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 as published by
   6  *   the Free Software Foundation, either version 2 of the License, or
   7  *   (at your option) any later version.
   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 package com.owncloud.android.ui.preview;
  19
  20 import java.io.File;
  21 import java.lang.ref.WeakReference;
  22 import java.util.ArrayList;
  23 import java.util.List;
  24
  25
  26 import android.accounts.Account;
  27 import android.annotation.SuppressLint;
  28 import android.app.Activity;
  29 import android.content.ActivityNotFoundException;
  30 import android.content.Intent;
  31 import android.graphics.Bitmap;
  32 import android.graphics.BitmapFactory;
  33 import android.graphics.BitmapFactory.Options;
  34 import android.graphics.Point;
  35 import android.net.Uri;
  36 import android.os.AsyncTask;
  37 import android.os.Bundle;
  38 import android.os.Handler;
  39 import android.support.v4.app.FragmentStatePagerAdapter;
  40 import android.util.Log;
  41 import android.view.Display;
  42 import android.view.LayoutInflater;
  43 import android.view.View;
  44 import android.view.View.OnTouchListener;
  45 import android.view.ViewGroup;
  46 import android.webkit.MimeTypeMap;
  47 import android.widget.ImageView;
  48 import android.widget.ProgressBar;
  49 import android.widget.TextView;
  50 import android.widget.Toast;
  51
  52 import com.actionbarsherlock.app.SherlockFragment;
  53 import com.actionbarsherlock.view.Menu;
  54 import com.actionbarsherlock.view.MenuInflater;
  55 import com.actionbarsherlock.view.MenuItem;
  56 import com.owncloud.android.datamodel.FileDataStorageManager;
  57 import com.owncloud.android.datamodel.OCFile;
  58 import com.owncloud.android.network.OwnCloudClientUtils;
  59 import com.owncloud.android.operations.OnRemoteOperationListener;
  60 import com.owncloud.android.operations.RemoteOperation;
  61 import com.owncloud.android.operations.RemoteOperationResult;
  62 import com.owncloud.android.operations.RemoveFileOperation;
  63 import com.owncloud.android.ui.fragment.ConfirmationDialogFragment;
  64 import com.owncloud.android.ui.fragment.FileFragment;
  65
  66 import com.owncloud.android.R;
  67 import eu.alefzero.webdav.WebdavClient;
  68 import eu.alefzero.webdav.WebdavUtils;
  69
  70
  71 /**
  72  * This fragment shows a preview of a downloaded image.
  73  *
  74  * Trying to get an instance with NULL {@link OCFile} or ownCloud {@link Account} values will produce an {@link IllegalStateException}.
  75  *
  76  * If the {@link OCFile} passed is not downloaded, an {@link IllegalStateException} is generated on instantiation too.
  77  *
  78  * @author David A. Velasco
  79  */
  80 public class PreviewImageFragment extends SherlockFragment implements   FileFragment,
  81                                                                         OnRemoteOperationListener,
  82                                                                         ConfirmationDialogFragment.ConfirmationDialogFragmentListener {
  83     public static final String EXTRA_FILE = "FILE";
  84     public static final String EXTRA_ACCOUNT = "ACCOUNT";
  85
  86     private View mView;
  87     private OCFile mFile;
  88     private Account mAccount;
  89     private FileDataStorageManager mStorageManager;
  90     private ImageView mImageView;
  91     private TextView mMessageView;
  92     private ProgressBar mProgressWheel;
  93
  94     public Bitmap mBitmap = null;
  95
  96     private Handler mHandler;
  97     private RemoteOperation mLastRemoteOperation;
  98
  99     private static final String TAG = PreviewImageFragment.class.getSimpleName();
 100
 101     private boolean mIgnoreFirstSavedState;
 102
 103
 104     /**
 105      * Creates a fragment to preview an image.
 106      *
 107      * When 'imageFile' or 'ocAccount' are null
 108      *
 109      * @param imageFile                 An {@link OCFile} to preview as an image in the fragment
 110      * @param ocAccount                 An ownCloud account; needed to start downloads
 111      * @param ignoreFirstSavedState     Flag to work around an unexpected behaviour of {@link FragmentStatePagerAdapter}; TODO better solution
 112      */
 113     public PreviewImageFragment(OCFile fileToDetail, Account ocAccount, boolean ignoreFirstSavedState) {
 114         mFile = fileToDetail;
 115         mAccount = ocAccount;
 116         mStorageManager = null; // we need a context to init this; the container activity is not available yet at this moment
 117         mIgnoreFirstSavedState = ignoreFirstSavedState;
 118     }
 119
 120
 121     /**
 122      *  Creates an empty fragment for image previews.
 123      *
 124      *  MUST BE KEPT: the system uses it when tries to reinstantiate a fragment automatically (for instance, when the device is turned a aside).
 125      *
 126      *  DO NOT CALL IT: an {@link OCFile} and {@link Account} must be provided for a successful construction
 127      */
 128     public PreviewImageFragment() {
 129         mFile = null;
 130         mAccount = null;
 131         mStorageManager = null;
 132         mIgnoreFirstSavedState = false;
 133     }
 134
 135
 136     /**
 137      * {@inheritDoc}
 138      */
 139     @Override
 140     public void onCreate(Bundle savedInstanceState) {
 141         super.onCreate(savedInstanceState);
 142         mHandler = new Handler();
 143         setHasOptionsMenu(true);
 144     }
 145
 146
 147     /**
 148      * {@inheritDoc}
 149      */
 150     @Override
 151     public View onCreateView(LayoutInflater inflater, ViewGroup container,
 152             Bundle savedInstanceState) {
 153         super.onCreateView(inflater, container, savedInstanceState);
 154         mView = inflater.inflate(R.layout.preview_image_fragment, container, false);
 155         mImageView = (ImageView)mView.findViewById(R.id.image);
 156         mImageView.setVisibility(View.GONE);
 157         mView.setOnTouchListener((OnTouchListener)getActivity());   // WATCH OUT THAT CAST
 158         mMessageView = (TextView)mView.findViewById(R.id.message);
 159         mMessageView.setVisibility(View.GONE);
 160         mProgressWheel = (ProgressBar)mView.findViewById(R.id.progressWheel);
 161         mProgressWheel.setVisibility(View.VISIBLE);
 162         return mView;
 163     }
 164
 165
 166     /**
 167      * {@inheritDoc}
 168      */
 169     @Override
 170     public void onAttach(Activity activity) {
 171         super.onAttach(activity);
 172         if (!(activity instanceof FileFragment.ContainerActivity))
 173             throw new ClassCastException(activity.toString() + " must implement " + FileFragment.ContainerActivity.class.getSimpleName());
 174     }
 175
 176
 177     /**
 178      * {@inheritDoc}
 179      */
 180     @Override
 181     public void onActivityCreated(Bundle savedInstanceState) {
 182         super.onActivityCreated(savedInstanceState);
 183         mStorageManager = new FileDataStorageManager(mAccount, getActivity().getApplicationContext().getContentResolver());
 184         if (savedInstanceState != null) {
 185             if (!mIgnoreFirstSavedState) {
 186                 mFile = savedInstanceState.getParcelable(PreviewImageFragment.EXTRA_FILE);
 187                 mAccount = savedInstanceState.getParcelable(PreviewImageFragment.EXTRA_ACCOUNT);
 188             } else {
 189                 mIgnoreFirstSavedState = false;
 190             }
 191         }
 192         if (mFile == null) {
 193             throw new IllegalStateException("Instanced with a NULL OCFile");
 194         }
 195         if (mAccount == null) {
 196             throw new IllegalStateException("Instanced with a NULL ownCloud Account");
 197         }
 198         if (!mFile.isDown()) {
 199             throw new IllegalStateException("There is no local file to preview");
 200         }
 201     }
 202
 203
 204     /**
 205      * {@inheritDoc}
 206      */
 207     @Override
 208     public void onSaveInstanceState(Bundle outState) {
 209         super.onSaveInstanceState(outState);
 210         outState.putParcelable(PreviewImageFragment.EXTRA_FILE, mFile);
 211         outState.putParcelable(PreviewImageFragment.EXTRA_ACCOUNT, mAccount);
 212     }
 213
 214
 215     @Override
 216     public void onStart() {
 217         super.onStart();
 218         if (mFile != null) {
 219            BitmapLoader bl = new BitmapLoader(mImageView, mMessageView, mProgressWheel);
 220            bl.execute(new String[]{mFile.getStoragePath()});
 221         }
 222     }
 223
 224
 225     /**
 226      * {@inheritDoc}
 227      */
 228     @Override
 229     public void onCreateOptionsMenu(Menu menu, MenuInflater inflater) {
 230         super.onCreateOptionsMenu(menu, inflater);
 231
 232         inflater.inflate(R.menu.file_actions_menu, menu);
 233         List<Integer> toHide = new ArrayList<Integer>();
 234
 235         MenuItem item = null;
 236         toHide.add(R.id.action_cancel_download);
 237         toHide.add(R.id.action_cancel_upload);
 238         toHide.add(R.id.action_download_file);
 239         toHide.add(R.id.action_rename_file);    // by now
 240
 241         for (int i : toHide) {
 242             item = menu.findItem(i);
 243             if (item != null) {
 244                 item.setVisible(false);
 245                 item.setEnabled(false);
 246             }
 247         }
 248
 249     }
 250
 251
 252     /**
 253      * {@inheritDoc}
 254      */
 255     @Override
 256     public boolean onOptionsItemSelected(MenuItem item) {
 257         switch (item.getItemId()) {
 258             case R.id.action_open_file_with: {
 259                 openFile();
 260                 return true;
 261             }
 262             case R.id.action_remove_file: {
 263                 removeFile();
 264                 return true;
 265             }
 266             case R.id.action_see_details: {
 267                 seeDetails();
 268                 return true;
 269             }
 270
 271             default:
 272                 return false;
 273         }
 274     }
 275
 276
 277     private void seeDetails() {
 278         ((FileFragment.ContainerActivity)getActivity()).showFragmentWithDetails(mFile);
 279     }
 280
 281
 282     @Override
 283     public void onResume() {
 284         super.onResume();
 285         //Log.e(TAG, "FRAGMENT, ONRESUME");
 286         /*
 287         mDownloadFinishReceiver = new DownloadFinishReceiver();
 288         IntentFilter filter = new IntentFilter(
 289                 FileDownloader.DOWNLOAD_FINISH_MESSAGE);
 290         getActivity().registerReceiver(mDownloadFinishReceiver, filter);
 291
 292         mUploadFinishReceiver = new UploadFinishReceiver();
 293         filter = new IntentFilter(FileUploader.UPLOAD_FINISH_MESSAGE);
 294         getActivity().registerReceiver(mUploadFinishReceiver, filter);
 295         */
 296
 297     }
 298
 299
 300     @Override
 301     public void onPause() {
 302         super.onPause();
 303         /*
 304         if (mVideoPreview.getVisibility() == View.VISIBLE) {
 305             mSavedPlaybackPosition = mVideoPreview.getCurrentPosition();
 306         }*/
 307         /*
 308         getActivity().unregisterReceiver(mDownloadFinishReceiver);
 309         mDownloadFinishReceiver = null;
 310
 311         getActivity().unregisterReceiver(mUploadFinishReceiver);
 312         mUploadFinishReceiver = null;
 313         */
 314     }
 315
 316
 317     @Override
 318     public void onDestroy() {
 319         super.onDestroy();
 320         if (mBitmap != null) {
 321             mBitmap.recycle();
 322         }
 323     }
 324
 325
 326     /**
 327      * Opens the previewed image with an external application.
 328      *
 329      * TODO - improve this; instead of prioritize the actions available for the MIME type in the server,
 330      * we should get a list of available apps for MIME tpye in the server and join it with the list of
 331      * available apps for the MIME type known from the file extension, to let the user choose
 332      */
 333     private void openFile() {
 334         String storagePath = mFile.getStoragePath();
 335         String encodedStoragePath = WebdavUtils.encodePath(storagePath);
 336         try {
 337             Intent i = new Intent(Intent.ACTION_VIEW);
 338             i.setDataAndType(Uri.parse("file://"+ encodedStoragePath), mFile.getMimetype());
 339             i.setFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION | Intent.FLAG_GRANT_WRITE_URI_PERMISSION);
 340             startActivity(i);
 341
 342         } catch (Throwable t) {
 343             Log.e(TAG, "Fail when trying to open with the mimeType provided from the ownCloud server: " + mFile.getMimetype());
 344             boolean toastIt = true;
 345             String mimeType = "";
 346             try {
 347                 Intent i = new Intent(Intent.ACTION_VIEW);
 348                 mimeType = MimeTypeMap.getSingleton().getMimeTypeFromExtension(storagePath.substring(storagePath.lastIndexOf('.') + 1));
 349                 if (mimeType == null || !mimeType.equals(mFile.getMimetype())) {
 350                     if (mimeType != null) {
 351                         i.setDataAndType(Uri.parse("file://"+ encodedStoragePath), mimeType);
 352                     } else {
 353                         // desperate try
 354                         i.setDataAndType(Uri.parse("file://"+ encodedStoragePath), "*-/*");
 355                     }
 356                     i.setFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION | Intent.FLAG_GRANT_WRITE_URI_PERMISSION);
 357                     startActivity(i);
 358                     toastIt = false;
 359                 }
 360
 361             } catch (IndexOutOfBoundsException e) {
 362                 Log.e(TAG, "Trying to find out MIME type of a file without extension: " + storagePath);
 363
 364             } catch (ActivityNotFoundException e) {
 365                 Log.e(TAG, "No activity found to handle: " + storagePath + " with MIME type " + mimeType + " obtained from extension");
 366
 367             } catch (Throwable th) {
 368                 Log.e(TAG, "Unexpected problem when opening: " + storagePath, th);
 369
 370             } finally {
 371                 if (toastIt) {
 372                     Toast.makeText(getActivity(), "There is no application to handle file " + mFile.getFileName(), Toast.LENGTH_SHORT).show();
 373                 }
 374             }
 375
 376         }
 377         finish();
 378     }
 379
 380
 381     /**
 382      * Starts a the removal of the previewed file.
 383      *
 384      * Shows a confirmation dialog. The action continues in {@link #onConfirmation(String)} , {@link #onNeutral(String)} or {@link #onCancel(String)},
 385      * depending upon the user selection in the dialog.
 386      */
 387     private void removeFile() {
 388         ConfirmationDialogFragment confDialog = ConfirmationDialogFragment.newInstance(
 389                 R.string.confirmation_remove_alert,
 390                 new String[]{mFile.getFileName()},
 391                 R.string.confirmation_remove_remote_and_local,
 392                 R.string.confirmation_remove_local,
 393                 R.string.common_cancel);
 394         confDialog.setOnConfirmationListener(this);
 395         confDialog.show(getFragmentManager(), ConfirmationDialogFragment.FTAG_CONFIRMATION);
 396     }
 397
 398
 399     /**
 400      * Performs the removal of the previewed file, both locally and in the server.
 401      */
 402     @Override
 403     public void onConfirmation(String callerTag) {
 404         if (mStorageManager.getFileById(mFile.getFileId()) != null) {   // check that the file is still there;
 405             mLastRemoteOperation = new RemoveFileOperation( mFile,      // TODO we need to review the interface with RemoteOperations, and use OCFile IDs instead of OCFile objects as parameters
 406                                                             true,
 407                                                             mStorageManager);
 408             WebdavClient wc = OwnCloudClientUtils.createOwnCloudClient(mAccount, getSherlockActivity().getApplicationContext());
 409             mLastRemoteOperation.execute(wc, this, mHandler);
 410
 411             getActivity().showDialog(PreviewImageActivity.DIALOG_SHORT_WAIT);
 412         }
 413     }
 414
 415
 416     /**
 417      * Removes the file from local storage
 418      */
 419     @Override
 420     public void onNeutral(String callerTag) {
 421         // TODO this code should be made in a secondary thread,
 422         if (mFile.isDown()) {   // checks it is still there
 423             File f = new File(mFile.getStoragePath());
 424             f.delete();
 425             mFile.setStoragePath(null);
 426             mStorageManager.saveFile(mFile);
 427             finish();
 428         }
 429     }
 430
 431     /**
 432      * User cancelled the removal action.
 433      */
 434     @Override
 435     public void onCancel(String callerTag) {
 436         // nothing to do here
 437     }
 438
 439
 440     /**
 441      * {@inheritDoc}
 442      */
 443     public OCFile getFile(){
 444         return mFile;
 445     }
 446
 447     /*
 448     /**
 449      * Use this method to signal this Activity that it shall update its view.
 450      *
 451      * @param file : An {@link OCFile}
 452      *-/
 453     public void updateFileDetails(OCFile file, Account ocAccount) {
 454         mFile = file;
 455         if (ocAccount != null && (
 456                 mStorageManager == null ||
 457                 (mAccount != null && !mAccount.equals(ocAccount))
 458            )) {
 459             mStorageManager = new FileDataStorageManager(ocAccount, getActivity().getApplicationContext().getContentResolver());
 460         }
 461         mAccount = ocAccount;
 462         updateFileDetails(false);
 463     }
 464     */
 465
 466
 467     private class BitmapLoader extends AsyncTask<String, Void, Bitmap> {
 468
 469         /**
 470          * Weak reference to the target {@link ImageView} where the bitmap will be loaded into.
 471          *
 472          * Using a weak reference will avoid memory leaks if the target ImageView is retired from memory before the load finishes.
 473          */
 474         private final WeakReference<ImageView> mImageViewRef;
 475
 476         /**
 477          * Weak reference to the target {@link TextView} where error messages will be written.
 478          *
 479          * Using a weak reference will avoid memory leaks if the target ImageView is retired from memory before the load finishes.
 480          */
 481         private final WeakReference<TextView> mMessageViewRef;
 482
 483
 484         /**
 485          * Weak reference to the target {@link Progressbar} shown while the load is in progress.
 486          *
 487          * Using a weak reference will avoid memory leaks if the target ImageView is retired from memory before the load finishes.
 488          */
 489         private final WeakReference<ProgressBar> mProgressWheelRef;
 490
 491
 492         /**
 493          * Error message to show when a load fails
 494          */
 495         private int mErrorMessageId;
 496
 497
 498         /**
 499          * Constructor.
 500          *
 501          * @param imageView     Target {@link ImageView} where the bitmap will be loaded into.
 502          */
 503         public BitmapLoader(ImageView imageView, TextView messageView, ProgressBar progressWheel) {
 504             mImageViewRef = new WeakReference<ImageView>(imageView);
 505             mMessageViewRef = new WeakReference<TextView>(messageView);
 506             mProgressWheelRef = new WeakReference<ProgressBar>(progressWheel);
 507         }
 508
 509
 510         @SuppressWarnings("deprecation")
 511         @SuppressLint({ "NewApi", "NewApi", "NewApi" }) // to avoid Lint errors since Android SDK r20
 512                 @Override
 513         protected Bitmap doInBackground(String... params) {
 514             Bitmap result = null;
 515             if (params.length != 1) return result;
 516             String storagePath = params[0];
 517             try {
 518                 // set desired options that will affect the size of the bitmap
 519                 BitmapFactory.Options options = new Options();
 520                 options.inScaled = true;
 521                 options.inPurgeable = true;
 522                 if (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.GINGERBREAD_MR1) {
 523                     options.inPreferQualityOverSpeed = false;
 524                 }
 525                 if (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.HONEYCOMB) {
 526                     options.inMutable = false;
 527                 }
 528                 // make a false load of the bitmap - just to be able to read outWidth, outHeight and outMimeType
 529                 options.inJustDecodeBounds = true;
 530                 BitmapFactory.decodeFile(storagePath, options);
 531
 532                 int width = options.outWidth;
 533                 int height = options.outHeight;
 534                 int scale = 1;
 535
 536                 Display display = getActivity().getWindowManager().getDefaultDisplay();
 537                 Point size = new Point();
 538                 int screenWidth;
 539                 int screenHeight;
 540                 if (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.HONEYCOMB_MR2) {
 541                     display.getSize(size);
 542                     screenWidth = size.x;
 543                     screenHeight = size.y;
 544                 } else {
 545                     screenWidth = display.getWidth();
 546                     screenHeight = display.getHeight();
 547                 }
 548
 549                 if (width > screenWidth) {
 550                     // second try to scale down the image , this time depending upon the screen size
 551                     scale = (int) Math.floor((float)width / screenWidth);
 552                 }
 553                 if (height > screenHeight) {
 554                     scale = Math.max(scale, (int) Math.floor((float)height / screenHeight));
 555                 }
 556                 options.inSampleSize = scale;
 557
 558                 // really load the bitmap
 559                 options.inJustDecodeBounds = false; // the next decodeFile call will be real
 560                 result = BitmapFactory.decodeFile(storagePath, options);
 561                 //Log.d(TAG, "Image loaded - width: " + options.outWidth + ", loaded height: " + options.outHeight);
 562
 563                 if (result == null) {
 564                     mErrorMessageId = R.string.preview_image_error_unknown_format;
 565                     Log.e(TAG, "File could not be loaded as a bitmap: " + storagePath);
 566                 }
 567
 568             } catch (OutOfMemoryError e) {
 569                 mErrorMessageId = R.string.preview_image_error_unknown_format;
 570                 Log.e(TAG, "Out of memory occured for file " + storagePath, e);
 571
 572             } catch (NoSuchFieldError e) {
 573                 mErrorMessageId = R.string.common_error_unknown;
 574                 Log.e(TAG, "Error from access to unexisting field despite protection; file " + storagePath, e);
 575
 576             } catch (Throwable t) {
 577                 mErrorMessageId = R.string.common_error_unknown;
 578                 Log.e(TAG, "Unexpected error loading " + mFile.getStoragePath(), t);
 579
 580             }
 581             return result;
 582         }
 583
 584         @Override
 585         protected void onPostExecute(Bitmap result) {
 586             hideProgressWheel();
 587             if (result != null) {
 588                 showLoadedImage(result);
 589             } else {
 590                 showErrorMessage();
 591             }
 592         }
 593
 594         private void showLoadedImage(Bitmap result) {
 595             if (mImageViewRef != null) {
 596                 final ImageView imageView = mImageViewRef.get();
 597                 if (imageView != null) {
 598                     imageView.setImageBitmap(result);
 599                     imageView.setVisibility(View.VISIBLE);
 600                     mBitmap  = result;
 601                 } // else , silently finish, the fragment was destroyed
 602             }
 603             if (mMessageViewRef != null) {
 604                 final TextView messageView = mMessageViewRef.get();
 605                 if (messageView != null) {
 606                     messageView.setVisibility(View.GONE);
 607                 } // else , silently finish, the fragment was destroyed
 608             }
 609         }
 610
 611         private void showErrorMessage() {
 612             if (mImageViewRef != null) {
 613                 final ImageView imageView = mImageViewRef.get();
 614                 if (imageView != null) {
 615                     // shows the default error icon
 616                     imageView.setVisibility(View.VISIBLE);
 617                 } // else , silently finish, the fragment was destroyed
 618             }
 619             if (mMessageViewRef != null) {
 620                 final TextView messageView = mMessageViewRef.get();
 621                 if (messageView != null) {
 622                     messageView.setText(mErrorMessageId);
 623                     messageView.setVisibility(View.VISIBLE);
 624                 } // else , silently finish, the fragment was destroyed
 625             }
 626         }
 627
 628         private void hideProgressWheel() {
 629             if (mProgressWheelRef != null) {
 630                 final ProgressBar progressWheel = mProgressWheelRef.get();
 631                 if (progressWheel != null) {
 632                     progressWheel.setVisibility(View.GONE);
 633                 }
 634             }
 635         }
 636
 637     }
 638
 639     /**
 640      * Helper method to test if an {@link OCFile} can be passed to a {@link PreviewImageFragment} to be previewed.
 641      *
 642      * @param file      File to test if can be previewed.
 643      * @return          'True' if the file can be handled by the fragment.
 644      */
 645     public static boolean canBePreviewed(OCFile file) {
 646         return (file != null && file.isImage());
 647     }
 648
 649
 650     /**
 651      * {@inheritDoc}
 652      */
 653     @Override
 654     public void onRemoteOperationFinish(RemoteOperation operation, RemoteOperationResult result) {
 655         if (operation.equals(mLastRemoteOperation) && operation instanceof RemoveFileOperation) {
 656             onRemoveFileOperationFinish((RemoveFileOperation)operation, result);
 657         }
 658     }
 659
 660     private void onRemoveFileOperationFinish(RemoveFileOperation operation, RemoteOperationResult result) {
 661         getActivity().dismissDialog(PreviewImageActivity.DIALOG_SHORT_WAIT);
 662
 663         if (result.isSuccess()) {
 664             Toast msg = Toast.makeText(getActivity().getApplicationContext(), R.string.remove_success_msg, Toast.LENGTH_LONG);
 665             msg.show();
 666             finish();
 667
 668         } else {
 669             Toast msg = Toast.makeText(getActivity(), R.string.remove_fail_msg, Toast.LENGTH_LONG);
 670             msg.show();
 671             if (result.isSslRecoverableException()) {
 672                 // TODO show the SSL warning dialog
 673             }
 674         }
 675     }
 676
 677     /**
 678      * Finishes the preview
 679      */
 680     private void finish() {
 681         Activity container = getActivity();
 682         container.finish();
 683     }
 684
 685
 686 }