Drawing a curve using a mouse

I don’t know if a paintable canvas is the way to go with this, but I’d like to build a screen where a user can hold down a mouse and trace a line/curve across an empty ‘chart’ (for lack of a better word), resulting in a line.

Another scenario is I would take a dataset of paired x,y values (about 50 total) – something like
etc etc. This I would graph out, and they could use the mouse to either drag the line up or down (as a way of entering a new value) or alternatively click to indicate a new value.

In both cases, after they have either drawn a line from scratch, or edited the line I provide them, I would like to then capture the new data and send it to a database.

Any ideas on how to get there? I’ve downloaded the sample project at https://inductiveautomation.com/forum/viewtopic.php?f=70&t=15425&p=56802&hilit=canvas#p56802
but I haven’t dived in enough to see if it can help. thx.