+
+        /**
+         * Add thumbnail to cache
+         * @param imageKey: thumb key
+         * @param bitmap:   image for extracting thumbnail
+         * @param path:     image path
+         * @param px:       thumbnail dp
+         * @return Bitmap
+         */
+        private Bitmap addThumbnailToCache(String imageKey, Bitmap bitmap, String path, int px){
+
+            Bitmap thumbnail = ThumbnailUtils.extractThumbnail(bitmap, px, px);
+
+            // Rotate image, obeying exif tag
+            thumbnail = BitmapUtils.rotateImage(thumbnail,path);
+
+            // Add thumbnail to cache
+            addBitmapToCache(imageKey, thumbnail);
+
+            return thumbnail;
+        }
+
+        /**
+         * Converts size of file icon from dp to pixel
+         * @return int
+         */
+        private int getThumbnailDimension(){
+            // Converts dp to pixel
+            Resources r = MainApp.getAppContext().getResources();
+            return Math.round(r.getDimension(R.dimen.file_icon_size_grid));
+        }
+
+        private Bitmap doOCFileInBackground() {
+            OCFile file = (OCFile)mFile;
+
+            final String imageKey = String.valueOf(file.getRemoteId());
+
+            // Check disk cache in background thread
+            Bitmap thumbnail = getBitmapFromDiskCache(imageKey);
+
+            // Not found in disk cache
+            if (thumbnail == null || file.needsUpdateThumbnail()) {
+
+                int px = getThumbnailDimension();
+
+                if (file.isDown()) {
+                    Bitmap temp = BitmapUtils.decodeSampledBitmapFromFile(
+                            file.getStoragePath(), px, px);
+                    Bitmap bitmap = ThumbnailUtils.extractThumbnail(temp, px, px);
+
+                    if (bitmap != null) {
+                        // Handle PNG
+                        if (file.getMimetype().equalsIgnoreCase("image/png")) {
+                            bitmap = handlePNG(bitmap, px);
+                        }
+
+                        thumbnail = addThumbnailToCache(imageKey, bitmap, file.getStoragePath(), px);
+
+                        file.setNeedsUpdateThumbnail(false);
+                        mStorageManager.saveFile(file);
+                    }
+
+                } else {
+                    // Download thumbnail from server
+                    OwnCloudVersion serverOCVersion = AccountUtils.getServerVersion(mAccount);
+                    if (mClient != null && serverOCVersion != null) {
+                        if (serverOCVersion.supportsRemoteThumbnails()) {
+                            try {
+                                String uri = mClient.getBaseUri() + "" +
+                                        "/index.php/apps/files/api/v1/thumbnail/" +
+                                        px + "/" + px + Uri.encode(file.getRemotePath(), "/");
+                                Log_OC.d("Thumbnail", "URI: " + uri);
+                                GetMethod get = new GetMethod(uri);
+                                int status = mClient.executeMethod(get);
+                                if (status == HttpStatus.SC_OK) {
+                                    InputStream inputStream = get.getResponseBodyAsStream();
+                                    Bitmap bitmap = BitmapFactory.decodeStream(inputStream);
+                                    thumbnail = ThumbnailUtils.extractThumbnail(bitmap, px, px);
+
+                                    // Handle PNG
+                                    if (file.getMimetype().equalsIgnoreCase("image/png")) {
+                                        thumbnail = handlePNG(thumbnail, px);
+                                    }
+
+                                    // Add thumbnail to cache
+                                    if (thumbnail != null) {
+                                        addBitmapToCache(imageKey, thumbnail);
+                                    }
+                                }
+                            } catch (Exception e) {
+                                e.printStackTrace();
+                            }
+                        } else {
+                            Log_OC.d(TAG, "Server too old");
+                        }
+                    }
+                }
+            }
+
+            return thumbnail;
+
+        }
+
+        private Bitmap handlePNG(Bitmap bitmap, int px){
+            Bitmap resultBitmap = Bitmap.createBitmap(px,
+                    px,
+                    Bitmap.Config.ARGB_8888);
+            Canvas c = new Canvas(resultBitmap);
+
+            c.drawColor(MainApp.getAppContext().getResources().
+                    getColor(R.color.background_color));
+            c.drawBitmap(bitmap, 0, 0, null);
+
+            return resultBitmap;
+        }
+
+        private Bitmap doFileInBackground() {
+            File file = (File)mFile;
+
+            final String imageKey = String.valueOf(file.hashCode());
+
+            // Check disk cache in background thread
+            Bitmap thumbnail = getBitmapFromDiskCache(imageKey);
+
+            // Not found in disk cache
+            if (thumbnail == null) {
+
+                int px = getThumbnailDimension();
+
+                Bitmap bitmap = BitmapUtils.decodeSampledBitmapFromFile(
+                        file.getAbsolutePath(), px, px);
+
+                if (bitmap != null) {
+                    thumbnail = addThumbnailToCache(imageKey, bitmap, file.getPath(), px);
+                }
+            }
+            return thumbnail;
+        }
+