DocumentsContract.java revision 9e0036ed7d3260d79cc5f9ffd8e3bbe760699924 
1/*
2 * Copyright (C) 2013 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17package android.provider;
18
19import android.content.ContentResolver;
20import android.content.ContentValues;
21import android.content.Intent;
22import android.content.res.AssetFileDescriptor;
23import android.graphics.Bitmap;
24import android.graphics.BitmapFactory;
25import android.graphics.Point;
26import android.net.Uri;
27import android.os.Bundle;
28import android.util.Log;
29
30import libcore.io.IoUtils;
31
32import java.io.IOException;
33import java.io.InputStream;
34
35/**
36 * The contract between a storage backend and the platform. Contains definitions
37 * for the supported URIs and columns.
38 */
39public final class DocumentsContract {
40    private static final String TAG = "Documents";
41
42    // content://com.example/docs/0/
43    // content://com.example/docs/0/contents/
44    // content://com.example/search/?query=pony
45
46    /**
47     * MIME type of a document which is a directory that may contain additional
48     * documents.
49     *
50     * @see #buildContentsUri(Uri)
51     */
52    public static final String MIME_TYPE_DIRECTORY = "vnd.android.cursor.dir/doc";
53
54    /** {@hide} */
55    public static final String META_DATA_DOCUMENT_PROVIDER = "android.content.DOCUMENT_PROVIDER";
56
57    /**
58     * {@link DocumentColumns#GUID} value representing the root directory of a
59     * storage backend.
60     */
61    public static final String ROOT_GUID = "0";
62
63    /**
64     * Flag indicating that a document is a directory that supports creation of
65     * new files within it.
66     *
67     * @see DocumentColumns#FLAGS
68     * @see #buildContentsUri(Uri)
69     */
70    public static final int FLAG_SUPPORTS_CREATE = 1;
71
72    /**
73     * Flag indicating that a document is renamable.
74     *
75     * @see DocumentColumns#FLAGS
76     * @see #renameDocument(ContentResolver, Uri, String)
77     */
78    public static final int FLAG_SUPPORTS_RENAME = 1 << 1;
79
80    /**
81     * Flag indicating that a document can be represented as a thumbnail.
82     *
83     * @see DocumentColumns#FLAGS
84     * @see #getThumbnail(ContentResolver, Uri, Point)
85     */
86    public static final int FLAG_SUPPORTS_THUMBNAIL = 1 << 2;
87
88    /**
89     * Optimal dimensions for a document thumbnail request, stored as a
90     * {@link Point} object. This is only a hint, and the returned thumbnail may
91     * have different dimensions.
92     */
93    public static final String EXTRA_THUMBNAIL_SIZE = "thumbnail_size";
94
95    private static final String PATH_DOCS = "docs";
96    private static final String PATH_CONTENTS = "contents";
97    private static final String PATH_SEARCH = "search";
98
99    private static final String PARAM_QUERY = "query";
100
101    /**
102     * Build URI representing the given {@link DocumentColumns#GUID} in a
103     * storage backend.
104     */
105    public static Uri buildDocumentUri(String authority, String guid) {
106        return new Uri.Builder().scheme(ContentResolver.SCHEME_CONTENT)
107                .authority(authority).appendPath(PATH_DOCS).appendPath(guid).build();
108    }
109
110    /**
111     * Build URI representing a search for matching documents in a storage
112     * backend.
113     */
114    public static Uri buildSearchUri(String authority, String query) {
115        return new Uri.Builder().scheme(ContentResolver.SCHEME_CONTENT).authority(authority)
116                .appendPath(PATH_SEARCH).appendQueryParameter(PARAM_QUERY, query).build();
117    }
118
119    /**
120     * Build URI representing the contents of the given directory in a storage
121     * backend. The given document must be {@link #MIME_TYPE_DIRECTORY}.
122     */
123    public static Uri buildContentsUri(Uri documentUri) {
124        return documentUri.buildUpon().appendPath(PATH_CONTENTS).build();
125    }
126
127    /**
128     * These are standard columns for document URIs. Storage backend providers
129     * <em>must</em> support at least these columns when queried.
130     *
131     * @see Intent#ACTION_OPEN_DOCUMENT
132     * @see Intent#ACTION_CREATE_DOCUMENT
133     */
134    public interface DocumentColumns extends OpenableColumns {
135        /**
136         * The globally unique ID for a document within a storage backend.
137         * Values <em>must</em> never change once returned.
138         * <p>
139         * Type: STRING
140         *
141         * @see DocumentsContract#ROOT_GUID
142         */
143        public static final String GUID = "guid";
144
145        /**
146         * MIME type of a document, matching the value returned by
147         * {@link ContentResolver#getType(android.net.Uri)}.
148         * <p>
149         * Type: STRING
150         *
151         * @see DocumentsContract#MIME_TYPE_DIRECTORY
152         */
153        public static final String MIME_TYPE = "mime_type";
154
155        /**
156         * Timestamp when a document was last modified, in milliseconds since
157         * January 1, 1970 00:00:00.0 UTC.
158         * <p>
159         * Type: INTEGER (long)
160         *
161         * @see System#currentTimeMillis()
162         */
163        public static final String LAST_MODIFIED = "last_modified";
164
165        /**
166         * Flags that apply to a specific document.
167         * <p>
168         * Type: INTEGER (int)
169         */
170        public static final String FLAGS = "flags";
171    }
172
173    /**
174     * Return thumbnail representing the document at the given URI. Callers are
175     * responsible for their own caching. Given document must have
176     * {@link #FLAG_SUPPORTS_THUMBNAIL} set.
177     *
178     * @return decoded thumbnail, or {@code null} if problem was encountered.
179     */
180    public static Bitmap getThumbnail(ContentResolver resolver, Uri documentUri, Point size) {
181        final Bundle opts = new Bundle();
182        opts.putParcelable(EXTRA_THUMBNAIL_SIZE, size);
183
184        InputStream is = null;
185        try {
186            is = new AssetFileDescriptor.AutoCloseInputStream(
187                    resolver.openTypedAssetFileDescriptor(documentUri, "image/*", opts));
188            return BitmapFactory.decodeStream(is);
189        } catch (IOException e) {
190            Log.w(TAG, "Failed to load thumbnail for " + documentUri + ": " + e);
191            return null;
192        } finally {
193            IoUtils.closeQuietly(is);
194        }
195    }
196
197    /**
198     * Rename the document at the given URI. Given document must have
199     * {@link #FLAG_SUPPORTS_RENAME} set.
200     *
201     * @return if rename was successful.
202     */
203    public static boolean renameDocument(
204            ContentResolver resolver, Uri documentUri, String displayName) {
205        final ContentValues values = new ContentValues();
206        values.put(DocumentColumns.DISPLAY_NAME, displayName);
207        return (resolver.update(documentUri, values, null, null) == 1);
208    }
209}
210