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.documentsui;
18 
19 import android.app.Activity;
20 import android.net.Uri;
21 import android.provider.DocumentsContract;
22 import android.provider.DocumentsContract.Path;
23 import android.util.Log;
24 
25 import androidx.annotation.Nullable;
26 
27 import com.android.documentsui.base.DocumentInfo;
28 import com.android.documentsui.base.DocumentStack;
29 import com.android.documentsui.base.PairedTask;
30 import com.android.documentsui.base.RootInfo;
31 import com.android.documentsui.base.UserId;
32 import com.android.documentsui.roots.ProvidersAccess;
33 
34 import java.util.List;
35 
36 /**
37  * Loads {@link DocumentStack} for given document. It provides its best effort to find the path of
38  * the given document.
39  *
40  * If it fails to load correct path it calls callback with different result
41  * depending on the nullness of given root. If given root is null it calls callback with null. If
42  * given root is not null it calls callback with a {@link DocumentStack} as if the given doc lives
43  * under the root doc.
44  */
45 public class LoadDocStackTask extends PairedTask<Activity, Uri, DocumentStack> {
46     private static final String TAG = "LoadDocStackTask";
47 
48     private final ProvidersAccess mProviders;
49     private final DocumentsAccess mDocs;
50     private final UserId mUserId;
51     private final LoadDocStackCallback mCallback;
52 
LoadDocStackTask( Activity activity, ProvidersAccess providers, DocumentsAccess docs, UserId userId, LoadDocStackCallback callback)53     public LoadDocStackTask(
54             Activity activity,
55             ProvidersAccess providers,
56             DocumentsAccess docs,
57             UserId userId,
58             LoadDocStackCallback callback) {
59         super(activity);
60         mProviders = providers;
61         mDocs = docs;
62         mUserId = userId;
63         mCallback = callback;
64     }
65 
66     @Override
run(Uri... uris)67     public @Nullable DocumentStack run(Uri... uris) {
68         if (mDocs.isDocumentUri(uris[0])) {
69             final Uri docUri;
70             if (DocumentsContract.isTreeUri(uris[0])) {
71                 // Reconstruct tree URI into a plain document URI so that we can get the full path
72                 // to the root.
73                 final String docId = DocumentsContract.getDocumentId(uris[0]);
74                 docUri = DocumentsContract.buildDocumentUri(uris[0].getAuthority(), docId);
75             } else {
76                 docUri = uris[0];
77             }
78 
79             try {
80                 final Path path = mDocs.findDocumentPath(docUri, mUserId);
81                 if (path != null) {
82                     return buildStack(docUri.getAuthority(), path);
83                 } else {
84                     Log.i(TAG, "Remote provider doesn't support findDocumentPath.");
85                 }
86             } catch (Exception e) {
87                 Log.e(TAG, "Failed to build document stack for uri: " + docUri, e);
88             }
89         }
90 
91         return null;
92     }
93 
94     @Override
finish(@ullable DocumentStack stack)95     public void finish(@Nullable DocumentStack stack){
96         mCallback.onDocumentStackLoaded(stack);
97     }
98 
buildStack(String authority, Path path)99     private DocumentStack buildStack(String authority, Path path) throws Exception {
100         final String rootId = path.getRootId();
101         if (rootId == null) {
102             throw new IllegalStateException("Provider doesn't provider root id.");
103         }
104 
105         RootInfo root = mProviders.getRootOneshot(mUserId, authority, path.getRootId());
106         if (root == null) {
107             throw new IllegalStateException(
108                     "Failed to load root on user " + root.userId + " for authority: " + authority
109                             + " and root ID: " + path.getRootId() + ".");
110         }
111 
112         List<DocumentInfo> docs = mDocs.getDocuments(root.userId, authority, path.getPath());
113 
114         return new DocumentStack(root, docs);
115     }
116 
117     @FunctionalInterface
118     public interface LoadDocStackCallback {
onDocumentStackLoaded(@ullable DocumentStack stack)119         void onDocumentStackLoaded(@Nullable DocumentStack stack);
120     }
121 }
122