src/com/owncloud/android/ui/preview/PreviewImageFragment.java

   1 /* ownCloud Android client application
   2  *   Copyright (C) 2012-2013 ownCloud Inc.
   3  *
   4  *   This program is free software: you can redistribute it and/or modify
   5  *   it under the terms of the GNU General Public License version 2,
   6  *   as published by the Free Software Foundation.
   7  *
   8  *   This program is distributed in the hope that it will be useful,
   9  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  11  *   GNU General Public License for more details.
  12  *
  13  *   You should have received a copy of the GNU General Public License
  14  *   along with this program.  If not, see <http://www.gnu.org/licenses/>.
  15  *
  16  */
  17 package com.owncloud.android.ui.preview;
  18
  19 import java.io.File;
  20 import java.lang.ref.WeakReference;
  21 import java.util.ArrayList;
  22 import java.util.List;
  23
  24
  25 import android.accounts.Account;
  26 import android.annotation.SuppressLint;
  27 import android.app.Activity;
  28 import android.content.ActivityNotFoundException;
  29 import android.content.Intent;
  30 import android.graphics.Bitmap;
  31 import android.graphics.BitmapFactory;
  32 import android.graphics.BitmapFactory.Options;
  33 import android.graphics.Point;
  34 import android.net.Uri;
  35 import android.os.AsyncTask;
  36 import android.os.Bundle;
  37 import android.os.Handler;
  38 import android.support.v4.app.FragmentStatePagerAdapter;
  39 import android.util.Log;
  40 import android.view.Display;
  41 import android.view.LayoutInflater;
  42 import android.view.View;
  43 import android.view.View.OnTouchListener;
  44 import android.view.ViewGroup;
  45 import android.webkit.MimeTypeMap;
  46 import android.widget.ImageView;
  47 import android.widget.ProgressBar;
  48 import android.widget.TextView;
  49 import android.widget.Toast;
  50
  51 import com.actionbarsherlock.app.SherlockFragment;
  52 import com.actionbarsherlock.view.Menu;
  53 import com.actionbarsherlock.view.MenuInflater;
  54 import com.actionbarsherlock.view.MenuItem;
  55 import com.owncloud.android.datamodel.FileDataStorageManager;
  56 import com.owncloud.android.datamodel.OCFile;
  57 import com.owncloud.android.network.OwnCloudClientUtils;
  58 import com.owncloud.android.operations.OnRemoteOperationListener;
  59 import com.owncloud.android.operations.RemoteOperation;
  60 import com.owncloud.android.operations.RemoteOperationResult;
  61 import com.owncloud.android.operations.RemoveFileOperation;
  62 import com.owncloud.android.ui.fragment.ConfirmationDialogFragment;
  63 import com.owncloud.android.ui.fragment.FileFragment;
  64
  65 import com.owncloud.android.R;
  66 import eu.alefzero.webdav.WebdavClient;
  67 import eu.alefzero.webdav.WebdavUtils;
  68
  69
  70 /**
  71  * This fragment shows a preview of a downloaded image.
  72  *
  73  * Trying to get an instance with NULL {@link OCFile} or ownCloud {@link Account} values will produce an {@link IllegalStateException}.
  74  *
  75  * If the {@link OCFile} passed is not downloaded, an {@link IllegalStateException} is generated on instantiation too.
  76  *
  77  * @author David A. Velasco
  78  */
  79 public class PreviewImageFragment extends SherlockFragment implements   FileFragment,
  80                                                                         OnRemoteOperationListener,
  81                                                                         ConfirmationDialogFragment.ConfirmationDialogFragmentListener {
  82     public static final String EXTRA_FILE = "FILE";
  83     public static final String EXTRA_ACCOUNT = "ACCOUNT";
  84
  85     private View mView;
  86     private OCFile mFile;
  87     private Account mAccount;
  88     private FileDataStorageManager mStorageManager;
  89     private ImageView mImageView;
  90     private TextView mMessageView;
  91     private ProgressBar mProgressWheel;
  92
  93     public Bitmap mBitmap = null;
  94
  95     private Handler mHandler;
  96     private RemoteOperation mLastRemoteOperation;
  97
  98     private static final String TAG = PreviewImageFragment.class.getSimpleName();
  99
 100     private boolean mIgnoreFirstSavedState;
 101
 102
 103     /**
 104      * Creates a fragment to preview an image.
 105      *
 106      * When 'imageFile' or 'ocAccount' are null
 107      *
 108      * @param imageFile                 An {@link OCFile} to preview as an image in the fragment
 109      * @param ocAccount                 An ownCloud account; needed to start downloads
 110      * @param ignoreFirstSavedState     Flag to work around an unexpected behaviour of {@link FragmentStatePagerAdapter}; TODO better solution
 111      */
 112     public PreviewImageFragment(OCFile fileToDetail, Account ocAccount, boolean ignoreFirstSavedState) {
 113         mFile = fileToDetail;
 114         mAccount = ocAccount;
 115         mStorageManager = null; // we need a context to init this; the container activity is not available yet at this moment
 116         mIgnoreFirstSavedState = ignoreFirstSavedState;
 117     }
 118
 119
 120     /**
 121      *  Creates an empty fragment for image previews.
 122      *
 123      *  MUST BE KEPT: the system uses it when tries to reinstantiate a fragment automatically (for instance, when the device is turned a aside).
 124      *
 125      *  DO NOT CALL IT: an {@link OCFile} and {@link Account} must be provided for a successful construction
 126      */
 127     public PreviewImageFragment() {
 128         mFile = null;
 129         mAccount = null;
 130         mStorageManager = null;
 131         mIgnoreFirstSavedState = false;
 132     }
 133
 134
 135     /**
 136      * {@inheritDoc}
 137      */
 138     @Override
 139     public void onCreate(Bundle savedInstanceState) {
 140         super.onCreate(savedInstanceState);
 141         mHandler = new Handler();
 142         setHasOptionsMenu(true);
 143     }
 144
 145
 146     /**
 147      * {@inheritDoc}
 148      */
 149     @Override
 150     public View onCreateView(LayoutInflater inflater, ViewGroup container,
 151             Bundle savedInstanceState) {
 152         super.onCreateView(inflater, container, savedInstanceState);
 153         mView = inflater.inflate(R.layout.preview_image_fragment, container, false);
 154         mImageView = (ImageView)mView.findViewById(R.id.image);
 155         mImageView.setVisibility(View.GONE);
 156         mView.setOnTouchListener((OnTouchListener)getActivity());   // WATCH OUT THAT CAST
 157         mMessageView = (TextView)mView.findViewById(R.id.message);
 158         mMessageView.setVisibility(View.GONE);
 159         mProgressWheel = (ProgressBar)mView.findViewById(R.id.progressWheel);
 160         mProgressWheel.setVisibility(View.VISIBLE);
 161         return mView;
 162     }
 163
 164
 165     /**
 166      * {@inheritDoc}
 167      */
 168     @Override
 169     public void onAttach(Activity activity) {
 170         super.onAttach(activity);
 171         if (!(activity instanceof FileFragment.ContainerActivity))
 172             throw new ClassCastException(activity.toString() + " must implement " + FileFragment.ContainerActivity.class.getSimpleName());
 173     }
 174
 175
 176     /**
 177      * {@inheritDoc}
 178      */
 179     @Override
 180     public void onActivityCreated(Bundle savedInstanceState) {
 181         super.onActivityCreated(savedInstanceState);
 182         mStorageManager = new FileDataStorageManager(mAccount, getActivity().getApplicationContext().getContentResolver());
 183         if (savedInstanceState != null) {
 184             if (!mIgnoreFirstSavedState) {
 185                 mFile = savedInstanceState.getParcelable(PreviewImageFragment.EXTRA_FILE);
 186                 mAccount = savedInstanceState.getParcelable(PreviewImageFragment.EXTRA_ACCOUNT);
 187             } else {
 188                 mIgnoreFirstSavedState = false;
 189             }
 190         }
 191         if (mFile == null) {
 192             throw new IllegalStateException("Instanced with a NULL OCFile");
 193         }
 194         if (mAccount == null) {
 195             throw new IllegalStateException("Instanced with a NULL ownCloud Account");
 196         }
 197         if (!mFile.isDown()) {
 198             throw new IllegalStateException("There is no local file to preview");
 199         }
 200     }
 201
 202
 203     /**
 204      * {@inheritDoc}
 205      */
 206     @Override
 207     public void onSaveInstanceState(Bundle outState) {
 208         super.onSaveInstanceState(outState);
 209         outState.putParcelable(PreviewImageFragment.EXTRA_FILE, mFile);
 210         outState.putParcelable(PreviewImageFragment.EXTRA_ACCOUNT, mAccount);
 211     }
 212
 213
 214     @Override
 215     public void onStart() {
 216         super.onStart();
 217         if (mFile != null) {
 218            BitmapLoader bl = new BitmapLoader(mImageView, mMessageView, mProgressWheel);
 219            bl.execute(new String[]{mFile.getStoragePath()});
 220         }
 221     }
 222
 223
 224     /**
 225      * {@inheritDoc}
 226      */
 227     @Override
 228     public void onCreateOptionsMenu(Menu menu, MenuInflater inflater) {
 229         super.onCreateOptionsMenu(menu, inflater);
 230
 231         inflater.inflate(R.menu.file_actions_menu, menu);
 232         List<Integer> toHide = new ArrayList<Integer>();
 233
 234         MenuItem item = null;
 235         toHide.add(R.id.action_cancel_download);
 236         toHide.add(R.id.action_cancel_upload);
 237         toHide.add(R.id.action_download_file);
 238         toHide.add(R.id.action_rename_file);    // by now
 239
 240         for (int i : toHide) {
 241             item = menu.findItem(i);
 242             if (item != null) {
 243                 item.setVisible(false);
 244                 item.setEnabled(false);
 245             }
 246         }
 247
 248     }
 249
 250
 251     /**
 252      * {@inheritDoc}
 253      */
 254     @Override
 255     public boolean onOptionsItemSelected(MenuItem item) {
 256         switch (item.getItemId()) {
 257             case R.id.action_open_file_with: {
 258                 openFile();
 259                 return true;
 260             }
 261             case R.id.action_remove_file: {
 262                 removeFile();
 263                 return true;
 264             }
 265             case R.id.action_see_details: {
 266                 seeDetails();
 267                 return true;
 268             }
 269
 270             default:
 271                 return false;
 272         }
 273     }
 274
 275
 276     private void seeDetails() {
 277         ((FileFragment.ContainerActivity)getActivity()).showFragmentWithDetails(mFile);
 278     }
 279
 280
 281     @Override
 282     public void onResume() {
 283         super.onResume();
 284         //Log.e(TAG, "FRAGMENT, ONRESUME");
 285         /*
 286         mDownloadFinishReceiver = new DownloadFinishReceiver();
 287         IntentFilter filter = new IntentFilter(
 288                 FileDownloader.DOWNLOAD_FINISH_MESSAGE);
 289         getActivity().registerReceiver(mDownloadFinishReceiver, filter);
 290
 291         mUploadFinishReceiver = new UploadFinishReceiver();
 292         filter = new IntentFilter(FileUploader.UPLOAD_FINISH_MESSAGE);
 293         getActivity().registerReceiver(mUploadFinishReceiver, filter);
 294         */
 295
 296     }
 297
 298
 299     @Override
 300     public void onPause() {
 301         super.onPause();
 302         /*
 303         if (mVideoPreview.getVisibility() == View.VISIBLE) {
 304             mSavedPlaybackPosition = mVideoPreview.getCurrentPosition();
 305         }*/
 306         /*
 307         getActivity().unregisterReceiver(mDownloadFinishReceiver);
 308         mDownloadFinishReceiver = null;
 309
 310         getActivity().unregisterReceiver(mUploadFinishReceiver);
 311         mUploadFinishReceiver = null;
 312         */
 313     }
 314
 315
 316     @Override
 317     public void onDestroy() {
 318         super.onDestroy();
 319         if (mBitmap != null) {
 320             mBitmap.recycle();
 321         }
 322     }
 323
 324
 325     /**
 326      * Opens the previewed image with an external application.
 327      *
 328      * TODO - improve this; instead of prioritize the actions available for the MIME type in the server,
 329      * we should get a list of available apps for MIME tpye in the server and join it with the list of
 330      * available apps for the MIME type known from the file extension, to let the user choose
 331      */
 332     private void openFile() {
 333         String storagePath = mFile.getStoragePath();
 334         String encodedStoragePath = WebdavUtils.encodePath(storagePath);
 335         try {
 336             Intent i = new Intent(Intent.ACTION_VIEW);
 337             i.setDataAndType(Uri.parse("file://"+ encodedStoragePath), mFile.getMimetype());
 338             i.setFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION | Intent.FLAG_GRANT_WRITE_URI_PERMISSION);
 339             startActivity(i);
 340
 341         } catch (Throwable t) {
 342             Log.e(TAG, "Fail when trying to open with the mimeType provided from the ownCloud server: " + mFile.getMimetype());
 343             boolean toastIt = true;
 344             String mimeType = "";
 345             try {
 346                 Intent i = new Intent(Intent.ACTION_VIEW);
 347                 mimeType = MimeTypeMap.getSingleton().getMimeTypeFromExtension(storagePath.substring(storagePath.lastIndexOf('.') + 1));
 348                 if (mimeType == null || !mimeType.equals(mFile.getMimetype())) {
 349                     if (mimeType != null) {
 350                         i.setDataAndType(Uri.parse("file://"+ encodedStoragePath), mimeType);
 351                     } else {
 352                         // desperate try
 353                         i.setDataAndType(Uri.parse("file://"+ encodedStoragePath), "*-/*");
 354                     }
 355                     i.setFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION | Intent.FLAG_GRANT_WRITE_URI_PERMISSION);
 356                     startActivity(i);
 357                     toastIt = false;
 358                 }
 359
 360             } catch (IndexOutOfBoundsException e) {
 361                 Log.e(TAG, "Trying to find out MIME type of a file without extension: " + storagePath);
 362
 363             } catch (ActivityNotFoundException e) {
 364                 Log.e(TAG, "No activity found to handle: " + storagePath + " with MIME type " + mimeType + " obtained from extension");
 365
 366             } catch (Throwable th) {
 367                 Log.e(TAG, "Unexpected problem when opening: " + storagePath, th);
 368
 369             } finally {
 370                 if (toastIt) {
 371                     Toast.makeText(getActivity(), "There is no application to handle file " + mFile.getFileName(), Toast.LENGTH_SHORT).show();
 372                 }
 373             }
 374
 375         }
 376         finish();
 377     }
 378
 379
 380     /**
 381      * Starts a the removal of the previewed file.
 382      *
 383      * Shows a confirmation dialog. The action continues in {@link #onConfirmation(String)} , {@link #onNeutral(String)} or {@link #onCancel(String)},
 384      * depending upon the user selection in the dialog.
 385      */
 386     private void removeFile() {
 387         ConfirmationDialogFragment confDialog = ConfirmationDialogFragment.newInstance(
 388                 R.string.confirmation_remove_alert,
 389                 new String[]{mFile.getFileName()},
 390                 R.string.confirmation_remove_remote_and_local,
 391                 R.string.confirmation_remove_local,
 392                 R.string.common_cancel);
 393         confDialog.setOnConfirmationListener(this);
 394         confDialog.show(getFragmentManager(), ConfirmationDialogFragment.FTAG_CONFIRMATION);
 395     }
 396
 397
 398     /**
 399      * Performs the removal of the previewed file, both locally and in the server.
 400      */
 401     @Override
 402     public void onConfirmation(String callerTag) {
 403         if (mStorageManager.getFileById(mFile.getFileId()) != null) {   // check that the file is still there;
 404             mLastRemoteOperation = new RemoveFileOperation( mFile,      // TODO we need to review the interface with RemoteOperations, and use OCFile IDs instead of OCFile objects as parameters
 405                                                             true,
 406                                                             mStorageManager);
 407             WebdavClient wc = OwnCloudClientUtils.createOwnCloudClient(mAccount, getSherlockActivity().getApplicationContext());
 408             mLastRemoteOperation.execute(wc, this, mHandler);
 409
 410             getActivity().showDialog(PreviewImageActivity.DIALOG_SHORT_WAIT);
 411         }
 412     }
 413
 414
 415     /**
 416      * Removes the file from local storage
 417      */
 418     @Override
 419     public void onNeutral(String callerTag) {
 420         // TODO this code should be made in a secondary thread,
 421         if (mFile.isDown()) {   // checks it is still there
 422             File f = new File(mFile.getStoragePath());
 423             f.delete();
 424             mFile.setStoragePath(null);
 425             mStorageManager.saveFile(mFile);
 426             finish();
 427         }
 428     }
 429
 430     /**
 431      * User cancelled the removal action.
 432      */
 433     @Override
 434     public void onCancel(String callerTag) {
 435         // nothing to do here
 436     }
 437
 438
 439     /**
 440      * {@inheritDoc}
 441      */
 442     public OCFile getFile(){
 443         return mFile;
 444     }
 445
 446     /*
 447     /**
 448      * Use this method to signal this Activity that it shall update its view.
 449      *
 450      * @param file : An {@link OCFile}
 451      *-/
 452     public void updateFileDetails(OCFile file, Account ocAccount) {
 453         mFile = file;
 454         if (ocAccount != null && (
 455                 mStorageManager == null ||
 456                 (mAccount != null && !mAccount.equals(ocAccount))
 457            )) {
 458             mStorageManager = new FileDataStorageManager(ocAccount, getActivity().getApplicationContext().getContentResolver());
 459         }
 460         mAccount = ocAccount;
 461         updateFileDetails(false);
 462     }
 463     */
 464
 465
 466     private class BitmapLoader extends AsyncTask<String, Void, Bitmap> {
 467
 468         /**
 469          * Weak reference to the target {@link ImageView} where the bitmap will be loaded into.
 470          *
 471          * Using a weak reference will avoid memory leaks if the target ImageView is retired from memory before the load finishes.
 472          */
 473         private final WeakReference<ImageView> mImageViewRef;
 474
 475         /**
 476          * Weak reference to the target {@link TextView} where error messages will be written.
 477          *
 478          * Using a weak reference will avoid memory leaks if the target ImageView is retired from memory before the load finishes.
 479          */
 480         private final WeakReference<TextView> mMessageViewRef;
 481
 482
 483         /**
 484          * Weak reference to the target {@link Progressbar} shown while the load is in progress.
 485          *
 486          * Using a weak reference will avoid memory leaks if the target ImageView is retired from memory before the load finishes.
 487          */
 488         private final WeakReference<ProgressBar> mProgressWheelRef;
 489
 490
 491         /**
 492          * Error message to show when a load fails
 493          */
 494         private int mErrorMessageId;
 495
 496
 497         /**
 498          * Constructor.
 499          *
 500          * @param imageView     Target {@link ImageView} where the bitmap will be loaded into.
 501          */
 502         public BitmapLoader(ImageView imageView, TextView messageView, ProgressBar progressWheel) {
 503             mImageViewRef = new WeakReference<ImageView>(imageView);
 504             mMessageViewRef = new WeakReference<TextView>(messageView);
 505             mProgressWheelRef = new WeakReference<ProgressBar>(progressWheel);
 506         }
 507
 508
 509         @SuppressWarnings("deprecation")
 510         @SuppressLint({ "NewApi", "NewApi", "NewApi" }) // to avoid Lint errors since Android SDK r20
 511                 @Override
 512         protected Bitmap doInBackground(String... params) {
 513             Bitmap result = null;
 514             if (params.length != 1) return result;
 515             String storagePath = params[0];
 516             try {
 517                 // set desired options that will affect the size of the bitmap
 518                 BitmapFactory.Options options = new Options();
 519                 options.inScaled = true;
 520                 options.inPurgeable = true;
 521                 if (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.GINGERBREAD_MR1) {
 522                     options.inPreferQualityOverSpeed = false;
 523                 }
 524                 if (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.HONEYCOMB) {
 525                     options.inMutable = false;
 526                 }
 527                 // make a false load of the bitmap - just to be able to read outWidth, outHeight and outMimeType
 528                 options.inJustDecodeBounds = true;
 529                 BitmapFactory.decodeFile(storagePath, options);
 530
 531                 int width = options.outWidth;
 532                 int height = options.outHeight;
 533                 int scale = 1;
 534
 535                 Display display = getActivity().getWindowManager().getDefaultDisplay();
 536                 Point size = new Point();
 537                 int screenWidth;
 538                 int screenHeight;
 539                 if (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.HONEYCOMB_MR2) {
 540                     display.getSize(size);
 541                     screenWidth = size.x;
 542                     screenHeight = size.y;
 543                 } else {
 544                     screenWidth = display.getWidth();
 545                     screenHeight = display.getHeight();
 546                 }
 547
 548                 if (width > screenWidth) {
 549                     // second try to scale down the image , this time depending upon the screen size
 550                     scale = (int) Math.floor((float)width / screenWidth);
 551                 }
 552                 if (height > screenHeight) {
 553                     scale = Math.max(scale, (int) Math.floor((float)height / screenHeight));
 554                 }
 555                 options.inSampleSize = scale;
 556
 557                 // really load the bitmap
 558                 options.inJustDecodeBounds = false; // the next decodeFile call will be real
 559                 result = BitmapFactory.decodeFile(storagePath, options);
 560                 //Log.d(TAG, "Image loaded - width: " + options.outWidth + ", loaded height: " + options.outHeight);
 561
 562                 if (result == null) {
 563                     mErrorMessageId = R.string.preview_image_error_unknown_format;
 564                     Log.e(TAG, "File could not be loaded as a bitmap: " + storagePath);
 565                 }
 566
 567             } catch (OutOfMemoryError e) {
 568                 mErrorMessageId = R.string.preview_image_error_unknown_format;
 569                 Log.e(TAG, "Out of memory occured for file " + storagePath, e);
 570
 571             } catch (NoSuchFieldError e) {
 572                 mErrorMessageId = R.string.common_error_unknown;
 573                 Log.e(TAG, "Error from access to unexisting field despite protection; file " + storagePath, e);
 574
 575             } catch (Throwable t) {
 576                 mErrorMessageId = R.string.common_error_unknown;
 577                 Log.e(TAG, "Unexpected error loading " + mFile.getStoragePath(), t);
 578
 579             }
 580             return result;
 581         }
 582
 583         @Override
 584         protected void onPostExecute(Bitmap result) {
 585             hideProgressWheel();
 586             if (result != null) {
 587                 showLoadedImage(result);
 588             } else {
 589                 showErrorMessage();
 590             }
 591         }
 592
 593         private void showLoadedImage(Bitmap result) {
 594             if (mImageViewRef != null) {
 595                 final ImageView imageView = mImageViewRef.get();
 596                 if (imageView != null) {
 597                     imageView.setImageBitmap(result);
 598                     imageView.setVisibility(View.VISIBLE);
 599                     mBitmap  = result;
 600                 } // else , silently finish, the fragment was destroyed
 601             }
 602             if (mMessageViewRef != null) {
 603                 final TextView messageView = mMessageViewRef.get();
 604                 if (messageView != null) {
 605                     messageView.setVisibility(View.GONE);
 606                 } // else , silently finish, the fragment was destroyed
 607             }
 608         }
 609
 610         private void showErrorMessage() {
 611             if (mImageViewRef != null) {
 612                 final ImageView imageView = mImageViewRef.get();
 613                 if (imageView != null) {
 614                     // shows the default error icon
 615                     imageView.setVisibility(View.VISIBLE);
 616                 } // else , silently finish, the fragment was destroyed
 617             }
 618             if (mMessageViewRef != null) {
 619                 final TextView messageView = mMessageViewRef.get();
 620                 if (messageView != null) {
 621                     messageView.setText(mErrorMessageId);
 622                     messageView.setVisibility(View.VISIBLE);
 623                 } // else , silently finish, the fragment was destroyed
 624             }
 625         }
 626
 627         private void hideProgressWheel() {
 628             if (mProgressWheelRef != null) {
 629                 final ProgressBar progressWheel = mProgressWheelRef.get();
 630                 if (progressWheel != null) {
 631                     progressWheel.setVisibility(View.GONE);
 632                 }
 633             }
 634         }
 635
 636     }
 637
 638     /**
 639      * Helper method to test if an {@link OCFile} can be passed to a {@link PreviewImageFragment} to be previewed.
 640      *
 641      * @param file      File to test if can be previewed.
 642      * @return          'True' if the file can be handled by the fragment.
 643      */
 644     public static boolean canBePreviewed(OCFile file) {
 645         return (file != null && file.isImage());
 646     }
 647
 648
 649     /**
 650      * {@inheritDoc}
 651      */
 652     @Override
 653     public void onRemoteOperationFinish(RemoteOperation operation, RemoteOperationResult result) {
 654         if (operation.equals(mLastRemoteOperation) && operation instanceof RemoveFileOperation) {
 655             onRemoveFileOperationFinish((RemoveFileOperation)operation, result);
 656         }
 657     }
 658
 659     private void onRemoveFileOperationFinish(RemoveFileOperation operation, RemoteOperationResult result) {
 660         getActivity().dismissDialog(PreviewImageActivity.DIALOG_SHORT_WAIT);
 661
 662         if (result.isSuccess()) {
 663             Toast msg = Toast.makeText(getActivity().getApplicationContext(), R.string.remove_success_msg, Toast.LENGTH_LONG);
 664             msg.show();
 665             finish();
 666
 667         } else {
 668             Toast msg = Toast.makeText(getActivity(), R.string.remove_fail_msg, Toast.LENGTH_LONG);
 669             msg.show();
 670             if (result.isSslRecoverableException()) {
 671                 // TODO show the SSL warning dialog
 672             }
 673         }
 674     }
 675
 676     /**
 677      * Finishes the preview
 678      */
 679     private void finish() {
 680         Activity container = getActivity();
 681         container.finish();
 682     }
 683
 684
 685 }