Add error message and name check

OsmAnd/res/values/strings.xml

@@ -9,6 +9,7 @@
          3. All your modified/created strings are in the top of the file (to make easier find what\'s translated).
     PLEASE: Have a look at http://code.google.com/p/osmand/wiki/UIConsistency, it may really improve your and our work  :-)  Thx - Hardy
     -->
+    <string name="wrong_input">Wrong input</string>
     <string name="enter_new_name">Enter new name</string>
     <string name="shared_string_back">Back</string>
     <string name="wrong_format">Wrong format</string>

OsmAnd/src/net/osmand/plus/mapmarkers/RenameMarkerBottomSheetDialogFragment.java

@@ -71,6 +71,7 @@ public class RenameMarkerBottomSheetDialogFragment extends BottomSheetDialogFrag
 			@Override
 			public void onClick(View view) {
 				String name = nameEditText.getText().toString();
+				if (name.replaceAll("\\s", "").length() > 0) {
 					marker.setName(name);
 					mapActivity.getMyApplication().getMapMarkersHelper().updateMapMarker(marker, true);
 					FragmentManager fm = mapActivity.getSupportFragmentManager();
@@ -79,6 +80,9 @@ public class RenameMarkerBottomSheetDialogFragment extends BottomSheetDialogFrag
 						((MarkerMenuOnMapFragment) fragment).dismiss();
 					}
 					dismiss();
+				} else {
+					nameEditText.setError(getString(R.string.wrong_input));
+				}
 			}
 		});