JavaFX: keep all components in center even when resizing a window

Question

I want all my components (TextFields, labels, etc.) stay in the center with fixed size. I am making it in scene builder and it works when I see the preview, but when I launch it, components don't stay in the center when I resize it.

Please see the picture here: http://postimg.org/image/r42kvvfbf/

FXML file:

<AnchorPane id="AnchorPane" fx:id="root" maxHeight="-1.0" maxWidth="-1.0" minHeight="400.0" minWidth="600.0" prefHeight="-1.0" prefWidth="-1.0" xmlns:fx="http://javafx.com/fxml/1" xmlns="http://javafx.com/javafx/2.2" fx:controller="myController">
  <children>
    <GridPane alignment="CENTER" prefHeight="-1.0" prefWidth="-1.0" AnchorPane.bottomAnchor="0.0" AnchorPane.leftAnchor="0.0" AnchorPane.rightAnchor="0.0" AnchorPane.topAnchor="0.0">
      <children>
        <VBox alignment="CENTER_LEFT" maxHeight="-Infinity" maxWidth="-Infinity" minHeight="-Infinity" minWidth="-Infinity" prefHeight="-1.0" prefWidth="-1.0" spacing="10.0" GridPane.columnIndex="0" GridPane.rowIndex="0">
          <children>
            <Label text="ID number" />
            <TextField fx:id="id" maxWidth="-Infinity" minWidth="-Infinity" prefWidth="210.0" promptText="" />
            <Label text="Password" />
            <TextField fx:id="password" maxWidth="-Infinity" minWidth="-Infinity" prefWidth="210.0" promptText="" />
            <HBox id="HBox" alignment="CENTER" spacing="5.0">
              <children>
                <Button mnemonicParsing="false" onAction="#loginAction" text="Вход" textAlignment="CENTER" textOverrun="ELLIPSIS" />
              </children>
            </HBox>
          </children>
          <padding>
            <Insets bottom="20.0" left="20.0" right="20.0" top="20.0" />
          </padding>
        </VBox>
      </children>
      <columnConstraints>
        <ColumnConstraints halignment="CENTER" hgrow="SOMETIMES" minWidth="10.0" prefWidth="100.0" />
      </columnConstraints>
      <rowConstraints>
        <RowConstraints minHeight="10.0" prefHeight="30.0" vgrow="SOMETIMES" />
      </rowConstraints>
    </GridPane>
  </children>
</AnchorPane>

I have tried using StackPane and only with VBox as well, but I can't achieve what I want. Please help!

Answer 1

It is SOLVED. Maybe this might be helpful for others.

It appears that I am using Group as a root for my Scene. As said in JavaFX documentation: "If a Group is used as the root, the contents of the scene graph will be clipped by the scene's width and height and changes to the scene's size (if user resizes the stage) will not alter the layout of the scene graph".

Link: http://docs.oracle.com/javafx/2/api/javafx/scene/Scene.html