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