Request: Option for line numbers on left margin

[rjzak]

Lots of text editors and IDEs show the line numbers to the left of the text being viewed. I know that the current line is shown in the status bar, but I'd find it more helpful to be able to see it to the left.

[raweden]

I've been experimenting with adding support for this:

But since everything related to rendering code-editing is implemented in the PText class it becomes really awkward to manage two coordinate spaces within the same view.
If this feature would be of interest for the repository owner and contributors I would suggest to split-up the implementation of PText class into:

• state/model (cursor-position, line model, selection state etc)
• text-container (a class that represent each view into the document)
• text-view (manages the state of split-view and line-gutter)

Also thinking of implementing support for folding text ranges and other controls that could be put in the line-no view such as decorators for breakpoints, lines with warning & errors.