83 lines
2.1 KiB
Java
83 lines
2.1 KiB
Java
/*
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* Copyright 2013 Robert von Burg <eitch@eitchnet.ch>
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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package li.strolch.agent.api;
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import li.strolch.model.StrolchRootElement;
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import li.strolch.model.Tags;
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/**
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* <p>
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* Implementing the observer pattern by allowing {@link Observer} to register themselves for updates to
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* {@link StrolchRootElement}
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* </p>
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*
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* <p>
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* Note: The key in all the methods can be any string, but as a convenience it is mostly one of the following:
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* </p>
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* <ul>
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* <li>{@link Tags#RESOURCE}</li>
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* <li>{@link Tags#ORDER}</li>
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* <li>{@link Tags#ACTIVITY}</li>
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* </ul>
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*
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* <p>
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* Should a special case arise, then it a contract must be defined by which a key is negotiated between an event
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* distributer and the observer
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* </p>
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*
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* @author Robert von Burg <eitch@eitchnet.ch>
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*/
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public interface ObserverHandler {
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/**
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* Update observers with the given event
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*
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* @param observerEvent
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* containing the updates
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*/
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void notify(ObserverEvent observerEvent);
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/**
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* Registers the {@link Observer} for notification of objects under the given key
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*
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* @param key
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* the key for which to the observer wants to be notified
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* @param observer
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* the observer to register
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*/
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void registerObserver(String key, Observer observer);
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/**
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* Unregister the given {@link Observer}
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*
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* @param key
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* the key for which to the observer was registered
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* @param observer
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* the observer unregister
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*/
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void unregisterObserver(String key, Observer observer);
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/**
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* Start the update thread
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*/
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void start();
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/**
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* Stop the update thread
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*/
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void stop();
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}
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