JrubyFX Progress Indicator Issue

src_progress_indicator.fxml

<?xml version="1.0" encoding="UTF-8"?>

<?import java.lang.*?>
<?import java.util.*?>
<?import javafx.scene.control.*?>
<?import javafx.scene.layout.*?>
<?import javafx.scene.paint.*?>

<AnchorPane id="AnchorPane" maxHeight="-Infinity" maxWidth="-Infinity" minHeight="-Infinity" minWidth="-Infinity" prefHeight="400.0" prefWidth="400.0" xmlns:fx="http://javafx.com/fxml">
  <children>
    <GridPane prefHeight="400.0" prefWidth="600.0" AnchorPane.bottomAnchor="0.0" AnchorPane.leftAnchor="0.0" AnchorPane.rightAnchor="0.0" AnchorPane.topAnchor="0.0">
      <children>
        <ProgressIndicator fx:id="prog1" maxHeight="-Infinity" maxWidth="-Infinity" minHeight="-Infinity" minWidth="-Infinity" prefHeight="50.0" prefWidth="50.0" progress="0.0" GridPane.columnIndex="1" GridPane.rowIndex="0" />
        <ProgressIndicator id="prog1" fx:id="prog2" maxHeight="-Infinity" maxWidth="-Infinity" minHeight="-Infinity" minWidth="-Infinity" prefHeight="50.0" prefWidth="50.0" progress="0.0" GridPane.columnIndex="0" GridPane.rowIndex="1" />
        <ProgressIndicator id="prog1" fx:id="prog3" maxHeight="-Infinity" maxWidth="-Infinity" minHeight="-Infinity" minWidth="-Infinity" prefHeight="50.0" prefWidth="50.0" progress="0.0" GridPane.columnIndex="1" GridPane.rowIndex="1" />
        <ProgressIndicator id="prog1" fx:id="prog4" maxHeight="-Infinity" maxWidth="-Infinity" minHeight="-Infinity" minWidth="-Infinity" prefHeight="50.0" prefWidth="50.0" progress="0.0" GridPane.columnIndex="2" GridPane.rowIndex="1" />
      </children>
      <columnConstraints>
        <ColumnConstraints hgrow="SOMETIMES" minWidth="10.0" prefWidth="100.0" />
        <ColumnConstraints hgrow="SOMETIMES" minWidth="10.0" prefWidth="100.0" />
        <ColumnConstraints hgrow="SOMETIMES" minWidth="10.0" prefWidth="100.0" />
      </columnConstraints>
      <rowConstraints>
        <RowConstraints minHeight="10.0" prefHeight="30.0" vgrow="SOMETIMES" />
        <RowConstraints minHeight="10.0" prefHeight="30.0" vgrow="SOMETIMES" />
        <RowConstraints minHeight="10.0" prefHeight="30.0" vgrow="SOMETIMES" />
      </rowConstraints>
    </GridPane>
  </children>
</AnchorPane>

src_progress_indicator_app.rb

require 'jrubyfx'
require '../src/progress_indicator_controller'

class ProgressIndicatorApp < JRubyFX::Application

	# To change this template use File | Settings | File Templates.

	def start(stage)
		# assign the title
		stage.title = 'AMN'

		ProgressIndicatorController.load_into stage, initialize: [self, 'To initialized']

		# finally, show our app
		stage.show
	end

end

ProgressIndicatorApp.launch

src_progress_indicator_controller.rb

require 'jrubyfx'

class ProgressIndicatorController
	# To change this template use File | Settings | File Templates.
	include JRubyFX::Controller
	include JRubyFX

	fxml 'progress_indicator.fxml', nil, '.'

	def initialize arg1, arg2

		#@prog1.setProgress -1.0
		@prog2.setProgress 0.25
		@prog3.setProgress 0.50
		@prog4.setProgress 1.0
	end

end