Teaching Java to students: what are the environments/guidelines?

Question

Java

Hello.
This semester, I'm leading a class for schoolchildren on Android programming. The ultimate goal is to use the smartphone's camera and Bluetooth to pass the robot through difficult tracks that cannot be passed on the robot's sensors alone.
Schoolchildren - grades 7-11, are already familiar with a C-like language, someone even knows a little that there are objects (Ceebot / Colobot). Question: what is the best way to start learning for clarity? I plan to start with GreenFoot - the students liked it during the last course, and there is even an opportunity to visually demonstrate inheritance, classes, objects and relationships between them. However, GreenFoot completely lacks the processing of events from the outside world by creating a handler class or implementing an interface, without which Android can’t do anything. Perhaps there are some similar free environments in which you can demonstrate this with simple examples?
Can anyone recommend a good tutorial book?
Thank you.

Answer 1

Or maybe stop playing (colobot is enough)? You can move on to something closer to life. For clarity, you can study js (work in the browser) or something like that.

Answer 2

processing? Simple, C-like, there is OOP, it works on Android, there is access to sensors.

Answer 3

OFFTOP . Oh, I wish there were such circles at school in my time. I envy today's students.