1 /* 2 * Copyright (C) 2020 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.documentsui.sidebar; 18 19 import static androidx.core.util.Preconditions.checkNotNull; 20 21 import com.android.documentsui.base.UserId; 22 23 import com.google.common.collect.ArrayListMultimap; 24 import com.google.common.collect.Lists; 25 import com.google.common.collect.Multimap; 26 27 import java.util.Collection; 28 import java.util.Collections; 29 import java.util.List; 30 31 /** 32 * A builder to build a list of root items to be displayed on the {@link RootsFragment}. The list 33 * should contain roots that the were added to this builder, except for those which support 34 * cross-profile. 35 * 36 * <p>If the root supports cross-profile, the list would only contain the root of the 37 * selected user. 38 * 39 * <p>If no root of the selected user was added but that of the other user was added, 40 * a stub root of that root for the selected user will be generated. 41 * 42 * <p>The builder group the roots using {@link Item#stringId} as key. 43 * 44 * <p>For example, if these items were added to the builder: itemA[0], itemA[10], itemB[0], 45 * itemC[10], itemX[0],itemY[10] where root itemX, itemY do not support cross profile. 46 * 47 * <p>When the selected user is user 0, {@link #getList()} returns itemA[0], itemB[0], 48 * stubC[0], itemX[0], itemY[10]. 49 * 50 * <p>When the selected user is user 10, {@link #getList()} returns itemA[10], stubB[10], 51 * itemC[10], itemX[0], itemY[10]. 52 */ 53 class RootItemListBuilder { 54 private final UserId mSelectedUser; 55 private final List<UserId> mUserIds; 56 private final Multimap<String, RootItem> mItems = ArrayListMultimap.create(); 57 RootItemListBuilder(UserId selectedUser, List<UserId> userIds)58 RootItemListBuilder(UserId selectedUser, List<UserId> userIds) { 59 mSelectedUser = checkNotNull(selectedUser); 60 mUserIds = userIds; 61 } 62 add(RootItem item)63 public void add(RootItem item) { 64 mItems.put(item.stringId, item); 65 } 66 67 /** 68 * Returns a lists of root items generated from the provided root items. 69 */ getList()70 public List<RootItem> getList() { 71 if (mUserIds.size() < 2) { 72 // If we only have one user, simply return everything that has added to this builder. 73 return Lists.newArrayList(mItems.values()); 74 } 75 List<RootItem> result = Lists.newArrayList(); 76 // Iterates through items by item.stringId. 77 for (Collection<RootItem> items : mItems.asMap().values()) { 78 result.addAll(getRootItemForSelectedUser(items)); 79 } 80 return result; 81 } 82 getRootItemForSelectedUser(Collection<RootItem> items)83 private Collection<RootItem> getRootItemForSelectedUser(Collection<RootItem> items) { 84 RootItem testRootItem = items.iterator().next(); 85 if (!testRootItem.root.supportsCrossProfile()) { 86 // If the root does not support cross-profile, return the entire list. 87 return items; 88 } 89 90 // If the root supports cross-profile, we return the added root or create a stub root if 91 // it was not added for the selected user. 92 for (RootItem item : items) { 93 if (item.userId.equals(mSelectedUser)) { 94 // If the item has and return the item if it is already in the items list. 95 return Collections.singletonList(item); 96 } 97 } 98 99 return Collections.singletonList(RootItem.createStubItem(testRootItem, mSelectedUser)); 100 } 101 } 102