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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
17package android.provider;
18
19import static android.net.TrafficStats.KB_IN_BYTES;
20import static android.system.OsConstants.SEEK_SET;
21
22import android.annotation.Nullable;
23import android.content.ContentProviderClient;
24import android.content.ContentResolver;
25import android.content.Context;
26import android.content.Intent;
27import android.content.pm.ResolveInfo;
28import android.content.res.AssetFileDescriptor;
29import android.database.Cursor;
30import android.graphics.Bitmap;
31import android.graphics.BitmapFactory;
32import android.graphics.Matrix;
33import android.graphics.Point;
34import android.media.ExifInterface;
35import android.net.Uri;
36import android.os.Bundle;
37import android.os.CancellationSignal;
38import android.os.OperationCanceledException;
39import android.os.ParcelFileDescriptor;
40import android.os.ParcelFileDescriptor.OnCloseListener;
41import android.os.RemoteException;
42import android.os.storage.StorageVolume;
43import android.system.ErrnoException;
44import android.system.Os;
45import android.util.Log;
46
47import libcore.io.IoUtils;
48
49import java.io.BufferedInputStream;
50import java.io.File;
51import java.io.FileDescriptor;
52import java.io.FileInputStream;
53import java.io.FileNotFoundException;
54import java.io.IOException;
55import java.util.List;
56
57/**
58 * Defines the contract between a documents provider and the platform.
59 * <p>
60 * To create a document provider, extend {@link DocumentsProvider}, which
61 * provides a foundational implementation of this contract.
62 * <p>
63 * All client apps must hold a valid URI permission grant to access documents,
64 * typically issued when a user makes a selection through
65 * {@link Intent#ACTION_OPEN_DOCUMENT}, {@link Intent#ACTION_CREATE_DOCUMENT},
66 * {@link Intent#ACTION_OPEN_DOCUMENT_TREE}, or
67 * {@link StorageVolume#createAccessIntent(String) StorageVolume.createAccessIntent}.
68 *
69 * @see DocumentsProvider
70 */
71public final class DocumentsContract {
72    private static final String TAG = "DocumentsContract";
73
74    // content://com.example/root/
75    // content://com.example/root/sdcard/
76    // content://com.example/root/sdcard/recent/
77    // content://com.example/root/sdcard/search/?query=pony
78    // content://com.example/document/12/
79    // content://com.example/document/12/children/
80    // content://com.example/tree/12/document/24/
81    // content://com.example/tree/12/document/24/children/
82
83    private DocumentsContract() {
84    }
85
86    /**
87     * Intent action used to identify {@link DocumentsProvider} instances. This
88     * is used in the {@code <intent-filter>} of a {@code <provider>}.
89     */
90    public static final String PROVIDER_INTERFACE = "android.content.action.DOCUMENTS_PROVIDER";
91
92    /** {@hide} */
93    public static final String EXTRA_PACKAGE_NAME = "android.content.extra.PACKAGE_NAME";
94
95    /** {@hide} */
96    public static final String EXTRA_SHOW_ADVANCED = "android.content.extra.SHOW_ADVANCED";
97
98    /** {@hide} */
99    public static final String EXTRA_SHOW_FILESIZE = "android.content.extra.SHOW_FILESIZE";
100
101    /** {@hide} */
102    public static final String EXTRA_FANCY_FEATURES = "android.content.extra.FANCY";
103
104    /** {@hide} */
105    public static final String EXTRA_TARGET_URI = "android.content.extra.TARGET_URI";
106
107    /**
108     * Set this in a DocumentsUI intent to cause a package's own roots to be
109     * excluded from the roots list.
110     */
111    public static final String EXTRA_EXCLUDE_SELF = "android.provider.extra.EXCLUDE_SELF";
112
113    /**
114     * Included in {@link AssetFileDescriptor#getExtras()} when returned
115     * thumbnail should be rotated.
116     *
117     * @see MediaStore.Images.ImageColumns#ORIENTATION
118     */
119    public static final String EXTRA_ORIENTATION = "android.provider.extra.ORIENTATION";
120
121    /**
122     * Overrides the default prompt text in DocumentsUI when set in an intent.
123     */
124    public static final String EXTRA_PROMPT = "android.provider.extra.PROMPT";
125
126    /** {@hide} */
127    public static final String ACTION_MANAGE_DOCUMENT = "android.provider.action.MANAGE_DOCUMENT";
128
129    /** {@hide} */
130    public static final String ACTION_BROWSE = "android.provider.action.BROWSE";
131
132    /** {@hide} */
133    public static final String
134            ACTION_DOCUMENT_ROOT_SETTINGS = "android.provider.action.DOCUMENT_ROOT_SETTINGS";
135
136    /**
137     * Buffer is large enough to rewind past any EXIF headers.
138     */
139    private static final int THUMBNAIL_BUFFER_SIZE = (int) (128 * KB_IN_BYTES);
140
141    /** {@hide} */
142    public static final String PACKAGE_DOCUMENTS_UI = "com.android.documentsui";
143
144    /**
145     * Constants related to a document, including {@link Cursor} column names
146     * and flags.
147     * <p>
148     * A document can be either an openable stream (with a specific MIME type),
149     * or a directory containing additional documents (with the
150     * {@link #MIME_TYPE_DIR} MIME type). A directory represents the top of a
151     * subtree containing zero or more documents, which can recursively contain
152     * even more documents and directories.
153     * <p>
154     * All columns are <em>read-only</em> to client applications.
155     */
156    public final static class Document {
157        private Document() {
158        }
159
160        /**
161         * Unique ID of a document. This ID is both provided by and interpreted
162         * by a {@link DocumentsProvider}, and should be treated as an opaque
163         * value by client applications. This column is required.
164         * <p>
165         * Each document must have a unique ID within a provider, but that
166         * single document may be included as a child of multiple directories.
167         * <p>
168         * A provider must always return durable IDs, since they will be used to
169         * issue long-term URI permission grants when an application interacts
170         * with {@link Intent#ACTION_OPEN_DOCUMENT} and
171         * {@link Intent#ACTION_CREATE_DOCUMENT}.
172         * <p>
173         * Type: STRING
174         */
175        public static final String COLUMN_DOCUMENT_ID = "document_id";
176
177        /**
178         * Concrete MIME type of a document. For example, "image/png" or
179         * "application/pdf" for openable files. A document can also be a
180         * directory containing additional documents, which is represented with
181         * the {@link #MIME_TYPE_DIR} MIME type. This column is required.
182         * <p>
183         * Type: STRING
184         *
185         * @see #MIME_TYPE_DIR
186         */
187        public static final String COLUMN_MIME_TYPE = "mime_type";
188
189        /**
190         * Display name of a document, used as the primary title displayed to a
191         * user. This column is required.
192         * <p>
193         * Type: STRING
194         */
195        public static final String COLUMN_DISPLAY_NAME = OpenableColumns.DISPLAY_NAME;
196
197        /**
198         * Summary of a document, which may be shown to a user. This column is
199         * optional, and may be {@code null}.
200         * <p>
201         * Type: STRING
202         */
203        public static final String COLUMN_SUMMARY = "summary";
204
205        /**
206         * Timestamp when a document was last modified, in milliseconds since
207         * January 1, 1970 00:00:00.0 UTC. This column is required, and may be
208         * {@code null} if unknown. A {@link DocumentsProvider} can update this
209         * field using events from {@link OnCloseListener} or other reliable
210         * {@link ParcelFileDescriptor} transports.
211         * <p>
212         * Type: INTEGER (long)
213         *
214         * @see System#currentTimeMillis()
215         */
216        public static final String COLUMN_LAST_MODIFIED = "last_modified";
217
218        /**
219         * Specific icon resource ID for a document. This column is optional,
220         * and may be {@code null} to use a platform-provided default icon based
221         * on {@link #COLUMN_MIME_TYPE}.
222         * <p>
223         * Type: INTEGER (int)
224         */
225        public static final String COLUMN_ICON = "icon";
226
227        /**
228         * Flags that apply to a document. This column is required.
229         * <p>
230         * Type: INTEGER (int)
231         *
232         * @see #FLAG_SUPPORTS_WRITE
233         * @see #FLAG_SUPPORTS_DELETE
234         * @see #FLAG_SUPPORTS_THUMBNAIL
235         * @see #FLAG_DIR_PREFERS_GRID
236         * @see #FLAG_DIR_PREFERS_LAST_MODIFIED
237         * @see #FLAG_VIRTUAL_DOCUMENT
238         * @see #FLAG_ARCHIVE
239         * @see #FLAG_SUPPORTS_COPY
240         * @see #FLAG_SUPPORTS_MOVE
241         * @see #FLAG_SUPPORTS_REMOVE
242         */
243        public static final String COLUMN_FLAGS = "flags";
244
245        /**
246         * Size of a document, in bytes, or {@code null} if unknown. This column
247         * is required.
248         * <p>
249         * Type: INTEGER (long)
250         */
251        public static final String COLUMN_SIZE = OpenableColumns.SIZE;
252
253        /**
254         * MIME type of a document which is a directory that may contain
255         * additional documents.
256         *
257         * @see #COLUMN_MIME_TYPE
258         */
259        public static final String MIME_TYPE_DIR = "vnd.android.document/directory";
260
261        /**
262         * Flag indicating that a document can be represented as a thumbnail.
263         *
264         * @see #COLUMN_FLAGS
265         * @see DocumentsContract#getDocumentThumbnail(ContentResolver, Uri,
266         *      Point, CancellationSignal)
267         * @see DocumentsProvider#openDocumentThumbnail(String, Point,
268         *      android.os.CancellationSignal)
269         */
270        public static final int FLAG_SUPPORTS_THUMBNAIL = 1;
271
272        /**
273         * Flag indicating that a document supports writing.
274         * <p>
275         * When a document is opened with {@link Intent#ACTION_OPEN_DOCUMENT},
276         * the calling application is granted both
277         * {@link Intent#FLAG_GRANT_READ_URI_PERMISSION} and
278         * {@link Intent#FLAG_GRANT_WRITE_URI_PERMISSION}. However, the actual
279         * writability of a document may change over time, for example due to
280         * remote access changes. This flag indicates that a document client can
281         * expect {@link ContentResolver#openOutputStream(Uri)} to succeed.
282         *
283         * @see #COLUMN_FLAGS
284         */
285        public static final int FLAG_SUPPORTS_WRITE = 1 << 1;
286
287        /**
288         * Flag indicating that a document is deletable.
289         *
290         * @see #COLUMN_FLAGS
291         * @see DocumentsContract#deleteDocument(ContentResolver, Uri)
292         * @see DocumentsProvider#deleteDocument(String)
293         */
294        public static final int FLAG_SUPPORTS_DELETE = 1 << 2;
295
296        /**
297         * Flag indicating that a document is a directory that supports creation
298         * of new files within it. Only valid when {@link #COLUMN_MIME_TYPE} is
299         * {@link #MIME_TYPE_DIR}.
300         *
301         * @see #COLUMN_FLAGS
302         * @see DocumentsProvider#createDocument(String, String, String)
303         */
304        public static final int FLAG_DIR_SUPPORTS_CREATE = 1 << 3;
305
306        /**
307         * Flag indicating that a directory prefers its contents be shown in a
308         * larger format grid. Usually suitable when a directory contains mostly
309         * pictures. Only valid when {@link #COLUMN_MIME_TYPE} is
310         * {@link #MIME_TYPE_DIR}.
311         *
312         * @see #COLUMN_FLAGS
313         */
314        public static final int FLAG_DIR_PREFERS_GRID = 1 << 4;
315
316        /**
317         * Flag indicating that a directory prefers its contents be sorted by
318         * {@link #COLUMN_LAST_MODIFIED}. Only valid when
319         * {@link #COLUMN_MIME_TYPE} is {@link #MIME_TYPE_DIR}.
320         *
321         * @see #COLUMN_FLAGS
322         */
323        public static final int FLAG_DIR_PREFERS_LAST_MODIFIED = 1 << 5;
324
325        /**
326         * Flag indicating that a document can be renamed.
327         *
328         * @see #COLUMN_FLAGS
329         * @see DocumentsContract#renameDocument(ContentProviderClient, Uri,
330         *      String)
331         * @see DocumentsProvider#renameDocument(String, String)
332         */
333        public static final int FLAG_SUPPORTS_RENAME = 1 << 6;
334
335        /**
336         * Flag indicating that a document can be copied to another location
337         * within the same document provider.
338         *
339         * @see #COLUMN_FLAGS
340         * @see DocumentsContract#copyDocument(ContentProviderClient, Uri, Uri)
341         * @see DocumentsProvider#copyDocument(String, String)
342         */
343        public static final int FLAG_SUPPORTS_COPY = 1 << 7;
344
345        /**
346         * Flag indicating that a document can be moved to another location
347         * within the same document provider.
348         *
349         * @see #COLUMN_FLAGS
350         * @see DocumentsContract#moveDocument(ContentProviderClient, Uri, Uri, Uri)
351         * @see DocumentsProvider#moveDocument(String, String, String)
352         */
353        public static final int FLAG_SUPPORTS_MOVE = 1 << 8;
354
355        /**
356         * Flag indicating that a document is virtual, and doesn't have byte
357         * representation in the MIME type specified as {@link #COLUMN_MIME_TYPE}.
358         *
359         * @see #COLUMN_FLAGS
360         * @see #COLUMN_MIME_TYPE
361         * @see DocumentsProvider#openTypedDocument(String, String, Bundle,
362         *      android.os.CancellationSignal)
363         * @see DocumentsProvider#getDocumentStreamTypes(String, String)
364         */
365        public static final int FLAG_VIRTUAL_DOCUMENT = 1 << 9;
366
367        /**
368         * Flag indicating that a document can be removed from a parent.
369         *
370         * @see #COLUMN_FLAGS
371         * @see DocumentsContract#removeDocument(ContentProviderClient, Uri, Uri)
372         * @see DocumentsProvider#removeDocument(String, String)
373         */
374        public static final int FLAG_SUPPORTS_REMOVE = 1 << 10;
375
376        /**
377         * Flag indicating that a document is an archive, and it's contents can be
378         * obtained via {@link DocumentsProvider#queryChildDocuments}.
379         * <p>
380         * The <em>provider</em> support library offers utility classes to add common
381         * archive support.
382         *
383         * @see #COLUMN_FLAGS
384         * @see DocumentsProvider#queryChildDocuments(String, String[], String)
385         * @hide
386         */
387        public static final int FLAG_ARCHIVE = 1 << 15;
388
389        /**
390         * Flag indicating that a document is not complete, likely its
391         * contents are being downloaded. Partial files cannot be opened,
392         * copied, moved in the UI. But they can be deleted and retried
393         * if they represent a failed download.
394         *
395         * @see #COLUMN_FLAGS
396         * @hide
397         */
398        public static final int FLAG_PARTIAL = 1 << 16;
399    }
400
401    /**
402     * Constants related to a root of documents, including {@link Cursor} column
403     * names and flags. A root is the start of a tree of documents, such as a
404     * physical storage device, or an account. Each root starts at the directory
405     * referenced by {@link Root#COLUMN_DOCUMENT_ID}, which can recursively
406     * contain both documents and directories.
407     * <p>
408     * All columns are <em>read-only</em> to client applications.
409     */
410    public final static class Root {
411        private Root() {
412        }
413
414        /**
415         * Unique ID of a root. This ID is both provided by and interpreted by a
416         * {@link DocumentsProvider}, and should be treated as an opaque value
417         * by client applications. This column is required.
418         * <p>
419         * Type: STRING
420         */
421        public static final String COLUMN_ROOT_ID = "root_id";
422
423        /**
424         * Flags that apply to a root. This column is required.
425         * <p>
426         * Type: INTEGER (int)
427         *
428         * @see #FLAG_LOCAL_ONLY
429         * @see #FLAG_SUPPORTS_CREATE
430         * @see #FLAG_SUPPORTS_RECENTS
431         * @see #FLAG_SUPPORTS_SEARCH
432         */
433        public static final String COLUMN_FLAGS = "flags";
434
435        /**
436         * Icon resource ID for a root. This column is required.
437         * <p>
438         * Type: INTEGER (int)
439         */
440        public static final String COLUMN_ICON = "icon";
441
442        /**
443         * Title for a root, which will be shown to a user. This column is
444         * required. For a single storage service surfacing multiple accounts as
445         * different roots, this title should be the name of the service.
446         * <p>
447         * Type: STRING
448         */
449        public static final String COLUMN_TITLE = "title";
450
451        /**
452         * Summary for this root, which may be shown to a user. This column is
453         * optional, and may be {@code null}. For a single storage service
454         * surfacing multiple accounts as different roots, this summary should
455         * be the name of the account.
456         * <p>
457         * Type: STRING
458         */
459        public static final String COLUMN_SUMMARY = "summary";
460
461        /**
462         * Document which is a directory that represents the top directory of
463         * this root. This column is required.
464         * <p>
465         * Type: STRING
466         *
467         * @see Document#COLUMN_DOCUMENT_ID
468         */
469        public static final String COLUMN_DOCUMENT_ID = "document_id";
470
471        /**
472         * Number of bytes available in this root. This column is optional, and
473         * may be {@code null} if unknown or unbounded.
474         * <p>
475         * Type: INTEGER (long)
476         */
477        public static final String COLUMN_AVAILABLE_BYTES = "available_bytes";
478
479        /**
480         * Capacity of a root in bytes. This column is optional, and may be
481         * {@code null} if unknown or unbounded.
482         * <p>
483         * Type: INTEGER (long)
484         */
485        public static final String COLUMN_CAPACITY_BYTES = "capacity_bytes";
486
487        /**
488         * MIME types supported by this root. This column is optional, and if
489         * {@code null} the root is assumed to support all MIME types. Multiple
490         * MIME types can be separated by a newline. For example, a root
491         * supporting audio might return "audio/*\napplication/x-flac".
492         * <p>
493         * Type: STRING
494         */
495        public static final String COLUMN_MIME_TYPES = "mime_types";
496
497        /** {@hide} */
498        public static final String MIME_TYPE_ITEM = "vnd.android.document/root";
499
500        /**
501         * Flag indicating that at least one directory under this root supports
502         * creating content. Roots with this flag will be shown when an
503         * application interacts with {@link Intent#ACTION_CREATE_DOCUMENT}.
504         *
505         * @see #COLUMN_FLAGS
506         */
507        public static final int FLAG_SUPPORTS_CREATE = 1;
508
509        /**
510         * Flag indicating that this root offers content that is strictly local
511         * on the device. That is, no network requests are made for the content.
512         *
513         * @see #COLUMN_FLAGS
514         * @see Intent#EXTRA_LOCAL_ONLY
515         */
516        public static final int FLAG_LOCAL_ONLY = 1 << 1;
517
518        /**
519         * Flag indicating that this root can be queried to provide recently
520         * modified documents.
521         *
522         * @see #COLUMN_FLAGS
523         * @see DocumentsContract#buildRecentDocumentsUri(String, String)
524         * @see DocumentsProvider#queryRecentDocuments(String, String[])
525         */
526        public static final int FLAG_SUPPORTS_RECENTS = 1 << 2;
527
528        /**
529         * Flag indicating that this root supports search.
530         *
531         * @see #COLUMN_FLAGS
532         * @see DocumentsContract#buildSearchDocumentsUri(String, String,
533         *      String)
534         * @see DocumentsProvider#querySearchDocuments(String, String,
535         *      String[])
536         */
537        public static final int FLAG_SUPPORTS_SEARCH = 1 << 3;
538
539        /**
540         * Flag indicating that this root supports testing parent child
541         * relationships.
542         *
543         * @see #COLUMN_FLAGS
544         * @see DocumentsProvider#isChildDocument(String, String)
545         */
546        public static final int FLAG_SUPPORTS_IS_CHILD = 1 << 4;
547
548        /**
549         * Flag indicating that this root is currently empty. This may be used
550         * to hide the root when opening documents, but the root will still be
551         * shown when creating documents and {@link #FLAG_SUPPORTS_CREATE} is
552         * also set. If the value of this flag changes, such as when a root
553         * becomes non-empty, you must send a content changed notification for
554         * {@link DocumentsContract#buildRootsUri(String)}.
555         *
556         * @see #COLUMN_FLAGS
557         * @see ContentResolver#notifyChange(Uri,
558         *      android.database.ContentObserver, boolean)
559         * @hide
560         */
561        public static final int FLAG_EMPTY = 1 << 16;
562
563        /**
564         * Flag indicating that this root should only be visible to advanced
565         * users.
566         *
567         * @see #COLUMN_FLAGS
568         * @hide
569         */
570        public static final int FLAG_ADVANCED = 1 << 17;
571
572        /**
573         * Flag indicating that this root has settings.
574         *
575         * @see #COLUMN_FLAGS
576         * @see DocumentsContract#ACTION_DOCUMENT_ROOT_SETTINGS
577         * @hide
578         */
579        public static final int FLAG_HAS_SETTINGS = 1 << 18;
580
581        /**
582         * Flag indicating that this root is on removable SD card storage.
583         *
584         * @see #COLUMN_FLAGS
585         * @hide
586         */
587        public static final int FLAG_REMOVABLE_SD = 1 << 19;
588
589        /**
590         * Flag indicating that this root is on removable USB storage.
591         *
592         * @see #COLUMN_FLAGS
593         * @hide
594         */
595        public static final int FLAG_REMOVABLE_USB = 1 << 20;
596    }
597
598    /**
599     * Optional boolean flag included in a directory {@link Cursor#getExtras()}
600     * indicating that a document provider is still loading data. For example, a
601     * provider has returned some results, but is still waiting on an
602     * outstanding network request. The provider must send a content changed
603     * notification when loading is finished.
604     *
605     * @see ContentResolver#notifyChange(Uri, android.database.ContentObserver,
606     *      boolean)
607     */
608    public static final String EXTRA_LOADING = "loading";
609
610    /**
611     * Optional string included in a directory {@link Cursor#getExtras()}
612     * providing an informational message that should be shown to a user. For
613     * example, a provider may wish to indicate that not all documents are
614     * available.
615     */
616    public static final String EXTRA_INFO = "info";
617
618    /**
619     * Optional string included in a directory {@link Cursor#getExtras()}
620     * providing an error message that should be shown to a user. For example, a
621     * provider may wish to indicate that a network error occurred. The user may
622     * choose to retry, resulting in a new query.
623     */
624    public static final String EXTRA_ERROR = "error";
625
626    /**
627     * Optional result (I'm thinking boolean) answer to a question.
628     * {@hide}
629     */
630    public static final String EXTRA_RESULT = "result";
631
632    /** {@hide} */
633    public static final String METHOD_CREATE_DOCUMENT = "android:createDocument";
634    /** {@hide} */
635    public static final String METHOD_RENAME_DOCUMENT = "android:renameDocument";
636    /** {@hide} */
637    public static final String METHOD_DELETE_DOCUMENT = "android:deleteDocument";
638    /** {@hide} */
639    public static final String METHOD_COPY_DOCUMENT = "android:copyDocument";
640    /** {@hide} */
641    public static final String METHOD_MOVE_DOCUMENT = "android:moveDocument";
642    /** {@hide} */
643    public static final String METHOD_IS_CHILD_DOCUMENT = "android:isChildDocument";
644    /** {@hide} */
645    public static final String METHOD_REMOVE_DOCUMENT = "android:removeDocument";
646
647    /** {@hide} */
648    public static final String EXTRA_PARENT_URI = "parentUri";
649    /** {@hide} */
650    public static final String EXTRA_URI = "uri";
651
652    private static final String PATH_ROOT = "root";
653    private static final String PATH_RECENT = "recent";
654    private static final String PATH_DOCUMENT = "document";
655    private static final String PATH_CHILDREN = "children";
656    private static final String PATH_SEARCH = "search";
657    private static final String PATH_TREE = "tree";
658
659    private static final String PARAM_QUERY = "query";
660    private static final String PARAM_MANAGE = "manage";
661
662    /**
663     * Build URI representing the roots of a document provider. When queried, a
664     * provider will return one or more rows with columns defined by
665     * {@link Root}.
666     *
667     * @see DocumentsProvider#queryRoots(String[])
668     */
669    public static Uri buildRootsUri(String authority) {
670        return new Uri.Builder().scheme(ContentResolver.SCHEME_CONTENT)
671                .authority(authority).appendPath(PATH_ROOT).build();
672    }
673
674    /**
675     * Build URI representing the given {@link Root#COLUMN_ROOT_ID} in a
676     * document provider.
677     *
678     * @see #getRootId(Uri)
679     */
680    public static Uri buildRootUri(String authority, String rootId) {
681        return new Uri.Builder().scheme(ContentResolver.SCHEME_CONTENT)
682                .authority(authority).appendPath(PATH_ROOT).appendPath(rootId).build();
683    }
684
685    /**
686     * Builds URI for user home directory on external (local) storage.
687     * {@hide}
688     */
689    public static Uri buildHomeUri() {
690        // TODO: Avoid this type of interpackage copying. Added here to avoid
691        // direct coupling, but not ideal.
692        return DocumentsContract.buildRootUri("com.android.externalstorage.documents", "home");
693    }
694
695    /**
696     * Build URI representing the recently modified documents of a specific root
697     * in a document provider. When queried, a provider will return zero or more
698     * rows with columns defined by {@link Document}.
699     *
700     * @see DocumentsProvider#queryRecentDocuments(String, String[])
701     * @see #getRootId(Uri)
702     */
703    public static Uri buildRecentDocumentsUri(String authority, String rootId) {
704        return new Uri.Builder().scheme(ContentResolver.SCHEME_CONTENT)
705                .authority(authority).appendPath(PATH_ROOT).appendPath(rootId)
706                .appendPath(PATH_RECENT).build();
707    }
708
709    /**
710     * Build URI representing access to descendant documents of the given
711     * {@link Document#COLUMN_DOCUMENT_ID}.
712     *
713     * @see #getTreeDocumentId(Uri)
714     */
715    public static Uri buildTreeDocumentUri(String authority, String documentId) {
716        return new Uri.Builder().scheme(ContentResolver.SCHEME_CONTENT).authority(authority)
717                .appendPath(PATH_TREE).appendPath(documentId).build();
718    }
719
720    /**
721     * Build URI representing the target {@link Document#COLUMN_DOCUMENT_ID} in
722     * a document provider. When queried, a provider will return a single row
723     * with columns defined by {@link Document}.
724     *
725     * @see DocumentsProvider#queryDocument(String, String[])
726     * @see #getDocumentId(Uri)
727     */
728    public static Uri buildDocumentUri(String authority, String documentId) {
729        return new Uri.Builder().scheme(ContentResolver.SCHEME_CONTENT)
730                .authority(authority).appendPath(PATH_DOCUMENT).appendPath(documentId).build();
731    }
732
733    /**
734     * Build URI representing the target {@link Document#COLUMN_DOCUMENT_ID} in
735     * a document provider. When queried, a provider will return a single row
736     * with columns defined by {@link Document}.
737     * <p>
738     * However, instead of directly accessing the target document, the returned
739     * URI will leverage access granted through a subtree URI, typically
740     * returned by {@link Intent#ACTION_OPEN_DOCUMENT_TREE}. The target document
741     * must be a descendant (child, grandchild, etc) of the subtree.
742     * <p>
743     * This is typically used to access documents under a user-selected
744     * directory tree, since it doesn't require the user to separately confirm
745     * each new document access.
746     *
747     * @param treeUri the subtree to leverage to gain access to the target
748     *            document. The target directory must be a descendant of this
749     *            subtree.
750     * @param documentId the target document, which the caller may not have
751     *            direct access to.
752     * @see Intent#ACTION_OPEN_DOCUMENT_TREE
753     * @see DocumentsProvider#isChildDocument(String, String)
754     * @see #buildDocumentUri(String, String)
755     */
756    public static Uri buildDocumentUriUsingTree(Uri treeUri, String documentId) {
757        return new Uri.Builder().scheme(ContentResolver.SCHEME_CONTENT)
758                .authority(treeUri.getAuthority()).appendPath(PATH_TREE)
759                .appendPath(getTreeDocumentId(treeUri)).appendPath(PATH_DOCUMENT)
760                .appendPath(documentId).build();
761    }
762
763    /** {@hide} */
764    public static Uri buildDocumentUriMaybeUsingTree(Uri baseUri, String documentId) {
765        if (isTreeUri(baseUri)) {
766            return buildDocumentUriUsingTree(baseUri, documentId);
767        } else {
768            return buildDocumentUri(baseUri.getAuthority(), documentId);
769        }
770    }
771
772    /**
773     * Build URI representing the children of the target directory in a document
774     * provider. When queried, a provider will return zero or more rows with
775     * columns defined by {@link Document}.
776     *
777     * @param parentDocumentId the document to return children for, which must
778     *            be a directory with MIME type of
779     *            {@link Document#MIME_TYPE_DIR}.
780     * @see DocumentsProvider#queryChildDocuments(String, String[], String)
781     * @see #getDocumentId(Uri)
782     */
783    public static Uri buildChildDocumentsUri(String authority, String parentDocumentId) {
784        return new Uri.Builder().scheme(ContentResolver.SCHEME_CONTENT).authority(authority)
785                .appendPath(PATH_DOCUMENT).appendPath(parentDocumentId).appendPath(PATH_CHILDREN)
786                .build();
787    }
788
789    /**
790     * Build URI representing the children of the target directory in a document
791     * provider. When queried, a provider will return zero or more rows with
792     * columns defined by {@link Document}.
793     * <p>
794     * However, instead of directly accessing the target directory, the returned
795     * URI will leverage access granted through a subtree URI, typically
796     * returned by {@link Intent#ACTION_OPEN_DOCUMENT_TREE}. The target
797     * directory must be a descendant (child, grandchild, etc) of the subtree.
798     * <p>
799     * This is typically used to access documents under a user-selected
800     * directory tree, since it doesn't require the user to separately confirm
801     * each new document access.
802     *
803     * @param treeUri the subtree to leverage to gain access to the target
804     *            document. The target directory must be a descendant of this
805     *            subtree.
806     * @param parentDocumentId the document to return children for, which the
807     *            caller may not have direct access to, and which must be a
808     *            directory with MIME type of {@link Document#MIME_TYPE_DIR}.
809     * @see Intent#ACTION_OPEN_DOCUMENT_TREE
810     * @see DocumentsProvider#isChildDocument(String, String)
811     * @see #buildChildDocumentsUri(String, String)
812     */
813    public static Uri buildChildDocumentsUriUsingTree(Uri treeUri, String parentDocumentId) {
814        return new Uri.Builder().scheme(ContentResolver.SCHEME_CONTENT)
815                .authority(treeUri.getAuthority()).appendPath(PATH_TREE)
816                .appendPath(getTreeDocumentId(treeUri)).appendPath(PATH_DOCUMENT)
817                .appendPath(parentDocumentId).appendPath(PATH_CHILDREN).build();
818    }
819
820    /**
821     * Build URI representing a search for matching documents under a specific
822     * root in a document provider. When queried, a provider will return zero or
823     * more rows with columns defined by {@link Document}.
824     *
825     * @see DocumentsProvider#querySearchDocuments(String, String, String[])
826     * @see #getRootId(Uri)
827     * @see #getSearchDocumentsQuery(Uri)
828     */
829    public static Uri buildSearchDocumentsUri(
830            String authority, String rootId, String query) {
831        return new Uri.Builder().scheme(ContentResolver.SCHEME_CONTENT).authority(authority)
832                .appendPath(PATH_ROOT).appendPath(rootId).appendPath(PATH_SEARCH)
833                .appendQueryParameter(PARAM_QUERY, query).build();
834    }
835
836    /**
837     * Test if the given URI represents a {@link Document} backed by a
838     * {@link DocumentsProvider}.
839     *
840     * @see #buildDocumentUri(String, String)
841     * @see #buildDocumentUriUsingTree(Uri, String)
842     */
843    public static boolean isDocumentUri(Context context, @Nullable Uri uri) {
844        if (isContentUri(uri) && isDocumentsProvider(context, uri.getAuthority())) {
845            final List<String> paths = uri.getPathSegments();
846            if (paths.size() == 2) {
847                return PATH_DOCUMENT.equals(paths.get(0));
848            } else if (paths.size() == 4) {
849                return PATH_TREE.equals(paths.get(0)) && PATH_DOCUMENT.equals(paths.get(2));
850            }
851        }
852        return false;
853    }
854
855    /** {@hide} */
856    public static boolean isRootUri(Context context, @Nullable Uri uri) {
857        if (isContentUri(uri) && isDocumentsProvider(context, uri.getAuthority())) {
858            final List<String> paths = uri.getPathSegments();
859            return (paths.size() == 2 && PATH_ROOT.equals(paths.get(0)));
860        }
861        return false;
862    }
863
864    /** {@hide} */
865    public static boolean isContentUri(@Nullable Uri uri) {
866        return uri != null && ContentResolver.SCHEME_CONTENT.equals(uri.getScheme());
867    }
868
869    /**
870     * Test if the given URI represents a {@link Document} tree.
871     *
872     * @see #buildTreeDocumentUri(String, String)
873     * @see #getTreeDocumentId(Uri, String)
874     */
875    public static boolean isTreeUri(Uri uri) {
876        final List<String> paths = uri.getPathSegments();
877        return (paths.size() >= 2 && PATH_TREE.equals(paths.get(0)));
878    }
879
880    private static boolean isDocumentsProvider(Context context, String authority) {
881        final Intent intent = new Intent(PROVIDER_INTERFACE);
882        final List<ResolveInfo> infos = context.getPackageManager()
883                .queryIntentContentProviders(intent, 0);
884        for (ResolveInfo info : infos) {
885            if (authority.equals(info.providerInfo.authority)) {
886                return true;
887            }
888        }
889        return false;
890    }
891
892    /**
893     * Extract the {@link Root#COLUMN_ROOT_ID} from the given URI.
894     */
895    public static String getRootId(Uri rootUri) {
896        final List<String> paths = rootUri.getPathSegments();
897        if (paths.size() >= 2 && PATH_ROOT.equals(paths.get(0))) {
898            return paths.get(1);
899        }
900        throw new IllegalArgumentException("Invalid URI: " + rootUri);
901    }
902
903    /**
904     * Extract the {@link Document#COLUMN_DOCUMENT_ID} from the given URI.
905     *
906     * @see #isDocumentUri(Context, Uri)
907     */
908    public static String getDocumentId(Uri documentUri) {
909        final List<String> paths = documentUri.getPathSegments();
910        if (paths.size() >= 2 && PATH_DOCUMENT.equals(paths.get(0))) {
911            return paths.get(1);
912        }
913        if (paths.size() >= 4 && PATH_TREE.equals(paths.get(0))
914                && PATH_DOCUMENT.equals(paths.get(2))) {
915            return paths.get(3);
916        }
917        throw new IllegalArgumentException("Invalid URI: " + documentUri);
918    }
919
920    /**
921     * Extract the via {@link Document#COLUMN_DOCUMENT_ID} from the given URI.
922     */
923    public static String getTreeDocumentId(Uri documentUri) {
924        final List<String> paths = documentUri.getPathSegments();
925        if (paths.size() >= 2 && PATH_TREE.equals(paths.get(0))) {
926            return paths.get(1);
927        }
928        throw new IllegalArgumentException("Invalid URI: " + documentUri);
929    }
930
931    /**
932     * Extract the search query from a URI built by
933     * {@link #buildSearchDocumentsUri(String, String, String)}.
934     */
935    public static String getSearchDocumentsQuery(Uri searchDocumentsUri) {
936        return searchDocumentsUri.getQueryParameter(PARAM_QUERY);
937    }
938
939    /** {@hide} */
940    public static Uri setManageMode(Uri uri) {
941        return uri.buildUpon().appendQueryParameter(PARAM_MANAGE, "true").build();
942    }
943
944    /** {@hide} */
945    public static boolean isManageMode(Uri uri) {
946        return uri.getBooleanQueryParameter(PARAM_MANAGE, false);
947    }
948
949    /**
950     * Return thumbnail representing the document at the given URI. Callers are
951     * responsible for their own in-memory caching.
952     *
953     * @param documentUri document to return thumbnail for, which must have
954     *            {@link Document#FLAG_SUPPORTS_THUMBNAIL} set.
955     * @param size optimal thumbnail size desired. A provider may return a
956     *            thumbnail of a different size, but never more than double the
957     *            requested size.
958     * @param signal signal used to indicate if caller is no longer interested
959     *            in the thumbnail.
960     * @return decoded thumbnail, or {@code null} if problem was encountered.
961     * @see DocumentsProvider#openDocumentThumbnail(String, Point,
962     *      android.os.CancellationSignal)
963     */
964    public static Bitmap getDocumentThumbnail(
965            ContentResolver resolver, Uri documentUri, Point size, CancellationSignal signal) {
966        final ContentProviderClient client = resolver.acquireUnstableContentProviderClient(
967                documentUri.getAuthority());
968        try {
969            return getDocumentThumbnail(client, documentUri, size, signal);
970        } catch (Exception e) {
971            if (!(e instanceof OperationCanceledException)) {
972                Log.w(TAG, "Failed to load thumbnail for " + documentUri + ": " + e);
973            }
974            return null;
975        } finally {
976            ContentProviderClient.releaseQuietly(client);
977        }
978    }
979
980    /** {@hide} */
981    public static Bitmap getDocumentThumbnail(
982            ContentProviderClient client, Uri documentUri, Point size, CancellationSignal signal)
983            throws RemoteException, IOException {
984        final Bundle openOpts = new Bundle();
985        openOpts.putParcelable(ContentResolver.EXTRA_SIZE, size);
986
987        AssetFileDescriptor afd = null;
988        Bitmap bitmap = null;
989        try {
990            afd = client.openTypedAssetFileDescriptor(documentUri, "image/*", openOpts, signal);
991
992            final FileDescriptor fd = afd.getFileDescriptor();
993            final long offset = afd.getStartOffset();
994
995            // Try seeking on the returned FD, since it gives us the most
996            // optimal decode path; otherwise fall back to buffering.
997            BufferedInputStream is = null;
998            try {
999                Os.lseek(fd, offset, SEEK_SET);
1000            } catch (ErrnoException e) {
1001                is = new BufferedInputStream(new FileInputStream(fd), THUMBNAIL_BUFFER_SIZE);
1002                is.mark(THUMBNAIL_BUFFER_SIZE);
1003            }
1004
1005            // We requested a rough thumbnail size, but the remote size may have
1006            // returned something giant, so defensively scale down as needed.
1007            final BitmapFactory.Options opts = new BitmapFactory.Options();
1008            opts.inJustDecodeBounds = true;
1009            if (is != null) {
1010                BitmapFactory.decodeStream(is, null, opts);
1011            } else {
1012                BitmapFactory.decodeFileDescriptor(fd, null, opts);
1013            }
1014
1015            final int widthSample = opts.outWidth / size.x;
1016            final int heightSample = opts.outHeight / size.y;
1017
1018            opts.inJustDecodeBounds = false;
1019            opts.inSampleSize = Math.min(widthSample, heightSample);
1020            if (is != null) {
1021                is.reset();
1022                bitmap = BitmapFactory.decodeStream(is, null, opts);
1023            } else {
1024                try {
1025                    Os.lseek(fd, offset, SEEK_SET);
1026                } catch (ErrnoException e) {
1027                    e.rethrowAsIOException();
1028                }
1029                bitmap = BitmapFactory.decodeFileDescriptor(fd, null, opts);
1030            }
1031
1032            // Transform the bitmap if requested. We use a side-channel to
1033            // communicate the orientation, since EXIF thumbnails don't contain
1034            // the rotation flags of the original image.
1035            final Bundle extras = afd.getExtras();
1036            final int orientation = (extras != null) ? extras.getInt(EXTRA_ORIENTATION, 0) : 0;
1037            if (orientation != 0) {
1038                final int width = bitmap.getWidth();
1039                final int height = bitmap.getHeight();
1040
1041                final Matrix m = new Matrix();
1042                m.setRotate(orientation, width / 2, height / 2);
1043                bitmap = Bitmap.createBitmap(bitmap, 0, 0, width, height, m, false);
1044            }
1045        } finally {
1046            IoUtils.closeQuietly(afd);
1047        }
1048
1049        return bitmap;
1050    }
1051
1052    /**
1053     * Create a new document with given MIME type and display name.
1054     *
1055     * @param parentDocumentUri directory with
1056     *            {@link Document#FLAG_DIR_SUPPORTS_CREATE}
1057     * @param mimeType MIME type of new document
1058     * @param displayName name of new document
1059     * @return newly created document, or {@code null} if failed
1060     */
1061    public static Uri createDocument(ContentResolver resolver, Uri parentDocumentUri,
1062            String mimeType, String displayName) {
1063        final ContentProviderClient client = resolver.acquireUnstableContentProviderClient(
1064                parentDocumentUri.getAuthority());
1065        try {
1066            return createDocument(client, parentDocumentUri, mimeType, displayName);
1067        } catch (Exception e) {
1068            Log.w(TAG, "Failed to create document", e);
1069            return null;
1070        } finally {
1071            ContentProviderClient.releaseQuietly(client);
1072        }
1073    }
1074
1075    /** {@hide} */
1076    public static Uri createDocument(ContentProviderClient client, Uri parentDocumentUri,
1077            String mimeType, String displayName) throws RemoteException {
1078        final Bundle in = new Bundle();
1079        in.putParcelable(DocumentsContract.EXTRA_URI, parentDocumentUri);
1080        in.putString(Document.COLUMN_MIME_TYPE, mimeType);
1081        in.putString(Document.COLUMN_DISPLAY_NAME, displayName);
1082
1083        final Bundle out = client.call(METHOD_CREATE_DOCUMENT, null, in);
1084        return out.getParcelable(DocumentsContract.EXTRA_URI);
1085    }
1086
1087    /** {@hide} */
1088    public static boolean isChildDocument(ContentProviderClient client, Uri parentDocumentUri,
1089            Uri childDocumentUri) throws RemoteException {
1090
1091        final Bundle in = new Bundle();
1092        in.putParcelable(DocumentsContract.EXTRA_URI, parentDocumentUri);
1093        in.putParcelable(DocumentsContract.EXTRA_TARGET_URI, childDocumentUri);
1094
1095        final Bundle out = client.call(METHOD_IS_CHILD_DOCUMENT, null, in);
1096        if (out == null) {
1097            throw new RemoteException("Failed to get a reponse from isChildDocument query.");
1098        }
1099        if (!out.containsKey(DocumentsContract.EXTRA_RESULT)) {
1100            throw new RemoteException("Response did not include result field..");
1101        }
1102        return out.getBoolean(DocumentsContract.EXTRA_RESULT);
1103    }
1104
1105    /**
1106     * Change the display name of an existing document.
1107     * <p>
1108     * If the underlying provider needs to create a new
1109     * {@link Document#COLUMN_DOCUMENT_ID} to represent the updated display
1110     * name, that new document is returned and the original document is no
1111     * longer valid. Otherwise, the original document is returned.
1112     *
1113     * @param documentUri document with {@link Document#FLAG_SUPPORTS_RENAME}
1114     * @param displayName updated name for document
1115     * @return the existing or new document after the rename, or {@code null} if
1116     *         failed.
1117     */
1118    public static Uri renameDocument(ContentResolver resolver, Uri documentUri,
1119            String displayName) {
1120        final ContentProviderClient client = resolver.acquireUnstableContentProviderClient(
1121                documentUri.getAuthority());
1122        try {
1123            return renameDocument(client, documentUri, displayName);
1124        } catch (Exception e) {
1125            Log.w(TAG, "Failed to rename document", e);
1126            return null;
1127        } finally {
1128            ContentProviderClient.releaseQuietly(client);
1129        }
1130    }
1131
1132    /** {@hide} */
1133    public static Uri renameDocument(ContentProviderClient client, Uri documentUri,
1134            String displayName) throws RemoteException {
1135        final Bundle in = new Bundle();
1136        in.putParcelable(DocumentsContract.EXTRA_URI, documentUri);
1137        in.putString(Document.COLUMN_DISPLAY_NAME, displayName);
1138
1139        final Bundle out = client.call(METHOD_RENAME_DOCUMENT, null, in);
1140        final Uri outUri = out.getParcelable(DocumentsContract.EXTRA_URI);
1141        return (outUri != null) ? outUri : documentUri;
1142    }
1143
1144    /**
1145     * Delete the given document.
1146     *
1147     * @param documentUri document with {@link Document#FLAG_SUPPORTS_DELETE}
1148     * @return if the document was deleted successfully.
1149     */
1150    public static boolean deleteDocument(ContentResolver resolver, Uri documentUri) {
1151        final ContentProviderClient client = resolver.acquireUnstableContentProviderClient(
1152                documentUri.getAuthority());
1153        try {
1154            deleteDocument(client, documentUri);
1155            return true;
1156        } catch (Exception e) {
1157            Log.w(TAG, "Failed to delete document", e);
1158            return false;
1159        } finally {
1160            ContentProviderClient.releaseQuietly(client);
1161        }
1162    }
1163
1164    /** {@hide} */
1165    public static void deleteDocument(ContentProviderClient client, Uri documentUri)
1166            throws RemoteException {
1167        final Bundle in = new Bundle();
1168        in.putParcelable(DocumentsContract.EXTRA_URI, documentUri);
1169
1170        client.call(METHOD_DELETE_DOCUMENT, null, in);
1171    }
1172
1173    /**
1174     * Copies the given document.
1175     *
1176     * @param sourceDocumentUri document with {@link Document#FLAG_SUPPORTS_COPY}
1177     * @param targetParentDocumentUri document which will become a parent of the source
1178     *         document's copy.
1179     * @return the copied document, or {@code null} if failed.
1180     */
1181    public static Uri copyDocument(ContentResolver resolver, Uri sourceDocumentUri,
1182            Uri targetParentDocumentUri) {
1183        final ContentProviderClient client = resolver.acquireUnstableContentProviderClient(
1184                sourceDocumentUri.getAuthority());
1185        try {
1186            return copyDocument(client, sourceDocumentUri, targetParentDocumentUri);
1187        } catch (Exception e) {
1188            Log.w(TAG, "Failed to copy document", e);
1189            return null;
1190        } finally {
1191            ContentProviderClient.releaseQuietly(client);
1192        }
1193    }
1194
1195    /** {@hide} */
1196    public static Uri copyDocument(ContentProviderClient client, Uri sourceDocumentUri,
1197            Uri targetParentDocumentUri) throws RemoteException {
1198        final Bundle in = new Bundle();
1199        in.putParcelable(DocumentsContract.EXTRA_URI, sourceDocumentUri);
1200        in.putParcelable(DocumentsContract.EXTRA_TARGET_URI, targetParentDocumentUri);
1201
1202        final Bundle out = client.call(METHOD_COPY_DOCUMENT, null, in);
1203        return out.getParcelable(DocumentsContract.EXTRA_URI);
1204    }
1205
1206    /**
1207     * Moves the given document under a new parent.
1208     *
1209     * @param sourceDocumentUri document with {@link Document#FLAG_SUPPORTS_MOVE}
1210     * @param sourceParentDocumentUri parent document of the document to move.
1211     * @param targetParentDocumentUri document which will become a new parent of the source
1212     *         document.
1213     * @return the moved document, or {@code null} if failed.
1214     */
1215    public static Uri moveDocument(ContentResolver resolver, Uri sourceDocumentUri,
1216            Uri sourceParentDocumentUri, Uri targetParentDocumentUri) {
1217        final ContentProviderClient client = resolver.acquireUnstableContentProviderClient(
1218                sourceDocumentUri.getAuthority());
1219        try {
1220            return moveDocument(client, sourceDocumentUri, sourceParentDocumentUri,
1221                    targetParentDocumentUri);
1222        } catch (Exception e) {
1223            Log.w(TAG, "Failed to move document", e);
1224            return null;
1225        } finally {
1226            ContentProviderClient.releaseQuietly(client);
1227        }
1228    }
1229
1230    /** {@hide} */
1231    public static Uri moveDocument(ContentProviderClient client, Uri sourceDocumentUri,
1232            Uri sourceParentDocumentUri, Uri targetParentDocumentUri) throws RemoteException {
1233        final Bundle in = new Bundle();
1234        in.putParcelable(DocumentsContract.EXTRA_URI, sourceDocumentUri);
1235        in.putParcelable(DocumentsContract.EXTRA_PARENT_URI, sourceParentDocumentUri);
1236        in.putParcelable(DocumentsContract.EXTRA_TARGET_URI, targetParentDocumentUri);
1237
1238        final Bundle out = client.call(METHOD_MOVE_DOCUMENT, null, in);
1239        return out.getParcelable(DocumentsContract.EXTRA_URI);
1240    }
1241
1242    /**
1243     * Removes the given document from a parent directory.
1244     *
1245     * <p>In contrast to {@link #deleteDocument} it requires specifying the parent.
1246     * This method is especially useful if the document can be in multiple parents.
1247     *
1248     * @param documentUri document with {@link Document#FLAG_SUPPORTS_REMOVE}
1249     * @param parentDocumentUri parent document of the document to remove.
1250     * @return true if the document was removed successfully.
1251     */
1252    public static boolean removeDocument(ContentResolver resolver, Uri documentUri,
1253            Uri parentDocumentUri) {
1254        final ContentProviderClient client = resolver.acquireUnstableContentProviderClient(
1255                documentUri.getAuthority());
1256        try {
1257            removeDocument(client, documentUri, parentDocumentUri);
1258            return true;
1259        } catch (Exception e) {
1260            Log.w(TAG, "Failed to remove document", e);
1261            return false;
1262        } finally {
1263            ContentProviderClient.releaseQuietly(client);
1264        }
1265    }
1266
1267    /** {@hide} */
1268    public static void removeDocument(ContentProviderClient client, Uri documentUri,
1269            Uri parentDocumentUri) throws RemoteException {
1270        final Bundle in = new Bundle();
1271        in.putParcelable(DocumentsContract.EXTRA_URI, documentUri);
1272        in.putParcelable(DocumentsContract.EXTRA_PARENT_URI, parentDocumentUri);
1273
1274        client.call(METHOD_REMOVE_DOCUMENT, null, in);
1275    }
1276
1277    /**
1278     * Open the given image for thumbnail purposes, using any embedded EXIF
1279     * thumbnail if available, and providing orientation hints from the parent
1280     * image.
1281     *
1282     * @hide
1283     */
1284    public static AssetFileDescriptor openImageThumbnail(File file) throws FileNotFoundException {
1285        final ParcelFileDescriptor pfd = ParcelFileDescriptor.open(
1286                file, ParcelFileDescriptor.MODE_READ_ONLY);
1287        Bundle extras = null;
1288
1289        try {
1290            final ExifInterface exif = new ExifInterface(file.getAbsolutePath());
1291
1292            switch (exif.getAttributeInt(ExifInterface.TAG_ORIENTATION, -1)) {
1293                case ExifInterface.ORIENTATION_ROTATE_90:
1294                    extras = new Bundle(1);
1295                    extras.putInt(EXTRA_ORIENTATION, 90);
1296                    break;
1297                case ExifInterface.ORIENTATION_ROTATE_180:
1298                    extras = new Bundle(1);
1299                    extras.putInt(EXTRA_ORIENTATION, 180);
1300                    break;
1301                case ExifInterface.ORIENTATION_ROTATE_270:
1302                    extras = new Bundle(1);
1303                    extras.putInt(EXTRA_ORIENTATION, 270);
1304                    break;
1305            }
1306
1307            final long[] thumb = exif.getThumbnailRange();
1308            if (thumb != null) {
1309                return new AssetFileDescriptor(pfd, thumb[0], thumb[1], extras);
1310            }
1311        } catch (IOException e) {
1312        }
1313
1314        return new AssetFileDescriptor(pfd, 0, AssetFileDescriptor.UNKNOWN_LENGTH, extras);
1315    }
1316}
1317