Hi, I send the data on a custom message and i can see it in analyze window without changing the code. But, for now, i really dont know how to create in the code a new widget.
Exists the option of the custom widget thats provides QGC but, there you can only show the same parameters that QGC shows in Settings.
when you want to find something on a code, de best way to find it, for me, its to use the CTRL+F command, in this case, in Github you can use the option Find File. If you write Analyze ther you can probably find all you need to start, but dont forget to try to understand the code cause prbably there are more files involucred that those that Find File shows you.
Sorry for my English, i really dont know more about it, Im learning too