JavaFX - How to make ComboBox hgrow?

Question

I have a problem with JavaFX(8), HBox, ComboBox and HGrow. HGrow does not work in combination with ComboBox.

(INFO: with TextField (instead of ComboBox), it works as expected!)

This is my FXML-Code:

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

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

<VBox prefHeight="117.0" prefWidth="285.0" xmlns="http://javafx.com/javafx/8" xmlns:fx="http://javafx.com/fxml/1" fx:controller="de.test.TestController">
  <children>
     <HBox prefHeight="105.0" prefWidth="196.0" VBox.vgrow="ALWAYS">
     <children>
        <ComboBox fx:id="fxCboTest" prefHeight="25.0" prefWidth="62.0" HBox.hgrow="ALWAYS" />
     </children>
    </HBox>
  </children>
</VBox>

this Code will result in:

i also tried following code (without success, this code does nothing):

HBox.setHgrow(uiController.fxCboTest, Priority.ALWAYS);

Does anyone has an idea how to make an ComboBox HGrow?

Answer 1

This is an answer to my own question.
After some testing, I found out that when setting Max Width to MAX_VALUE, it works:

This will result in following code/xml from SceneBuilder:

...
<children>
   <ComboBox maxWidth="1.7976931348623157E308" prefWidth="150.0" HBox.hgrow="ALWAYS" />
</children>
...

where 1.7976931348623157E308 looks like Double.MAX_VALUE.

This will also work with multiple controls in Hbox.

In my opinion, this is not very consequently/consistently.
I still don't unserstand why HGrow does not work for ComboBox.

Answer 2

This is a hack, but it should work. Inside the controller's intialize method, define a binding.

@Override
public void initialize(URL location, ResourceBundle resources) {
    fxCboTest.prefWidthProperty().bind(hbox.widthProperty());
}