1559b5e8554651ffc9f9cc639f8e363b9494fc98aGeorge Mount/* 2559b5e8554651ffc9f9cc639f8e363b9494fc98aGeorge Mount * Copyright (C) 2009 The Android Open Source Project 3559b5e8554651ffc9f9cc639f8e363b9494fc98aGeorge Mount * 4559b5e8554651ffc9f9cc639f8e363b9494fc98aGeorge Mount * Licensed under the Apache License, Version 2.0 (the "License"); 5559b5e8554651ffc9f9cc639f8e363b9494fc98aGeorge Mount * you may not use this file except in compliance with the License. 6559b5e8554651ffc9f9cc639f8e363b9494fc98aGeorge Mount * You may obtain a copy of the License at 7559b5e8554651ffc9f9cc639f8e363b9494fc98aGeorge Mount * 8559b5e8554651ffc9f9cc639f8e363b9494fc98aGeorge Mount * http://www.apache.org/licenses/LICENSE-2.0 9559b5e8554651ffc9f9cc639f8e363b9494fc98aGeorge Mount * 10559b5e8554651ffc9f9cc639f8e363b9494fc98aGeorge Mount * Unless required by applicable law or agreed to in writing, software 11559b5e8554651ffc9f9cc639f8e363b9494fc98aGeorge Mount * distributed under the License is distributed on an "AS IS" BASIS, 12559b5e8554651ffc9f9cc639f8e363b9494fc98aGeorge Mount * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13559b5e8554651ffc9f9cc639f8e363b9494fc98aGeorge Mount * See the License for the specific language governing permissions and 14559b5e8554651ffc9f9cc639f8e363b9494fc98aGeorge Mount * limitations under the License. 15559b5e8554651ffc9f9cc639f8e363b9494fc98aGeorge Mount */ 16559b5e8554651ffc9f9cc639f8e363b9494fc98aGeorge Mount 17559b5e8554651ffc9f9cc639f8e363b9494fc98aGeorge Mountpackage android.support.v4.util; 18559b5e8554651ffc9f9cc639f8e363b9494fc98aGeorge Mount 19559b5e8554651ffc9f9cc639f8e363b9494fc98aGeorge Mount/** 20559b5e8554651ffc9f9cc639f8e363b9494fc98aGeorge Mount * Container to ease passing around a tuple of two objects. This object provides a sensible 21559b5e8554651ffc9f9cc639f8e363b9494fc98aGeorge Mount * implementation of equals(), returning true if equals() is true on each of the contained 22559b5e8554651ffc9f9cc639f8e363b9494fc98aGeorge Mount * objects. 23559b5e8554651ffc9f9cc639f8e363b9494fc98aGeorge Mount */ 24559b5e8554651ffc9f9cc639f8e363b9494fc98aGeorge Mountpublic class Pair<F, S> { 25559b5e8554651ffc9f9cc639f8e363b9494fc98aGeorge Mount public final F first; 26559b5e8554651ffc9f9cc639f8e363b9494fc98aGeorge Mount public final S second; 27559b5e8554651ffc9f9cc639f8e363b9494fc98aGeorge Mount 28559b5e8554651ffc9f9cc639f8e363b9494fc98aGeorge Mount /** 29559b5e8554651ffc9f9cc639f8e363b9494fc98aGeorge Mount * Constructor for a Pair. 30559b5e8554651ffc9f9cc639f8e363b9494fc98aGeorge Mount * 31559b5e8554651ffc9f9cc639f8e363b9494fc98aGeorge Mount * @param first the first object in the Pair 32559b5e8554651ffc9f9cc639f8e363b9494fc98aGeorge Mount * @param second the second object in the pair 33559b5e8554651ffc9f9cc639f8e363b9494fc98aGeorge Mount */ 34559b5e8554651ffc9f9cc639f8e363b9494fc98aGeorge Mount public Pair(F first, S second) { 35559b5e8554651ffc9f9cc639f8e363b9494fc98aGeorge Mount this.first = first; 36559b5e8554651ffc9f9cc639f8e363b9494fc98aGeorge Mount this.second = second; 37559b5e8554651ffc9f9cc639f8e363b9494fc98aGeorge Mount } 38559b5e8554651ffc9f9cc639f8e363b9494fc98aGeorge Mount 39559b5e8554651ffc9f9cc639f8e363b9494fc98aGeorge Mount /** 40559b5e8554651ffc9f9cc639f8e363b9494fc98aGeorge Mount * Checks the two objects for equality by delegating to their respective 41559b5e8554651ffc9f9cc639f8e363b9494fc98aGeorge Mount * {@link Object#equals(Object)} methods. 42559b5e8554651ffc9f9cc639f8e363b9494fc98aGeorge Mount * 43559b5e8554651ffc9f9cc639f8e363b9494fc98aGeorge Mount * @param o the {@link Pair} to which this one is to be checked for equality 44559b5e8554651ffc9f9cc639f8e363b9494fc98aGeorge Mount * @return true if the underlying objects of the Pair are both considered 45559b5e8554651ffc9f9cc639f8e363b9494fc98aGeorge Mount * equal 46559b5e8554651ffc9f9cc639f8e363b9494fc98aGeorge Mount */ 47559b5e8554651ffc9f9cc639f8e363b9494fc98aGeorge Mount @Override 48559b5e8554651ffc9f9cc639f8e363b9494fc98aGeorge Mount public boolean equals(Object o) { 49559b5e8554651ffc9f9cc639f8e363b9494fc98aGeorge Mount if (!(o instanceof Pair)) { 50559b5e8554651ffc9f9cc639f8e363b9494fc98aGeorge Mount return false; 51559b5e8554651ffc9f9cc639f8e363b9494fc98aGeorge Mount } 52559b5e8554651ffc9f9cc639f8e363b9494fc98aGeorge Mount Pair<?, ?> p = (Pair<?, ?>) o; 53559b5e8554651ffc9f9cc639f8e363b9494fc98aGeorge Mount return objectsEqual(p.first, first) && objectsEqual(p.second, second); 54559b5e8554651ffc9f9cc639f8e363b9494fc98aGeorge Mount } 55559b5e8554651ffc9f9cc639f8e363b9494fc98aGeorge Mount 56559b5e8554651ffc9f9cc639f8e363b9494fc98aGeorge Mount private static boolean objectsEqual(Object a, Object b) { 57559b5e8554651ffc9f9cc639f8e363b9494fc98aGeorge Mount return a == b || (a != null && a.equals(b)); 58559b5e8554651ffc9f9cc639f8e363b9494fc98aGeorge Mount } 59559b5e8554651ffc9f9cc639f8e363b9494fc98aGeorge Mount 60559b5e8554651ffc9f9cc639f8e363b9494fc98aGeorge Mount /** 61559b5e8554651ffc9f9cc639f8e363b9494fc98aGeorge Mount * Compute a hash code using the hash codes of the underlying objects 62559b5e8554651ffc9f9cc639f8e363b9494fc98aGeorge Mount * 63559b5e8554651ffc9f9cc639f8e363b9494fc98aGeorge Mount * @return a hashcode of the Pair 64559b5e8554651ffc9f9cc639f8e363b9494fc98aGeorge Mount */ 65559b5e8554651ffc9f9cc639f8e363b9494fc98aGeorge Mount @Override 66559b5e8554651ffc9f9cc639f8e363b9494fc98aGeorge Mount public int hashCode() { 67559b5e8554651ffc9f9cc639f8e363b9494fc98aGeorge Mount return (first == null ? 0 : first.hashCode()) ^ (second == null ? 0 : second.hashCode()); 68559b5e8554651ffc9f9cc639f8e363b9494fc98aGeorge Mount } 69559b5e8554651ffc9f9cc639f8e363b9494fc98aGeorge Mount 70559b5e8554651ffc9f9cc639f8e363b9494fc98aGeorge Mount /** 71559b5e8554651ffc9f9cc639f8e363b9494fc98aGeorge Mount * Convenience method for creating an appropriately typed pair. 72559b5e8554651ffc9f9cc639f8e363b9494fc98aGeorge Mount * @param a the first object in the Pair 73559b5e8554651ffc9f9cc639f8e363b9494fc98aGeorge Mount * @param b the second object in the pair 74559b5e8554651ffc9f9cc639f8e363b9494fc98aGeorge Mount * @return a Pair that is templatized with the types of a and b 75559b5e8554651ffc9f9cc639f8e363b9494fc98aGeorge Mount */ 76559b5e8554651ffc9f9cc639f8e363b9494fc98aGeorge Mount public static <A, B> Pair <A, B> create(A a, B b) { 77559b5e8554651ffc9f9cc639f8e363b9494fc98aGeorge Mount return new Pair<A, B>(a, b); 78559b5e8554651ffc9f9cc639f8e363b9494fc98aGeorge Mount } 79559b5e8554651ffc9f9cc639f8e363b9494fc98aGeorge Mount} 80