How to add a calculated (instead of data input from OpenIGTLInk IO) proxy node in SequenceBrowser when recording an ultrasound sequences?

Hi everyone,

I am trying to write my first extension module to do a real-time ultrasound annotation.
I am now able to write a module for offline annotation with ultrasound sequences recorded as SequenceBrowsers in module Sequences.

However, both widgetRepresentation() and logic() of module Sequences do not have public functions of live data retrieval that can be called in a customer extension module.

How can I add an annotation (PointList) sequence node into a SequenceBrowser with the Proxy-Node being a PointList that is calculated using my own code (instead of data retrieved from OpenIGTLink IO)?

Please let me know if this expectation is currently not possible.

Thank you so much in advance!