| /* |
| * Copyright (C) 2013 The Android Open Source Project |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| package com.android.documentsui.model; |
| |
| import android.content.ContentResolver; |
| import android.provider.DocumentsProvider; |
| |
| import java.io.DataInputStream; |
| import java.io.DataOutputStream; |
| import java.io.FileNotFoundException; |
| import java.io.IOException; |
| import java.net.ProtocolException; |
| import java.util.Collection; |
| import java.util.LinkedList; |
| |
| /** |
| * Representation of a stack of {@link DocumentInfo}, usually the result of a |
| * user-driven traversal. |
| */ |
| public class DocumentStack extends LinkedList<DocumentInfo> implements Durable { |
| private static final int VERSION_INIT = 1; |
| private static final int VERSION_ADD_ROOT = 2; |
| |
| public RootInfo root; |
| |
| public String getTitle() { |
| if (size() == 1 && root != null) { |
| return root.title; |
| } else if (size() > 1) { |
| return peek().displayName; |
| } else { |
| return null; |
| } |
| } |
| |
| public boolean isRecents() { |
| return size() == 0; |
| } |
| |
| public void updateRoot(Collection<RootInfo> matchingRoots) throws FileNotFoundException { |
| for (RootInfo root : matchingRoots) { |
| if (root.equals(this.root)) { |
| this.root = root; |
| return; |
| } |
| } |
| throw new FileNotFoundException("Failed to find matching root for " + root); |
| } |
| |
| /** |
| * Update a possibly stale restored stack against a live |
| * {@link DocumentsProvider}. |
| */ |
| public void updateDocuments(ContentResolver resolver) throws FileNotFoundException { |
| for (DocumentInfo info : this) { |
| info.updateSelf(resolver); |
| } |
| } |
| |
| /** |
| * Build key that uniquely identifies this stack. It omits most of the raw |
| * details included in {@link #write(DataOutputStream)}, since they change |
| * too regularly to be used as a key. |
| */ |
| public String buildKey() { |
| final StringBuilder builder = new StringBuilder(); |
| if (root != null) { |
| builder.append(root.authority).append('#'); |
| builder.append(root.rootId).append('#'); |
| } else { |
| builder.append("[null]").append('#'); |
| } |
| for (DocumentInfo doc : this) { |
| builder.append(doc.documentId).append('#'); |
| } |
| return builder.toString(); |
| } |
| |
| @Override |
| public void reset() { |
| clear(); |
| root = null; |
| } |
| |
| @Override |
| public void read(DataInputStream in) throws IOException { |
| final int version = in.readInt(); |
| switch (version) { |
| case VERSION_INIT: |
| throw new ProtocolException("Ignored upgrade"); |
| case VERSION_ADD_ROOT: |
| if (in.readBoolean()) { |
| root = new RootInfo(); |
| root.read(in); |
| } |
| final int size = in.readInt(); |
| for (int i = 0; i < size; i++) { |
| final DocumentInfo doc = new DocumentInfo(); |
| doc.read(in); |
| add(doc); |
| } |
| break; |
| default: |
| throw new ProtocolException("Unknown version " + version); |
| } |
| } |
| |
| @Override |
| public void write(DataOutputStream out) throws IOException { |
| out.writeInt(VERSION_ADD_ROOT); |
| if (root != null) { |
| out.writeBoolean(true); |
| root.write(out); |
| } else { |
| out.writeBoolean(false); |
| } |
| final int size = size(); |
| out.writeInt(size); |
| for (int i = 0; i < size; i++) { |
| final DocumentInfo doc = get(i); |
| doc.write(out); |
| } |
| } |
| } |