/*
* 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.
*
* Contributions from 2013-2017 where performed either by US government
* employees, or under US Veterans Health Administration contracts.
*
* US Veterans Health Administration contributions by government employees
* are work of the U.S. Government and are not subject to copyright
* protection in the United States. Portions contributed by government
* employees are USGovWork (17USC ยง105). Not subject to copyright.
*
* Contribution by contractors to the US Veterans Health Administration
* during this period are contractually contributed under the
* Apache License, Version 2.0.
*
* See: https://www.usa.gov/government-works
*
* Contributions prior to 2013:
*
* Copyright (C) International Health Terminology Standards Development Organisation.
* Licensed under the Apache License, Version 2.0.
*
*/
package sh.isaac.model.coordinate;
//~--- JDK imports ------------------------------------------------------------
import java.lang.ref.WeakReference;
//~--- non-JDK imports --------------------------------------------------------
import javafx.beans.WeakListener;
import javafx.collections.ArrayChangeListener;
import javafx.collections.ObservableIntegerArray;
//~--- classes ----------------------------------------------------------------
/**
* The listener interface for receiving weakArrayChange events.
* The class that is interested in processing a weakArrayChange
* event implements this interface, and the object created
* with that class is registered with a component using the
* component's <code>addWeakArrayChangeListener<code> method. When
* the weakArrayChange event occurs, that object's appropriate
* method is invoked.
*
* @author kec
*/
public class WeakArrayChangeListener
implements WeakListener, ArrayChangeListener<ObservableIntegerArray> {
/** The ref. */
private final WeakReference<ArrayChangeListener<ObservableIntegerArray>> ref;
//~--- constructors --------------------------------------------------------
/**
* Instantiates a new weak array change listener.
*
* @param listener the listener
*/
public WeakArrayChangeListener(ArrayChangeListener<ObservableIntegerArray> listener) {
this.ref = new WeakReference<>(listener);
}
//~--- methods -------------------------------------------------------------
/**
* On changed.
*
* @param observableArray the observable array
* @param sizeChanged the size changed
* @param from the from
* @param to the to
*/
@Override
public void onChanged(ObservableIntegerArray observableArray, boolean sizeChanged, int from, int to) {
final ArrayChangeListener<ObservableIntegerArray> listener = this.ref.get();
if (listener != null) {
listener.onChanged(observableArray, sizeChanged, from, to);
} else {
// The weakly reference listener has been garbage collected,
// so this WeakListener will now unhook itself from the
// source bean
observableArray.removeListener(this);
}
}
/**
* Was garbage collected.
*
* @return true, if successful
*/
@Override
public boolean wasGarbageCollected() {
return (this.ref.get() == null);
}
}