Hello!

I'm working in the same topic, in the context of a StandaloneTextArea. I've found the answer observing the StandaloneTextArea's initGutter() method. There, you can see how the gutter is set by mean of "view.gutter.lineNumbers" jEdit property.

Therefore, in my extending class (of StandaloneTextArea) constructor, I include the next call:

props.setProperty("view.gutter.lineNumbers", "true");

... in wich "props" is my instance variable storing jEdit properties.

I hope this can help you. Bye!

- Antonio