1 /* 2 * Copyright (C) 2016 The Android Open Source Project 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 * http://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 17 package com.android.dialer.app.contactinfo; 18 19 import android.os.Bundle; 20 import android.support.annotation.NonNull; 21 import android.support.v4.app.Fragment; 22 import android.support.v4.app.FragmentManager; 23 import android.support.v7.app.AppCompatActivity; 24 import com.android.dialer.phonenumbercache.ContactInfo; 25 import com.android.dialer.util.ExpirableCache; 26 27 /** 28 * Fragment without any UI whose purpose is to retain an instance of {@link ExpirableCache} across 29 * configuration change through the use of {@link #setRetainInstance(boolean)}. This is done as 30 * opposed to implementing {@link android.os.Parcelable} as it is a less widespread change. 31 */ 32 public class ExpirableCacheHeadlessFragment extends Fragment { 33 34 private static final String FRAGMENT_TAG = "ExpirableCacheHeadlessFragment"; 35 private static final int CONTACT_INFO_CACHE_SIZE = 100; 36 37 private ExpirableCache<NumberWithCountryIso, ContactInfo> retainedCache; 38 39 @NonNull 40 public static ExpirableCacheHeadlessFragment attach(@NonNull AppCompatActivity parentActivity) { 41 return attach(parentActivity.getSupportFragmentManager()); 42 } 43 44 @NonNull 45 private static ExpirableCacheHeadlessFragment attach(FragmentManager fragmentManager) { 46 ExpirableCacheHeadlessFragment fragment = 47 (ExpirableCacheHeadlessFragment) fragmentManager.findFragmentByTag(FRAGMENT_TAG); 48 if (fragment == null) { 49 fragment = new ExpirableCacheHeadlessFragment(); 50 // Allowing state loss since in rare cases this is called after activity's state is saved and 51 // it's fine if the cache is lost. 52 fragmentManager.beginTransaction().add(fragment, FRAGMENT_TAG).commitNowAllowingStateLoss(); 53 } 54 return fragment; 55 } 56 57 @Override 58 public void onCreate(Bundle savedInstanceState) { 59 super.onCreate(savedInstanceState); 60 retainedCache = ExpirableCache.create(CONTACT_INFO_CACHE_SIZE); 61 setRetainInstance(true); 62 } 63 64 public ExpirableCache<NumberWithCountryIso, ContactInfo> getRetainedCache() { 65 return retainedCache; 66 } 67 } 68
