src/com/owncloud/android/files/services/FileDownloader.java

   1 /* ownCloud Android client application
   2  *   Copyright (C) 2012 Bartek Przybylski
   3  *   Copyright (C) 2012-2013 ownCloud Inc.
   4  *
   5  *   This program is free software: you can redistribute it and/or modify
   6  *   it under the terms of the GNU General Public License version 2,
   7  *   as published by the Free Software Foundation.
   8  *
   9  *   This program is distributed in the hope that it will be useful,
  10  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  *   GNU General Public License for more details.
  13  *
  14  *   You should have received a copy of the GNU General Public License
  15  *   along with this program.  If not, see <http://www.gnu.org/licenses/>.
  16  *
  17  */
  18
  19 package com.owncloud.android.files.services;
  20
  21 import java.io.File;
  22 import java.io.IOException;
  23 import java.util.AbstractList;
  24 import java.util.ArrayList;
  25 import java.util.HashMap;
  26 import java.util.Iterator;
  27 import java.util.Map;
  28 import java.util.Vector;
  29 import java.util.concurrent.ConcurrentHashMap;
  30 import java.util.concurrent.ConcurrentMap;
  31
  32 import com.owncloud.android.R;
  33 import com.owncloud.android.authentication.AuthenticatorActivity;
  34 import com.owncloud.android.datamodel.FileDataStorageManager;
  35 import com.owncloud.android.datamodel.OCFile;
  36
  37 import com.owncloud.android.lib.common.network.OnDatatransferProgressListener;
  38 import com.owncloud.android.lib.common.OwnCloudAccount;
  39 import com.owncloud.android.lib.common.OwnCloudClient;
  40 import com.owncloud.android.lib.common.OwnCloudClientManagerFactory;
  41 import com.owncloud.android.notifications.NotificationBuilderWithProgressBar;
  42 import com.owncloud.android.notifications.NotificationDelayer;
  43 import com.owncloud.android.lib.common.operations.RemoteOperationResult;
  44 import com.owncloud.android.lib.common.operations.RemoteOperationResult.ResultCode;
  45 import com.owncloud.android.lib.common.utils.Log_OC;
  46 import com.owncloud.android.lib.resources.files.FileUtils;
  47 import com.owncloud.android.operations.DownloadFileOperation;
  48 import com.owncloud.android.ui.activity.FileActivity;
  49 import com.owncloud.android.ui.activity.FileDisplayActivity;
  50 import com.owncloud.android.ui.preview.PreviewImageActivity;
  51 import com.owncloud.android.ui.preview.PreviewImageFragment;
  52 import com.owncloud.android.utils.ErrorMessageAdapter;
  53
  54 import android.accounts.Account;
  55 import android.accounts.AccountsException;
  56 import android.app.NotificationManager;
  57 import android.app.PendingIntent;
  58 import android.app.Service;
  59 import android.content.Intent;
  60 import android.os.Binder;
  61 import android.os.Handler;
  62 import android.os.HandlerThread;
  63 import android.os.IBinder;
  64 import android.os.Looper;
  65 import android.os.Message;
  66 import android.os.Process;
  67 import android.support.v4.app.NotificationCompat;
  68
  69 public class FileDownloader extends Service implements OnDatatransferProgressListener {
  70
  71     public static final String EXTRA_ACCOUNT = "ACCOUNT";
  72     public static final String EXTRA_FILE = "FILE";
  73
  74     public static final String ACTION_CANCEL_FILE_DOWNLOAD = "CANCEL_FILE_DOWNLOAD";
  75
  76     private static final String DOWNLOAD_ADDED_MESSAGE = "DOWNLOAD_ADDED";
  77     private static final String DOWNLOAD_FINISH_MESSAGE = "DOWNLOAD_FINISH";
  78     public static final String EXTRA_DOWNLOAD_RESULT = "RESULT";
  79     public static final String EXTRA_FILE_PATH = "FILE_PATH";
  80     public static final String EXTRA_REMOTE_PATH = "REMOTE_PATH";
  81     public static final String ACCOUNT_NAME = "ACCOUNT_NAME";
  82
  83     private static final String TAG = "FileDownloader";
  84
  85     private Looper mServiceLooper;
  86     private ServiceHandler mServiceHandler;
  87     private IBinder mBinder;
  88     private OwnCloudClient mDownloadClient = null;
  89     private Account mLastAccount = null;
  90     private FileDataStorageManager mStorageManager;
  91
  92     private ConcurrentMap<String, DownloadFileOperation> mPendingDownloads = new ConcurrentHashMap<String, DownloadFileOperation>();
  93     private DownloadFileOperation mCurrentDownload = null;
  94
  95     private NotificationManager mNotificationManager;
  96     private NotificationCompat.Builder mNotificationBuilder;
  97     private int mLastPercent;
  98
  99
 100     public static String getDownloadAddedMessage() {
 101         return FileDownloader.class.getName().toString() + DOWNLOAD_ADDED_MESSAGE;
 102     }
 103
 104     public static String getDownloadFinishMessage() {
 105         return FileDownloader.class.getName().toString() + DOWNLOAD_FINISH_MESSAGE;
 106     }
 107
 108     /**
 109      * Builds a key for mPendingDownloads from the account and file to download
 110      *
 111      * @param account   Account where the file to download is stored
 112      * @param file      File to download
 113      */
 114     private String buildRemoteName(Account account, OCFile file) {
 115         return account.name + file.getRemotePath();
 116     }
 117
 118
 119     /**
 120      * Service initialization
 121      */
 122     @Override
 123     public void onCreate() {
 124         super.onCreate();
 125         mNotificationManager = (NotificationManager) getSystemService(NOTIFICATION_SERVICE);
 126         HandlerThread thread = new HandlerThread("FileDownloaderThread",
 127                 Process.THREAD_PRIORITY_BACKGROUND);
 128         thread.start();
 129         mServiceLooper = thread.getLooper();
 130         mServiceHandler = new ServiceHandler(mServiceLooper, this);
 131         mBinder = new FileDownloaderBinder();
 132     }
 133
 134     /**
 135      * Entry point to add one or several files to the queue of downloads.
 136      *
 137      * New downloads are added calling to startService(), resulting in a call to this method. This ensures the service will keep on working
 138      * although the caller activity goes away.
 139      */
 140     @Override
 141     public int onStartCommand(Intent intent, int flags, int startId) {
 142         if (    !intent.hasExtra(EXTRA_ACCOUNT) ||
 143                 !intent.hasExtra(EXTRA_FILE)
 144                 /*!intent.hasExtra(EXTRA_FILE_PATH) ||
 145                 !intent.hasExtra(EXTRA_REMOTE_PATH)*/
 146            ) {
 147             Log_OC.e(TAG, "Not enough information provided in intent");
 148             return START_NOT_STICKY;
 149         } else {
 150             final Account account = intent.getParcelableExtra(EXTRA_ACCOUNT);
 151             final OCFile file = intent.getParcelableExtra(EXTRA_FILE);
 152
 153             if (ACTION_CANCEL_FILE_DOWNLOAD.equals(intent.getAction())) {
 154
 155                 new Thread(new Runnable() {
 156                     public void run() {
 157                         // Cancel the download
 158                         cancel(account, file);
 159                     }
 160                 }).start();
 161
 162             } else {
 163
 164                 AbstractList<String> requestedDownloads = new Vector<String>(); // dvelasco: now this always contains just one element, but that can change in a near future (download of multiple selection)
 165                 String downloadKey = buildRemoteName(account, file);
 166                 try {
 167                     DownloadFileOperation newDownload = new DownloadFileOperation(account, file);
 168                     mPendingDownloads.putIfAbsent(downloadKey, newDownload);
 169                     newDownload.addDatatransferProgressListener(this);
 170                     newDownload.addDatatransferProgressListener((FileDownloaderBinder) mBinder);
 171                     requestedDownloads.add(downloadKey);
 172                     sendBroadcastNewDownload(newDownload);
 173
 174                 } catch (IllegalArgumentException e) {
 175                     Log_OC.e(TAG, "Not enough information provided in intent: " + e.getMessage());
 176                     return START_NOT_STICKY;
 177                 }
 178
 179                 if (requestedDownloads.size() > 0) {
 180                     Message msg = mServiceHandler.obtainMessage();
 181                     msg.arg1 = startId;
 182                     msg.obj = requestedDownloads;
 183                     mServiceHandler.sendMessage(msg);
 184                 }
 185             }
 186         }
 187
 188         return START_NOT_STICKY;
 189     }
 190
 191
 192     /**
 193      * Provides a binder object that clients can use to perform operations on the queue of downloads, excepting the addition of new files.
 194      *
 195      * Implemented to perform cancellation, pause and resume of existing downloads.
 196      */
 197     @Override
 198     public IBinder onBind(Intent arg0) {
 199         return mBinder;
 200     }
 201
 202
 203     /**
 204      * Called when ALL the bound clients were onbound.
 205      */
 206     @Override
 207     public boolean onUnbind(Intent intent) {
 208         ((FileDownloaderBinder)mBinder).clearListeners();
 209         return false;   // not accepting rebinding (default behaviour)
 210     }
 211
 212
 213     /**
 214      *  Binder to let client components to perform operations on the queue of downloads.
 215      *
 216      *  It provides by itself the available operations.
 217      */
 218     public class FileDownloaderBinder extends Binder implements OnDatatransferProgressListener {
 219
 220         /**
 221          * Map of listeners that will be reported about progress of downloads from a {@link FileDownloaderBinder} instance
 222          */
 223         private Map<String, OnDatatransferProgressListener> mBoundListeners = new HashMap<String, OnDatatransferProgressListener>();
 224
 225
 226         /**
 227          * Cancels a pending or current download of a remote file.
 228          *
 229          * @param account       Owncloud account where the remote file is stored.
 230          * @param file          A file in the queue of pending downloads
 231          */
 232         public void cancel(Account account, OCFile file) {
 233             DownloadFileOperation download = null;
 234             synchronized (mPendingDownloads) {
 235                 download = mPendingDownloads.remove(buildRemoteName(account, file));
 236             }
 237             if (download != null) {
 238                 download.cancel();
 239             }
 240         }
 241
 242
 243         public void clearListeners() {
 244             mBoundListeners.clear();
 245         }
 246
 247
 248         /**
 249          * Returns True when the file described by 'file' in the ownCloud account 'account' is downloading or waiting to download.
 250          *
 251          * If 'file' is a directory, returns 'true' if some of its descendant files is downloading or waiting to download.
 252          *
 253          * @param account       Owncloud account where the remote file is stored.
 254          * @param file          A file that could be in the queue of downloads.
 255          */
 256         public boolean isDownloading(Account account, OCFile file) {
 257             if (account == null || file == null) return false;
 258             String targetKey = buildRemoteName(account, file);
 259             synchronized (mPendingDownloads) {
 260                 if (file.isFolder()) {
 261                     // this can be slow if there are many downloads :(
 262                     Iterator<String> it = mPendingDownloads.keySet().iterator();
 263                     boolean found = false;
 264                     while (it.hasNext() && !found) {
 265                         found = it.next().startsWith(targetKey);
 266                     }
 267                     return found;
 268                 } else {
 269                     return (mPendingDownloads.containsKey(targetKey));
 270                 }
 271             }
 272         }
 273
 274
 275         /**
 276          * Adds a listener interested in the progress of the download for a concrete file.
 277          *
 278          * @param listener      Object to notify about progress of transfer.
 279          * @param account       ownCloud account holding the file of interest.
 280          * @param file          {@link OCfile} of interest for listener.
 281          */
 282         public void addDatatransferProgressListener (OnDatatransferProgressListener listener, Account account, OCFile file) {
 283             if (account == null || file == null || listener == null) return;
 284             String targetKey = buildRemoteName(account, file);
 285             mBoundListeners.put(targetKey, listener);
 286         }
 287
 288
 289         /**
 290          * Removes a listener interested in the progress of the download for a concrete file.
 291          *
 292          * @param listener      Object to notify about progress of transfer.
 293          * @param account       ownCloud account holding the file of interest.
 294          * @param file          {@link OCfile} of interest for listener.
 295          */
 296         public void removeDatatransferProgressListener (OnDatatransferProgressListener listener, Account account, OCFile file) {
 297             if (account == null || file == null || listener == null) return;
 298             String targetKey = buildRemoteName(account, file);
 299             if (mBoundListeners.get(targetKey) == listener) {
 300                 mBoundListeners.remove(targetKey);
 301             }
 302         }
 303
 304         @Override
 305         public void onTransferProgress(long progressRate, long totalTransferredSoFar, long totalToTransfer,
 306                 String fileName) {
 307             String key = buildRemoteName(mCurrentDownload.getAccount(), mCurrentDownload.getFile());
 308             OnDatatransferProgressListener boundListener = mBoundListeners.get(key);
 309             if (boundListener != null) {
 310                 boundListener.onTransferProgress(progressRate, totalTransferredSoFar, totalToTransfer, fileName);
 311             }
 312         }
 313
 314     }
 315
 316
 317     /**
 318      * Download worker. Performs the pending downloads in the order they were requested.
 319      *
 320      * Created with the Looper of a new thread, started in {@link FileUploader#onCreate()}.
 321      */
 322     private static class ServiceHandler extends Handler {
 323         // don't make it a final class, and don't remove the static ; lint will warn about a possible memory leak
 324         FileDownloader mService;
 325         public ServiceHandler(Looper looper, FileDownloader service) {
 326             super(looper);
 327             if (service == null)
 328                 throw new IllegalArgumentException("Received invalid NULL in parameter 'service'");
 329             mService = service;
 330         }
 331
 332         @Override
 333         public void handleMessage(Message msg) {
 334             @SuppressWarnings("unchecked")
 335             AbstractList<String> requestedDownloads = (AbstractList<String>) msg.obj;
 336             if (msg.obj != null) {
 337                 Iterator<String> it = requestedDownloads.iterator();
 338                 while (it.hasNext()) {
 339                     mService.downloadFile(it.next());
 340                 }
 341             }
 342             mService.stopSelf(msg.arg1);
 343         }
 344     }
 345
 346
 347     /**
 348      * Core download method: requests a file to download and stores it.
 349      *
 350      * @param downloadKey   Key to access the download to perform, contained in mPendingDownloads
 351      */
 352     private void downloadFile(String downloadKey) {
 353
 354         synchronized(mPendingDownloads) {
 355             mCurrentDownload = mPendingDownloads.get(downloadKey);
 356         }
 357
 358         if (mCurrentDownload != null) {
 359
 360             notifyDownloadStart(mCurrentDownload);
 361
 362             RemoteOperationResult downloadResult = null;
 363             try {
 364                 /// prepare client object to send the request to the ownCloud server
 365                 if (mDownloadClient == null || !mLastAccount.equals(mCurrentDownload.getAccount())) {
 366                     mLastAccount = mCurrentDownload.getAccount();
 367                     mStorageManager =
 368                             new FileDataStorageManager(mLastAccount, getContentResolver());
 369                     OwnCloudAccount ocAccount = new OwnCloudAccount(mLastAccount, this);
 370                     mDownloadClient = OwnCloudClientManagerFactory.getDefaultSingleton().
 371                             getClientFor(ocAccount, this);
 372                 }
 373
 374                 /// perform the download
 375                 downloadResult = mCurrentDownload.execute(mDownloadClient);
 376                 if (downloadResult.isSuccess()) {
 377                     saveDownloadedFile();
 378                 }
 379
 380             } catch (AccountsException e) {
 381                 Log_OC.e(TAG, "Error while trying to get autorization for " + mLastAccount.name, e);
 382                 downloadResult = new RemoteOperationResult(e);
 383             } catch (IOException e) {
 384                 Log_OC.e(TAG, "Error while trying to get autorization for " + mLastAccount.name, e);
 385                 downloadResult = new RemoteOperationResult(e);
 386
 387             } finally {
 388                 synchronized(mPendingDownloads) {
 389                     mPendingDownloads.remove(downloadKey);
 390                 }
 391             }
 392
 393
 394             /// notify result
 395             notifyDownloadResult(mCurrentDownload, downloadResult);
 396
 397             sendBroadcastDownloadFinished(mCurrentDownload, downloadResult);
 398         }
 399     }
 400
 401
 402     /**
 403      * Updates the OC File after a successful download.
 404      */
 405     private void saveDownloadedFile() {
 406         OCFile file = mStorageManager.getFileById(mCurrentDownload.getFile().getFileId());
 407         long syncDate = System.currentTimeMillis();
 408         file.setLastSyncDateForProperties(syncDate);
 409         file.setLastSyncDateForData(syncDate);
 410         file.setNeedsUpdateThumbnail(true);
 411         file.setModificationTimestamp(mCurrentDownload.getModificationTimestamp());
 412         file.setModificationTimestampAtLastSyncForData(mCurrentDownload.getModificationTimestamp());
 413         // file.setEtag(mCurrentDownload.getEtag());    // TODO Etag, where available
 414         file.setMimetype(mCurrentDownload.getMimeType());
 415         file.setStoragePath(mCurrentDownload.getSavePath());
 416         file.setFileLength((new File(mCurrentDownload.getSavePath()).length()));
 417         file.setRemoteId(mCurrentDownload.getFile().getRemoteId());
 418         file.setDownloading(false);
 419         file.setUploading(false);
 420         mStorageManager.saveFile(file);
 421         mStorageManager.triggerMediaScan(file.getStoragePath());
 422     }
 423
 424
 425     /**
 426      * Creates a status notification to show the download progress
 427      *
 428      * @param download  Download operation starting.
 429      */
 430     private void notifyDownloadStart(DownloadFileOperation download) {
 431         /// create status notification with a progress bar
 432         mLastPercent = 0;
 433         mNotificationBuilder =
 434                 NotificationBuilderWithProgressBar.newNotificationBuilderWithProgressBar(this);
 435         mNotificationBuilder
 436                 .setSmallIcon(R.drawable.notification_icon)
 437                 .setTicker(getString(R.string.downloader_download_in_progress_ticker))
 438                 .setContentTitle(getString(R.string.downloader_download_in_progress_ticker))
 439                 .setOngoing(true)
 440                 .setProgress(100, 0, download.getSize() < 0)
 441                 .setContentText(
 442                         String.format(getString(R.string.downloader_download_in_progress_content), 0,
 443                                 new File(download.getSavePath()).getName())
 444                 );
 445
 446         /// includes a pending intent in the notification showing the details view of the file
 447         Intent showDetailsIntent = null;
 448         if (PreviewImageFragment.canBePreviewed(download.getFile())) {
 449             showDetailsIntent = new Intent(this, PreviewImageActivity.class);
 450         } else {
 451             showDetailsIntent = new Intent(this, FileDisplayActivity.class);
 452         }
 453         showDetailsIntent.putExtra(FileActivity.EXTRA_FILE, download.getFile());
 454         showDetailsIntent.putExtra(FileActivity.EXTRA_ACCOUNT, download.getAccount());
 455         showDetailsIntent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
 456
 457         mNotificationBuilder.setContentIntent(PendingIntent.getActivity(
 458             this, (int) System.currentTimeMillis(), showDetailsIntent, 0
 459         ));
 460
 461         mNotificationManager.notify(R.string.downloader_download_in_progress_ticker, mNotificationBuilder.build());
 462     }
 463
 464
 465     /**
 466      * Callback method to update the progress bar in the status notification.
 467      */
 468     @Override
 469     public void onTransferProgress(long progressRate, long totalTransferredSoFar, long totalToTransfer, String filePath) {
 470         int percent = (int)(100.0*((double)totalTransferredSoFar)/((double)totalToTransfer));
 471         if (percent != mLastPercent) {
 472             mNotificationBuilder.setProgress(100, percent, totalToTransfer < 0);
 473             String fileName = filePath.substring(filePath.lastIndexOf(FileUtils.PATH_SEPARATOR) + 1);
 474             String text = String.format(getString(R.string.downloader_download_in_progress_content), percent, fileName);
 475             mNotificationBuilder.setContentText(text);
 476             mNotificationManager.notify(R.string.downloader_download_in_progress_ticker, mNotificationBuilder.build());
 477         }
 478         mLastPercent = percent;
 479     }
 480
 481
 482     /**
 483      * Updates the status notification with the result of a download operation.
 484      *
 485      * @param downloadResult    Result of the download operation.
 486      * @param download          Finished download operation
 487      */
 488     private void notifyDownloadResult(DownloadFileOperation download, RemoteOperationResult downloadResult) {
 489         mNotificationManager.cancel(R.string.downloader_download_in_progress_ticker);
 490         if (!downloadResult.isCancelled()) {
 491             int tickerId = (downloadResult.isSuccess()) ? R.string.downloader_download_succeeded_ticker :
 492                 R.string.downloader_download_failed_ticker;
 493
 494             boolean needsToUpdateCredentials = (
 495                     downloadResult.getCode() == ResultCode.UNAUTHORIZED ||
 496                     downloadResult.isIdPRedirection()
 497             );
 498             tickerId = (needsToUpdateCredentials) ?
 499                     R.string.downloader_download_failed_credentials_error : tickerId;
 500
 501             mNotificationBuilder
 502             .setTicker(getString(tickerId))
 503             .setContentTitle(getString(tickerId))
 504             .setAutoCancel(true)
 505             .setOngoing(false)
 506             .setProgress(0, 0, false);
 507
 508             if (needsToUpdateCredentials) {
 509
 510                 // let the user update credentials with one click
 511                 Intent updateAccountCredentials = new Intent(this, AuthenticatorActivity.class);
 512                 updateAccountCredentials.putExtra(AuthenticatorActivity.EXTRA_ACCOUNT, download.getAccount());
 513                 updateAccountCredentials.putExtra(AuthenticatorActivity.EXTRA_ACTION, AuthenticatorActivity.ACTION_UPDATE_EXPIRED_TOKEN);
 514                 updateAccountCredentials.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
 515                 updateAccountCredentials.addFlags(Intent.FLAG_ACTIVITY_EXCLUDE_FROM_RECENTS);
 516                 updateAccountCredentials.addFlags(Intent.FLAG_FROM_BACKGROUND);
 517                 mNotificationBuilder
 518                     .setContentIntent(PendingIntent.getActivity(
 519                         this, (int) System.currentTimeMillis(), updateAccountCredentials, PendingIntent.FLAG_ONE_SHOT));
 520
 521                 mDownloadClient = null;   // grant that future retries on the same account will get the fresh credentials
 522
 523             } else {
 524                 // TODO put something smart in showDetailsIntent
 525                 Intent   showDetailsIntent = new Intent();
 526                 mNotificationBuilder
 527                     .setContentIntent(PendingIntent.getActivity(
 528                         this, (int) System.currentTimeMillis(), showDetailsIntent, 0));
 529             }
 530
 531             mNotificationBuilder.setContentText(ErrorMessageAdapter.getErrorCauseMessage(downloadResult, download, getResources()));
 532             mNotificationManager.notify(tickerId, mNotificationBuilder.build());
 533
 534             // Remove success notification
 535             if (downloadResult.isSuccess()) {
 536                 // Sleep 2 seconds, so show the notification before remove it
 537                 NotificationDelayer.cancelWithDelay(
 538                         mNotificationManager,
 539                         R.string.downloader_download_succeeded_ticker,
 540                         2000);
 541             }
 542
 543         }
 544     }
 545
 546
 547     /**
 548      * Sends a broadcast when a download finishes in order to the interested activities can update their view
 549      *
 550      * @param download          Finished download operation
 551      * @param downloadResult    Result of the download operation
 552      */
 553     private void sendBroadcastDownloadFinished(DownloadFileOperation download, RemoteOperationResult downloadResult) {
 554         Intent end = new Intent(getDownloadFinishMessage());
 555         end.putExtra(EXTRA_DOWNLOAD_RESULT, downloadResult.isSuccess());
 556         end.putExtra(ACCOUNT_NAME, download.getAccount().name);
 557         end.putExtra(EXTRA_REMOTE_PATH, download.getRemotePath());
 558         end.putExtra(EXTRA_FILE_PATH, download.getSavePath());
 559         sendStickyBroadcast(end);
 560     }
 561
 562
 563     /**
 564      * Sends a broadcast when a new download is added to the queue.
 565      *
 566      * @param download          Added download operation
 567      */
 568     private void sendBroadcastNewDownload(DownloadFileOperation download) {
 569         Intent added = new Intent(getDownloadAddedMessage());
 570         added.putExtra(ACCOUNT_NAME, download.getAccount().name);
 571         added.putExtra(EXTRA_REMOTE_PATH, download.getRemotePath());
 572         added.putExtra(EXTRA_FILE_PATH, download.getSavePath());
 573         sendStickyBroadcast(added);
 574     }
 575
 576     /**
 577      * Cancel operation
 578      * @param account       Owncloud account where the remote file is stored.
 579      * @param file          File OCFile
 580      */
 581     public void cancel(Account account, OCFile file){
 582         DownloadFileOperation download = null;
 583         String targetKey = buildRemoteName(account, file);
 584         ArrayList<String> keyItems = new ArrayList<String>();
 585         synchronized (mPendingDownloads) {
 586             if (file.isFolder()) {
 587                 Log_OC.d(TAG, "Folder download. Canceling pending downloads (from folder)");
 588                 Iterator<String> it = mPendingDownloads.keySet().iterator();
 589                 boolean found = false;
 590                 while (it.hasNext()) {
 591                     String keyDownloadOperation = it.next();
 592                     found = keyDownloadOperation.startsWith(targetKey);
 593                     if (found) {
 594                         keyItems.add(keyDownloadOperation);
 595                     }
 596                 }
 597             } else {
 598                 // this is not really expected...
 599                 Log_OC.d(TAG, "Canceling file download");
 600                 keyItems.add(buildRemoteName(account, file));
 601             }
 602         }
 603         for (String item: keyItems) {
 604             download = mPendingDownloads.remove(item);
 605             Log_OC.d(TAG, "Key removed: " + item);
 606
 607             if (download != null) {
 608                 download.cancel();
 609             }
 610         }
 611     }
 612 }