ui/src/main/java/ucar/util/prefs/ui/Field.java
protected void setNewValueFromStore() {
    Object newValue = getStoreValue(validValue);
    if (acceptIfDifferent(newValue)) {
      setEditValue(newValue);
      sendEvent();
    }
  }
protected void setNewValueFromStore() {
    Object newValue = getStoreValue(validValue);
    if (acceptIfDifferent(newValue)) {
      setEditValue(newValue);
      sendEvent();
    }
  }
The value in the store has changed: update the edit component
send event if its different from previous