/**
* 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.isis.viewer.wicket.model.hints;
import org.apache.wicket.event.IEvent;
/**
* Broadcast down by <tt>PageAbstract</tt> to all child components
*/
public class IsisEnvelopeEvent extends IsisEventAbstract {
private final IsisEventLetterAbstract letter;
public IsisEnvelopeEvent(IsisEventLetterAbstract ev) {
super(ev.getTarget());
this.letter = ev;
}
public IsisEventLetterAbstract getLetter() {
return letter;
}
/**
* Opens the event, checks the event is an {@link org.apache.isis.viewer.wicket.model.hints.IsisEnvelopeEvent envelope} (event),
* fetches the {@link org.apache.isis.viewer.wicket.model.hints.IsisEventLetterAbstract letter} (event) inside, and
* returns if the letter is of the required type.
*
* <p>
* Otherwise returns <tt>null</tt>.
* </p>
*/
public static <T> T openLetter(final IEvent<?> event, Class<T> letterEventClass) {
if(!(event.getPayload() instanceof IsisEnvelopeEvent)) {
return null;
}
final IsisEnvelopeEvent ev = (IsisEnvelopeEvent) event.getPayload();
final IsisEventLetterAbstract letter = ev.getLetter();
if(letter == null) {
return null;
}
if(!letterEventClass.isAssignableFrom(letter.getClass())) {
return null;
}
return letterEventClass.cast(letter);
}
}