Straight line to curve, quickest way:

Option-click on the line.

For more than one line to curves, select the lines, then control-click or right-click anywhere on the lines and use the popup menu and choose “Convert > To Curves”.

Curve to straight line, quickest way:

Shift-click on the curve to select it, then control-click or right-click on the curve and use the popup menu and choose “Convert > To Lines”.

Thank you

Even though I am working in Windows I found the way.

For the straight-line to curve transformation it’s Alt-click.

George Triantafyllakos - backpacker.gr

For the straight-line to curve transformation it’s Alt-click.

I was going to guess that, but I wasn’t sure.