How-to customize NERDTree behavior

Question

I recently added NERDTree and NERDTreeTabs to my vim configuration and I'm quite happy about it.

However, I wanted to configure it a bit further and have the following behavior:

Ctrl+Left:

• If inside the NERDTree, do nothing.

• If inside the edited file, go to the opened NERDTree, opening one first if none is present. I guess NERDTreeTabsToggle should be used, but to use it, I must be able to detect if a NERDTree is already open, not to close it by "toggling" it.

Ctrl+Right:

• If inside the NERDTree, go back to the edited file without closing NERDTree. (Just like what Ctrl-w, Right would do.)

• If inside the edited file, hide/close the NERDTree.

However, my Vim script skills are way to low for me to get any satisfying result. For instance, I can't figure out how to check what the current active window is or how to write the appropriate conditional statements.

Can someone help me with that ?

Thank you.

Answer 1

If finally found a way.

I edited the nerdtree_plugin/vim-nerdtree-tabs.vim file, adding these functions:

" === Stepped Open/Close functions ===
" focus the NERDTree view, creating one first if none is present
fun! s:NERDTreeSteppedOpen()
  if !s:IsCurrentWindowNERDTree()
    if s:IsNERDTreeOpenInCurrentTab()
      call s:NERDTreeFocus()
    else
      call s:NERDTreeMirrorOrCreate()
    endif
  endif
endfun

" unfocus the NERDTree view or closes it if it hadn't had focus at the time of
" the call
fun! s:NERDTreeSteppedClose()
  if s:IsCurrentWindowNERDTree()
    call s:NERDTreeUnfocus()
  else
    let l:nerdtree_open = s:IsNERDTreeOpenInCurrentTab()

    if l:nerdtree_open
      silent NERDTreeClose
    endif
  endif
endfun

I also made a pull-request to the author to ask him if he wants to add theses functions upstream.

The author added my pull-request to the main repository, so with the next release, you can just call the functions directly.

Hope it helps people.