How can I add a JSeparator to the main toolbar?

It’s easy to add a separator to the menus by editing the module’s layer file; in fact, the Action wizard will do this for you. Items in the main toolbar are also configured through the layer file, but you may find that adding a separator as you would for the menu does not work in the toolbar. So how do you add a separator to the toolbar?

You can do this by creating a class like:

package com.example.util.widgets;

public class VerticalSeparator extends JSeparator {

    public VerticalSeparator() {
        super(JSeparator.VERTICAL);
    }

    @Override
    public Dimension getMaximumSize() {
        return new Dimension(getPreferredSize().width, super.getMaximumSize().height);
    }

    @Override
    public Dimension getSize() {
        return new Dimension(getPreferredSize().width, super.getSize().height);
    }
}

Then simply reference an instance of this separator in the layer file:

<file name="SeparatorAfterModelToolbarActions.instance">
    <attr name="instanceClass" stringvalue="com.example.util.widgets.VerticalSeparator"/>
    <attr name="position" intvalue="25"/>
</file>

Apache NetBeans 23

How can I add a JSeparator to the main toolbar?