org.apache.wicket.util.watch.IModificationWatcher Maven / Gradle / Ivy
/*
* 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
*
* 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.apache.wicket.util.watch;
import java.util.Set;
import org.apache.wicket.util.listener.IChangeListener;
import org.apache.wicket.util.time.Duration;
/**
* Monitors one or more IModifiable
objects, calling a {@link IChangeListener
* IChangeListener} when a given object's modification time changes.
*
* @author Juergen Donnerstag
*/
public interface IModificationWatcher
{
/**
* Adds an IModifiable
object and an IChangeListener
object to call
* when the modifiable object is modified.
*
* @param modifiable
* an IModifiable
object to monitor
* @param listener
* an IChangeListener
to call if the IModifiable
object is
* modified
* @return true
if the set did not already contain the specified element
*/
boolean add(final IModifiable modifiable, final IChangeListener listener);
/**
* Removes all entries associated with an IModifiable
object.
*
* @param modifiable
* an IModifiable
object
* @return the IModifiable
object that was removed, else null
*/
IModifiable remove(final IModifiable modifiable);
/**
* Starts watching at a given Duration
polling rate.
*
* @param pollFrequency
* the polling rate Duration
*/
void start(final Duration pollFrequency);
/**
* Stops this ModificationWatcher
.
*/
void destroy();
/**
* Retrieves a key set of all IModifiable
objects currently being monitored.
*
* @return a Set
of all IModifiable
entries currently maintained
*/
Set getEntries();
}