Vim: When folding code allow tabs to remain

Question

In vim I would like to change the folding behavior. Suppose I fold this block:

=== fileName ===

        == summary ==

                I think that this defines the class to use for the authentication
                and the parameters to pass the class.

        == tags ==

                <bla bla>
                </bla bla>

It becomes:

=== fileName ===

        == summary ==

+---  2 lines: I think that this defines the class to use for the authentication------------

        == tags ==

                <bla bla>
                </bla bla>

I think that it would be easier to read if it became:

=== fileName ===

        == summary ==

                +---  2 lines: I think that this defines the class to use for the authentication------------

        == tags ==

                <bla bla>
                </bla bla>

(The desired result has an extra tab)

FYI: I have this in my vimrc:

"use indents as the folding method
set foldmethod=indent

"make vim save and load the folding of the document each time it loads
au BufWinLeave * mkview
au BufWinEnter * silent loadview

Update

Upon recommendation from njd I tried setting the foldtext to my own function. I tried both the one that he suggested and the one below. However neither had any effect.

function! MyFoldText()
  return 'johnny'
endfunction

set foldtext=MyFoldText()

What am I missing here?

Note: I also have this: set foldmethod=indent in my .vimrc.

Answer 1

So you want to have the fold message line up with the indent of the folded text?

You need to set the 'foldtext' option to something other than the default foldtext() function.

Something like this:

function! MyFoldText()
  let lines = 1 + v:foldend - v:foldstart
  let spaces = repeat(' ', indent(v:foldstart))

  let linestxt = 'lines'
  if lines == 1
    linestxt = 'line'
  endif

  let firstline = getline(v:foldstart)
  let line = firstline[ind : ind+80]

  return spaces . '+' . v:folddashes . ' ' . lines . ' ' . linestxt . ': ' . line . ' '
endfunction

Then

:set foldtext=MyFoldText()