* If the presented status listener is not found, the method returns without exception.
*
* @param shellStatusListener to remove (cannot be null)
*/
void removeShellStatusListener(ShellStatusListener shellStatusListener);
/**
* Returns the current shell status.
*
* @return the current status (never null)
*/
ShellStatus getShellStatus();
}