Beside the usecase mentioned by Tomas - the following thread on stackoverflow indicate that it might in some cases make a difference!
http://stackoverflow.com/questions/15670631/does-the-order-of-classes-listed-on-an-item-affect-the-css Tom Von meinem iPhone gesendet > Am 21.05.2015 um 07:39 schrieb Tomas Mikula <tomas.mik...@gmail.com>: > > Hi Roland, > > I don't know why it is a List (maybe it is just copying it being a > list in the DOM), but it makes sense to me that a style class can be > present multiple times (for that matter, a multi-set would work just > as well): > > If I have two places in my code that add and remove the same style > class, it makes sense to me the style class being removed after both > of them have removed it, not just the first one. Say that I have two > different conditions, either of which makes a node "highlighted". When > both are true, and then one of them stops being true, I still want the > node to stay highlighted. > > Why do you need to make a contains-check? > > Tomas > >> On Thu, May 21, 2015 at 1:17 AM, Roland C <roland.ci...@gmail.com> wrote: >> I was recently toying around with CSS in JavaFX and noticed that I got the >> same style multiple times in the style list of my node. >> >> Since the order of the styles is defined by the order in the css file and >> not by the order of the list that getStyleClass() of a node returns, I was >> wondering if there is a special reason for that. >> >> Example: >> >> application.css >> >> .bg-color-1 { >> -fx-background-color:red; }.bg-color-2 { >> -fx-background-color:green;} >> >> Main.java >> >> public class Main extends Application { >> @Override >> public void start(Stage primaryStage) { >> try { >> BorderPane root = new BorderPane(); >> >> root.getStyleClass().add( "bg-color-1"); >> root.getStyleClass().add( "bg-color-2"); >> >> Scene scene = new Scene(root,400,400); >> >> scene.getStylesheets().add(getClass().getResource("application.css").toExternalForm()); >> primaryStage.setScene(scene); >> primaryStage.show(); >> } catch(Exception e) { >> e.printStackTrace(); >> } >> } >> >> public static void main(String[] args) { >> launch(args); >> }} >> >> It doesn't matter if you write >> >> root.getStyleClass().add( "bg-color-1"); >> root.getStyleClass().add( "bg-color-2"); >> >> or change the order to >> >> root.getStyleClass().add( "bg-color-2"); >> root.getStyleClass().add( "bg-color-1"); >> >> The used style will always be the last in the css file, i. e. "bg-color-2". >> >> *Question* >> >> Why is a List used instead of a Set? A list is less performing than a Set >> and it clutters the code if you always have to make a contains-check first. >> >> >> Thank you very much!
