check and set preview enable before fetching from server blindly

Signed-off-by: alperozturk96 <alper_ozturk@proton.me>

Author: alperozturk96

app/src/main/java/com/owncloud/android/datamodel/ThumbnailsCacheManager.java

@@ -638,8 +638,14 @@ private Bitmap doThumbnailFromOCFileInBackground() {
                 }
             }
 
+            boolean serverHasPreview = !(file instanceof OCFile) || ((OCFile) file).isPreviewAvailable();
+
+            if (thumbnail == null && !serverHasPreview) {
+                Log_OC.d(TAG, "Server reports no preview for file: " + file.getFileName());
+            }
+
             // Download thumbnail from server if still null
-            if (thumbnail == null && mClient != null) {
+            if (thumbnail == null && mClient != null && serverHasPreview) {
                 Log_OC.d(TAG, "Attempting to download thumbnail from server for file: " + file.getFileName());
                 GetMethod getMethod = null;
 

app/src/main/java/com/owncloud/android/operations/UploadFileOperation.java

@@ -1785,6 +1785,7 @@ private void updateOCFile(OCFile file, RemoteFile remoteFile) {
         file.setRemoteId(remoteFile.getRemoteId());
         file.setPermissions(remoteFile.getPermissions());
         file.setUploadTimestamp(remoteFile.getUploadTimestamp());
+        file.setPreviewAvailable(remoteFile.isHasPreview());
     }
 
     public interface OnRenameListener {