I have a java applet and the only look and feel that works properly is the native mac one. I wanted to make the fonts a bit larger and tried using the standard UIManager methods
UIManager.put("Label.font", new Font("Georgia", Font.PLAIN, 18));
This produces no change. It does not throw an exception, of course.
Does anyone know if the native mac look and feel ignores these?
I know there are specific ways to make controls different sizes on mac but these only seem to make them smaller. You cannot make the controls larger than regular.
The updateComponentTreeUI(...) method (referenced in the Changing the LAF After Startup link provided by trashgod) will only work on a FontUIResource, not a Font. This is only relevant if you need to change the Font multiple times after startup.
It appears to work on Mac OS X with any installed L&F.
Addendum: If you are trying to change the setting after startup, see How to Set the Look and Feel under Changing the Look and Feel After Startup.