public static void updateUILater() {
		synchronized( FlatLaf.class ) {
			if( updateUIPending )
				return;

			updateUIPending = true;
		}

		EventQueue.invokeLater( () -> {
			updateUI();
			synchronized( FlatLaf.class ) {
				updateUIPending = false;
			}
		} );
	}
Update UI of all application windows later.
flatlaf-core/src/main/java/com/formdev/flatlaf/FlatLaf.java