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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 
     17 package android.provider;
     18 
     19 import static android.net.TrafficStats.KB_IN_BYTES;
     20 import static android.system.OsConstants.SEEK_SET;
     21 import static com.android.internal.util.Preconditions.checkArgument;
     22 import static com.android.internal.util.Preconditions.checkCollectionElementsNotNull;
     23 import static com.android.internal.util.Preconditions.checkCollectionNotEmpty;
     24 
     25 import android.annotation.Nullable;
     26 import android.content.ContentProviderClient;
     27 import android.content.ContentResolver;
     28 import android.content.Context;
     29 import android.content.Intent;
     30 import android.content.IntentSender;
     31 import android.content.pm.PackageManager;
     32 import android.content.pm.ResolveInfo;
     33 import android.content.res.AssetFileDescriptor;
     34 import android.database.Cursor;
     35 import android.graphics.Bitmap;
     36 import android.graphics.BitmapFactory;
     37 import android.graphics.Matrix;
     38 import android.graphics.Point;
     39 import android.media.ExifInterface;
     40 import android.net.Uri;
     41 import android.os.Build;
     42 import android.os.Bundle;
     43 import android.os.CancellationSignal;
     44 import android.os.OperationCanceledException;
     45 import android.os.Parcel;
     46 import android.os.ParcelFileDescriptor;
     47 import android.os.ParcelFileDescriptor.OnCloseListener;
     48 import android.os.Parcelable;
     49 import android.os.ParcelableException;
     50 import android.os.RemoteException;
     51 import android.os.storage.StorageVolume;
     52 import android.system.ErrnoException;
     53 import android.system.Os;
     54 import android.util.Log;
     55 
     56 import libcore.io.IoUtils;
     57 
     58 import java.io.BufferedInputStream;
     59 import java.io.File;
     60 import java.io.FileDescriptor;
     61 import java.io.FileInputStream;
     62 import java.io.FileNotFoundException;
     63 import java.io.IOException;
     64 import java.util.List;
     65 import 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  */
     81 public 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