PseudoClass represents one unique pseudo-class state. Introducing a pseudo-class into a JavaFX class only requires that the method javafx.scene.Node.pseudoClassStateChanged(javafx.css.PseudoClass, boolean) be called when the pseudo-class state changes. Typically, the pseudoClassStateChanged method is called from the protected void invalidated() method of one of the property base classes in the javafx.beans.property package.

Note that if a node has a default pseudo-class state, a horizontal orientation for example, pseudoClassStateChanged should be called from the constructor to set the initial state.

The following example would allow "xyzzy" to be used as a pseudo-class in a CSS selector.

  public boolean isMagic() {
       return magic.get();
   }

   public BooleanProperty magicProperty() {
       return magic;
   }

   public BooleanProperty magic =
       new BooleanPropertyBase(false) {

        @Override protected void invalidated() {
           pseudoClassStateChanged(MAGIC_PSEUDO_CLASS. get());
       }

        @Override public Object getBean() {
           return MyControl.this;
       }

        @Override public String getName() {
           return "magic";
       }
   }

   private static final PseudoClass
       MAGIC_PSEUDO_CLASS = PseudoClass.getPseudoClass("xyzzy");
 

Since:  JavaFX 8.0