Stage loses fill (gradient) after simply creating a new control - javafx

Question

I have reduced my recreate of this to the following. The line where a ToggleButton is instantiated causes my stage to lose its fill color; it goes white. I am just getting started with JavaFX, so please let me know if I'm doing something I shouldn't, here. This is using jre1.8.0_92 with Eclipse Neon (jfx8_2.3.0 plugin) on Windows 7 sp1.
public class Main extends Application {
public static void main(String[] args) {
if(args.length > 0) {
String s = args[0].toLowerCase();
if(s.equals("full"))
Machine.isFullScreen = true;
}
launch(args);
}
#Override
public void start(Stage primaryStage) throws Exception {
Machine.startMachine(primaryStage);
}
}
public class Machine {
static boolean isFullScreen = false;
static Rectangle2D screenRect, backRect;
static Stage backStage;
static Scene backScene;
static Pane backPane;
private Machine() {}
static public void startMachine(Stage primaryStage) {
// backscreen
startScene(primaryStage);
// This line causes the fill to be lost
ToggleButton foo = new ToggleButton("hi");
}
static private void startScene(Stage primaryStage) {
// Stage
backStage = primaryStage;
backStage.initStyle(StageStyle.UNDECORATED);
backStage.setFullScreen(isFullScreen);
screenRect = Screen.getPrimary().getBounds();
if(!isFullScreen) {
int w = 1000, h = 500, t = 20;
backStage.setWidth(w);
backStage.setHeight(h);
backStage.setX((screenRect.getWidth() - w)/2);
backStage.setY(t);
}
backRect = new Rectangle2D(backStage.getX(), backStage.getY(),
backStage.getWidth(), backStage.getHeight());
// Scene
backScene = new Scene(backPane = new Pane());
// backScene.getStylesheets().add(Machine.class.getResource("mainStyle.css").toExternalForm());
// backScene.getRoot().setStyle("-fx-background-color: #CCFF99;");
backScene.setFill(new LinearGradient(0,0,1,1, true, CycleMethod.NO_CYCLE,
new Stop[]{
new Stop(0,Color.web("#4977A3")),
new Stop(0.5, Color.web("#B0C6DA")),
new Stop(1,Color.web("#9CB6CF")), } ));
// Logo
Text logo = new Text("AMT");
logo.setFill(Color.DEEPSKYBLUE);
Font font = Font.font("Times New Roman", FontWeight.BOLD, FontPosture.ITALIC, 96);
logo.setFont(font);
logo.setX(100);
logo.setY(150);
backPane.getChildren().add(logo);
backStage.setScene(backScene);
backStage.setFullScreenExitKeyCombination(KeyCombination.NO_MATCH);
backStage.show();
}
}

Answer 1

The setFill() API suggests that this may be a stylesheet effect. The default stylesheet is installed statically when the first Control is instantiated. If that stylesheet is Modena, "the default fill is set to be a light gray color." Instead of backScene.setFill(), try backPane.setBackground(), as suggested here and here.
// Scene
backPane = new Pane();
backScene = new Scene(backPane);
LinearGradient linearGradient = new LinearGradient(
0, 0, 1, 1, true, CycleMethod.NO_CYCLE,
new Stop(0, Color.web("#4977A3")),
new Stop(0.5, Color.web("#B0C6DA")),
new Stop(1, Color.web("#9CB6CF")));
backPane.setBackground(new Background(new BackgroundFill(
linearGradient, CornerRadii.EMPTY, Insets.EMPTY)));
As an aside, note that the varargs constructor parameter of LinearGradient allows you to add instances of Stop directly, without creating a new array.