1 /*
2  * Copyright (C) 2015 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 com.android.messaging.datamodel;
18 
19 import android.content.ContentResolver;
20 import android.content.Context;
21 import android.database.Cursor;
22 import android.database.MatrixCursor;
23 import android.database.MatrixCursor.RowBuilder;
24 import android.net.Uri;
25 import android.provider.OpenableColumns;
26 import android.support.v4.util.SimpleArrayMap;
27 import android.text.TextUtils;
28 
29 import com.android.messaging.Factory;
30 import com.android.messaging.util.Assert;
31 import com.android.messaging.util.LogUtil;
32 import com.google.common.annotations.VisibleForTesting;
33 
34 import java.io.File;
35 import java.util.List;
36 
37 /**
38  * A very simple content provider that can serve media files from our cache directory.
39  */
40 public class MediaScratchFileProvider extends FileProvider {
41     private static final String TAG = LogUtil.BUGLE_TAG;
42 
43     private static final SimpleArrayMap<Uri, String> sUriToDisplayNameMap =
44             new SimpleArrayMap<Uri, String>();
45 
46     @VisibleForTesting
47     public static final String AUTHORITY =
48             "com.android.messaging.datamodel.MediaScratchFileProvider";
49     private static final String MEDIA_SCRATCH_SPACE_DIR = "mediascratchspace";
50 
isMediaScratchSpaceUri(final Uri uri)51     public static boolean isMediaScratchSpaceUri(final Uri uri) {
52         if (uri == null) {
53             return false;
54         }
55 
56         final List<String> segments = uri.getPathSegments();
57         return (TextUtils.equals(uri.getScheme(), ContentResolver.SCHEME_CONTENT) &&
58                 TextUtils.equals(uri.getAuthority(), AUTHORITY) &&
59                 segments.size() == 1 && FileProvider.isValidFileId(segments.get(0)));
60     }
61 
62     /**
63      * Returns a uri that can be used to access a raw mms file.
64      *
65      * @return the URI for an raw mms file
66      */
buildMediaScratchSpaceUri(final String extension)67     public static Uri buildMediaScratchSpaceUri(final String extension) {
68         final Uri uri = FileProvider.buildFileUri(AUTHORITY, extension);
69         final File file = getFileWithExtension(uri.getPath(), extension);
70         if (!ensureFileExists(file)) {
71             LogUtil.e(TAG, "Failed to create temp file " + file.getAbsolutePath());
72         }
73         return uri;
74     }
75 
getFileFromUri(final Uri uri)76     public static File getFileFromUri(final Uri uri) {
77         Assert.equals(AUTHORITY, uri.getAuthority());
78         return getFileWithExtension(uri.getPath(), getExtensionFromUri(uri));
79     }
80 
getUriBuilder()81     public static Uri.Builder getUriBuilder() {
82         return (new Uri.Builder()).authority(AUTHORITY).scheme(ContentResolver.SCHEME_CONTENT);
83     }
84 
85     @Override
getFile(final String path, final String extension)86     File getFile(final String path, final String extension) {
87         return getFileWithExtension(path, extension);
88     }
89 
getFileWithExtension(final String path, final String extension)90     private static File getFileWithExtension(final String path, final String extension) {
91         final Context context = Factory.get().getApplicationContext();
92         return new File(getDirectory(context),
93                 TextUtils.isEmpty(extension) ? path : path + "." + extension);
94     }
95 
getDirectory(final Context context)96     private static File getDirectory(final Context context) {
97         return new File(context.getCacheDir(), MEDIA_SCRATCH_SPACE_DIR);
98     }
99 
100     @Override
query(final Uri uri, final String[] projection, final String selection, final String[] selectionArgs, final String sortOrder)101     public Cursor query(final Uri uri, final String[] projection, final String selection,
102             final String[] selectionArgs, final String sortOrder) {
103         if (projection != null && projection.length > 0 &&
104                 TextUtils.equals(projection[0], OpenableColumns.DISPLAY_NAME) &&
105                 isMediaScratchSpaceUri(uri)) {
106             // Retrieve the display name associated with a temp file. This is used by the Contacts
107             // ImportVCardActivity to retrieve the name of the contact(s) being imported.
108             String displayName;
109             synchronized (sUriToDisplayNameMap) {
110                 displayName = sUriToDisplayNameMap.get(uri);
111             }
112             if (!TextUtils.isEmpty(displayName)) {
113                 MatrixCursor cursor =
114                         new MatrixCursor(new String[] { OpenableColumns.DISPLAY_NAME });
115                 RowBuilder row = cursor.newRow();
116                 row.add(displayName);
117                 return cursor;
118             }
119         }
120         return null;
121     }
122 
addUriToDisplayNameEntry(final Uri scratchFileUri, final String displayName)123     public static void addUriToDisplayNameEntry(final Uri scratchFileUri,
124             final String displayName) {
125         if (TextUtils.isEmpty(displayName)) {
126             return;
127         }
128         synchronized (sUriToDisplayNameMap) {
129             sUriToDisplayNameMap.put(scratchFileUri, displayName);
130         }
131     }
132 }
133