1 /* 2 * Copyright (C) 2013 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.model; 18 19 import android.content.ContentResolver; 20 import android.os.Parcel; 21 import android.os.Parcelable; 22 import android.provider.DocumentsProvider; 23 24 import java.io.DataInputStream; 25 import java.io.DataOutputStream; 26 import java.io.FileNotFoundException; 27 import java.io.IOException; 28 import java.net.ProtocolException; 29 import java.util.Collection; 30 import java.util.LinkedList; 31 32 /** 33 * Representation of a stack of {@link DocumentInfo}, usually the result of a 34 * user-driven traversal. 35 */ 36 public class DocumentStack extends LinkedList<DocumentInfo> implements Durable, Parcelable { 37 private static final int VERSION_INIT = 1; 38 private static final int VERSION_ADD_ROOT = 2; 39 40 public RootInfo root; 41 getTitle()42 public String getTitle() { 43 if (size() == 1 && root != null) { 44 return root.title; 45 } else if (size() > 1) { 46 return peek().displayName; 47 } else { 48 return null; 49 } 50 } 51 isRecents()52 public boolean isRecents() { 53 return size() == 0; 54 } 55 updateRoot(Collection<RootInfo> matchingRoots)56 public void updateRoot(Collection<RootInfo> matchingRoots) throws FileNotFoundException { 57 for (RootInfo root : matchingRoots) { 58 if (root.equals(this.root)) { 59 this.root = root; 60 return; 61 } 62 } 63 throw new FileNotFoundException("Failed to find matching root for " + root); 64 } 65 66 /** 67 * Update a possibly stale restored stack against a live 68 * {@link DocumentsProvider}. 69 */ updateDocuments(ContentResolver resolver)70 public void updateDocuments(ContentResolver resolver) throws FileNotFoundException { 71 for (DocumentInfo info : this) { 72 info.updateSelf(resolver); 73 } 74 } 75 76 /** 77 * Build key that uniquely identifies this stack. It omits most of the raw 78 * details included in {@link #write(DataOutputStream)}, since they change 79 * too regularly to be used as a key. 80 */ buildKey()81 public String buildKey() { 82 final StringBuilder builder = new StringBuilder(); 83 if (root != null) { 84 builder.append(root.authority).append('#'); 85 builder.append(root.rootId).append('#'); 86 } else { 87 builder.append("[null]").append('#'); 88 } 89 for (DocumentInfo doc : this) { 90 builder.append(doc.documentId).append('#'); 91 } 92 return builder.toString(); 93 } 94 95 @Override reset()96 public void reset() { 97 clear(); 98 root = null; 99 } 100 101 @Override read(DataInputStream in)102 public void read(DataInputStream in) throws IOException { 103 final int version = in.readInt(); 104 switch (version) { 105 case VERSION_INIT: 106 throw new ProtocolException("Ignored upgrade"); 107 case VERSION_ADD_ROOT: 108 if (in.readBoolean()) { 109 root = new RootInfo(); 110 root.read(in); 111 } 112 final int size = in.readInt(); 113 for (int i = 0; i < size; i++) { 114 final DocumentInfo doc = new DocumentInfo(); 115 doc.read(in); 116 add(doc); 117 } 118 break; 119 default: 120 throw new ProtocolException("Unknown version " + version); 121 } 122 } 123 124 @Override write(DataOutputStream out)125 public void write(DataOutputStream out) throws IOException { 126 out.writeInt(VERSION_ADD_ROOT); 127 if (root != null) { 128 out.writeBoolean(true); 129 root.write(out); 130 } else { 131 out.writeBoolean(false); 132 } 133 final int size = size(); 134 out.writeInt(size); 135 for (int i = 0; i < size; i++) { 136 final DocumentInfo doc = get(i); 137 doc.write(out); 138 } 139 } 140 141 @Override describeContents()142 public int describeContents() { 143 return 0; 144 } 145 146 @Override writeToParcel(Parcel dest, int flags)147 public void writeToParcel(Parcel dest, int flags) { 148 DurableUtils.writeToParcel(dest, this); 149 } 150 151 public static final Creator<DocumentStack> CREATOR = new Creator<DocumentStack>() { 152 @Override 153 public DocumentStack createFromParcel(Parcel in) { 154 final DocumentStack stack = new DocumentStack(); 155 DurableUtils.readFromParcel(in, stack); 156 return stack; 157 } 158 159 @Override 160 public DocumentStack[] newArray(int size) { 161 return new DocumentStack[size]; 162 } 163 }; 164 } 165