Sorry, I thought I’d already pointed to it before but I think that was a different conversation and may have been offline.
This is what the glass style definition looks like:
https://code.google.com/p/jmonkeyplatform-contributions/source/browse/trunk/Lemur/src/com/simsilica/lemur/style/base/glass-styles.groovy
Style resources like that are setup to auto merge the files if it finds multiple ones… this is why Lemur-Proto was able to easily extend the glass style for its new components just by having a properly named file in the right place:
https://code.google.com/p/jmonkeyplatform-contributions/source/browse/trunk/Lemur/extensions/LemurProto/src/main/resources/com/simsilica/lemur/style/base/glass-styles.groovy
In each of those cases, selector(“foo”, “bar”) is similar to (in Java) calling Styles.getSelector(“foo”, “bar”) and then setting values on the Attributes object. Any of the stylable properties are annotated on the particular class… so Label lets you set font, font size, text, alignment, etc. through styles.
The groovy-based style definitions are less verbose and feel more like CSS but the functionality is the same.
Here is a longer article on styling in case you haven’t seen it.