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;
21import static com.android.internal.util.Preconditions.checkArgument;
22import static com.android.internal.util.Preconditions.checkCollectionElementsNotNull;
23import static com.android.internal.util.Preconditions.checkCollectionNotEmpty;
24
25import android.annotation.Nullable;
26import android.content.ContentProviderClient;
27import android.content.ContentResolver;
28import android.content.Context;
29import android.content.Intent;
30import android.content.IntentSender;
31import android.content.pm.PackageManager;
32import android.content.pm.ResolveInfo;
33import android.content.res.AssetFileDescriptor;
34import android.database.Cursor;
35import android.graphics.Bitmap;
36import android.graphics.BitmapFactory;
37import android.graphics.Matrix;
38import android.graphics.Point;
39import android.media.ExifInterface;
40import android.net.Uri;
41import android.os.Build;
42import android.os.Bundle;
43import android.os.CancellationSignal;
44import android.os.OperationCanceledException;
45import android.os.Parcel;
46import android.os.ParcelFileDescriptor;
47import android.os.ParcelFileDescriptor.OnCloseListener;
48import android.os.Parcelable;
49import android.os.ParcelableException;
50import android.os.RemoteException;
51import android.os.storage.StorageVolume;
52import android.system.ErrnoException;
53import android.system.Os;
54import android.util.Log;
55
56import libcore.io.IoUtils;
57
58import java.io.BufferedInputStream;
59import java.io.File;
60import java.io.FileDescriptor;
61import java.io.FileInputStream;
62import java.io.FileNotFoundException;
63import java.io.IOException;
64import java.util.List;
65import java.util.Objects;
66
67/**
68 * Defines the contract between a documents provider and the platform.
69 * <p>
70 * To create a document provider, extend {@link DocumentsProvider}, which
71 * provides a foundational implementation of this contract.
72 * <p>
73 * All client apps must hold a valid URI permission grant to access documents,
74 * typically issued when a user makes a selection through
75 * {@link Intent#ACTION_OPEN_DOCUMENT}, {@link Intent#ACTION_CREATE_DOCUMENT},
76 * {@link Intent#ACTION_OPEN_DOCUMENT_TREE}, or
77 * {@link StorageVolume#createAccessIntent(String) StorageVolume.createAccessIntent}.
78 *
79 * @see DocumentsProvider
80 */
81public final class DocumentsContract {
82    private static final String TAG = "DocumentsContract";
83
84    // content://com.example/root/
85    // content://com.example/root/sdcard/
86    // content://com.example/root/sdcard/recent/
87    // content://com.example/root/sdcard/search/?query=pony
88    // content://com.example/document/12/
89    // content://com.example/document/12/children/
90    // content://com.example/tree/12/document/24/
91    // content://com.example/tree/12/document/24/children/
92
93    private DocumentsContract() {
94    }
95
96    /**
97     * Intent action used to identify {@link DocumentsProvider} instances. This
98     * is used in the {@code <intent-filter>} of a {@code <provider>}.
99     */
100    public static final String PROVIDER_INTERFACE = "android.content.action.DOCUMENTS_PROVIDER";
101
102    /** {@hide} */
103    public static final String EXTRA_PACKAGE_NAME = "android.content.extra.PACKAGE_NAME";
104
105    /** {@hide} */
106    public static final String EXTRA_SHOW_ADVANCED = "android.content.extra.SHOW_ADVANCED";
107
108    /** {@hide} */
109    public static final String EXTRA_TARGET_URI = "android.content.extra.TARGET_URI";
110
111    /**
112     * Sets the desired initial location visible to user when file chooser is shown.
113     *
114     * <p>Applicable to {@link Intent} with actions:
115     * <ul>
116     *      <li>{@link Intent#ACTION_OPEN_DOCUMENT}</li>
117     *      <li>{@link Intent#ACTION_CREATE_DOCUMENT}</li>
118     *      <li>{@link Intent#ACTION_OPEN_DOCUMENT_TREE}</li>
119     * </ul>
120     *
121     * <p>Location should specify a document URI or a tree URI with document ID. If
122     * this URI identifies a non-directory, document navigator will attempt to use the parent
123     * of the document as the initial location.
124     *
125     * <p>The initial location is system specific if this extra is missing or document navigator
126     * failed to locate the desired initial location.
127     */
128    public static final String EXTRA_INITIAL_URI = "android.provider.extra.INITIAL_URI";
129
130    /**
131     * Set this in a DocumentsUI intent to cause a package's own roots to be
132     * excluded from the roots list.
133     */
134    public static final String EXTRA_EXCLUDE_SELF = "android.provider.extra.EXCLUDE_SELF";
135
136    /**
137     * Included in {@link AssetFileDescriptor#getExtras()} when returned
138     * thumbnail should be rotated.
139     *
140     * @see MediaStore.Images.ImageColumns#ORIENTATION
141     */
142    public static final String EXTRA_ORIENTATION = "android.provider.extra.ORIENTATION";
143
144    /**
145     * Overrides the default prompt text in DocumentsUI when set in an intent.
146     */
147    public static final String EXTRA_PROMPT = "android.provider.extra.PROMPT";
148
149    /**
150     * Action of intent issued by DocumentsUI when user wishes to open/configure/manage a particular
151     * document in the provider application.
152     *
153     * <p>When issued, the intent will include the URI of the document as the intent data.
154     *
155     * <p>A provider wishing to provide support for this action should do two things.
156     * <li>Add an {@code <intent-filter>} matching this action.
157     * <li>When supplying information in {@link DocumentsProvider#queryChildDocuments}, include
158     * {@link Document#FLAG_SUPPORTS_SETTINGS} in the flags for each document that supports
159     * settings.
160     *
161     * @see DocumentsContact#Document#FLAG_SUPPORTS_SETTINGS
162     */
163    public static final String
164            ACTION_DOCUMENT_SETTINGS = "android.provider.action.DOCUMENT_SETTINGS";
165
166    /** {@hide} */
167    public static final String ACTION_MANAGE_DOCUMENT = "android.provider.action.MANAGE_DOCUMENT";
168
169    /** {@hide} */
170    public static final String
171            ACTION_DOCUMENT_ROOT_SETTINGS = "android.provider.action.DOCUMENT_ROOT_SETTINGS";
172
173    /**
174     * Buffer is large enough to rewind past any EXIF headers.
175     */
176    private static final int THUMBNAIL_BUFFER_SIZE = (int) (128 * KB_IN_BYTES);
177
178    /** {@hide} */
179    public static final String EXTERNAL_STORAGE_PROVIDER_AUTHORITY =
180            "com.android.externalstorage.documents";
181
182    /** {@hide} */
183    public static final String PACKAGE_DOCUMENTS_UI = "com.android.documentsui";
184
185    /**
186     * Constants related to a document, including {@link Cursor} column names
187     * and flags.
188     * <p>
189     * A document can be either an openable stream (with a specific MIME type),
190     * or a directory containing additional documents (with the
191     * {@link #MIME_TYPE_DIR} MIME type). A directory represents the top of a
192     * subtree containing zero or more documents, which can recursively contain
193     * even more documents and directories.
194     * <p>
195     * All columns are <em>read-only</em> to client applications.
196     */
197    public final static class Document {
198        private Document() {
199        }
200
201        /**
202         * Unique ID of a document. This ID is both provided by and interpreted
203         * by a {@link DocumentsProvider}, and should be treated as an opaque
204         * value by client applications. This column is required.
205         * <p>
206         * Each document must have a unique ID within a provider, but that
207         * single document may be included as a child of multiple directories.
208         * <p>
209         * A provider must always return durable IDs, since they will be used to
210         * issue long-term URI permission grants when an application interacts
211         * with {@link Intent#ACTION_OPEN_DOCUMENT} and
212         * {@link Intent#ACTION_CREATE_DOCUMENT}.
213         * <p>
214         * Type: STRING
215         */
216        public static final String COLUMN_DOCUMENT_ID = "document_id";
217
218        /**
219         * Concrete MIME type of a document. For example, "image/png" or
220         * "application/pdf" for openable files. A document can also be a
221         * directory containing additional documents, which is represented with
222         * the {@link #MIME_TYPE_DIR} MIME type. This column is required.
223         * <p>
224         * Type: STRING
225         *
226         * @see #MIME_TYPE_DIR
227         */
228        public static final String COLUMN_MIME_TYPE = "mime_type";
229
230        /**
231         * Display name of a document, used as the primary title displayed to a
232         * user. This column is required.
233         * <p>
234         * Type: STRING
235         */
236        public static final String COLUMN_DISPLAY_NAME = OpenableColumns.DISPLAY_NAME;
237
238        /**
239         * Summary of a document, which may be shown to a user. This column is
240         * optional, and may be {@code null}.
241         * <p>
242         * Type: STRING
243         */
244        public static final String COLUMN_SUMMARY = "summary";
245
246        /**
247         * Timestamp when a document was last modified, in milliseconds since
248         * January 1, 1970 00:00:00.0 UTC. This column is required, and may be
249         * {@code null} if unknown. A {@link DocumentsProvider} can update this
250         * field using events from {@link OnCloseListener} or other reliable
251         * {@link ParcelFileDescriptor} transports.
252         * <p>
253         * Type: INTEGER (long)
254         *
255         * @see System#currentTimeMillis()
256         */
257        public static final String COLUMN_LAST_MODIFIED = "last_modified";
258
259        /**
260         * Specific icon resource ID for a document. This column is optional,
261         * and may be {@code null} to use a platform-provided default icon based
262         * on {@link #COLUMN_MIME_TYPE}.
263         * <p>
264         * Type: INTEGER (int)
265         */
266        public static final String COLUMN_ICON = "icon";
267
268        /**
269         * Flags that apply to a document. This column is required.
270         * <p>
271         * Type: INTEGER (int)
272         *
273         * @see #FLAG_SUPPORTS_WRITE
274         * @see #FLAG_SUPPORTS_DELETE
275         * @see #FLAG_SUPPORTS_THUMBNAIL
276         * @see #FLAG_DIR_PREFERS_GRID
277         * @see #FLAG_DIR_PREFERS_LAST_MODIFIED
278         * @see #FLAG_VIRTUAL_DOCUMENT
279         * @see #FLAG_SUPPORTS_COPY
280         * @see #FLAG_SUPPORTS_MOVE
281         * @see #FLAG_SUPPORTS_REMOVE
282         */
283        public static final String COLUMN_FLAGS = "flags";
284
285        /**
286         * Size of a document, in bytes, or {@code null} if unknown. This column
287         * is required.
288         * <p>
289         * Type: INTEGER (long)
290         */
291        public static final String COLUMN_SIZE = OpenableColumns.SIZE;
292
293        /**
294         * MIME type of a document which is a directory that may contain
295         * additional documents.
296         *
297         * @see #COLUMN_MIME_TYPE
298         */
299        public static final String MIME_TYPE_DIR = "vnd.android.document/directory";
300
301        /**
302         * Flag indicating that a document can be represented as a thumbnail.
303         *
304         * @see #COLUMN_FLAGS
305         * @see DocumentsContract#getDocumentThumbnail(ContentResolver, Uri,
306         *      Point, CancellationSignal)
307         * @see DocumentsProvider#openDocumentThumbnail(String, Point,
308         *      android.os.CancellationSignal)
309         */
310        public static final int FLAG_SUPPORTS_THUMBNAIL = 1;
311
312        /**
313         * Flag indicating that a document supports writing.
314         * <p>
315         * When a document is opened with {@link Intent#ACTION_OPEN_DOCUMENT},
316         * the calling application is granted both
317         * {@link Intent#FLAG_GRANT_READ_URI_PERMISSION} and
318         * {@link Intent#FLAG_GRANT_WRITE_URI_PERMISSION}. However, the actual
319         * writability of a document may change over time, for example due to
320         * remote access changes. This flag indicates that a document client can
321         * expect {@link ContentResolver#openOutputStream(Uri)} to succeed.
322         *
323         * @see #COLUMN_FLAGS
324         */
325        public static final int FLAG_SUPPORTS_WRITE = 1 << 1;
326
327        /**
328         * Flag indicating that a document is deletable.
329         *
330         * @see #COLUMN_FLAGS
331         * @see DocumentsContract#deleteDocument(ContentResolver, Uri)
332         * @see DocumentsProvider#deleteDocument(String)
333         */
334        public static final int FLAG_SUPPORTS_DELETE = 1 << 2;
335
336        /**
337         * Flag indicating that a document is a directory that supports creation
338         * of new files within it. Only valid when {@link #COLUMN_MIME_TYPE} is
339         * {@link #MIME_TYPE_DIR}.
340         *
341         * @see #COLUMN_FLAGS
342         * @see DocumentsProvider#createDocument(String, String, String)
343         */
344        public static final int FLAG_DIR_SUPPORTS_CREATE = 1 << 3;
345
346        /**
347         * Flag indicating that a directory prefers its contents be shown in a
348         * larger format grid. Usually suitable when a directory contains mostly
349         * pictures. Only valid when {@link #COLUMN_MIME_TYPE} is
350         * {@link #MIME_TYPE_DIR}.
351         *
352         * @see #COLUMN_FLAGS
353         */
354        public static final int FLAG_DIR_PREFERS_GRID = 1 << 4;
355
356        /**
357         * Flag indicating that a directory prefers its contents be sorted by
358         * {@link #COLUMN_LAST_MODIFIED}. Only valid when
359         * {@link #COLUMN_MIME_TYPE} is {@link #MIME_TYPE_DIR}.
360         *
361         * @see #COLUMN_FLAGS
362         */
363        public static final int FLAG_DIR_PREFERS_LAST_MODIFIED = 1 << 5;
364
365        /**
366         * Flag indicating that a document can be renamed.
367         *
368         * @see #COLUMN_FLAGS
369         * @see DocumentsContract#renameDocument(ContentResolver, Uri,
370         *      String)
371         * @see DocumentsProvider#renameDocument(String, String)
372         */
373        public static final int FLAG_SUPPORTS_RENAME = 1 << 6;
374
375        /**
376         * Flag indicating that a document can be copied to another location
377         * within the same document provider.
378         *
379         * @see #COLUMN_FLAGS
380         * @see DocumentsContract#copyDocument(ContentResolver, Uri, Uri)
381         * @see DocumentsProvider#copyDocument(String, String)
382         */
383        public static final int FLAG_SUPPORTS_COPY = 1 << 7;
384
385        /**
386         * Flag indicating that a document can be moved to another location
387         * within the same document provider.
388         *
389         * @see #COLUMN_FLAGS
390         * @see DocumentsContract#moveDocument(ContentResolver, Uri, Uri, Uri)
391         * @see DocumentsProvider#moveDocument(String, String, String)
392         */
393        public static final int FLAG_SUPPORTS_MOVE = 1 << 8;
394
395        /**
396         * Flag indicating that a document is virtual, and doesn't have byte
397         * representation in the MIME type specified as {@link #COLUMN_MIME_TYPE}.
398         *
399         * <p><em>Virtual documents must have at least one alternative streamable
400         * format via {@link DocumentsProvider#openTypedDocument}</em>
401         *
402         * @see #COLUMN_FLAGS
403         * @see #COLUMN_MIME_TYPE
404         * @see DocumentsProvider#openTypedDocument(String, String, Bundle,
405         *      android.os.CancellationSignal)
406         * @see DocumentsProvider#getDocumentStreamTypes(String, String)
407         */
408        public static final int FLAG_VIRTUAL_DOCUMENT = 1 << 9;
409
410        /**
411         * Flag indicating that a document can be removed from a parent.
412         *
413         * @see #COLUMN_FLAGS
414         * @see DocumentsContract#removeDocument(ContentResolver, Uri, Uri)
415         * @see DocumentsProvider#removeDocument(String, String)
416         */
417        public static final int FLAG_SUPPORTS_REMOVE = 1 << 10;
418
419        /**
420         * Flag indicating that a document has settings that can be configured by user.
421         *
422         * @see #COLUMN_FLAGS
423         * @see #ACTION_DOCUMENT_SETTINGS
424         */
425        public static final int FLAG_SUPPORTS_SETTINGS = 1 << 11;
426
427        /**
428         * Flag indicating that a Web link can be obtained for the document.
429         *
430         * @see #COLUMN_FLAGS
431         * @see DocumentsContract#createWebLinkIntent(PackageManager, Uri, Bundle)
432         */
433        public static final int FLAG_WEB_LINKABLE = 1 << 12;
434
435        /**
436         * Flag indicating that a document is not complete, likely its
437         * contents are being downloaded. Partial files cannot be opened,
438         * copied, moved in the UI. But they can be deleted and retried
439         * if they represent a failed download.
440         *
441         * @see #COLUMN_FLAGS
442         * @hide
443         */
444        public static final int FLAG_PARTIAL = 1 << 16;
445    }
446
447    /**
448     * Constants related to a root of documents, including {@link Cursor} column
449     * names and flags. A root is the start of a tree of documents, such as a
450     * physical storage device, or an account. Each root starts at the directory
451     * referenced by {@link Root#COLUMN_DOCUMENT_ID}, which can recursively
452     * contain both documents and directories.
453     * <p>
454     * All columns are <em>read-only</em> to client applications.
455     */
456    public final static class Root {
457        private Root() {
458        }
459
460        /**
461         * Unique ID of a root. This ID is both provided by and interpreted by a
462         * {@link DocumentsProvider}, and should be treated as an opaque value
463         * by client applications. This column is required.
464         * <p>
465         * Type: STRING
466         */
467        public static final String COLUMN_ROOT_ID = "root_id";
468
469        /**
470         * Flags that apply to a root. This column is required.
471         * <p>
472         * Type: INTEGER (int)
473         *
474         * @see #FLAG_LOCAL_ONLY
475         * @see #FLAG_SUPPORTS_CREATE
476         * @see #FLAG_SUPPORTS_RECENTS
477         * @see #FLAG_SUPPORTS_SEARCH
478         */
479        public static final String COLUMN_FLAGS = "flags";
480
481        /**
482         * Icon resource ID for a root. This column is required.
483         * <p>
484         * Type: INTEGER (int)
485         */
486        public static final String COLUMN_ICON = "icon";
487
488        /**
489         * Title for a root, which will be shown to a user. This column is
490         * required. For a single storage service surfacing multiple accounts as
491         * different roots, this title should be the name of the service.
492         * <p>
493         * Type: STRING
494         */
495        public static final String COLUMN_TITLE = "title";
496
497        /**
498         * Summary for this root, which may be shown to a user. This column is
499         * optional, and may be {@code null}. For a single storage service
500         * surfacing multiple accounts as different roots, this summary should
501         * be the name of the account.
502         * <p>
503         * Type: STRING
504         */
505        public static final String COLUMN_SUMMARY = "summary";
506
507        /**
508         * Document which is a directory that represents the top directory of
509         * this root. This column is required.
510         * <p>
511         * Type: STRING
512         *
513         * @see Document#COLUMN_DOCUMENT_ID
514         */
515        public static final String COLUMN_DOCUMENT_ID = "document_id";
516
517        /**
518         * Number of bytes available in this root. This column is optional, and
519         * may be {@code null} if unknown or unbounded.
520         * <p>
521         * Type: INTEGER (long)
522         */
523        public static final String COLUMN_AVAILABLE_BYTES = "available_bytes";
524
525        /**
526         * Capacity of a root in bytes. This column is optional, and may be
527         * {@code null} if unknown or unbounded.
528         * <p>
529         * Type: INTEGER (long)
530         */
531        public static final String COLUMN_CAPACITY_BYTES = "capacity_bytes";
532
533        /**
534         * MIME types supported by this root. This column is optional, and if
535         * {@code null} the root is assumed to support all MIME types. Multiple
536         * MIME types can be separated by a newline. For example, a root
537         * supporting audio might return "audio/*\napplication/x-flac".
538         * <p>
539         * Type: STRING
540         */
541        public static final String COLUMN_MIME_TYPES = "mime_types";
542
543        /**
544         * MIME type for a root.
545         */
546        public static final String MIME_TYPE_ITEM = "vnd.android.document/root";
547
548        /**
549         * Flag indicating that at least one directory under this root supports
550         * creating content. Roots with this flag will be shown when an
551         * application interacts with {@link Intent#ACTION_CREATE_DOCUMENT}.
552         *
553         * @see #COLUMN_FLAGS
554         */
555        public static final int FLAG_SUPPORTS_CREATE = 1;
556
557        /**
558         * Flag indicating that this root offers content that is strictly local
559         * on the device. That is, no network requests are made for the content.
560         *
561         * @see #COLUMN_FLAGS
562         * @see Intent#EXTRA_LOCAL_ONLY
563         */
564        public static final int FLAG_LOCAL_ONLY = 1 << 1;
565
566        /**
567         * Flag indicating that this root can be queried to provide recently
568         * modified documents.
569         *
570         * @see #COLUMN_FLAGS
571         * @see DocumentsContract#buildRecentDocumentsUri(String, String)
572         * @see DocumentsProvider#queryRecentDocuments(String, String[])
573         */
574        public static final int FLAG_SUPPORTS_RECENTS = 1 << 2;
575
576        /**
577         * Flag indicating that this root supports search.
578         *
579         * @see #COLUMN_FLAGS
580         * @see DocumentsContract#buildSearchDocumentsUri(String, String,
581         *      String)
582         * @see DocumentsProvider#querySearchDocuments(String, String,
583         *      String[])
584         */
585        public static final int FLAG_SUPPORTS_SEARCH = 1 << 3;
586
587        /**
588         * Flag indicating that this root supports testing parent child
589         * relationships.
590         *
591         * @see #COLUMN_FLAGS
592         * @see DocumentsProvider#isChildDocument(String, String)
593         */
594        public static final int FLAG_SUPPORTS_IS_CHILD = 1 << 4;
595
596        /**
597         * Flag indicating that this root can be ejected.
598         *
599         * @see #COLUMN_FLAGS
600         * @see DocumentsContract#ejectRoot(ContentResolver, Uri)
601         * @see DocumentsProvider#ejectRoot(String)
602         */
603        public static final int FLAG_SUPPORTS_EJECT = 1 << 5;
604
605        /**
606         * Flag indicating that this root is currently empty. This may be used
607         * to hide the root when opening documents, but the root will still be
608         * shown when creating documents and {@link #FLAG_SUPPORTS_CREATE} is
609         * also set. If the value of this flag changes, such as when a root
610         * becomes non-empty, you must send a content changed notification for
611         * {@link DocumentsContract#buildRootsUri(String)}.
612         *
613         * @see #COLUMN_FLAGS
614         * @see ContentResolver#notifyChange(Uri,
615         *      android.database.ContentObserver, boolean)
616         * @hide
617         */
618        public static final int FLAG_EMPTY = 1 << 16;
619
620        /**
621         * Flag indicating that this root should only be visible to advanced
622         * users.
623         *
624         * @see #COLUMN_FLAGS
625         * @hide
626         */
627        public static final int FLAG_ADVANCED = 1 << 17;
628
629        /**
630         * Flag indicating that this root has settings.
631         *
632         * @see #COLUMN_FLAGS
633         * @see DocumentsContract#ACTION_DOCUMENT_ROOT_SETTINGS
634         * @hide
635         */
636        public static final int FLAG_HAS_SETTINGS = 1 << 18;
637
638        /**
639         * Flag indicating that this root is on removable SD card storage.
640         *
641         * @see #COLUMN_FLAGS
642         * @hide
643         */
644        public static final int FLAG_REMOVABLE_SD = 1 << 19;
645
646        /**
647         * Flag indicating that this root is on removable USB storage.
648         *
649         * @see #COLUMN_FLAGS
650         * @hide
651         */
652        public static final int FLAG_REMOVABLE_USB = 1 << 20;
653    }
654
655    /**
656     * Optional boolean flag included in a directory {@link Cursor#getExtras()}
657     * indicating that a document provider is still loading data. For example, a
658     * provider has returned some results, but is still waiting on an
659     * outstanding network request. The provider must send a content changed
660     * notification when loading is finished.
661     *
662     * @see ContentResolver#notifyChange(Uri, android.database.ContentObserver,
663     *      boolean)
664     */
665    public static final String EXTRA_LOADING = "loading";
666
667    /**
668     * Optional string included in a directory {@link Cursor#getExtras()}
669     * providing an informational message that should be shown to a user. For
670     * example, a provider may wish to indicate that not all documents are
671     * available.
672     */
673    public static final String EXTRA_INFO = "info";
674
675    /**
676     * Optional string included in a directory {@link Cursor#getExtras()}
677     * providing an error message that should be shown to a user. For example, a
678     * provider may wish to indicate that a network error occurred. The user may
679     * choose to retry, resulting in a new query.
680     */
681    public static final String EXTRA_ERROR = "error";
682
683    /**
684     * Optional result (I'm thinking boolean) answer to a question.
685     * {@hide}
686     */
687    public static final String EXTRA_RESULT = "result";
688
689    /** {@hide} */
690    public static final String METHOD_CREATE_DOCUMENT = "android:createDocument";
691    /** {@hide} */
692    public static final String METHOD_RENAME_DOCUMENT = "android:renameDocument";
693    /** {@hide} */
694    public static final String METHOD_DELETE_DOCUMENT = "android:deleteDocument";
695    /** {@hide} */
696    public static final String METHOD_COPY_DOCUMENT = "android:copyDocument";
697    /** {@hide} */
698    public static final String METHOD_MOVE_DOCUMENT = "android:moveDocument";
699    /** {@hide} */
700    public static final String METHOD_IS_CHILD_DOCUMENT = "android:isChildDocument";
701    /** {@hide} */
702    public static final String METHOD_REMOVE_DOCUMENT = "android:removeDocument";
703    /** {@hide} */
704    public static final String METHOD_EJECT_ROOT = "android:ejectRoot";
705    /** {@hide} */
706    public static final String METHOD_FIND_DOCUMENT_PATH = "android:findDocumentPath";
707    /** {@hide} */
708    public static final String METHOD_CREATE_WEB_LINK_INTENT = "android:createWebLinkIntent";
709
710    /** {@hide} */
711    public static final String EXTRA_PARENT_URI = "parentUri";
712    /** {@hide} */
713    public static final String EXTRA_URI = "uri";
714
715    /**
716     * @see #createWebLinkIntent(ContentResolver, Uri, Bundle)
717     * {@hide}
718     */
719    public static final String EXTRA_OPTIONS = "options";
720
721    private static final String PATH_ROOT = "root";
722    private static final String PATH_RECENT = "recent";
723    private static final String PATH_DOCUMENT = "document";
724    private static final String PATH_CHILDREN = "children";
725    private static final String PATH_SEARCH = "search";
726    private static final String PATH_TREE = "tree";
727
728    private static final String PARAM_QUERY = "query";
729    private static final String PARAM_MANAGE = "manage";
730
731    /**
732     * Build URI representing the roots of a document provider. When queried, a
733     * provider will return one or more rows with columns defined by
734     * {@link Root}.
735     *
736     * @see DocumentsProvider#queryRoots(String[])
737     */
738    public static Uri buildRootsUri(String authority) {
739        return new Uri.Builder().scheme(ContentResolver.SCHEME_CONTENT)
740                .authority(authority).appendPath(PATH_ROOT).build();
741    }
742
743    /**
744     * Build URI representing the given {@link Root#COLUMN_ROOT_ID} in a
745     * document provider.
746     *
747     * @see #getRootId(Uri)
748     */
749    public static Uri buildRootUri(String authority, String rootId) {
750        return new Uri.Builder().scheme(ContentResolver.SCHEME_CONTENT)
751                .authority(authority).appendPath(PATH_ROOT).appendPath(rootId).build();
752    }
753
754    /**
755     * Builds URI for user home directory on external (local) storage.
756     * {@hide}
757     */
758    public static Uri buildHomeUri() {
759        // TODO: Avoid this type of interpackage copying. Added here to avoid
760        // direct coupling, but not ideal.
761        return DocumentsContract.buildRootUri(EXTERNAL_STORAGE_PROVIDER_AUTHORITY, "home");
762    }
763
764    /**
765     * Build URI representing the recently modified documents of a specific root
766     * in a document provider. When queried, a provider will return zero or more
767     * rows with columns defined by {@link Document}.
768     *
769     * @see DocumentsProvider#queryRecentDocuments(String, String[])
770     * @see #getRootId(Uri)
771     */
772    public static Uri buildRecentDocumentsUri(String authority, String rootId) {
773        return new Uri.Builder().scheme(ContentResolver.SCHEME_CONTENT)
774                .authority(authority).appendPath(PATH_ROOT).appendPath(rootId)
775                .appendPath(PATH_RECENT).build();
776    }
777
778    /**
779     * Build URI representing access to descendant documents of the given
780     * {@link Document#COLUMN_DOCUMENT_ID}.
781     *
782     * @see #getTreeDocumentId(Uri)
783     */
784    public static Uri buildTreeDocumentUri(String authority, String documentId) {
785        return new Uri.Builder().scheme(ContentResolver.SCHEME_CONTENT).authority(authority)
786                .appendPath(PATH_TREE).appendPath(documentId).build();
787    }
788
789    /**
790     * Build URI representing the target {@link Document#COLUMN_DOCUMENT_ID} in
791     * a document provider. When queried, a provider will return a single row
792     * with columns defined by {@link Document}.
793     *
794     * @see DocumentsProvider#queryDocument(String, String[])
795     * @see #getDocumentId(Uri)
796     */
797    public static Uri buildDocumentUri(String authority, String documentId) {
798        return new Uri.Builder().scheme(ContentResolver.SCHEME_CONTENT)
799                .authority(authority).appendPath(PATH_DOCUMENT).appendPath(documentId).build();
800    }
801
802    /**
803     * Build URI representing the target {@link Document#COLUMN_DOCUMENT_ID} in
804     * a document provider. When queried, a provider will return a single row
805     * with columns defined by {@link Document}.
806     * <p>
807     * However, instead of directly accessing the target document, the returned
808     * URI will leverage access granted through a subtree URI, typically
809     * returned by {@link Intent#ACTION_OPEN_DOCUMENT_TREE}. The target document
810     * must be a descendant (child, grandchild, etc) of the subtree.
811     * <p>
812     * This is typically used to access documents under a user-selected
813     * directory tree, since it doesn't require the user to separately confirm
814     * each new document access.
815     *
816     * @param treeUri the subtree to leverage to gain access to the target
817     *            document. The target directory must be a descendant of this
818     *            subtree.
819     * @param documentId the target document, which the caller may not have
820     *            direct access to.
821     * @see Intent#ACTION_OPEN_DOCUMENT_TREE
822     * @see DocumentsProvider#isChildDocument(String, String)
823     * @see #buildDocumentUri(String, String)
824     */
825    public static Uri buildDocumentUriUsingTree(Uri treeUri, String documentId) {
826        return new Uri.Builder().scheme(ContentResolver.SCHEME_CONTENT)
827                .authority(treeUri.getAuthority()).appendPath(PATH_TREE)
828                .appendPath(getTreeDocumentId(treeUri)).appendPath(PATH_DOCUMENT)
829                .appendPath(documentId).build();
830    }
831
832    /** {@hide} */
833    public static Uri buildDocumentUriMaybeUsingTree(Uri baseUri, String documentId) {
834        if (isTreeUri(baseUri)) {
835            return buildDocumentUriUsingTree(baseUri, documentId);
836        } else {
837            return buildDocumentUri(baseUri.getAuthority(), documentId);
838        }
839    }
840
841    /**
842     * Build URI representing the children of the target directory in a document
843     * provider. When queried, a provider will return zero or more rows with
844     * columns defined by {@link Document}.
845     *
846     * @param parentDocumentId the document to return children for, which must
847     *            be a directory with MIME type of
848     *            {@link Document#MIME_TYPE_DIR}.
849     * @see DocumentsProvider#queryChildDocuments(String, String[], String)
850     * @see #getDocumentId(Uri)
851     */
852    public static Uri buildChildDocumentsUri(String authority, String parentDocumentId) {
853        return new Uri.Builder().scheme(ContentResolver.SCHEME_CONTENT).authority(authority)
854                .appendPath(PATH_DOCUMENT).appendPath(parentDocumentId).appendPath(PATH_CHILDREN)
855                .build();
856    }
857
858    /**
859     * Build URI representing the children of the target directory in a document
860     * provider. When queried, a provider will return zero or more rows with
861     * columns defined by {@link Document}.
862     * <p>
863     * However, instead of directly accessing the target directory, the returned
864     * URI will leverage access granted through a subtree URI, typically
865     * returned by {@link Intent#ACTION_OPEN_DOCUMENT_TREE}. The target
866     * directory must be a descendant (child, grandchild, etc) of the subtree.
867     * <p>
868     * This is typically used to access documents under a user-selected
869     * directory tree, since it doesn't require the user to separately confirm
870     * each new document access.
871     *
872     * @param treeUri the subtree to leverage to gain access to the target
873     *            document. The target directory must be a descendant of this
874     *            subtree.
875     * @param parentDocumentId the document to return children for, which the
876     *            caller may not have direct access to, and which must be a
877     *            directory with MIME type of {@link Document#MIME_TYPE_DIR}.
878     * @see Intent#ACTION_OPEN_DOCUMENT_TREE
879     * @see DocumentsProvider#isChildDocument(String, String)
880     * @see #buildChildDocumentsUri(String, String)
881     */
882    public static Uri buildChildDocumentsUriUsingTree(Uri treeUri, String parentDocumentId) {
883        return new Uri.Builder().scheme(ContentResolver.SCHEME_CONTENT)
884                .authority(treeUri.getAuthority()).appendPath(PATH_TREE)
885                .appendPath(getTreeDocumentId(treeUri)).appendPath(PATH_DOCUMENT)
886                .appendPath(parentDocumentId).appendPath(PATH_CHILDREN).build();
887    }
888
889    /**
890     * Build URI representing a search for matching documents under a specific
891     * root in a document provider. When queried, a provider will return zero or
892     * more rows with columns defined by {@link Document}.
893     *
894     * @see DocumentsProvider#querySearchDocuments(String, String, String[])
895     * @see #getRootId(Uri)
896     * @see #getSearchDocumentsQuery(Uri)
897     */
898    public static Uri buildSearchDocumentsUri(
899            String authority, String rootId, String query) {
900        return new Uri.Builder().scheme(ContentResolver.SCHEME_CONTENT).authority(authority)
901                .appendPath(PATH_ROOT).appendPath(rootId).appendPath(PATH_SEARCH)
902                .appendQueryParameter(PARAM_QUERY, query).build();
903    }
904
905    /**
906     * Test if the given URI represents a {@link Document} backed by a
907     * {@link DocumentsProvider}.
908     *
909     * @see #buildDocumentUri(String, String)
910     * @see #buildDocumentUriUsingTree(Uri, String)
911     */
912    public static boolean isDocumentUri(Context context, @Nullable Uri uri) {
913        if (isContentUri(uri) && isDocumentsProvider(context, uri.getAuthority())) {
914            final List<String> paths = uri.getPathSegments();
915            if (paths.size() == 2) {
916                return PATH_DOCUMENT.equals(paths.get(0));
917            } else if (paths.size() == 4) {
918                return PATH_TREE.equals(paths.get(0)) && PATH_DOCUMENT.equals(paths.get(2));
919            }
920        }
921        return false;
922    }
923
924    /** {@hide} */
925    public static boolean isRootUri(Context context, @Nullable Uri uri) {
926        if (isContentUri(uri) && isDocumentsProvider(context, uri.getAuthority())) {
927            final List<String> paths = uri.getPathSegments();
928            return (paths.size() == 2 && PATH_ROOT.equals(paths.get(0)));
929        }
930        return false;
931    }
932
933    /** {@hide} */
934    public static boolean isContentUri(@Nullable Uri uri) {
935        return uri != null && ContentResolver.SCHEME_CONTENT.equals(uri.getScheme());
936    }
937
938    /**
939     * Test if the given URI represents a {@link Document} tree.
940     *
941     * @see #buildTreeDocumentUri(String, String)
942     * @see #getTreeDocumentId(Uri)
943     */
944    public static boolean isTreeUri(Uri uri) {
945        final List<String> paths = uri.getPathSegments();
946        return (paths.size() >= 2 && PATH_TREE.equals(paths.get(0)));
947    }
948
949    private static boolean isDocumentsProvider(Context context, String authority) {
950        final Intent intent = new Intent(PROVIDER_INTERFACE);
951        final List<ResolveInfo> infos = context.getPackageManager()
952                .queryIntentContentProviders(intent, 0);
953        for (ResolveInfo info : infos) {
954            if (authority.equals(info.providerInfo.authority)) {
955                return true;
956            }
957        }
958        return false;
959    }
960
961    /**
962     * Extract the {@link Root#COLUMN_ROOT_ID} from the given URI.
963     */
964    public static String getRootId(Uri rootUri) {
965        final List<String> paths = rootUri.getPathSegments();
966        if (paths.size() >= 2 && PATH_ROOT.equals(paths.get(0))) {
967            return paths.get(1);
968        }
969        throw new IllegalArgumentException("Invalid URI: " + rootUri);
970    }
971
972    /**
973     * Extract the {@link Document#COLUMN_DOCUMENT_ID} from the given URI.
974     *
975     * @see #isDocumentUri(Context, Uri)
976     */
977    public static String getDocumentId(Uri documentUri) {
978        final List<String> paths = documentUri.getPathSegments();
979        if (paths.size() >= 2 && PATH_DOCUMENT.equals(paths.get(0))) {
980            return paths.get(1);
981        }
982        if (paths.size() >= 4 && PATH_TREE.equals(paths.get(0))
983                && PATH_DOCUMENT.equals(paths.get(2))) {
984            return paths.get(3);
985        }
986        throw new IllegalArgumentException("Invalid URI: " + documentUri);
987    }
988
989    /**
990     * Extract the via {@link Document#COLUMN_DOCUMENT_ID} from the given URI.
991     */
992    public static String getTreeDocumentId(Uri documentUri) {
993        final List<String> paths = documentUri.getPathSegments();
994        if (paths.size() >= 2 && PATH_TREE.equals(paths.get(0))) {
995            return paths.get(1);
996        }
997        throw new IllegalArgumentException("Invalid URI: " + documentUri);
998    }
999
1000    /**
1001     * Extract the search query from a URI built by
1002     * {@link #buildSearchDocumentsUri(String, String, String)}.
1003     */
1004    public static String getSearchDocumentsQuery(Uri searchDocumentsUri) {
1005        return searchDocumentsUri.getQueryParameter(PARAM_QUERY);
1006    }
1007
1008    /** {@hide} */
1009    public static Uri setManageMode(Uri uri) {
1010        return uri.buildUpon().appendQueryParameter(PARAM_MANAGE, "true").build();
1011    }
1012
1013    /** {@hide} */
1014    public static boolean isManageMode(Uri uri) {
1015        return uri.getBooleanQueryParameter(PARAM_MANAGE, false);
1016    }
1017
1018    /**
1019     * Return thumbnail representing the document at the given URI. Callers are
1020     * responsible for their own in-memory caching.
1021     *
1022     * @param documentUri document to return thumbnail for, which must have
1023     *            {@link Document#FLAG_SUPPORTS_THUMBNAIL} set.
1024     * @param size optimal thumbnail size desired. A provider may return a
1025     *            thumbnail of a different size, but never more than double the
1026     *            requested size.
1027     * @param signal signal used to indicate if caller is no longer interested
1028     *            in the thumbnail.
1029     * @return decoded thumbnail, or {@code null} if problem was encountered.
1030     * @see DocumentsProvider#openDocumentThumbnail(String, Point,
1031     *      android.os.CancellationSignal)
1032     */
1033    public static Bitmap getDocumentThumbnail(
1034            ContentResolver resolver, Uri documentUri, Point size, CancellationSignal signal)
1035            throws FileNotFoundException {
1036        final ContentProviderClient client = resolver.acquireUnstableContentProviderClient(
1037                documentUri.getAuthority());
1038        try {
1039            return getDocumentThumbnail(client, documentUri, size, signal);
1040        } catch (Exception e) {
1041            if (!(e instanceof OperationCanceledException)) {
1042                Log.w(TAG, "Failed to load thumbnail for " + documentUri + ": " + e);
1043            }
1044            rethrowIfNecessary(resolver, e);
1045            return null;
1046        } finally {
1047            ContentProviderClient.releaseQuietly(client);
1048        }
1049    }
1050
1051    /** {@hide} */
1052    public static Bitmap getDocumentThumbnail(
1053            ContentProviderClient client, Uri documentUri, Point size, CancellationSignal signal)
1054            throws RemoteException, IOException {
1055        final Bundle openOpts = new Bundle();
1056        openOpts.putParcelable(ContentResolver.EXTRA_SIZE, size);
1057
1058        AssetFileDescriptor afd = null;
1059        Bitmap bitmap = null;
1060        try {
1061            afd = client.openTypedAssetFileDescriptor(documentUri, "image/*", openOpts, signal);
1062
1063            final FileDescriptor fd = afd.getFileDescriptor();
1064            final long offset = afd.getStartOffset();
1065
1066            // Try seeking on the returned FD, since it gives us the most
1067            // optimal decode path; otherwise fall back to buffering.
1068            BufferedInputStream is = null;
1069            try {
1070                Os.lseek(fd, offset, SEEK_SET);
1071            } catch (ErrnoException e) {
1072                is = new BufferedInputStream(new FileInputStream(fd), THUMBNAIL_BUFFER_SIZE);
1073                is.mark(THUMBNAIL_BUFFER_SIZE);
1074            }
1075
1076            // We requested a rough thumbnail size, but the remote size may have
1077            // returned something giant, so defensively scale down as needed.
1078            final BitmapFactory.Options opts = new BitmapFactory.Options();
1079            opts.inJustDecodeBounds = true;
1080            if (is != null) {
1081                BitmapFactory.decodeStream(is, null, opts);
1082            } else {
1083                BitmapFactory.decodeFileDescriptor(fd, null, opts);
1084            }
1085
1086            final int widthSample = opts.outWidth / size.x;
1087            final int heightSample = opts.outHeight / size.y;
1088
1089            opts.inJustDecodeBounds = false;
1090            opts.inSampleSize = Math.min(widthSample, heightSample);
1091            if (is != null) {
1092                is.reset();
1093                bitmap = BitmapFactory.decodeStream(is, null, opts);
1094            } else {
1095                try {
1096                    Os.lseek(fd, offset, SEEK_SET);
1097                } catch (ErrnoException e) {
1098                    e.rethrowAsIOException();
1099                }
1100                bitmap = BitmapFactory.decodeFileDescriptor(fd, null, opts);
1101            }
1102
1103            // Transform the bitmap if requested. We use a side-channel to
1104            // communicate the orientation, since EXIF thumbnails don't contain
1105            // the rotation flags of the original image.
1106            final Bundle extras = afd.getExtras();
1107            final int orientation = (extras != null) ? extras.getInt(EXTRA_ORIENTATION, 0) : 0;
1108            if (orientation != 0) {
1109                final int width = bitmap.getWidth();
1110                final int height = bitmap.getHeight();
1111
1112                final Matrix m = new Matrix();
1113                m.setRotate(orientation, width / 2, height / 2);
1114                bitmap = Bitmap.createBitmap(bitmap, 0, 0, width, height, m, false);
1115            }
1116        } finally {
1117            IoUtils.closeQuietly(afd);
1118        }
1119
1120        return bitmap;
1121    }
1122
1123    /**
1124     * Create a new document with given MIME type and display name.
1125     *
1126     * @param parentDocumentUri directory with {@link Document#FLAG_DIR_SUPPORTS_CREATE}
1127     * @param mimeType MIME type of new document
1128     * @param displayName name of new document
1129     * @return newly created document, or {@code null} if failed
1130     */
1131    public static Uri createDocument(ContentResolver resolver, Uri parentDocumentUri,
1132            String mimeType, String displayName) throws FileNotFoundException {
1133        final ContentProviderClient client = resolver.acquireUnstableContentProviderClient(
1134                parentDocumentUri.getAuthority());
1135        try {
1136            return createDocument(client, parentDocumentUri, mimeType, displayName);
1137        } catch (Exception e) {
1138            Log.w(TAG, "Failed to create document", e);
1139            rethrowIfNecessary(resolver, e);
1140            return null;
1141        } finally {
1142            ContentProviderClient.releaseQuietly(client);
1143        }
1144    }
1145
1146    /** {@hide} */
1147    public static Uri createDocument(ContentProviderClient client, Uri parentDocumentUri,
1148            String mimeType, String displayName) throws RemoteException {
1149        final Bundle in = new Bundle();
1150        in.putParcelable(DocumentsContract.EXTRA_URI, parentDocumentUri);
1151        in.putString(Document.COLUMN_MIME_TYPE, mimeType);
1152        in.putString(Document.COLUMN_DISPLAY_NAME, displayName);
1153
1154        final Bundle out = client.call(METHOD_CREATE_DOCUMENT, null, in);
1155        return out.getParcelable(DocumentsContract.EXTRA_URI);
1156    }
1157
1158    /** {@hide} */
1159    public static boolean isChildDocument(ContentProviderClient client, Uri parentDocumentUri,
1160            Uri childDocumentUri) throws RemoteException {
1161
1162        final Bundle in = new Bundle();
1163        in.putParcelable(DocumentsContract.EXTRA_URI, parentDocumentUri);
1164        in.putParcelable(DocumentsContract.EXTRA_TARGET_URI, childDocumentUri);
1165
1166        final Bundle out = client.call(METHOD_IS_CHILD_DOCUMENT, null, in);
1167        if (out == null) {
1168            throw new RemoteException("Failed to get a reponse from isChildDocument query.");
1169        }
1170        if (!out.containsKey(DocumentsContract.EXTRA_RESULT)) {
1171            throw new RemoteException("Response did not include result field..");
1172        }
1173        return out.getBoolean(DocumentsContract.EXTRA_RESULT);
1174    }
1175
1176    /**
1177     * Change the display name of an existing document.
1178     * <p>
1179     * If the underlying provider needs to create a new
1180     * {@link Document#COLUMN_DOCUMENT_ID} to represent the updated display
1181     * name, that new document is returned and the original document is no
1182     * longer valid. Otherwise, the original document is returned.
1183     *
1184     * @param documentUri document with {@link Document#FLAG_SUPPORTS_RENAME}
1185     * @param displayName updated name for document
1186     * @return the existing or new document after the rename, or {@code null} if
1187     *         failed.
1188     */
1189    public static Uri renameDocument(ContentResolver resolver, Uri documentUri,
1190            String displayName) throws FileNotFoundException {
1191        final ContentProviderClient client = resolver.acquireUnstableContentProviderClient(
1192                documentUri.getAuthority());
1193        try {
1194            return renameDocument(client, documentUri, displayName);
1195        } catch (Exception e) {
1196            Log.w(TAG, "Failed to rename document", e);
1197            rethrowIfNecessary(resolver, e);
1198            return null;
1199        } finally {
1200            ContentProviderClient.releaseQuietly(client);
1201        }
1202    }
1203
1204    /** {@hide} */
1205    public static Uri renameDocument(ContentProviderClient client, Uri documentUri,
1206            String displayName) throws RemoteException {
1207        final Bundle in = new Bundle();
1208        in.putParcelable(DocumentsContract.EXTRA_URI, documentUri);
1209        in.putString(Document.COLUMN_DISPLAY_NAME, displayName);
1210
1211        final Bundle out = client.call(METHOD_RENAME_DOCUMENT, null, in);
1212        final Uri outUri = out.getParcelable(DocumentsContract.EXTRA_URI);
1213        return (outUri != null) ? outUri : documentUri;
1214    }
1215
1216    /**
1217     * Delete the given document.
1218     *
1219     * @param documentUri document with {@link Document#FLAG_SUPPORTS_DELETE}
1220     * @return if the document was deleted successfully.
1221     */
1222    public static boolean deleteDocument(ContentResolver resolver, Uri documentUri)
1223            throws FileNotFoundException {
1224        final ContentProviderClient client = resolver.acquireUnstableContentProviderClient(
1225                documentUri.getAuthority());
1226        try {
1227            deleteDocument(client, documentUri);
1228            return true;
1229        } catch (Exception e) {
1230            Log.w(TAG, "Failed to delete document", e);
1231            rethrowIfNecessary(resolver, e);
1232            return false;
1233        } finally {
1234            ContentProviderClient.releaseQuietly(client);
1235        }
1236    }
1237
1238    /** {@hide} */
1239    public static void deleteDocument(ContentProviderClient client, Uri documentUri)
1240            throws RemoteException {
1241        final Bundle in = new Bundle();
1242        in.putParcelable(DocumentsContract.EXTRA_URI, documentUri);
1243
1244        client.call(METHOD_DELETE_DOCUMENT, null, in);
1245    }
1246
1247    /**
1248     * Copies the given document.
1249     *
1250     * @param sourceDocumentUri document with {@link Document#FLAG_SUPPORTS_COPY}
1251     * @param targetParentDocumentUri document which will become a parent of the source
1252     *         document's copy.
1253     * @return the copied document, or {@code null} if failed.
1254     */
1255    public static Uri copyDocument(ContentResolver resolver, Uri sourceDocumentUri,
1256            Uri targetParentDocumentUri) throws FileNotFoundException {
1257        final ContentProviderClient client = resolver.acquireUnstableContentProviderClient(
1258                sourceDocumentUri.getAuthority());
1259        try {
1260            return copyDocument(client, sourceDocumentUri, targetParentDocumentUri);
1261        } catch (Exception e) {
1262            Log.w(TAG, "Failed to copy document", e);
1263            rethrowIfNecessary(resolver, e);
1264            return null;
1265        } finally {
1266            ContentProviderClient.releaseQuietly(client);
1267        }
1268    }
1269
1270    /** {@hide} */
1271    public static Uri copyDocument(ContentProviderClient client, Uri sourceDocumentUri,
1272            Uri targetParentDocumentUri) throws RemoteException {
1273        final Bundle in = new Bundle();
1274        in.putParcelable(DocumentsContract.EXTRA_URI, sourceDocumentUri);
1275        in.putParcelable(DocumentsContract.EXTRA_TARGET_URI, targetParentDocumentUri);
1276
1277        final Bundle out = client.call(METHOD_COPY_DOCUMENT, null, in);
1278        return out.getParcelable(DocumentsContract.EXTRA_URI);
1279    }
1280
1281    /**
1282     * Moves the given document under a new parent.
1283     *
1284     * @param sourceDocumentUri document with {@link Document#FLAG_SUPPORTS_MOVE}
1285     * @param sourceParentDocumentUri parent document of the document to move.
1286     * @param targetParentDocumentUri document which will become a new parent of the source
1287     *         document.
1288     * @return the moved document, or {@code null} if failed.
1289     */
1290    public static Uri moveDocument(ContentResolver resolver, Uri sourceDocumentUri,
1291            Uri sourceParentDocumentUri, Uri targetParentDocumentUri) throws FileNotFoundException {
1292        final ContentProviderClient client = resolver.acquireUnstableContentProviderClient(
1293                sourceDocumentUri.getAuthority());
1294        try {
1295            return moveDocument(client, sourceDocumentUri, sourceParentDocumentUri,
1296                    targetParentDocumentUri);
1297        } catch (Exception e) {
1298            Log.w(TAG, "Failed to move document", e);
1299            rethrowIfNecessary(resolver, e);
1300            return null;
1301        } finally {
1302            ContentProviderClient.releaseQuietly(client);
1303        }
1304    }
1305
1306    /** {@hide} */
1307    public static Uri moveDocument(ContentProviderClient client, Uri sourceDocumentUri,
1308            Uri sourceParentDocumentUri, Uri targetParentDocumentUri) throws RemoteException {
1309        final Bundle in = new Bundle();
1310        in.putParcelable(DocumentsContract.EXTRA_URI, sourceDocumentUri);
1311        in.putParcelable(DocumentsContract.EXTRA_PARENT_URI, sourceParentDocumentUri);
1312        in.putParcelable(DocumentsContract.EXTRA_TARGET_URI, targetParentDocumentUri);
1313
1314        final Bundle out = client.call(METHOD_MOVE_DOCUMENT, null, in);
1315        return out.getParcelable(DocumentsContract.EXTRA_URI);
1316    }
1317
1318    /**
1319     * Removes the given document from a parent directory.
1320     *
1321     * <p>In contrast to {@link #deleteDocument} it requires specifying the parent.
1322     * This method is especially useful if the document can be in multiple parents.
1323     *
1324     * @param documentUri document with {@link Document#FLAG_SUPPORTS_REMOVE}
1325     * @param parentDocumentUri parent document of the document to remove.
1326     * @return true if the document was removed successfully.
1327     */
1328    public static boolean removeDocument(ContentResolver resolver, Uri documentUri,
1329            Uri parentDocumentUri) throws FileNotFoundException {
1330        final ContentProviderClient client = resolver.acquireUnstableContentProviderClient(
1331                documentUri.getAuthority());
1332        try {
1333            removeDocument(client, documentUri, parentDocumentUri);
1334            return true;
1335        } catch (Exception e) {
1336            Log.w(TAG, "Failed to remove document", e);
1337            rethrowIfNecessary(resolver, e);
1338            return false;
1339        } finally {
1340            ContentProviderClient.releaseQuietly(client);
1341        }
1342    }
1343
1344    /** {@hide} */
1345    public static void removeDocument(ContentProviderClient client, Uri documentUri,
1346            Uri parentDocumentUri) throws RemoteException {
1347        final Bundle in = new Bundle();
1348        in.putParcelable(DocumentsContract.EXTRA_URI, documentUri);
1349        in.putParcelable(DocumentsContract.EXTRA_PARENT_URI, parentDocumentUri);
1350
1351        client.call(METHOD_REMOVE_DOCUMENT, null, in);
1352    }
1353
1354    /**
1355     * Ejects the given root. It throws {@link IllegalStateException} when ejection failed.
1356     *
1357     * @param rootUri root with {@link Root#FLAG_SUPPORTS_EJECT} to be ejected
1358     */
1359    public static void ejectRoot(ContentResolver resolver, Uri rootUri) {
1360        final ContentProviderClient client = resolver.acquireUnstableContentProviderClient(
1361                rootUri.getAuthority());
1362        try {
1363            ejectRoot(client, rootUri);
1364        } catch (RemoteException e) {
1365            e.rethrowAsRuntimeException();
1366        } finally {
1367            ContentProviderClient.releaseQuietly(client);
1368        }
1369    }
1370
1371    /** {@hide} */
1372    public static void ejectRoot(ContentProviderClient client, Uri rootUri)
1373            throws RemoteException {
1374        final Bundle in = new Bundle();
1375        in.putParcelable(DocumentsContract.EXTRA_URI, rootUri);
1376
1377        client.call(METHOD_EJECT_ROOT, null, in);
1378    }
1379
1380    /**
1381     * Finds the canonical path from the top of the document tree.
1382     *
1383     * The {@link Path#getPath()} of the return value contains the document ID
1384     * of all documents along the path from the top the document tree to the
1385     * requested document, both inclusive.
1386     *
1387     * The {@link Path#getRootId()} of the return value returns {@code null}.
1388     *
1389     * @param treeUri treeUri of the document which path is requested.
1390     * @return the path of the document, or {@code null} if failed.
1391     * @see DocumentsProvider#findDocumentPath(String, String)
1392     */
1393    public static Path findDocumentPath(ContentResolver resolver, Uri treeUri)
1394            throws FileNotFoundException {
1395        checkArgument(isTreeUri(treeUri), treeUri + " is not a tree uri.");
1396
1397        final ContentProviderClient client = resolver.acquireUnstableContentProviderClient(
1398                treeUri.getAuthority());
1399        try {
1400            return findDocumentPath(client, treeUri);
1401        } catch (Exception e) {
1402            Log.w(TAG, "Failed to find path", e);
1403            rethrowIfNecessary(resolver, e);
1404            return null;
1405        } finally {
1406            ContentProviderClient.releaseQuietly(client);
1407        }
1408    }
1409
1410    /**
1411     * Finds the canonical path. If uri is a document uri returns path from a root and
1412     * its associated root id. If uri is a tree uri returns the path from the top of
1413     * the tree. The {@link Path#getPath()} of the return value contains document ID
1414     * starts from the top of the tree or the root document to the requested document,
1415     * both inclusive.
1416     *
1417     * Callers can expect the root ID returned from multiple calls to this method is
1418     * consistent.
1419     *
1420     * @param uri uri of the document which path is requested. It can be either a
1421     *          plain document uri or a tree uri.
1422     * @return the path of the document.
1423     * @see DocumentsProvider#findDocumentPath(String, String)
1424     *
1425     * {@hide}
1426     */
1427    public static Path findDocumentPath(ContentProviderClient client, Uri uri)
1428            throws RemoteException {
1429
1430        final Bundle in = new Bundle();
1431        in.putParcelable(DocumentsContract.EXTRA_URI, uri);
1432
1433        final Bundle out = client.call(METHOD_FIND_DOCUMENT_PATH, null, in);
1434
1435        return out.getParcelable(DocumentsContract.EXTRA_RESULT);
1436    }
1437
1438    /**
1439     * Creates an intent for obtaining a web link for the specified document.
1440     *
1441     * <p>Note, that due to internal limitations, if there is already a web link
1442     * intent created for the specified document but with different options,
1443     * then it may be overriden.
1444     *
1445     * <p>Providers are required to show confirmation UI for all new permissions granted
1446     * for the linked document.
1447     *
1448     * <p>If list of recipients is known, then it should be passed in options as
1449     * {@link Intent#EXTRA_EMAIL} as a list of email addresses. Note, that
1450     * this is just a hint for the provider, which can ignore the list. In either
1451     * case the provider is required to show a UI for letting the user confirm
1452     * any new permission grants.
1453     *
1454     * <p>Note, that the entire <code>options</code> bundle will be sent to the provider
1455     * backing the passed <code>uri</code>. Make sure that you trust the provider
1456     * before passing any sensitive information.
1457     *
1458     * <p>Since this API may show a UI, it cannot be called from background.
1459     *
1460     * <p>In order to obtain the Web Link use code like this:
1461     * <pre><code>
1462     * void onSomethingHappened() {
1463     *   IntentSender sender = DocumentsContract.createWebLinkIntent(<i>...</i>);
1464     *   if (sender != null) {
1465     *     startIntentSenderForResult(
1466     *         sender,
1467     *         WEB_LINK_REQUEST_CODE,
1468     *         null, 0, 0, 0, null);
1469     *   }
1470     * }
1471     *
1472     * <i>(...)</i>
1473     *
1474     * void onActivityResult(int requestCode, int resultCode, Intent data) {
1475     *   if (requestCode == WEB_LINK_REQUEST_CODE && resultCode == RESULT_OK) {
1476     *     Uri weblinkUri = data.getData();
1477     *     <i>...</i>
1478     *   }
1479     * }
1480     * </code></pre>
1481     *
1482     * @param uri uri for the document to create a link to.
1483     * @param options Extra information for generating the link.
1484     * @return an intent sender to obtain the web link, or null if the document
1485     *      is not linkable, or creating the intent sender failed.
1486     * @see DocumentsProvider#createWebLinkIntent(String, Bundle)
1487     * @see Intent#EXTRA_EMAIL
1488     */
1489    public static IntentSender createWebLinkIntent(ContentResolver resolver, Uri uri,
1490            Bundle options) throws FileNotFoundException {
1491        final ContentProviderClient client = resolver.acquireUnstableContentProviderClient(
1492                uri.getAuthority());
1493        try {
1494            return createWebLinkIntent(client, uri, options);
1495        } catch (Exception e) {
1496            Log.w(TAG, "Failed to create a web link intent", e);
1497            rethrowIfNecessary(resolver, e);
1498            return null;
1499        } finally {
1500            ContentProviderClient.releaseQuietly(client);
1501        }
1502    }
1503
1504    /**
1505     * {@hide}
1506     */
1507    public static IntentSender createWebLinkIntent(ContentProviderClient client, Uri uri,
1508            Bundle options) throws RemoteException {
1509        final Bundle in = new Bundle();
1510        in.putParcelable(DocumentsContract.EXTRA_URI, uri);
1511
1512        // Options may be provider specific, so put them in a separate bundle to
1513        // avoid overriding the Uri.
1514        if (options != null) {
1515            in.putBundle(EXTRA_OPTIONS, options);
1516        }
1517
1518        final Bundle out = client.call(METHOD_CREATE_WEB_LINK_INTENT, null, in);
1519        return out.getParcelable(DocumentsContract.EXTRA_RESULT);
1520    }
1521
1522    /**
1523     * Open the given image for thumbnail purposes, using any embedded EXIF
1524     * thumbnail if available, and providing orientation hints from the parent
1525     * image.
1526     *
1527     * @hide
1528     */
1529    public static AssetFileDescriptor openImageThumbnail(File file) throws FileNotFoundException {
1530        final ParcelFileDescriptor pfd = ParcelFileDescriptor.open(
1531                file, ParcelFileDescriptor.MODE_READ_ONLY);
1532        Bundle extras = null;
1533
1534        try {
1535            final ExifInterface exif = new ExifInterface(file.getAbsolutePath());
1536
1537            switch (exif.getAttributeInt(ExifInterface.TAG_ORIENTATION, -1)) {
1538                case ExifInterface.ORIENTATION_ROTATE_90:
1539                    extras = new Bundle(1);
1540                    extras.putInt(EXTRA_ORIENTATION, 90);
1541                    break;
1542                case ExifInterface.ORIENTATION_ROTATE_180:
1543                    extras = new Bundle(1);
1544                    extras.putInt(EXTRA_ORIENTATION, 180);
1545                    break;
1546                case ExifInterface.ORIENTATION_ROTATE_270:
1547                    extras = new Bundle(1);
1548                    extras.putInt(EXTRA_ORIENTATION, 270);
1549                    break;
1550            }
1551
1552            final long[] thumb = exif.getThumbnailRange();
1553            if (thumb != null) {
1554                return new AssetFileDescriptor(pfd, thumb[0], thumb[1], extras);
1555            }
1556        } catch (IOException e) {
1557        }
1558
1559        return new AssetFileDescriptor(pfd, 0, AssetFileDescriptor.UNKNOWN_LENGTH, extras);
1560    }
1561
1562    private static void rethrowIfNecessary(ContentResolver resolver, Exception e)
1563            throws FileNotFoundException {
1564        // We only want to throw applications targetting O and above
1565        if (resolver.getTargetSdkVersion() >= Build.VERSION_CODES.O) {
1566            if (e instanceof ParcelableException) {
1567                ((ParcelableException) e).maybeRethrow(FileNotFoundException.class);
1568            } else if (e instanceof RemoteException) {
1569                ((RemoteException) e).rethrowAsRuntimeException();
1570            } else if (e instanceof RuntimeException) {
1571                throw (RuntimeException) e;
1572            }
1573        }
1574    }
1575
1576    /**
1577     * Holds a path from a document to a particular document under it. It
1578     * may also contains the root ID where the path resides.
1579     */
1580    public static final class Path implements Parcelable {
1581
1582        private final @Nullable String mRootId;
1583        private final List<String> mPath;
1584
1585        /**
1586         * Creates a Path.
1587         *
1588         * @param rootId the ID of the root. May be null.
1589         * @param path the list of document ID from the parent document at
1590         *          position 0 to the child document.
1591         */
1592        public Path(@Nullable String rootId, List<String> path) {
1593            checkCollectionNotEmpty(path, "path");
1594            checkCollectionElementsNotNull(path, "path");
1595
1596            mRootId = rootId;
1597            mPath = path;
1598        }
1599
1600        /**
1601         * Returns the root id or null if the calling package doesn't have
1602         * permission to access root information.
1603         */
1604        public @Nullable String getRootId() {
1605            return mRootId;
1606        }
1607
1608        /**
1609         * Returns the path. The path is trimmed to the top of tree if
1610         * calling package doesn't have permission to access those
1611         * documents.
1612         */
1613        public List<String> getPath() {
1614            return mPath;
1615        }
1616
1617        @Override
1618        public boolean equals(Object o) {
1619            if (this == o) {
1620                return true;
1621            }
1622            if (o == null || !(o instanceof Path)) {
1623                return false;
1624            }
1625            Path path = (Path) o;
1626            return Objects.equals(mRootId, path.mRootId) &&
1627                    Objects.equals(mPath, path.mPath);
1628        }
1629
1630        @Override
1631        public int hashCode() {
1632            return Objects.hash(mRootId, mPath);
1633        }
1634
1635        @Override
1636        public String toString() {
1637            return new StringBuilder()
1638                    .append("DocumentsContract.Path{")
1639                    .append("rootId=")
1640                    .append(mRootId)
1641                    .append(", path=")
1642                    .append(mPath)
1643                    .append("}")
1644                    .toString();
1645        }
1646
1647        @Override
1648        public void writeToParcel(Parcel dest, int flags) {
1649            dest.writeString(mRootId);
1650            dest.writeStringList(mPath);
1651        }
1652
1653        @Override
1654        public int describeContents() {
1655            return 0;
1656        }
1657
1658        public static final Creator<Path> CREATOR = new Creator<Path>() {
1659            @Override
1660            public Path createFromParcel(Parcel in) {
1661                final String rootId = in.readString();
1662                final List<String> path = in.createStringArrayList();
1663                return new Path(rootId, path);
1664            }
1665
1666            @Override
1667            public Path[] newArray(int size) {
1668                return new Path[size];
1669            }
1670        };
1671    }
1672}
1673