Difference setClassName and addClassName

Can someone explain to me the difference of using setClassName and addClassName? I realized I used both in my project but don’t know whether I should be using only one of them? Is addClassName for adding multiple ones and set overwrites the current class names?

Yes: setClassName will override any previous value. addClassName will append it to the class name list. This should be mentioned in the JavaDoc of the methods, and if it isn’t, I’d consider it a bug.