FXML referencing CSS variables - css

Question

I have google'd around a bit without an answer. In FXML I know how to reference a css, a style, etc using the styleClass and style tags. I'd like to know if it is possible to reference a single css variable adhoc.
For instance, if I want to set the padding of a pane is it possible to achieve the following, or something similar:
example.css
/* ---------- Constants ---------- */
*{
margin_small: 1.0em;
margin_large: 2.0em;
}
example fxml
<padding>
<Insets bottom="margin_small" left="margin_small" right="margin_small" top="margin_large" />
</padding>
The alternative would be to make a css style for every combination of these, or to reference them with the style tag. I'd prefer to avoid both of those options.
Is this possible ?

Answer 1

I couldn't get to the solution I actually wanted, I would've hoped to be able to include a file (fxml, css, values, etc) and reference directly. The best I could do is to create a POJO with a property for each constant, then defining an instance of the POJO in fxml.
The problem with this is each fxml will be creating a new instance of a class, which is a little wasteful seeing as the constants are static in nature.
The following is what I did:
FXMLConstants.java
// Class instance containing global variables to be referenced in fxml files. This is to allow us to use constants similarly to how Android's xml structure does
public class FXMLConstants
{
private static final DoubleProperty marginSmall = new SimpleDoubleProperty(10);
private static final DoubleProperty marginMedium = new SimpleDoubleProperty(15);
private static final DoubleProperty marginLarge = new SimpleDoubleProperty(25);
public Double getMarginSmall()
{
return marginSmall.getValue();
}
public Double getMarginMedium()
{
return marginMedium.getValue();
}
public Double getMarginLarge()
{
return marginLarge.getValue();
}
}
Example.fxml
<?xml version="1.0" encoding="UTF-8"?>
<?import java.lang.*?>
<?import java.net.*?>
<?import javafx.geometry.*?>
<?import javafx.scene.control.*?>
<?import javafx.scene.layout.*?>
<?import javafx.scene.text.*?>
<?import com.example.FXMLConstants?>
<GridPane xmlns="http://javafx.com/javafx/8" xmlns:fx="http://javafx.com/fxml/1">
<fx:define>
<FXMLConstants fx:id="fxmlConsts" />
</fx:define>
<padding>
<Insets bottom="$fxmlConsts.marginMedium" left="$fxmlConsts.marginLarge" right="$fxmlConsts.marginLarge" top="$fxmlConsts.marginMedium" />
</padding>
<children>
<Label text="Test" GridPane.columnIndex="0" GridPane.rowIndex="0" />
</children>
</GridPane>