I've seen a similar question has been asked already 6 years ago with no answer:
Is there any way to add the event listeners in the desktop app? I noticed that the ggbApplet object contains a lot more than what is documented. Is there any complete documentation or a readable source file to see all it's methods?
I found this: https://dev.geogebra.org/tr...
It contains some great ideas, but It seems to be completely outdated.