1 /* 2 * Copyright 2021 Google LLC 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * https://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 package com.google.android.enterprise.connectedapps.parcelablewrappers; 17 18 import android.os.Parcel; 19 import android.os.Parcelable; 20 import android.util.Pair; 21 import com.google.android.enterprise.connectedapps.internal.Bundler; 22 import com.google.android.enterprise.connectedapps.internal.BundlerType; 23 24 /** Wrapper for reading & writing {@link Pair} instances from and to {@link Parcel} instances. */ 25 public class ParcelablePair<F, S> implements Parcelable { 26 27 private static final int NULL = -1; 28 private static final int NOT_NULL = 1; 29 30 private final Bundler bundler; 31 private final BundlerType type; 32 private final Pair<F, S> pair; 33 34 /** 35 * Create a wrapper for a given pair. 36 * 37 * <p>The passed in {@link Bundler} must be capable of bundling {@code E} and {@code F}. 38 */ of(Bundler bundler, BundlerType type, Pair<F, S> pair)39 public static <F, S> ParcelablePair<F, S> of(Bundler bundler, BundlerType type, Pair<F, S> pair) { 40 return new ParcelablePair<>(bundler, type, pair); 41 } 42 get()43 public Pair<F, S> get() { 44 return pair; 45 } 46 ParcelablePair(Bundler bundler, BundlerType type, Pair<F, S> pair)47 private ParcelablePair(Bundler bundler, BundlerType type, Pair<F, S> pair) { 48 if (bundler == null || type == null) { 49 throw new NullPointerException(); 50 } 51 this.bundler = bundler; 52 this.type = type; 53 this.pair = pair; 54 } 55 ParcelablePair(Parcel in)56 private ParcelablePair(Parcel in) { 57 bundler = in.readParcelable(Bundler.class.getClassLoader()); 58 int present = in.readInt(); 59 60 if (present == NULL) { 61 type = null; 62 pair = null; 63 return; 64 } 65 66 type = (BundlerType) in.readParcelable(Bundler.class.getClassLoader()); 67 BundlerType fType = type.typeArguments().get(0); 68 BundlerType sType = type.typeArguments().get(1); 69 70 @SuppressWarnings("unchecked") 71 F first = (F) bundler.readFromParcel(in, fType); 72 @SuppressWarnings("unchecked") 73 S second = (S) bundler.readFromParcel(in, sType); 74 75 pair = new Pair<>(first, second); 76 } 77 78 @Override writeToParcel(Parcel dest, int flags)79 public void writeToParcel(Parcel dest, int flags) { 80 dest.writeParcelable(bundler, flags); 81 82 if (pair == null) { 83 dest.writeInt(NULL); 84 return; 85 } 86 87 dest.writeInt(NOT_NULL); 88 dest.writeParcelable(type, flags); 89 90 BundlerType fType = type.typeArguments().get(0); 91 BundlerType sType = type.typeArguments().get(1); 92 93 bundler.writeToParcel(dest, pair.first, fType, flags); 94 bundler.writeToParcel(dest, pair.second, sType, flags); 95 } 96 97 @Override describeContents()98 public int describeContents() { 99 return 0; 100 } 101 102 @SuppressWarnings("rawtypes") 103 public static final Creator<ParcelablePair> CREATOR = 104 new Creator<ParcelablePair>() { 105 @Override 106 public ParcelablePair createFromParcel(Parcel in) { 107 return new ParcelablePair(in); 108 } 109 110 @Override 111 public ParcelablePair[] newArray(int size) { 112 return new ParcelablePair[size]; 113 } 114 }; 115 } 116