com.google.gwt.activity.shared.CachingActivityMapper Maven / Gradle / Ivy
/*
* Copyright 2010 Google Inc.
*
* 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 com.google.gwt.activity.shared;
import com.google.gwt.place.shared.Place;
/**
* Wraps another {@link ActivityMapper} and caches the last activity it
* returned, to be re-used if we see the same place twice.
*/
public class CachingActivityMapper implements ActivityMapper {
private final ActivityMapper wrapped;
private Place lastPlace;
private Activity lastActivity;
/**
* Constructs a CachingActivityMapper object.
*
* @param wrapped an ActivityMapper object
*/
public CachingActivityMapper(ActivityMapper wrapped) {
this.wrapped = wrapped;
}
public Activity getActivity(Place place) {
if (!place.equals(lastPlace)) {
lastPlace = place;
lastActivity = wrapped.getActivity(place);
}
return lastActivity;
}
}