/*
* Copyright (C) 2008 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.android.email.provider;
import com.android.email.Email;
import com.android.email.mail.internet.MimeUtility;
import com.android.email.provider.EmailContent.Attachment;
import com.android.email.provider.EmailContent.AttachmentColumns;
import com.android.email.provider.EmailContent.Message;
import com.android.email.provider.EmailContent.MessageColumns;
import android.content.ContentProvider;
import android.content.ContentResolver;
import android.content.ContentUris;
import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.database.MatrixCursor;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.net.Uri;
import android.os.ParcelFileDescriptor;
import android.text.TextUtils;
import android.webkit.MimeTypeMap;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.util.List;
/*
* A simple ContentProvider that allows file access to Email's attachments.
*
* The URI scheme is as follows. For raw file access:
* content://com.android.email.attachmentprovider/acct#/attach#/RAW
*
* And for access to thumbnails:
* content://com.android.email.attachmentprovider/acct#/attach#/THUMBNAIL/width#/height#
*
* The on-disk (storage) schema is as follows.
*
* Attachments are stored at: <database-path>/account#.db_att/item#
* Thumbnails are stored at: <cache-path>/thmb_account#_item#
*
* Using the standard application context, account #10 and attachment # 20, this would be:
* /data/data/com.android.email/databases/10.db_att/20
* /data/data/com.android.email/cache/thmb_10_20
*/
public class AttachmentProvider extends ContentProvider {
public static final String AUTHORITY = "com.android.email.attachmentprovider";
public static final Uri CONTENT_URI = Uri.parse( "content://" + AUTHORITY);
private static final String FORMAT_RAW = "RAW";
private static final String FORMAT_THUMBNAIL = "THUMBNAIL";
public static class AttachmentProviderColumns {
public static final String _ID = "_id";
public static final String DATA = "_data";
public static final String DISPLAY_NAME = "_display_name";
public static final String SIZE = "_size";
}
private static final String[] MIME_TYPE_PROJECTION = new String[] {
AttachmentColumns.MIME_TYPE, AttachmentColumns.FILENAME };
private static final int MIME_TYPE_COLUMN_MIME_TYPE = 0;
private static final int MIME_TYPE_COLUMN_FILENAME = 1;
private static final String[] PROJECTION_QUERY = new String[] { AttachmentColumns.FILENAME,
AttachmentColumns.SIZE, AttachmentColumns.CONTENT_URI };
public static Uri getAttachmentUri(long accountId, long id) {
return CONTENT_URI.buildUpon()
.appendPath(Long.toString(accountId))
.appendPath(Long.toString(id))
.appendPath(FORMAT_RAW)
.build();
}
public static Uri getAttachmentThumbnailUri(long accountId, long id,
int width, int height) {
return CONTENT_URI.buildUpon()
.appendPath(Long.toString(accountId))
.appendPath(Long.toString(id))
.appendPath(FORMAT_THUMBNAIL)
.appendPath(Integer.toString(width))
.appendPath(Integer.toString(height))
.build();
}
/**
* Return the filename for a given attachment. This should be used by any code that is
* going to *write* attachments.
*
* This does not create or write the file, or even the directories. It simply builds
* the filename that should be used.
*/
public static File getAttachmentFilename(Context context, long accountId, long attachmentId) {
return new File(getAttachmentDirectory(context, accountId), Long.toString(attachmentId));
}
/**
* Return the directory for a given attachment. This should be used by any code that is
* going to *write* attachments.
*
* This does not create or write the directory. It simply builds the pathname that should be
* used.
*/
public static File getAttachmentDirectory(Context context, long accountId) {
return context.getDatabasePath(accountId + ".db_att");
}
@Override
public boolean onCreate() {
/*
* We use the cache dir as a temporary directory (since Android doesn't give us one) so
* on startup we'll clean up any .tmp files from the last run.
*/
File[] files = getContext().getCacheDir().listFiles();
for (File file : files) {
String filename = file.getName();
if (filename.endsWith(".tmp") || filename.startsWith("thmb_")) {
file.delete();
}
}
return true;
}
/**
* Returns the mime type for a given attachment. There are three possible results:
* - If thumbnail Uri, always returns "image/png" (even if there's no attachment)
* - If the attachment does not exist, returns null
* - Returns the mime type of the attachment
*/
@Override
public String getType(Uri uri) {
List<String> segments = uri.getPathSegments();
String accountId = segments.get(0);
String id = segments.get(1);
String format = segments.get(2);
if (FORMAT_THUMBNAIL.equals(format)) {
return "image/png";
} else {
uri = ContentUris.withAppendedId(Attachment.CONTENT_URI, Long.parseLong(id));
Cursor c = getContext().getContentResolver().query(uri, MIME_TYPE_PROJECTION,
null, null, null);
try {
if (c.moveToFirst()) {
String mimeType = c.getString(MIME_TYPE_COLUMN_MIME_TYPE);
String fileName = c.getString(MIME_TYPE_COLUMN_FILENAME);
mimeType = inferMimeType(fileName, mimeType);
return mimeType;
}
} finally {
c.close();
}
return null;
}
}
/**
* Helper to convert unknown or unmapped attachments to something useful based on filename
* extensions. Imperfect, but helps.
*
* If the given mime type is non-empty and anything other than "application/octet-stream",
* just return it. (This is the most common case.)
* If the filename has a recognizable extension and it converts to a mime type, return that.
* If the filename has an unrecognized extension, return "application/extension"
* Otherwise return "application/octet-stream".
*
* @param fileName The given filename
* @param mimeType The given mime type
* @return A likely mime type for the attachment
*/
public static String inferMimeType(String fileName, String mimeType) {
// If the given mime type appears to be non-empty and non-generic - return it
if (!TextUtils.isEmpty(mimeType) &&
!"application/octet-stream".equalsIgnoreCase(mimeType)) {
return mimeType;
}
// Try to find an extension in the filename
if (!TextUtils.isEmpty(fileName)) {
int lastDot = fileName.lastIndexOf('.');
String extension = null;
if ((lastDot > 0) && (lastDot < fileName.length() - 1)) {
extension = fileName.substring(lastDot + 1).toLowerCase();
}
if (!TextUtils.isEmpty(extension)) {
// Extension found. Look up mime type, or synthesize if none found.
mimeType = MimeTypeMap.getSingleton().getMimeTypeFromExtension(extension);
if (mimeType == null) {
mimeType = "application/" + extension;
}
return mimeType;
}
}
// Fallback case - no good guess could be made.
return "application/octet-stream";
}
/**
* Open an attachment file. There are two "modes" - "raw", which returns an actual file,
* and "thumbnail", which attempts to generate a thumbnail image.
*
* Thumbnails are cached for easy space recovery and cleanup.
*
* TODO: The thumbnail mode returns null for its failure cases, instead of throwing
* FileNotFoundException, and should be fixed for consistency.
*
* @throws FileNotFoundException
*/
@Override
public ParcelFileDescriptor openFile(Uri uri, String mode) throws FileNotFoundException {
List<String> segments = uri.getPathSegments();
String accountId = segments.get(0);
String id = segments.get(1);
String format = segments.get(2);
if (FORMAT_THUMBNAIL.equals(format)) {
int width = Integer.parseInt(segments.get(3));
int height = Integer.parseInt(segments.get(4));
String filename = "thmb_" + accountId + "_" + id;
File dir = getContext().getCacheDir();
File file = new File(dir, filename);
if (!file.exists()) {
Uri attachmentUri = getAttachmentUri(Long.parseLong(accountId), Long.parseLong(id));
Cursor c = query(attachmentUri,
new String[] { AttachmentProviderColumns.DATA }, null, null, null);
if (c != null) {
try {
if (c.moveToFirst()) {
attachmentUri = Uri.parse(c.getString(0));
} else {
return null;
}
} finally {
c.close();
}
}
String type = getContext().getContentResolver().getType(attachmentUri);
try {
InputStream in =
getContext().getContentResolver().openInputStream(attachmentUri);
Bitmap thumbnail = createThumbnail(type, in);
thumbnail = Bitmap.createScaledBitmap(thumbnail, width, height, true);
FileOutputStream out = new FileOutputStream(file);
thumbnail.compress(Bitmap.CompressFormat.PNG, 100, out);
out.close();
in.close();
}
catch (IOException ioe) {
return null;
}
}
return ParcelFileDescriptor.open(file, ParcelFileDescriptor.MODE_READ_ONLY);
}
else {
return ParcelFileDescriptor.open(
new File(getContext().getDatabasePath(accountId + ".db_att"), id),
ParcelFileDescriptor.MODE_READ_ONLY);
}
}
@Override
public int delete(Uri uri, String arg1, String[] arg2) {
return 0;
}
@Override
public Uri insert(Uri uri, ContentValues values) {
return null;
}
/**
* Returns a cursor based on the data in the attachments table, or null if the attachment
* is not recorded in the table.
*
* Supports REST Uri only, for a single row - selection, selection args, and sortOrder are
* ignored (non-null values should probably throw an exception....)
*/
@Override
public Cursor query(Uri uri, String[] projection, String selection, String[] selectionArgs,
String sortOrder) {
if (projection == null) {
projection =
new String[] {
AttachmentProviderColumns._ID,
AttachmentProviderColumns.DATA,
};
}
List<String> segments = uri.getPathSegments();
String accountId = segments.get(0);
String id = segments.get(1);
String format = segments.get(2);
String name = null;
int size = -1;
String contentUri = null;
uri = ContentUris.withAppendedId(Attachment.CONTENT_URI, Long.parseLong(id));
Cursor c = getContext().getContentResolver().query(uri, PROJECTION_QUERY,
null, null, null);
try {
if (c.moveToFirst()) {
name = c.getString(0);
size = c.getInt(1);
contentUri = c.getString(2);
} else {
return null;
}
} finally {
c.close();
}
MatrixCursor ret = new MatrixCursor(projection);
Object[] values = new Object[projection.length];
for (int i = 0, count = projection.length; i < count; i++) {
String column = projection[i];
if (AttachmentProviderColumns._ID.equals(column)) {
values[i] = id;
}
else if (AttachmentProviderColumns.DATA.equals(column)) {
values[i] = contentUri;
}
else if (AttachmentProviderColumns.DISPLAY_NAME.equals(column)) {
values[i] = name;
}
else if (AttachmentProviderColumns.SIZE.equals(column)) {
values[i] = size;
}
}
ret.addRow(values);
return ret;
}
@Override
public int update(Uri uri, ContentValues values, String selection, String[] selectionArgs) {
return 0;
}
private Bitmap createThumbnail(String type, InputStream data) {
if(MimeUtility.mimeTypeMatches(type, "image/*")) {
return createImageThumbnail(data);
}
return null;
}
private Bitmap createImageThumbnail(InputStream data) {
try {
Bitmap bitmap = BitmapFactory.decodeStream(data);
return bitmap;
}
catch (OutOfMemoryError oome) {
/*
* Improperly downloaded images, corrupt bitmaps and the like can commonly
* cause OOME due to invalid allocation sizes. We're happy with a null bitmap in
* that case. If the system is really out of memory we'll know about it soon
* enough.
*/
return null;
}
catch (Exception e) {
return null;
}
}
/**
* Resolve attachment id to content URI. Returns the resolved content URI (from the attachment
* DB) or, if not found, simply returns the incoming value.
*
* @param attachmentUri
* @return resolved content URI
*
* TODO: Throws an SQLite exception on a missing DB file (e.g. unknown URI) instead of just
* returning the incoming uri, as it should.
*/
public static Uri resolveAttachmentIdToContentUri(ContentResolver resolver, Uri attachmentUri) {
Cursor c = resolver.query(attachmentUri,
new String[] { AttachmentProvider.AttachmentProviderColumns.DATA },
null, null, null);
if (c != null) {
try {
if (c.moveToFirst()) {
final String strUri = c.getString(0);
if (strUri != null) {
return Uri.parse(strUri);
} else {
Email.log("AttachmentProvider: attachment with null contentUri");
}
}
} finally {
c.close();
}
}
return attachmentUri;
}
/**
* In support of deleting a message, find all attachments and delete associated attachment
* files.
* @param context
* @param accountId the account for the message
* @param messageId the message
*/
public static void deleteAllAttachmentFiles(Context context, long accountId, long messageId) {
Uri uri = ContentUris.withAppendedId(Attachment.MESSAGE_ID_URI, messageId);
Cursor c = context.getContentResolver().query(uri, Attachment.ID_PROJECTION,
null, null, null);
try {
while (c.moveToNext()) {
long attachmentId = c.getLong(Attachment.ID_PROJECTION_COLUMN);
File attachmentFile = getAttachmentFilename(context, accountId, attachmentId);
// Note, delete() throws no exceptions for basic FS errors (e.g. file not found)
// it just returns false, which we ignore, and proceed to the next file.
// This entire loop is best-effort only.
attachmentFile.delete();
}
} finally {
c.close();
}
}
/**
* In support of deleting a mailbox, find all messages and delete their attachments.
*
* @param context
* @param accountId the account for the mailbox
* @param mailboxId the mailbox for the messages
*/
public static void deleteAllMailboxAttachmentFiles(Context context, long accountId,
long mailboxId) {
Cursor c = context.getContentResolver().query(Message.CONTENT_URI,
Message.ID_COLUMN_PROJECTION, MessageColumns.MAILBOX_KEY + "=?",
new String[] { Long.toString(mailboxId) }, null);
try {
while (c.moveToNext()) {
long messageId = c.getLong(Message.ID_PROJECTION_COLUMN);
deleteAllAttachmentFiles(context, accountId, messageId);
}
} finally {
c.close();
}
}
}