Hello, the problem is that it isn't clear how the mechanism works. A list suggests that there is an order. But there isn't. The only order that is valid is the one of the css file. Took me a while to figure out that it's not a bug in my code as to why the colors are displayed wrong. It was a "feature" of the css mechanism.
I noticed it when I created a grid to paint on. Here's an example: http://stackoverflow.com/questions/30117351/how-to-detect-mouse-movement-over-node-while-button-is-pressed In that example I paint the cells by adding a "highlight" style class, I remove the paint by removing the style class. I ended up having 15 "highlight" classes in the list of a node because I painted over it multiple times. Not that it mattered for the display, it just flood-filled the style class list unnecessarily. Roland On Thu, May 21, 2015 at 8:04 AM, Tom Schindl <tom.schi...@bestsolution.at> wrote: > 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! >
