do not show document content if protection is enabled

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

src/main/java/com/owncloud/android/providers/DocumentsStorageProvider.java

@@ -26,6 +26,7 @@ import android.annotation.TargetApi;
 import android.content.ContentResolver;
 import android.content.Context;
 import android.content.Intent;
+import android.content.SharedPreferences;
 import android.content.res.AssetFileDescriptor;
 import android.database.Cursor;
 import android.graphics.Point;
@@ -34,6 +35,7 @@ import android.os.CancellationSignal;
 import android.os.Handler;
 import android.os.Looper;
 import android.os.ParcelFileDescriptor;
+import android.preference.PreferenceManager;
 import android.provider.DocumentsProvider;
 import android.util.Log;
 import android.widget.Toast;
@@ -47,6 +49,7 @@ import com.owncloud.android.files.services.FileDownloader;
 import com.owncloud.android.lib.common.operations.RemoteOperationResult;
 import com.owncloud.android.operations.SynchronizeFileOperation;
 import com.owncloud.android.ui.activity.ConflictsResolveActivity;
+import com.owncloud.android.ui.activity.Preferences;
 import com.owncloud.android.utils.FileStorageUtils;
 
 import org.nextcloud.providers.cursors.FileCursor;
@@ -68,6 +71,13 @@ public class DocumentsStorageProvider extends DocumentsProvider {
 
     @Override
     public Cursor queryRoots(String[] projection) throws FileNotFoundException {
+
+        SharedPreferences appPrefs = PreferenceManager.getDefaultSharedPreferences(MainApp.getAppContext());
+        if (appPrefs.getString(Preferences.PREFERENCE_LOCK, "").equals(Preferences.LOCK_PASSCODE) ||
+                appPrefs.getString(Preferences.PREFERENCE_LOCK, "").equals(Preferences.LOCK_DEVICE_CREDENTIALS)) {
+            return new FileCursor(new String[]{});
+        }
+        
         initiateStorageMap();
 
         final RootCursor result = new RootCursor(projection);