// Copyright (C) 2012 The Android Open Source Project // // 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.gerrit.client.ui; public class ListenableOldValue<T> extends ListenableValue<T> { private T oldValue; public T getOld() { return oldValue; } public void set(final T value) { try { oldValue = get(); super.set(value); } finally { oldValue = null; // allow it to be gced before the next event } } }