Constant resetting to initial-state when adding/remove styleclasses

[Dr. Michael Paus]

If anyone is counting these votes for better performance I'll add 1+ too :-)

Am 22.12.15 um 07:15 schrieb Tom Schindl:
> Hi,
>
> While debugging some code I attached a listener to a property and
> noticed that whenever a style-class is added to the control or even
> worse somewhere in the parent hierarchy that FX resets the value to its
> initial state (Node#reapplyCss & CssStyleHelper) only to set it back to
> it's real value with the next CSS-Pass triggered by the next pulse.
>
> I don't want to imagine if this happens with many value set via CSS and
> eg adding/remove a styleclass to the scene root. Is this behavior really
> by design like this?
>
> You can try that yourself with the attached program below and using the
> css at the end. I'm writing this because of Kevins request what the team
> should invest time to because of Java9 delays and frankly all of those
> bugs/features sound relevant and interesting but JavaFX performance
> (most important CSS-Performance) is still miles away from eg browsers
> who are the main competitors.
>
> It doesn't help me to get an java.awt.Desktop replacement if my
> input-forms do not render in a decent time frame - I would even say
> rendering them in 2015 most be almost instant.
>
> Tom
>
>> package application;
>>
>> import javafx.application.Application;
>> import javafx.stage.Stage;
>> import javafx.scene.Scene;
>> import javafx.scene.control.Button;
>> import javafx.scene.layout.BorderPane;
>> import javafx.scene.layout.HBox;
>> import javafx.scene.layout.StackPane;
>>
>>
>> public class Main extends Application {
>> 	@Override
>> 	public void start(Stage primaryStage) {
>> 		try {
>> 			BorderPane root = new BorderPane();
>>
>> 			StackPane p = new StackPane();
>> 			p.getStyleClass().add("test-css");
>> 			p.maxWidthProperty().addListener( (o, ol, ne) -> {
>> 				System.err.println("Modified : " + ol + " " + ne);
>> 				Thread.dumpStack();
>> 			});
>>
>> 			root.setCenter(p);
>>
>> 			HBox box = new HBox();
>>
>> 			{
>> 				Button b = new Button("Modify Pane CSS");
>> 				b.setOnAction( e -> p.getStyleClass().add("dummy"));
>> 				box.getChildren().add(b);
>> 			}
>>
>> 			{
>> 				Button b = new Button("Modify Root CSS");
>> 				b.setOnAction( e -> {
>> 					root.getStyleClass().add("dummy");
>> 				});
>> 				box.getChildren().add(b);
>> 			}
>>
>> 			root.setBottom(box);
>>
>> 			Scene scene = new Scene(root,400,400);
>> 			scene.getStylesheets().addAll(getClass().getResource("application.css").toExternalForm());
>> 			primaryStage.setScene(scene);
>> 			primaryStage.show();
>> 		} catch(Exception e) {
>> 			e.printStackTrace();
>> 		}
>> 	}
>>
>> 	public static void main(String[] args) {
>> 		launch(args);
>> 	}
>> }
>
>> .test-css {
>> 	-fx-max-width: 300;
>> }
>
>