Load fxml as background process - Javafx

Question

My initial fxml(say home.fxml) has a lot of functionalities, hence it takes a lot of time to load completely. So to avoid the time gap between program start and

Answer 1

your approach using Task was already correct. you were just missing a bit more: you were just missing another Platform#invokeLater() to update the UI:

    new Thread(new Task() {

        @Override
        protected Object call() throws Exception {
            // Simulating long loading
            Thread.sleep(5000);

            FXMLLoader loader = new FXMLLoader(getClass().getResource("home.fxml"));
            Parent root = loader.load();

            Scene scene = new Scene(root);

            // Updating the UI requires another Platform.runLater()
            Platform.runLater(new Runnable() {

                @Override
                public void run() {
                    mainStage.setScene(scene);
                    mainStage.show();
                    stage.hide();
                    System.out.println("Stage showing");
                    // Get current screen of the stage
                    ObservableList screens = Screen.getScreensForRectangle(new Rectangle2D(mainStage.getX(), mainStage.getY(), mainStage.getWidth(), mainStage.getHeight()));
                    // Change stage properties
                    Rectangle2D bounds = screens.get(0).getVisualBounds();
                    mainStage.setX(bounds.getMinX());
                    mainStage.setY(bounds.getMinY());
                    mainStage.setWidth(bounds.getWidth());
                    mainStage.setHeight(bounds.getHeight());
                    System.out.println("thread complete");
                }
            });
            return null;
        }
    }).start();