ModifiableFontPreferences () { if (!(fontPreferences instanceof ModifiableFontPreferences)) { ModifiableFontPreferences editableFontPreferences = new FontPreferencesImpl(); fontPreferences.copyTo(editableFontPreferences); fontPreferences = editableFontPreferences; ((FontPreferencesImpl)fontPreferences).addChangeListener((source) -> initFonts()); } return (ModifiableFontPreferences)fontPreferences; }