Where are default widgets in Mendix Project directory located?

I need to edit the textarea default widget. Can anyone tell me where all default widgets in Mendix located? I can’t seem to find those.
1 answers

Alas, you will not find them. To the best of my knowledge (hoping to stand corrected) Mendix has kept that closed source. Therefore you can not change the default text widget. You will have to create your own.

It is possible to create your own text widget, which is described here on docs.mendix.com.