[Feature] Add lines that are off-screen

[za3k]

For very long indented sections (think multi-page functions) it would be really nice to show the first line of each indentation, even if it's off the top of the screen. Ex in python:

class ABC():
    def short_function():
        pass
    def long_function():
        ...

In the middle of long_function, you could always see

class ABC():
    def long_function():

in a separate background color on the top of the screen if they are otherwise not physically on screen.

Don't know if that's doable, just an idea I think is neat! And it should require only knowledge of indentation, not the language in question.

I would personally find this useful for my TODO systems, in which I sometimes take very long notes.