AttachmentProvider.java revision 7436601fae756e8bc1f916560a1c2d1f8ce576fc 
1/*
2 * Copyright (C) 2008 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 com.android.email.provider;
18
19import java.io.File;
20import java.io.FileInputStream;
21import java.io.FileNotFoundException;
22import java.io.FileOutputStream;
23import java.io.IOException;
24import java.io.InputStream;
25import java.util.List;
26
27import android.content.ContentProvider;
28import android.content.ContentResolver;
29import android.content.ContentValues;
30import android.database.Cursor;
31import android.database.MatrixCursor;
32import android.database.sqlite.SQLiteDatabase;
33import android.graphics.Bitmap;
34import android.graphics.BitmapFactory;
35import android.net.Uri;
36import android.os.ParcelFileDescriptor;
37import android.provider.OpenableColumns;
38import android.util.Config;
39import android.util.Log;
40
41import com.android.email.Account;
42import com.android.email.Email;
43import com.android.email.Utility;
44import com.android.email.mail.internet.MimeUtility;
45
46/*
47 * A simple ContentProvider that allows file access to Email's attachments.
48 */
49public class AttachmentProvider extends ContentProvider {
50    public static final Uri CONTENT_URI = Uri.parse( "content://com.android.email.attachmentprovider");
51
52    private static final String FORMAT_RAW = "RAW";
53    private static final String FORMAT_THUMBNAIL = "THUMBNAIL";
54
55    public static class AttachmentProviderColumns {
56        public static final String _ID = "_id";
57        public static final String DATA = "_data";
58        public static final String DISPLAY_NAME = "_display_name";
59        public static final String SIZE = "_size";
60    }
61
62    public static Uri getAttachmentUri(Account account, long id) {
63        return CONTENT_URI.buildUpon()
64                .appendPath(account.getUuid() + ".db")
65                .appendPath(Long.toString(id))
66                .appendPath(FORMAT_RAW)
67                .build();
68    }
69
70    public static Uri getAttachmentThumbnailUri(Account account, long id, int width, int height) {
71        return CONTENT_URI.buildUpon()
72                .appendPath(account.getUuid() + ".db")
73                .appendPath(Long.toString(id))
74                .appendPath(FORMAT_THUMBNAIL)
75                .appendPath(Integer.toString(width))
76                .appendPath(Integer.toString(height))
77                .build();
78    }
79
80    public static Uri getAttachmentUri(String db, long id) {
81        return CONTENT_URI.buildUpon()
82                .appendPath(db)
83                .appendPath(Long.toString(id))
84                .appendPath(FORMAT_RAW)
85                .build();
86    }
87
88    @Override
89    public boolean onCreate() {
90        /*
91         * We use the cache dir as a temporary directory (since Android doesn't give us one) so
92         * on startup we'll clean up any .tmp files from the last run.
93         */
94        File[] files = getContext().getCacheDir().listFiles();
95        for (File file : files) {
96            if (file.getName().endsWith(".tmp")) {
97                file.delete();
98            }
99        }
100        return true;
101    }
102
103    @Override
104    public String getType(Uri uri) {
105        List<String> segments = uri.getPathSegments();
106        String dbName = segments.get(0);
107        String id = segments.get(1);
108        String format = segments.get(2);
109        if (FORMAT_THUMBNAIL.equals(format)) {
110            return "image/png";
111        }
112        else {
113            String path = getContext().getDatabasePath(dbName).getAbsolutePath();
114            SQLiteDatabase db = null;
115            Cursor cursor = null;
116            try {
117                db = SQLiteDatabase.openDatabase(path, null, 0);
118                cursor = db.query(
119                        "attachments",
120                        new String[] { "mime_type" },
121                        "id = ?",
122                        new String[] { id },
123                        null,
124                        null,
125                        null);
126                cursor.moveToFirst();
127                String type = cursor.getString(0);
128                cursor.close();
129                db.close();
130                return type;
131
132            }
133            finally {
134                if (cursor != null) {
135                    cursor.close();
136                }
137                if (db != null) {
138                    db.close();
139                }
140
141            }
142        }
143    }
144
145    @Override
146    public ParcelFileDescriptor openFile(Uri uri, String mode) throws FileNotFoundException {
147        List<String> segments = uri.getPathSegments();
148        String dbName = segments.get(0);
149        String id = segments.get(1);
150        String format = segments.get(2);
151        if (FORMAT_THUMBNAIL.equals(format)) {
152            int width = Integer.parseInt(segments.get(3));
153            int height = Integer.parseInt(segments.get(4));
154            String filename = "thmb_" + dbName + "_" + id;
155            File dir = getContext().getCacheDir();
156            File file = new File(dir, filename);
157            if (!file.exists()) {
158                Uri attachmentUri = getAttachmentUri(dbName, Long.parseLong(id));
159                Cursor c = query(attachmentUri,
160                        new String[] { AttachmentProviderColumns.DATA }, null, null, null);
161                if (c != null) {
162                    try {
163                        if (c.moveToFirst()) {
164                            attachmentUri = Uri.parse(c.getString(0));
165                        }
166                    } finally {
167                        c.close();
168                    }
169                }
170                String type = getContext().getContentResolver().getType(attachmentUri);
171                try {
172                    InputStream in =
173                        getContext().getContentResolver().openInputStream(attachmentUri);
174                    Bitmap thumbnail = createThumbnail(type, in);
175                    thumbnail = Bitmap.createScaledBitmap(thumbnail, width, height, true);
176                    FileOutputStream out = new FileOutputStream(file);
177                    thumbnail.compress(Bitmap.CompressFormat.PNG, 100, out);
178                    out.close();
179                    in.close();
180                }
181                catch (IOException ioe) {
182                    return null;
183                }
184            }
185            return ParcelFileDescriptor.open(file, ParcelFileDescriptor.MODE_READ_ONLY);
186        }
187        else {
188            return ParcelFileDescriptor.open(
189                    new File(getContext().getDatabasePath(dbName + "_att"), id),
190                    ParcelFileDescriptor.MODE_READ_ONLY);
191        }
192    }
193
194    @Override
195    public int delete(Uri uri, String arg1, String[] arg2) {
196        return 0;
197    }
198
199    @Override
200    public Uri insert(Uri uri, ContentValues values) {
201        return null;
202    }
203
204    @Override
205    public Cursor query(Uri uri, String[] projection, String selection, String[] selectionArgs,
206            String sortOrder) {
207        if (projection == null) {
208            projection =
209                new String[] {
210                    AttachmentProviderColumns._ID,
211                    AttachmentProviderColumns.DATA,
212                    };
213        }
214
215        List<String> segments = uri.getPathSegments();
216        String dbName = segments.get(0);
217        String id = segments.get(1);
218        String format = segments.get(2);
219        String path = getContext().getDatabasePath(dbName).getAbsolutePath();
220        String name = null;
221        int size = -1;
222        String contentUri = null;
223        SQLiteDatabase db = null;
224        Cursor cursor = null;
225        try {
226            db = SQLiteDatabase.openDatabase(path, null, 0);
227            cursor = db.query(
228                    "attachments",
229                    new String[] { "name", "size", "content_uri" },
230                    "id = ?",
231                    new String[] { id },
232                    null,
233                    null,
234                    null);
235            if (!cursor.moveToFirst()) {
236                return null;
237            }
238            name = cursor.getString(0);
239            size = cursor.getInt(1);
240            contentUri = cursor.getString(2);
241        }
242        finally {
243            if (cursor != null) {
244                cursor.close();
245            }
246            if (db != null) {
247                db.close();
248            }
249        }
250
251        MatrixCursor ret = new MatrixCursor(projection);
252        Object[] values = new Object[projection.length];
253        for (int i = 0, count = projection.length; i < count; i++) {
254            String column = projection[i];
255            if (AttachmentProviderColumns._ID.equals(column)) {
256                values[i] = id;
257            }
258            else if (AttachmentProviderColumns.DATA.equals(column)) {
259                values[i] = contentUri;
260            }
261            else if (AttachmentProviderColumns.DISPLAY_NAME.equals(column)) {
262                values[i] = name;
263            }
264            else if (AttachmentProviderColumns.SIZE.equals(column)) {
265                values[i] = size;
266            }
267        }
268        ret.addRow(values);
269        return ret;
270    }
271
272    @Override
273    public int update(Uri uri, ContentValues values, String selection, String[] selectionArgs) {
274        return 0;
275    }
276
277    private Bitmap createThumbnail(String type, InputStream data) {
278        if(MimeUtility.mimeTypeMatches(type, "image/*")) {
279            return createImageThumbnail(data);
280        }
281        return null;
282    }
283
284    private Bitmap createImageThumbnail(InputStream data) {
285        try {
286            Bitmap bitmap = BitmapFactory.decodeStream(data);
287            return bitmap;
288        }
289        catch (OutOfMemoryError oome) {
290            /*
291             * Improperly downloaded images, corrupt bitmaps and the like can commonly
292             * cause OOME due to invalid allocation sizes. We're happy with a null bitmap in
293             * that case. If the system is really out of memory we'll know about it soon
294             * enough.
295             */
296            return null;
297        }
298        catch (Exception e) {
299            return null;
300        }
301    }
302    /**
303     * Resolve attachment id to content URI.
304     *
305     * @param attachmentUri
306     * @return resolved content URI
307     */
308    public static Uri resolveAttachmentIdToContentUri(ContentResolver resolver, Uri attachmentUri) {
309        Cursor c = resolver.query(attachmentUri,
310                new String[] { AttachmentProvider.AttachmentProviderColumns.DATA },
311                null, null, null);
312        if (c != null) {
313            try {
314                if (c.moveToFirst()) {
315                    return Uri.parse(c.getString(0));
316                }
317            } finally {
318                c.close();
319            }
320        }
321        return attachmentUri;
322    }
323}
324