| /* |
| * 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; |
| } |
| } |