I try to create a plugin that prints the current surface of all rooms dynamically.

I start learning the compute surface plugin, ok

I succeed in adding a roomlistener and it works. Nevertheless, this callback is called only at the beginning of the creation of a new room.

Can I intercept any other updates like : point moved, drawing finished ?

At present, the last room has a surface of zero. This value is updated only with the correct value when a new room is created