@Override
			public void propertyChange( PropertyChangeEvent e ) {
				switch( e.getPropertyName() ) {
					case "lookAndFeel":
						// it is not necessary (and possible) to remove listener of old LaF defaults
						if( e.getNewValue() instanceof LookAndFeel )
							UIManager.getLookAndFeelDefaults().addPropertyChangeListener( this );
						updateScaleFactor();
						break;

					case "defaultFont":
					case "Label.font":
						updateScaleFactor();
						break;
				}
			}
Returns the system scale factor for the given graphics configuration.
flatlaf-core/src/main/java/com/formdev/flatlaf/util/UIScale.java