re: the above. Nah, I just need to add the add/removeFocusChangeListener() calls to Panel.java.
If it helps, philosophically, Lemur is a collection of “subsystems” for making a UI library. It just ALSO happens to provide some default implementations tying them together.
So Label, Button, etc. are just convenience wrappers around a JME Spatial with a GuiControl. They provide some convenient setup and some nice settable properties that are stylable, etc… but anyone can make their own GUI elements in a similar way, use the same styling, same GuiControl, and so on.
You can actually add a GuiControl to any JME spatial and it can participate in a UI, presuming you give it a good size and stuff.
The point is that when I’ve forgotten to add some convenience method to the Panel-related classes, there are always the underlying subsystems that can be tapped directly.
Edit: in case you haven’t seen it already, this is kind of an overview of the subsystems: https://github.com/jMonkeyEngine-Contributions/Lemur/wiki/Modules#modules