only use ifPreviewIsAvailable for thumbnail generation

Signed-off-by: tobiasKaminsky <tobias@kaminsky.me>

src/main/java/com/owncloud/android/ui/adapter/OCFileListAdapter.java

@@ -38,7 +38,12 @@ import android.widget.Filter;
 import android.widget.ImageView;
 import android.widget.LinearLayout;
 import android.widget.TextView;
-
+import androidx.annotation.NonNull;
+import androidx.core.graphics.drawable.RoundedBitmapDrawable;
+import androidx.core.graphics.drawable.RoundedBitmapDrawableFactory;
+import androidx.recyclerview.widget.RecyclerView;
+import butterknife.BindView;
+import butterknife.ButterKnife;
 import com.bumptech.glide.Glide;
 import com.bumptech.glide.request.target.BitmapImageViewTarget;
 import com.nextcloud.client.preferences.AppPreferences;
@@ -71,8 +76,6 @@ import com.owncloud.android.utils.FileStorageUtils;
 import com.owncloud.android.utils.MimeTypeUtil;
 import com.owncloud.android.utils.ThemeUtils;
 
-import com.nextcloud.client.preferences.PreferenceManager;
-
 import java.io.File;
 import java.util.ArrayList;
 import java.util.HashSet;
@@ -81,13 +84,6 @@ import java.util.Locale;
 import java.util.Set;
 import java.util.Vector;
 
-import androidx.annotation.NonNull;
-import androidx.core.graphics.drawable.RoundedBitmapDrawable;
-import androidx.core.graphics.drawable.RoundedBitmapDrawableFactory;
-import androidx.recyclerview.widget.RecyclerView;
-import butterknife.BindView;
-import butterknife.ButterKnife;
-
 /**
  * This Adapter populates a RecyclerView with all files and folders in a Nextcloud instance.
  */
@@ -465,8 +461,7 @@ public class OCFileListAdapter extends RecyclerView.Adapter<RecyclerView.ViewHol
                             file.isSharedWithSharee(), file.isSharedViaLink(), file.isEncrypted(), file.getMountType(),
                     mContext));
         } else {
-            if ((MimeTypeUtil.isImage(file) || MimeTypeUtil.isVideo(file)) && file.getRemoteId() != null &&
-                file.isPreviewAvailable()) {
+            if (file.getRemoteId() != null && file.isPreviewAvailable()) {
                 // Thumbnail in cache?
                 Bitmap thumbnail = ThumbnailsCacheManager.getBitmapFromDiskCache(
                         ThumbnailsCacheManager.PREFIX_THUMBNAIL + file.getRemoteId()