Hello
I don't remember that I created samples like this using HarbourPWCT, sure you can do it, but you will program from scratch to handle the mouse events and you will use the GUI library functions.
I used HarbourPWCT for developing (database applications) where the GUI needs is not advanced like (design tools)
Anyway, I don't use HarbourPWCT from many years ago, I moved to CPWCT in 2013 to start the Ring language implementation
Then in 2016 I moved to Ring.
The GUI library used by HarbourPWCT is (HarbourMiniGUI Extended)
In Ring, we have Qt and the (Form Designer) is an example about a complete design tool
You will find many examples for drawing using the mouse.
Greetings,
Mahmoud