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 android.provider;
18 
19 import static android.net.TrafficStats.KB_IN_BYTES;
20 import static android.system.OsConstants.SEEK_SET;
21 
22 import android.content.ContentProviderClient;
23 import android.content.ContentResolver;
24 import android.content.Context;
25 import android.content.Intent;
26 import android.content.pm.ResolveInfo;
27 import android.content.res.AssetFileDescriptor;
28 import android.database.Cursor;
29 import android.graphics.Bitmap;
30 import android.graphics.BitmapFactory;
31 import android.graphics.Matrix;
32 import android.graphics.Point;
33 import android.media.ExifInterface;
34 import android.net.Uri;
35 import android.os.Bundle;
36 import android.os.CancellationSignal;
37 import android.os.OperationCanceledException;
38 import android.os.ParcelFileDescriptor;
39 import android.os.ParcelFileDescriptor.OnCloseListener;
40 import android.os.RemoteException;
41 import android.system.ErrnoException;
42 import android.system.Os;
43 import android.util.Log;
44 
45 import libcore.io.IoUtils;
46 
47 import java.io.BufferedInputStream;
48 import java.io.File;
49 import java.io.FileDescriptor;
50 import java.io.FileInputStream;
51 import java.io.FileNotFoundException;
52 import java.io.IOException;
53 import java.util.List;
54 
55 /**
56  * Defines the contract between a documents provider and the platform.
57  * <p>
58  * To create a document provider, extend {@link DocumentsProvider}, which
59  * provides a foundational implementation of this contract.
60  * <p>
61  * All client apps must hold a valid URI permission grant to access documents,
62  * typically issued when a user makes a selection through
63  * {@link Intent#ACTION_OPEN_DOCUMENT}, {@link Intent#ACTION_CREATE_DOCUMENT},
64  * or {@link Intent#ACTION_OPEN_DOCUMENT_TREE}.
65  *
66  * @see DocumentsProvider
67  */
68 public final class DocumentsContract {
69     private static final String TAG = "Documents";
70 
71     // content://com.example/root/
72     // content://com.example/root/sdcard/
73     // content://com.example/root/sdcard/recent/
74     // content://com.example/root/sdcard/search/?query=pony
75     // content://com.example/document/12/
76     // content://com.example/document/12/children/
77     // content://com.example/tree/12/document/24/
78     // content://com.example/tree/12/document/24/children/
79 
DocumentsContract()80     private DocumentsContract() {
81     }
82 
83     /**
84      * Intent action used to identify {@link DocumentsProvider} instances. This
85      * is used in the {@code <intent-filter>} of a {@code <provider>}.
86      */
87     public static final String PROVIDER_INTERFACE = "android.content.action.DOCUMENTS_PROVIDER";
88 
89     /** {@hide} */
90     public static final String EXTRA_PACKAGE_NAME = "android.content.extra.PACKAGE_NAME";
91 
92     /** {@hide} */
93     public static final String EXTRA_SHOW_ADVANCED = "android.content.extra.SHOW_ADVANCED";
94 
95     /**
96      * Included in {@link AssetFileDescriptor#getExtras()} when returned
97      * thumbnail should be rotated.
98      *
99      * @see MediaStore.Images.ImageColumns#ORIENTATION
100      * @hide
101      */
102     public static final String EXTRA_ORIENTATION = "android.content.extra.ORIENTATION";
103 
104     /** {@hide} */
105     public static final String ACTION_MANAGE_ROOT = "android.provider.action.MANAGE_ROOT";
106     /** {@hide} */
107     public static final String ACTION_MANAGE_DOCUMENT = "android.provider.action.MANAGE_DOCUMENT";
108 
109     /**
110      * Buffer is large enough to rewind past any EXIF headers.
111      */
112     private static final int THUMBNAIL_BUFFER_SIZE = (int) (128 * KB_IN_BYTES);
113 
114     /**
115      * Constants related to a document, including {@link Cursor} column names
116      * and flags.
117      * <p>
118      * A document can be either an openable stream (with a specific MIME type),
119      * or a directory containing additional documents (with the
120      * {@link #MIME_TYPE_DIR} MIME type). A directory represents the top of a
121      * subtree containing zero or more documents, which can recursively contain
122      * even more documents and directories.
123      * <p>
124      * All columns are <em>read-only</em> to client applications.
125      */
126     public final static class Document {
Document()127         private Document() {
128         }
129 
130         /**
131          * Unique ID of a document. This ID is both provided by and interpreted
132          * by a {@link DocumentsProvider}, and should be treated as an opaque
133          * value by client applications. This column is required.
134          * <p>
135          * Each document must have a unique ID within a provider, but that
136          * single document may be included as a child of multiple directories.
137          * <p>
138          * A provider must always return durable IDs, since they will be used to
139          * issue long-term URI permission grants when an application interacts
140          * with {@link Intent#ACTION_OPEN_DOCUMENT} and
141          * {@link Intent#ACTION_CREATE_DOCUMENT}.
142          * <p>
143          * Type: STRING
144          */
145         public static final String COLUMN_DOCUMENT_ID = "document_id";
146 
147         /**
148          * Concrete MIME type of a document. For example, "image/png" or
149          * "application/pdf" for openable files. A document can also be a
150          * directory containing additional documents, which is represented with
151          * the {@link #MIME_TYPE_DIR} MIME type. This column is required.
152          * <p>
153          * Type: STRING
154          *
155          * @see #MIME_TYPE_DIR
156          */
157         public static final String COLUMN_MIME_TYPE = "mime_type";
158 
159         /**
160          * Display name of a document, used as the primary title displayed to a
161          * user. This column is required.
162          * <p>
163          * Type: STRING
164          */
165         public static final String COLUMN_DISPLAY_NAME = OpenableColumns.DISPLAY_NAME;
166 
167         /**
168          * Summary of a document, which may be shown to a user. This column is
169          * optional, and may be {@code null}.
170          * <p>
171          * Type: STRING
172          */
173         public static final String COLUMN_SUMMARY = "summary";
174 
175         /**
176          * Timestamp when a document was last modified, in milliseconds since
177          * January 1, 1970 00:00:00.0 UTC. This column is required, and may be
178          * {@code null} if unknown. A {@link DocumentsProvider} can update this
179          * field using events from {@link OnCloseListener} or other reliable
180          * {@link ParcelFileDescriptor} transports.
181          * <p>
182          * Type: INTEGER (long)
183          *
184          * @see System#currentTimeMillis()
185          */
186         public static final String COLUMN_LAST_MODIFIED = "last_modified";
187 
188         /**
189          * Specific icon resource ID for a document. This column is optional,
190          * and may be {@code null} to use a platform-provided default icon based
191          * on {@link #COLUMN_MIME_TYPE}.
192          * <p>
193          * Type: INTEGER (int)
194          */
195         public static final String COLUMN_ICON = "icon";
196 
197         /**
198          * Flags that apply to a document. This column is required.
199          * <p>
200          * Type: INTEGER (int)
201          *
202          * @see #FLAG_SUPPORTS_WRITE
203          * @see #FLAG_SUPPORTS_DELETE
204          * @see #FLAG_SUPPORTS_THUMBNAIL
205          * @see #FLAG_DIR_PREFERS_GRID
206          * @see #FLAG_DIR_PREFERS_LAST_MODIFIED
207          */
208         public static final String COLUMN_FLAGS = "flags";
209 
210         /**
211          * Size of a document, in bytes, or {@code null} if unknown. This column
212          * is required.
213          * <p>
214          * Type: INTEGER (long)
215          */
216         public static final String COLUMN_SIZE = OpenableColumns.SIZE;
217 
218         /**
219          * MIME type of a document which is a directory that may contain
220          * additional documents.
221          *
222          * @see #COLUMN_MIME_TYPE
223          */
224         public static final String MIME_TYPE_DIR = "vnd.android.document/directory";
225 
226         /**
227          * Flag indicating that a document can be represented as a thumbnail.
228          *
229          * @see #COLUMN_FLAGS
230          * @see DocumentsContract#getDocumentThumbnail(ContentResolver, Uri,
231          *      Point, CancellationSignal)
232          * @see DocumentsProvider#openDocumentThumbnail(String, Point,
233          *      android.os.CancellationSignal)
234          */
235         public static final int FLAG_SUPPORTS_THUMBNAIL = 1;
236 
237         /**
238          * Flag indicating that a document supports writing.
239          * <p>
240          * When a document is opened with {@link Intent#ACTION_OPEN_DOCUMENT},
241          * the calling application is granted both
242          * {@link Intent#FLAG_GRANT_READ_URI_PERMISSION} and
243          * {@link Intent#FLAG_GRANT_WRITE_URI_PERMISSION}. However, the actual
244          * writability of a document may change over time, for example due to
245          * remote access changes. This flag indicates that a document client can
246          * expect {@link ContentResolver#openOutputStream(Uri)} to succeed.
247          *
248          * @see #COLUMN_FLAGS
249          */
250         public static final int FLAG_SUPPORTS_WRITE = 1 << 1;
251 
252         /**
253          * Flag indicating that a document is deletable.
254          *
255          * @see #COLUMN_FLAGS
256          * @see DocumentsContract#deleteDocument(ContentResolver, Uri)
257          * @see DocumentsProvider#deleteDocument(String)
258          */
259         public static final int FLAG_SUPPORTS_DELETE = 1 << 2;
260 
261         /**
262          * Flag indicating that a document is a directory that supports creation
263          * of new files within it. Only valid when {@link #COLUMN_MIME_TYPE} is
264          * {@link #MIME_TYPE_DIR}.
265          *
266          * @see #COLUMN_FLAGS
267          * @see DocumentsProvider#createDocument(String, String, String)
268          */
269         public static final int FLAG_DIR_SUPPORTS_CREATE = 1 << 3;
270 
271         /**
272          * Flag indicating that a directory prefers its contents be shown in a
273          * larger format grid. Usually suitable when a directory contains mostly
274          * pictures. Only valid when {@link #COLUMN_MIME_TYPE} is
275          * {@link #MIME_TYPE_DIR}.
276          *
277          * @see #COLUMN_FLAGS
278          */
279         public static final int FLAG_DIR_PREFERS_GRID = 1 << 4;
280 
281         /**
282          * Flag indicating that a directory prefers its contents be sorted by
283          * {@link #COLUMN_LAST_MODIFIED}. Only valid when
284          * {@link #COLUMN_MIME_TYPE} is {@link #MIME_TYPE_DIR}.
285          *
286          * @see #COLUMN_FLAGS
287          */
288         public static final int FLAG_DIR_PREFERS_LAST_MODIFIED = 1 << 5;
289 
290         /**
291          * Flag indicating that a document can be renamed.
292          *
293          * @see #COLUMN_FLAGS
294          * @see DocumentsContract#renameDocument(ContentProviderClient, Uri,
295          *      String)
296          * @see DocumentsProvider#renameDocument(String, String)
297          */
298         public static final int FLAG_SUPPORTS_RENAME = 1 << 6;
299 
300         /**
301          * Flag indicating that document titles should be hidden when viewing
302          * this directory in a larger format grid. For example, a directory
303          * containing only images may want the image thumbnails to speak for
304          * themselves. Only valid when {@link #COLUMN_MIME_TYPE} is
305          * {@link #MIME_TYPE_DIR}.
306          *
307          * @see #COLUMN_FLAGS
308          * @see #FLAG_DIR_PREFERS_GRID
309          * @hide
310          */
311         public static final int FLAG_DIR_HIDE_GRID_TITLES = 1 << 16;
312     }
313 
314     /**
315      * Constants related to a root of documents, including {@link Cursor} column
316      * names and flags. A root is the start of a tree of documents, such as a
317      * physical storage device, or an account. Each root starts at the directory
318      * referenced by {@link Root#COLUMN_DOCUMENT_ID}, which can recursively
319      * contain both documents and directories.
320      * <p>
321      * All columns are <em>read-only</em> to client applications.
322      */
323     public final static class Root {
Root()324         private Root() {
325         }
326 
327         /**
328          * Unique ID of a root. This ID is both provided by and interpreted by a
329          * {@link DocumentsProvider}, and should be treated as an opaque value
330          * by client applications. This column is required.
331          * <p>
332          * Type: STRING
333          */
334         public static final String COLUMN_ROOT_ID = "root_id";
335 
336         /**
337          * Flags that apply to a root. This column is required.
338          * <p>
339          * Type: INTEGER (int)
340          *
341          * @see #FLAG_LOCAL_ONLY
342          * @see #FLAG_SUPPORTS_CREATE
343          * @see #FLAG_SUPPORTS_RECENTS
344          * @see #FLAG_SUPPORTS_SEARCH
345          */
346         public static final String COLUMN_FLAGS = "flags";
347 
348         /**
349          * Icon resource ID for a root. This column is required.
350          * <p>
351          * Type: INTEGER (int)
352          */
353         public static final String COLUMN_ICON = "icon";
354 
355         /**
356          * Title for a root, which will be shown to a user. This column is
357          * required. For a single storage service surfacing multiple accounts as
358          * different roots, this title should be the name of the service.
359          * <p>
360          * Type: STRING
361          */
362         public static final String COLUMN_TITLE = "title";
363 
364         /**
365          * Summary for this root, which may be shown to a user. This column is
366          * optional, and may be {@code null}. For a single storage service
367          * surfacing multiple accounts as different roots, this summary should
368          * be the name of the account.
369          * <p>
370          * Type: STRING
371          */
372         public static final String COLUMN_SUMMARY = "summary";
373 
374         /**
375          * Document which is a directory that represents the top directory of
376          * this root. This column is required.
377          * <p>
378          * Type: STRING
379          *
380          * @see Document#COLUMN_DOCUMENT_ID
381          */
382         public static final String COLUMN_DOCUMENT_ID = "document_id";
383 
384         /**
385          * Number of bytes available in this root. This column is optional, and
386          * may be {@code null} if unknown or unbounded.
387          * <p>
388          * Type: INTEGER (long)
389          */
390         public static final String COLUMN_AVAILABLE_BYTES = "available_bytes";
391 
392         /**
393          * MIME types supported by this root. This column is optional, and if
394          * {@code null} the root is assumed to support all MIME types. Multiple
395          * MIME types can be separated by a newline. For example, a root
396          * supporting audio might return "audio/*\napplication/x-flac".
397          * <p>
398          * Type: STRING
399          */
400         public static final String COLUMN_MIME_TYPES = "mime_types";
401 
402         /** {@hide} */
403         public static final String MIME_TYPE_ITEM = "vnd.android.document/root";
404 
405         /**
406          * Flag indicating that at least one directory under this root supports
407          * creating content. Roots with this flag will be shown when an
408          * application interacts with {@link Intent#ACTION_CREATE_DOCUMENT}.
409          *
410          * @see #COLUMN_FLAGS
411          */
412         public static final int FLAG_SUPPORTS_CREATE = 1;
413 
414         /**
415          * Flag indicating that this root offers content that is strictly local
416          * on the device. That is, no network requests are made for the content.
417          *
418          * @see #COLUMN_FLAGS
419          * @see Intent#EXTRA_LOCAL_ONLY
420          */
421         public static final int FLAG_LOCAL_ONLY = 1 << 1;
422 
423         /**
424          * Flag indicating that this root can be queried to provide recently
425          * modified documents.
426          *
427          * @see #COLUMN_FLAGS
428          * @see DocumentsContract#buildRecentDocumentsUri(String, String)
429          * @see DocumentsProvider#queryRecentDocuments(String, String[])
430          */
431         public static final int FLAG_SUPPORTS_RECENTS = 1 << 2;
432 
433         /**
434          * Flag indicating that this root supports search.
435          *
436          * @see #COLUMN_FLAGS
437          * @see DocumentsContract#buildSearchDocumentsUri(String, String,
438          *      String)
439          * @see DocumentsProvider#querySearchDocuments(String, String,
440          *      String[])
441          */
442         public static final int FLAG_SUPPORTS_SEARCH = 1 << 3;
443 
444         /**
445          * Flag indicating that this root supports testing parent child
446          * relationships.
447          *
448          * @see #COLUMN_FLAGS
449          * @see DocumentsProvider#isChildDocument(String, String)
450          */
451         public static final int FLAG_SUPPORTS_IS_CHILD = 1 << 4;
452 
453         /**
454          * Flag indicating that this root is currently empty. This may be used
455          * to hide the root when opening documents, but the root will still be
456          * shown when creating documents and {@link #FLAG_SUPPORTS_CREATE} is
457          * also set. If the value of this flag changes, such as when a root
458          * becomes non-empty, you must send a content changed notification for
459          * {@link DocumentsContract#buildRootsUri(String)}.
460          *
461          * @see #COLUMN_FLAGS
462          * @see ContentResolver#notifyChange(Uri,
463          *      android.database.ContentObserver, boolean)
464          * @hide
465          */
466         public static final int FLAG_EMPTY = 1 << 16;
467 
468         /**
469          * Flag indicating that this root should only be visible to advanced
470          * users.
471          *
472          * @see #COLUMN_FLAGS
473          * @hide
474          */
475         public static final int FLAG_ADVANCED = 1 << 17;
476     }
477 
478     /**
479      * Optional boolean flag included in a directory {@link Cursor#getExtras()}
480      * indicating that a document provider is still loading data. For example, a
481      * provider has returned some results, but is still waiting on an
482      * outstanding network request. The provider must send a content changed
483      * notification when loading is finished.
484      *
485      * @see ContentResolver#notifyChange(Uri, android.database.ContentObserver,
486      *      boolean)
487      */
488     public static final String EXTRA_LOADING = "loading";
489 
490     /**
491      * Optional string included in a directory {@link Cursor#getExtras()}
492      * providing an informational message that should be shown to a user. For
493      * example, a provider may wish to indicate that not all documents are
494      * available.
495      */
496     public static final String EXTRA_INFO = "info";
497 
498     /**
499      * Optional string included in a directory {@link Cursor#getExtras()}
500      * providing an error message that should be shown to a user. For example, a
501      * provider may wish to indicate that a network error occurred. The user may
502      * choose to retry, resulting in a new query.
503      */
504     public static final String EXTRA_ERROR = "error";
505 
506     /** {@hide} */
507     public static final String METHOD_CREATE_DOCUMENT = "android:createDocument";
508     /** {@hide} */
509     public static final String METHOD_RENAME_DOCUMENT = "android:renameDocument";
510     /** {@hide} */
511     public static final String METHOD_DELETE_DOCUMENT = "android:deleteDocument";
512 
513     /** {@hide} */
514     public static final String EXTRA_URI = "uri";
515 
516     private static final String PATH_ROOT = "root";
517     private static final String PATH_RECENT = "recent";
518     private static final String PATH_DOCUMENT = "document";
519     private static final String PATH_CHILDREN = "children";
520     private static final String PATH_SEARCH = "search";
521     private static final String PATH_TREE = "tree";
522 
523     private static final String PARAM_QUERY = "query";
524     private static final String PARAM_MANAGE = "manage";
525 
526     /**
527      * Build URI representing the roots of a document provider. When queried, a
528      * provider will return one or more rows with columns defined by
529      * {@link Root}.
530      *
531      * @see DocumentsProvider#queryRoots(String[])
532      */
buildRootsUri(String authority)533     public static Uri buildRootsUri(String authority) {
534         return new Uri.Builder().scheme(ContentResolver.SCHEME_CONTENT)
535                 .authority(authority).appendPath(PATH_ROOT).build();
536     }
537 
538     /**
539      * Build URI representing the given {@link Root#COLUMN_ROOT_ID} in a
540      * document provider.
541      *
542      * @see #getRootId(Uri)
543      */
buildRootUri(String authority, String rootId)544     public static Uri buildRootUri(String authority, String rootId) {
545         return new Uri.Builder().scheme(ContentResolver.SCHEME_CONTENT)
546                 .authority(authority).appendPath(PATH_ROOT).appendPath(rootId).build();
547     }
548 
549     /**
550      * Build URI representing the recently modified documents of a specific root
551      * in a document provider. When queried, a provider will return zero or more
552      * rows with columns defined by {@link Document}.
553      *
554      * @see DocumentsProvider#queryRecentDocuments(String, String[])
555      * @see #getRootId(Uri)
556      */
buildRecentDocumentsUri(String authority, String rootId)557     public static Uri buildRecentDocumentsUri(String authority, String rootId) {
558         return new Uri.Builder().scheme(ContentResolver.SCHEME_CONTENT)
559                 .authority(authority).appendPath(PATH_ROOT).appendPath(rootId)
560                 .appendPath(PATH_RECENT).build();
561     }
562 
563     /**
564      * Build URI representing access to descendant documents of the given
565      * {@link Document#COLUMN_DOCUMENT_ID}.
566      *
567      * @see #getTreeDocumentId(Uri)
568      */
buildTreeDocumentUri(String authority, String documentId)569     public static Uri buildTreeDocumentUri(String authority, String documentId) {
570         return new Uri.Builder().scheme(ContentResolver.SCHEME_CONTENT).authority(authority)
571                 .appendPath(PATH_TREE).appendPath(documentId).build();
572     }
573 
574     /**
575      * Build URI representing the target {@link Document#COLUMN_DOCUMENT_ID} in
576      * a document provider. When queried, a provider will return a single row
577      * with columns defined by {@link Document}.
578      *
579      * @see DocumentsProvider#queryDocument(String, String[])
580      * @see #getDocumentId(Uri)
581      */
buildDocumentUri(String authority, String documentId)582     public static Uri buildDocumentUri(String authority, String documentId) {
583         return new Uri.Builder().scheme(ContentResolver.SCHEME_CONTENT)
584                 .authority(authority).appendPath(PATH_DOCUMENT).appendPath(documentId).build();
585     }
586 
587     /**
588      * Build URI representing the target {@link Document#COLUMN_DOCUMENT_ID} in
589      * a document provider. When queried, a provider will return a single row
590      * with columns defined by {@link Document}.
591      * <p>
592      * However, instead of directly accessing the target document, the returned
593      * URI will leverage access granted through a subtree URI, typically
594      * returned by {@link Intent#ACTION_OPEN_DOCUMENT_TREE}. The target document
595      * must be a descendant (child, grandchild, etc) of the subtree.
596      * <p>
597      * This is typically used to access documents under a user-selected
598      * directory tree, since it doesn't require the user to separately confirm
599      * each new document access.
600      *
601      * @param treeUri the subtree to leverage to gain access to the target
602      *            document. The target directory must be a descendant of this
603      *            subtree.
604      * @param documentId the target document, which the caller may not have
605      *            direct access to.
606      * @see Intent#ACTION_OPEN_DOCUMENT_TREE
607      * @see DocumentsProvider#isChildDocument(String, String)
608      * @see #buildDocumentUri(String, String)
609      */
buildDocumentUriUsingTree(Uri treeUri, String documentId)610     public static Uri buildDocumentUriUsingTree(Uri treeUri, String documentId) {
611         return new Uri.Builder().scheme(ContentResolver.SCHEME_CONTENT)
612                 .authority(treeUri.getAuthority()).appendPath(PATH_TREE)
613                 .appendPath(getTreeDocumentId(treeUri)).appendPath(PATH_DOCUMENT)
614                 .appendPath(documentId).build();
615     }
616 
617     /** {@hide} */
buildDocumentUriMaybeUsingTree(Uri baseUri, String documentId)618     public static Uri buildDocumentUriMaybeUsingTree(Uri baseUri, String documentId) {
619         if (isTreeUri(baseUri)) {
620             return buildDocumentUriUsingTree(baseUri, documentId);
621         } else {
622             return buildDocumentUri(baseUri.getAuthority(), documentId);
623         }
624     }
625 
626     /**
627      * Build URI representing the children of the target directory in a document
628      * provider. When queried, a provider will return zero or more rows with
629      * columns defined by {@link Document}.
630      *
631      * @param parentDocumentId the document to return children for, which must
632      *            be a directory with MIME type of
633      *            {@link Document#MIME_TYPE_DIR}.
634      * @see DocumentsProvider#queryChildDocuments(String, String[], String)
635      * @see #getDocumentId(Uri)
636      */
buildChildDocumentsUri(String authority, String parentDocumentId)637     public static Uri buildChildDocumentsUri(String authority, String parentDocumentId) {
638         return new Uri.Builder().scheme(ContentResolver.SCHEME_CONTENT).authority(authority)
639                 .appendPath(PATH_DOCUMENT).appendPath(parentDocumentId).appendPath(PATH_CHILDREN)
640                 .build();
641     }
642 
643     /**
644      * Build URI representing the children of the target directory in a document
645      * provider. When queried, a provider will return zero or more rows with
646      * columns defined by {@link Document}.
647      * <p>
648      * However, instead of directly accessing the target directory, the returned
649      * URI will leverage access granted through a subtree URI, typically
650      * returned by {@link Intent#ACTION_OPEN_DOCUMENT_TREE}. The target
651      * directory must be a descendant (child, grandchild, etc) of the subtree.
652      * <p>
653      * This is typically used to access documents under a user-selected
654      * directory tree, since it doesn't require the user to separately confirm
655      * each new document access.
656      *
657      * @param treeUri the subtree to leverage to gain access to the target
658      *            document. The target directory must be a descendant of this
659      *            subtree.
660      * @param parentDocumentId the document to return children for, which the
661      *            caller may not have direct access to, and which must be a
662      *            directory with MIME type of {@link Document#MIME_TYPE_DIR}.
663      * @see Intent#ACTION_OPEN_DOCUMENT_TREE
664      * @see DocumentsProvider#isChildDocument(String, String)
665      * @see #buildChildDocumentsUri(String, String)
666      */
buildChildDocumentsUriUsingTree(Uri treeUri, String parentDocumentId)667     public static Uri buildChildDocumentsUriUsingTree(Uri treeUri, String parentDocumentId) {
668         return new Uri.Builder().scheme(ContentResolver.SCHEME_CONTENT)
669                 .authority(treeUri.getAuthority()).appendPath(PATH_TREE)
670                 .appendPath(getTreeDocumentId(treeUri)).appendPath(PATH_DOCUMENT)
671                 .appendPath(parentDocumentId).appendPath(PATH_CHILDREN).build();
672     }
673 
674     /**
675      * Build URI representing a search for matching documents under a specific
676      * root in a document provider. When queried, a provider will return zero or
677      * more rows with columns defined by {@link Document}.
678      *
679      * @see DocumentsProvider#querySearchDocuments(String, String, String[])
680      * @see #getRootId(Uri)
681      * @see #getSearchDocumentsQuery(Uri)
682      */
buildSearchDocumentsUri( String authority, String rootId, String query)683     public static Uri buildSearchDocumentsUri(
684             String authority, String rootId, String query) {
685         return new Uri.Builder().scheme(ContentResolver.SCHEME_CONTENT).authority(authority)
686                 .appendPath(PATH_ROOT).appendPath(rootId).appendPath(PATH_SEARCH)
687                 .appendQueryParameter(PARAM_QUERY, query).build();
688     }
689 
690     /**
691      * Test if the given URI represents a {@link Document} backed by a
692      * {@link DocumentsProvider}.
693      *
694      * @see #buildDocumentUri(String, String)
695      * @see #buildDocumentUriUsingTree(Uri, String)
696      */
isDocumentUri(Context context, Uri uri)697     public static boolean isDocumentUri(Context context, Uri uri) {
698         final List<String> paths = uri.getPathSegments();
699         if (paths.size() == 2 && PATH_DOCUMENT.equals(paths.get(0))) {
700             return isDocumentsProvider(context, uri.getAuthority());
701         }
702         if (paths.size() == 4 && PATH_TREE.equals(paths.get(0))
703                 && PATH_DOCUMENT.equals(paths.get(2))) {
704             return isDocumentsProvider(context, uri.getAuthority());
705         }
706         return false;
707     }
708 
709     /** {@hide} */
isTreeUri(Uri uri)710     public static boolean isTreeUri(Uri uri) {
711         final List<String> paths = uri.getPathSegments();
712         return (paths.size() >= 2 && PATH_TREE.equals(paths.get(0)));
713     }
714 
isDocumentsProvider(Context context, String authority)715     private static boolean isDocumentsProvider(Context context, String authority) {
716         final Intent intent = new Intent(PROVIDER_INTERFACE);
717         final List<ResolveInfo> infos = context.getPackageManager()
718                 .queryIntentContentProviders(intent, 0);
719         for (ResolveInfo info : infos) {
720             if (authority.equals(info.providerInfo.authority)) {
721                 return true;
722             }
723         }
724         return false;
725     }
726 
727     /**
728      * Extract the {@link Root#COLUMN_ROOT_ID} from the given URI.
729      */
getRootId(Uri rootUri)730     public static String getRootId(Uri rootUri) {
731         final List<String> paths = rootUri.getPathSegments();
732         if (paths.size() >= 2 && PATH_ROOT.equals(paths.get(0))) {
733             return paths.get(1);
734         }
735         throw new IllegalArgumentException("Invalid URI: " + rootUri);
736     }
737 
738     /**
739      * Extract the {@link Document#COLUMN_DOCUMENT_ID} from the given URI.
740      *
741      * @see #isDocumentUri(Context, Uri)
742      */
getDocumentId(Uri documentUri)743     public static String getDocumentId(Uri documentUri) {
744         final List<String> paths = documentUri.getPathSegments();
745         if (paths.size() >= 2 && PATH_DOCUMENT.equals(paths.get(0))) {
746             return paths.get(1);
747         }
748         if (paths.size() >= 4 && PATH_TREE.equals(paths.get(0))
749                 && PATH_DOCUMENT.equals(paths.get(2))) {
750             return paths.get(3);
751         }
752         throw new IllegalArgumentException("Invalid URI: " + documentUri);
753     }
754 
755     /**
756      * Extract the via {@link Document#COLUMN_DOCUMENT_ID} from the given URI.
757      */
getTreeDocumentId(Uri documentUri)758     public static String getTreeDocumentId(Uri documentUri) {
759         final List<String> paths = documentUri.getPathSegments();
760         if (paths.size() >= 2 && PATH_TREE.equals(paths.get(0))) {
761             return paths.get(1);
762         }
763         throw new IllegalArgumentException("Invalid URI: " + documentUri);
764     }
765 
766     /**
767      * Extract the search query from a URI built by
768      * {@link #buildSearchDocumentsUri(String, String, String)}.
769      */
getSearchDocumentsQuery(Uri searchDocumentsUri)770     public static String getSearchDocumentsQuery(Uri searchDocumentsUri) {
771         return searchDocumentsUri.getQueryParameter(PARAM_QUERY);
772     }
773 
774     /** {@hide} */
setManageMode(Uri uri)775     public static Uri setManageMode(Uri uri) {
776         return uri.buildUpon().appendQueryParameter(PARAM_MANAGE, "true").build();
777     }
778 
779     /** {@hide} */
isManageMode(Uri uri)780     public static boolean isManageMode(Uri uri) {
781         return uri.getBooleanQueryParameter(PARAM_MANAGE, false);
782     }
783 
784     /**
785      * Return thumbnail representing the document at the given URI. Callers are
786      * responsible for their own in-memory caching.
787      *
788      * @param documentUri document to return thumbnail for, which must have
789      *            {@link Document#FLAG_SUPPORTS_THUMBNAIL} set.
790      * @param size optimal thumbnail size desired. A provider may return a
791      *            thumbnail of a different size, but never more than double the
792      *            requested size.
793      * @param signal signal used to indicate if caller is no longer interested
794      *            in the thumbnail.
795      * @return decoded thumbnail, or {@code null} if problem was encountered.
796      * @see DocumentsProvider#openDocumentThumbnail(String, Point,
797      *      android.os.CancellationSignal)
798      */
getDocumentThumbnail( ContentResolver resolver, Uri documentUri, Point size, CancellationSignal signal)799     public static Bitmap getDocumentThumbnail(
800             ContentResolver resolver, Uri documentUri, Point size, CancellationSignal signal) {
801         final ContentProviderClient client = resolver.acquireUnstableContentProviderClient(
802                 documentUri.getAuthority());
803         try {
804             return getDocumentThumbnail(client, documentUri, size, signal);
805         } catch (Exception e) {
806             if (!(e instanceof OperationCanceledException)) {
807                 Log.w(TAG, "Failed to load thumbnail for " + documentUri + ": " + e);
808             }
809             return null;
810         } finally {
811             ContentProviderClient.releaseQuietly(client);
812         }
813     }
814 
815     /** {@hide} */
getDocumentThumbnail( ContentProviderClient client, Uri documentUri, Point size, CancellationSignal signal)816     public static Bitmap getDocumentThumbnail(
817             ContentProviderClient client, Uri documentUri, Point size, CancellationSignal signal)
818             throws RemoteException, IOException {
819         final Bundle openOpts = new Bundle();
820         openOpts.putParcelable(ContentResolver.EXTRA_SIZE, size);
821 
822         AssetFileDescriptor afd = null;
823         Bitmap bitmap = null;
824         try {
825             afd = client.openTypedAssetFileDescriptor(documentUri, "image/*", openOpts, signal);
826 
827             final FileDescriptor fd = afd.getFileDescriptor();
828             final long offset = afd.getStartOffset();
829 
830             // Try seeking on the returned FD, since it gives us the most
831             // optimal decode path; otherwise fall back to buffering.
832             BufferedInputStream is = null;
833             try {
834                 Os.lseek(fd, offset, SEEK_SET);
835             } catch (ErrnoException e) {
836                 is = new BufferedInputStream(new FileInputStream(fd), THUMBNAIL_BUFFER_SIZE);
837                 is.mark(THUMBNAIL_BUFFER_SIZE);
838             }
839 
840             // We requested a rough thumbnail size, but the remote size may have
841             // returned something giant, so defensively scale down as needed.
842             final BitmapFactory.Options opts = new BitmapFactory.Options();
843             opts.inJustDecodeBounds = true;
844             if (is != null) {
845                 BitmapFactory.decodeStream(is, null, opts);
846             } else {
847                 BitmapFactory.decodeFileDescriptor(fd, null, opts);
848             }
849 
850             final int widthSample = opts.outWidth / size.x;
851             final int heightSample = opts.outHeight / size.y;
852 
853             opts.inJustDecodeBounds = false;
854             opts.inSampleSize = Math.min(widthSample, heightSample);
855             if (is != null) {
856                 is.reset();
857                 bitmap = BitmapFactory.decodeStream(is, null, opts);
858             } else {
859                 try {
860                     Os.lseek(fd, offset, SEEK_SET);
861                 } catch (ErrnoException e) {
862                     e.rethrowAsIOException();
863                 }
864                 bitmap = BitmapFactory.decodeFileDescriptor(fd, null, opts);
865             }
866 
867             // Transform the bitmap if requested. We use a side-channel to
868             // communicate the orientation, since EXIF thumbnails don't contain
869             // the rotation flags of the original image.
870             final Bundle extras = afd.getExtras();
871             final int orientation = (extras != null) ? extras.getInt(EXTRA_ORIENTATION, 0) : 0;
872             if (orientation != 0) {
873                 final int width = bitmap.getWidth();
874                 final int height = bitmap.getHeight();
875 
876                 final Matrix m = new Matrix();
877                 m.setRotate(orientation, width / 2, height / 2);
878                 bitmap = Bitmap.createBitmap(bitmap, 0, 0, width, height, m, false);
879             }
880         } finally {
881             IoUtils.closeQuietly(afd);
882         }
883 
884         return bitmap;
885     }
886 
887     /**
888      * Create a new document with given MIME type and display name.
889      *
890      * @param parentDocumentUri directory with
891      *            {@link Document#FLAG_DIR_SUPPORTS_CREATE}
892      * @param mimeType MIME type of new document
893      * @param displayName name of new document
894      * @return newly created document, or {@code null} if failed
895      */
createDocument(ContentResolver resolver, Uri parentDocumentUri, String mimeType, String displayName)896     public static Uri createDocument(ContentResolver resolver, Uri parentDocumentUri,
897             String mimeType, String displayName) {
898         final ContentProviderClient client = resolver.acquireUnstableContentProviderClient(
899                 parentDocumentUri.getAuthority());
900         try {
901             return createDocument(client, parentDocumentUri, mimeType, displayName);
902         } catch (Exception e) {
903             Log.w(TAG, "Failed to create document", e);
904             return null;
905         } finally {
906             ContentProviderClient.releaseQuietly(client);
907         }
908     }
909 
910     /** {@hide} */
createDocument(ContentProviderClient client, Uri parentDocumentUri, String mimeType, String displayName)911     public static Uri createDocument(ContentProviderClient client, Uri parentDocumentUri,
912             String mimeType, String displayName) throws RemoteException {
913         final Bundle in = new Bundle();
914         in.putParcelable(DocumentsContract.EXTRA_URI, parentDocumentUri);
915         in.putString(Document.COLUMN_MIME_TYPE, mimeType);
916         in.putString(Document.COLUMN_DISPLAY_NAME, displayName);
917 
918         final Bundle out = client.call(METHOD_CREATE_DOCUMENT, null, in);
919         return out.getParcelable(DocumentsContract.EXTRA_URI);
920     }
921 
922     /**
923      * Change the display name of an existing document.
924      * <p>
925      * If the underlying provider needs to create a new
926      * {@link Document#COLUMN_DOCUMENT_ID} to represent the updated display
927      * name, that new document is returned and the original document is no
928      * longer valid. Otherwise, the original document is returned.
929      *
930      * @param documentUri document with {@link Document#FLAG_SUPPORTS_RENAME}
931      * @param displayName updated name for document
932      * @return the existing or new document after the rename, or {@code null} if
933      *         failed.
934      */
renameDocument(ContentResolver resolver, Uri documentUri, String displayName)935     public static Uri renameDocument(ContentResolver resolver, Uri documentUri,
936             String displayName) {
937         final ContentProviderClient client = resolver.acquireUnstableContentProviderClient(
938                 documentUri.getAuthority());
939         try {
940             return renameDocument(client, documentUri, displayName);
941         } catch (Exception e) {
942             Log.w(TAG, "Failed to rename document", e);
943             return null;
944         } finally {
945             ContentProviderClient.releaseQuietly(client);
946         }
947     }
948 
949     /** {@hide} */
renameDocument(ContentProviderClient client, Uri documentUri, String displayName)950     public static Uri renameDocument(ContentProviderClient client, Uri documentUri,
951             String displayName) throws RemoteException {
952         final Bundle in = new Bundle();
953         in.putParcelable(DocumentsContract.EXTRA_URI, documentUri);
954         in.putString(Document.COLUMN_DISPLAY_NAME, displayName);
955 
956         final Bundle out = client.call(METHOD_RENAME_DOCUMENT, null, in);
957         final Uri outUri = out.getParcelable(DocumentsContract.EXTRA_URI);
958         return (outUri != null) ? outUri : documentUri;
959     }
960 
961     /**
962      * Delete the given document.
963      *
964      * @param documentUri document with {@link Document#FLAG_SUPPORTS_DELETE}
965      * @return if the document was deleted successfully.
966      */
deleteDocument(ContentResolver resolver, Uri documentUri)967     public static boolean deleteDocument(ContentResolver resolver, Uri documentUri) {
968         final ContentProviderClient client = resolver.acquireUnstableContentProviderClient(
969                 documentUri.getAuthority());
970         try {
971             deleteDocument(client, documentUri);
972             return true;
973         } catch (Exception e) {
974             Log.w(TAG, "Failed to delete document", e);
975             return false;
976         } finally {
977             ContentProviderClient.releaseQuietly(client);
978         }
979     }
980 
981     /** {@hide} */
deleteDocument(ContentProviderClient client, Uri documentUri)982     public static void deleteDocument(ContentProviderClient client, Uri documentUri)
983             throws RemoteException {
984         final Bundle in = new Bundle();
985         in.putParcelable(DocumentsContract.EXTRA_URI, documentUri);
986 
987         client.call(METHOD_DELETE_DOCUMENT, null, in);
988     }
989 
990     /**
991      * Open the given image for thumbnail purposes, using any embedded EXIF
992      * thumbnail if available, and providing orientation hints from the parent
993      * image.
994      *
995      * @hide
996      */
openImageThumbnail(File file)997     public static AssetFileDescriptor openImageThumbnail(File file) throws FileNotFoundException {
998         final ParcelFileDescriptor pfd = ParcelFileDescriptor.open(
999                 file, ParcelFileDescriptor.MODE_READ_ONLY);
1000         Bundle extras = null;
1001 
1002         try {
1003             final ExifInterface exif = new ExifInterface(file.getAbsolutePath());
1004 
1005             switch (exif.getAttributeInt(ExifInterface.TAG_ORIENTATION, -1)) {
1006                 case ExifInterface.ORIENTATION_ROTATE_90:
1007                     extras = new Bundle(1);
1008                     extras.putInt(EXTRA_ORIENTATION, 90);
1009                     break;
1010                 case ExifInterface.ORIENTATION_ROTATE_180:
1011                     extras = new Bundle(1);
1012                     extras.putInt(EXTRA_ORIENTATION, 180);
1013                     break;
1014                 case ExifInterface.ORIENTATION_ROTATE_270:
1015                     extras = new Bundle(1);
1016                     extras.putInt(EXTRA_ORIENTATION, 270);
1017                     break;
1018             }
1019 
1020             final long[] thumb = exif.getThumbnailRange();
1021             if (thumb != null) {
1022                 return new AssetFileDescriptor(pfd, thumb[0], thumb[1], extras);
1023             }
1024         } catch (IOException e) {
1025         }
1026 
1027         return new AssetFileDescriptor(pfd, 0, AssetFileDescriptor.UNKNOWN_LENGTH, extras);
1028     }
1029 }
1030