dotfiles/.vim/plugin/NERD_tree.vim

" ============================================================================
" File:        NERD_tree.vim
" Description: vim global plugin that provides a nice tree explorer
" Maintainer:  Martin Grenfell <martin.grenfell at gmail dot com>
" Last Change: 28 December, 2011
" License:     This program is free software. It comes without any warranty,
"              to the extent permitted by applicable law. You can redistribute
"              it and/or modify it under the terms of the Do What The Fuck You
"              Want To Public License, Version 2, as published by Sam Hocevar.
"              See http://sam.zoy.org/wtfpl/COPYING for more details.
"
" ============================================================================
let s:NERD_tree_version = '4.2.0'

" SECTION: Script init stuff {{{1
"============================================================
if exists("loaded_nerd_tree")
    finish
endif
if v:version < 700
    echoerr "NERDTree: this plugin requires vim >= 7. DOWNLOAD IT! You'll thank me later!"
    finish
endif
let loaded_nerd_tree = 1

"for line continuation - i.e dont want C in &cpo
let s:old_cpo = &cpo
set cpo&vim

let s:running_windows = has("win16") || has("win32") || has("win64")

"Function: s:initVariable() function {{{2
"This function is used to initialise a given variable to a given value. The
"variable is only initialised if it does not exist prior
"
"Args:
"var: the name of the var to be initialised
"value: the value to initialise var to
"
"Returns:
"1 if the var is set, 0 otherwise
function! s:initVariable(var, value)
    if !exists(a:var)
        exec 'let ' . a:var . ' = ' . "'" . substitute(a:value, "'", "''", "g") . "'"
        return 1
    endif
    return 0
endfunction

"SECTION: Init variable calls and other random constants {{{2
call s:initVariable("g:NERDChristmasTree", 1)
call s:initVariable("g:NERDTreeAutoCenter", 1)
call s:initVariable("g:NERDTreeAutoCenterThreshold", 3)
call s:initVariable("g:NERDTreeCaseSensitiveSort", 0)
call s:initVariable("g:NERDTreeChDirMode", 0)
call s:initVariable("g:NERDTreeMinimalUI", 0)
if !exists("g:NERDTreeIgnore")
    let g:NERDTreeIgnore = ['\~$']
endif
call s:initVariable("g:NERDTreeBookmarksFile", expand('$HOME') . '/.NERDTreeBookmarks')
call s:initVariable("g:NERDTreeHighlightCursorline", 1)
call s:initVariable("g:NERDTreeHijackNetrw", 1)
call s:initVariable("g:NERDTreeMouseMode", 1)
call s:initVariable("g:NERDTreeNotificationThreshold", 100)
call s:initVariable("g:NERDTreeQuitOnOpen", 0)
call s:initVariable("g:NERDTreeShowBookmarks", 0)
call s:initVariable("g:NERDTreeShowFiles", 1)
call s:initVariable("g:NERDTreeShowHidden", 0)
call s:initVariable("g:NERDTreeShowLineNumbers", 0)
call s:initVariable("g:NERDTreeSortDirs", 1)
call s:initVariable("g:NERDTreeDirArrows", !s:running_windows)

if !exists("g:NERDTreeSortOrder")
    let g:NERDTreeSortOrder = ['\/$', '*', '\.swp$',  '\.bak$', '\~$']
else
    "if there isnt a * in the sort sequence then add one
    if count(g:NERDTreeSortOrder, '*') < 1
        call add(g:NERDTreeSortOrder, '*')
    endif
endif

"we need to use this number many times for sorting... so we calculate it only
"once here
let s:NERDTreeSortStarIndex = index(g:NERDTreeSortOrder, '*')

if !exists('g:NERDTreeStatusline')

    "the exists() crap here is a hack to stop vim spazzing out when
    "loading a session that was created with an open nerd tree. It spazzes
    "because it doesnt store b:NERDTreeRoot (its a b: var, and its a hash)
    let g:NERDTreeStatusline = "%{exists('b:NERDTreeRoot')?b:NERDTreeRoot.path.str():''}"

endif
call s:initVariable("g:NERDTreeWinPos", "left")
call s:initVariable("g:NERDTreeWinSize", 31)

"init the shell commands that will be used to copy nodes, and remove dir trees
"
"Note: the space after the command is important
if s:running_windows
    call s:initVariable("g:NERDTreeRemoveDirCmd", 'rmdir /s /q ')
else
    call s:initVariable("g:NERDTreeRemoveDirCmd", 'rm -rf ')
    call s:initVariable("g:NERDTreeCopyCmd", 'cp -r ')
endif


"SECTION: Init variable calls for key mappings {{{2
call s:initVariable("g:NERDTreeMapActivateNode", "o")
call s:initVariable("g:NERDTreeMapChangeRoot", "C")
call s:initVariable("g:NERDTreeMapChdir", "cd")
call s:initVariable("g:NERDTreeMapCloseChildren", "X")
call s:initVariable("g:NERDTreeMapCloseDir", "x")
call s:initVariable("g:NERDTreeMapDeleteBookmark", "D")
call s:initVariable("g:NERDTreeMapMenu", "m")
call s:initVariable("g:NERDTreeMapHelp", "?")
call s:initVariable("g:NERDTreeMapJumpFirstChild", "K")
call s:initVariable("g:NERDTreeMapJumpLastChild", "J")
call s:initVariable("g:NERDTreeMapJumpNextSibling", "<C-j>")
call s:initVariable("g:NERDTreeMapJumpParent", "p")
call s:initVariable("g:NERDTreeMapJumpPrevSibling", "<C-k>")
call s:initVariable("g:NERDTreeMapJumpRoot", "P")
call s:initVariable("g:NERDTreeMapOpenExpl", "e")
call s:initVariable("g:NERDTreeMapOpenInTab", "t")
call s:initVariable("g:NERDTreeMapOpenInTabSilent", "T")
call s:initVariable("g:NERDTreeMapOpenRecursively", "O")
call s:initVariable("g:NERDTreeMapOpenSplit", "i")
call s:initVariable("g:NERDTreeMapOpenVSplit", "s")
call s:initVariable("g:NERDTreeMapPreview", "g" . NERDTreeMapActivateNode)
call s:initVariable("g:NERDTreeMapPreviewSplit", "g" . NERDTreeMapOpenSplit)
call s:initVariable("g:NERDTreeMapPreviewVSplit", "g" . NERDTreeMapOpenVSplit)
call s:initVariable("g:NERDTreeMapQuit", "q")
call s:initVariable("g:NERDTreeMapRefresh", "r")
call s:initVariable("g:NERDTreeMapRefreshRoot", "R")
call s:initVariable("g:NERDTreeMapToggleBookmarks", "B")
call s:initVariable("g:NERDTreeMapToggleFiles", "F")
call s:initVariable("g:NERDTreeMapToggleFilters", "f")
call s:initVariable("g:NERDTreeMapToggleHidden", "I")
call s:initVariable("g:NERDTreeMapToggleZoom", "A")
call s:initVariable("g:NERDTreeMapUpdir", "u")
call s:initVariable("g:NERDTreeMapUpdirKeepOpen", "U")

"SECTION: Script level variable declaration{{{2
if s:running_windows
    let s:escape_chars =  " `\|\"#%&,?()\*^<>"
else
    let s:escape_chars =  " \\`\|\"#%&,?()\*^<>[]"
endif
let s:NERDTreeBufName = 'NERD_tree_'

let s:tree_wid = 2
let s:tree_markup_reg = '^[ `|]*[\-+~▾▸ ]\+'
let s:tree_up_dir_line = '.. (up a dir)'

"the number to add to the nerd tree buffer name to make the buf name unique
let s:next_buffer_number = 1

" SECTION: Commands {{{1
"============================================================
"init the command that users start the nerd tree with
command! -n=? -complete=dir -bar NERDTree :call s:initNerdTree('<args>')
command! -n=? -complete=dir -bar NERDTreeToggle :call s:toggle('<args>')
command! -n=0 -bar NERDTreeClose :call s:closeTreeIfOpen()
command! -n=1 -complete=customlist,s:completeBookmarks -bar NERDTreeFromBookmark call s:initNerdTree('<args>')
command! -n=0 -bar NERDTreeMirror call s:initNerdTreeMirror()
command! -n=0 -bar NERDTreeFind call s:findAndRevealPath()
" SECTION: Auto commands {{{1
"============================================================
augroup NERDTree
    "Save the cursor position whenever we close the nerd tree
    exec "autocmd BufWinLeave ". s:NERDTreeBufName ."* call <SID>saveScreenState()"

    "disallow insert mode in the NERDTree
    exec "autocmd BufEnter ". s:NERDTreeBufName ."* stopinsert"

    "cache bookmarks when vim loads
    autocmd VimEnter * call s:Bookmark.CacheBookmarks(0)

    "load all nerdtree plugins after vim starts
    autocmd VimEnter * runtime! nerdtree_plugin/**/*.vim
augroup END

if g:NERDTreeHijackNetrw
    augroup NERDTreeHijackNetrw
        autocmd VimEnter * silent! autocmd! FileExplorer
        au BufEnter,VimEnter * call s:checkForBrowse(expand("<amatch>"))
    augroup END
endif

"SECTION: Classes {{{1
"============================================================
"CLASS: Bookmark {{{2
"============================================================
let s:Bookmark = {}
" FUNCTION: Bookmark.activate() {{{3
function! s:Bookmark.activate()
    if self.path.isDirectory
        call self.toRoot()
    else
        if self.validate()
            let n = s:TreeFileNode.New(self.path)
            call n.open()
            call s:closeTreeIfQuitOnOpen()
        endif
    endif
endfunction
" FUNCTION: Bookmark.AddBookmark(name, path) {{{3
" Class method to add a new bookmark to the list, if a previous bookmark exists
" with the same name, just update the path for that bookmark
function! s:Bookmark.AddBookmark(name, path)
    for i in s:Bookmark.Bookmarks()
        if i.name ==# a:name
            let i.path = a:path
            return
        endif
    endfor
    call add(s:Bookmark.Bookmarks(), s:Bookmark.New(a:name, a:path))
    call s:Bookmark.Sort()
endfunction
" Function: Bookmark.Bookmarks()   {{{3
" Class method to get all bookmarks. Lazily initializes the bookmarks global
" variable
function! s:Bookmark.Bookmarks()
    if !exists("g:NERDTreeBookmarks")
        let g:NERDTreeBookmarks = []
    endif
    return g:NERDTreeBookmarks
endfunction
" Function: Bookmark.BookmarkExistsFor(name)   {{{3
" class method that returns 1 if a bookmark with the given name is found, 0
" otherwise
function! s:Bookmark.BookmarkExistsFor(name)
    try
        call s:Bookmark.BookmarkFor(a:name)
        return 1
    catch /^NERDTree.BookmarkNotFoundError/
        return 0
    endtry
endfunction
" Function: Bookmark.BookmarkFor(name)   {{{3
" Class method to get the bookmark that has the given name. {} is return if no
" bookmark is found
function! s:Bookmark.BookmarkFor(name)
    for i in s:Bookmark.Bookmarks()
        if i.name ==# a:name
            return i
        endif
    endfor
    throw "NERDTree.BookmarkNotFoundError: no bookmark found for name: \"". a:name  .'"'
endfunction
" Function: Bookmark.BookmarkNames()   {{{3
" Class method to return an array of all bookmark names
function! s:Bookmark.BookmarkNames()
    let names = []
    for i in s:Bookmark.Bookmarks()
        call add(names, i.name)
    endfor
    return names
endfunction
" FUNCTION: Bookmark.CacheBookmarks(silent) {{{3
" Class method to read all bookmarks from the bookmarks file intialize
" bookmark objects for each one.
"
" Args:
" silent - dont echo an error msg if invalid bookmarks are found
function! s:Bookmark.CacheBookmarks(silent)
    if filereadable(g:NERDTreeBookmarksFile)
        let g:NERDTreeBookmarks = []
        let g:NERDTreeInvalidBookmarks = []
        let bookmarkStrings = readfile(g:NERDTreeBookmarksFile)
        let invalidBookmarksFound = 0
        for i in bookmarkStrings

            "ignore blank lines
            if i != ''

                let name = substitute(i, '^\(.\{-}\) .*$', '\1', '')
                let path = substitute(i, '^.\{-} \(.*\)$', '\1', '')

                try
                    let bookmark = s:Bookmark.New(name, s:Path.New(path))
                    call add(g:NERDTreeBookmarks, bookmark)
                catch /^NERDTree.InvalidArgumentsError/
                    call add(g:NERDTreeInvalidBookmarks, i)
                    let invalidBookmarksFound += 1
                endtry
            endif
        endfor
        if invalidBookmarksFound
            call s:Bookmark.Write()
            if !a:silent
                call s:echo(invalidBookmarksFound . " invalid bookmarks were read. See :help NERDTreeInvalidBookmarks for info.")
            endif
        endif
        call s:Bookmark.Sort()
    endif
endfunction
" FUNCTION: Bookmark.compareTo(otherbookmark) {{{3
" Compare these two bookmarks for sorting purposes
function! s:Bookmark.compareTo(otherbookmark)
    return a:otherbookmark.name < self.name
endfunction
" FUNCTION: Bookmark.ClearAll() {{{3
" Class method to delete all bookmarks.
function! s:Bookmark.ClearAll()
    for i in s:Bookmark.Bookmarks()
        call i.delete()
    endfor
    call s:Bookmark.Write()
endfunction
" FUNCTION: Bookmark.delete() {{{3
" Delete this bookmark. If the node for this bookmark is under the current
" root, then recache bookmarks for its Path object
function! s:Bookmark.delete()
    let node = {}
    try
        let node = self.getNode(1)
    catch /^NERDTree.BookmarkedNodeNotFoundError/
    endtry
    call remove(s:Bookmark.Bookmarks(), index(s:Bookmark.Bookmarks(), self))
    if !empty(node)
        call node.path.cacheDisplayString()
    endif
    call s:Bookmark.Write()
endfunction
" FUNCTION: Bookmark.getNode(searchFromAbsoluteRoot) {{{3
" Gets the treenode for this bookmark
"
" Args:
" searchFromAbsoluteRoot: specifies whether we should search from the current
" tree root, or the highest cached node
function! s:Bookmark.getNode(searchFromAbsoluteRoot)
    let searchRoot = a:searchFromAbsoluteRoot ? s:TreeDirNode.AbsoluteTreeRoot() : b:NERDTreeRoot
    let targetNode = searchRoot.findNode(self.path)
    if empty(targetNode)
        throw "NERDTree.BookmarkedNodeNotFoundError: no node was found for bookmark: " . self.name
    endif
    return targetNode
endfunction
" FUNCTION: Bookmark.GetNodeForName(name, searchFromAbsoluteRoot) {{{3
" Class method that finds the bookmark with the given name and returns the
" treenode for it.
function! s:Bookmark.GetNodeForName(name, searchFromAbsoluteRoot)
    let bookmark = s:Bookmark.BookmarkFor(a:name)
    return bookmark.getNode(a:searchFromAbsoluteRoot)
endfunction
" FUNCTION: Bookmark.GetSelected() {{{3
" returns the Bookmark the cursor is over, or {}
function! s:Bookmark.GetSelected()
    let line = getline(".")
    let name = substitute(line, '^>\(.\{-}\) .\+$', '\1', '')
    if name != line
        try
            return s:Bookmark.BookmarkFor(name)
        catch /^NERDTree.BookmarkNotFoundError/
            return {}
        endtry
    endif
    return {}
endfunction

" Function: Bookmark.InvalidBookmarks()   {{{3
" Class method to get all invalid bookmark strings read from the bookmarks
" file
function! s:Bookmark.InvalidBookmarks()
    if !exists("g:NERDTreeInvalidBookmarks")
        let g:NERDTreeInvalidBookmarks = []
    endif
    return g:NERDTreeInvalidBookmarks
endfunction
" FUNCTION: Bookmark.mustExist() {{{3
function! s:Bookmark.mustExist()
    if !self.path.exists()
        call s:Bookmark.CacheBookmarks(1)
        throw "NERDTree.BookmarkPointsToInvalidLocationError: the bookmark \"".
            \ self.name ."\" points to a non existing location: \"". self.path.str()
    endif
endfunction
" FUNCTION: Bookmark.New(name, path) {{{3
" Create a new bookmark object with the given name and path object
function! s:Bookmark.New(name, path)
    if a:name =~# ' '
        throw "NERDTree.IllegalBookmarkNameError: illegal name:" . a:name
    endif

    let newBookmark = copy(self)
    let newBookmark.name = a:name
    let newBookmark.path = a:path
    return newBookmark
endfunction
" FUNCTION: Bookmark.openInNewTab(options) {{{3
" Create a new bookmark object with the given name and path object
function! s:Bookmark.openInNewTab(options)
    let currentTab = tabpagenr()
    if self.path.isDirectory
        tabnew
        call s:initNerdTree(self.name)
    else
        exec "tabedit " . self.path.str({'format': 'Edit'})
    endif

    if has_key(a:options, 'stayInCurrentTab')
        exec "tabnext " . currentTab
    endif
endfunction
" Function: Bookmark.setPath(path)   {{{3
" makes this bookmark point to the given path
function! s:Bookmark.setPath(path)
    let self.path = a:path
endfunction
" Function: Bookmark.Sort()   {{{3
" Class method that sorts all bookmarks
function! s:Bookmark.Sort()
    let CompareFunc = function("s:compareBookmarks")
    call sort(s:Bookmark.Bookmarks(), CompareFunc)
endfunction
" Function: Bookmark.str()   {{{3
" Get the string that should be rendered in the view for this bookmark
function! s:Bookmark.str()
    let pathStrMaxLen = winwidth(s:getTreeWinNum()) - 4 - len(self.name)
    if &nu
        let pathStrMaxLen = pathStrMaxLen - &numberwidth
    endif

    let pathStr = self.path.str({'format': 'UI'})
    if len(pathStr) > pathStrMaxLen
        let pathStr = '<' . strpart(pathStr, len(pathStr) - pathStrMaxLen)
    endif
    return '>' . self.name . ' ' . pathStr
endfunction
" FUNCTION: Bookmark.toRoot() {{{3
" Make the node for this bookmark the new tree root
function! s:Bookmark.toRoot()
    if self.validate()
        try
            let targetNode = self.getNode(1)
        catch /^NERDTree.BookmarkedNodeNotFoundError/
            let targetNode = s:TreeFileNode.New(s:Bookmark.BookmarkFor(self.name).path)
        endtry
        call targetNode.makeRoot()
        call s:renderView()
        call targetNode.putCursorHere(0, 0)
    endif
endfunction
" FUNCTION: Bookmark.ToRoot(name) {{{3
" Make the node for this bookmark the new tree root
function! s:Bookmark.ToRoot(name)
    let bookmark = s:Bookmark.BookmarkFor(a:name)
    call bookmark.toRoot()
endfunction


"FUNCTION: Bookmark.validate() {{{3
function! s:Bookmark.validate()
    if self.path.exists()
        return 1
    else
        call s:Bookmark.CacheBookmarks(1)
        call s:renderView()
        call s:echo(self.name . "now points to an invalid location. See :help NERDTreeInvalidBookmarks for info.")
        return 0
    endif
endfunction

" Function: Bookmark.Write()   {{{3
" Class method to write all bookmarks to the bookmarks file
function! s:Bookmark.Write()
    let bookmarkStrings = []
    for i in s:Bookmark.Bookmarks()
        call add(bookmarkStrings, i.name . ' ' . i.path.str())
    endfor

    "add a blank line before the invalid ones
    call add(bookmarkStrings, "")

    for j in s:Bookmark.InvalidBookmarks()
        call add(bookmarkStrings, j)
    endfor
    call writefile(bookmarkStrings, g:NERDTreeBookmarksFile)
endfunction
"CLASS: KeyMap {{{2
"============================================================
let s:KeyMap = {}
"FUNCTION: KeyMap.All() {{{3
function! s:KeyMap.All()
    if !exists("s:keyMaps")
        let s:keyMaps = []
    endif
    return s:keyMaps
endfunction

"FUNCTION: KeyMap.BindAll() {{{3
function! s:KeyMap.BindAll()
    for i in s:KeyMap.All()
        call i.bind()
    endfor
endfunction

"FUNCTION: KeyMap.bind() {{{3
function! s:KeyMap.bind()
    exec "nnoremap <silent> <buffer> ". self.key ." :call ". self.callback ."()<cr>"
endfunction

"FUNCTION: KeyMap.Create(options) {{{3
function! s:KeyMap.Create(options)
    let newKeyMap = copy(self)
    let newKeyMap.key = a:options['key']
    let newKeyMap.quickhelpText = a:options['quickhelpText']
    let newKeyMap.callback = a:options['callback']
    call add(s:KeyMap.All(), newKeyMap)
endfunction
"CLASS: MenuController {{{2
"============================================================
let s:MenuController = {}
"FUNCTION: MenuController.New(menuItems) {{{3
"create a new menu controller that operates on the given menu items
function! s:MenuController.New(menuItems)
    let newMenuController =  copy(self)
    if a:menuItems[0].isSeparator()
        let newMenuController.menuItems = a:menuItems[1:-1]
    else
        let newMenuController.menuItems = a:menuItems
    endif
    return newMenuController
endfunction

"FUNCTION: MenuController.showMenu() {{{3
"start the main loop of the menu and get the user to choose/execute a menu
"item
function! s:MenuController.showMenu()
    call self._saveOptions()

    try
        let self.selection = 0

        let done = 0
        while !done
            redraw!
            call self._echoPrompt()
            let key = nr2char(getchar())
            let done = self._handleKeypress(key)
        endwhile
    finally
        call self._restoreOptions()
    endtry

    if self.selection != -1
        let m = self._current()
        call m.execute()
    endif
endfunction

"FUNCTION: MenuController._echoPrompt() {{{3
function! s:MenuController._echoPrompt()
    echo "NERDTree Menu. Use j/k/enter and the shortcuts indicated"
    echo "=========================================================="

    for i in range(0, len(self.menuItems)-1)
        if self.selection == i
            echo "> " . self.menuItems[i].text
        else
            echo "  " . self.menuItems[i].text
        endif
    endfor
endfunction

"FUNCTION: MenuController._current(key) {{{3
"get the MenuItem that is currently selected
function! s:MenuController._current()
    return self.menuItems[self.selection]
endfunction

"FUNCTION: MenuController._handleKeypress(key) {{{3
"change the selection (if appropriate) and return 1 if the user has made
"their choice, 0 otherwise
function! s:MenuController._handleKeypress(key)
    if a:key == 'j'
        call self._cursorDown()
    elseif a:key == 'k'
        call self._cursorUp()
    elseif a:key == nr2char(27) "escape
        let self.selection = -1
        return 1
    elseif a:key == "\r" || a:key == "\n" "enter and ctrl-j
        return 1
    else
        let index = self._nextIndexFor(a:key)
        if index != -1
            let self.selection = index
            if len(self._allIndexesFor(a:key)) == 1
                return 1
            endif
        endif
    endif

    return 0
endfunction

"FUNCTION: MenuController._allIndexesFor(shortcut) {{{3
"get indexes to all menu items with the given shortcut
function! s:MenuController._allIndexesFor(shortcut)
    let toReturn = []

    for i in range(0, len(self.menuItems)-1)
        if self.menuItems[i].shortcut == a:shortcut
            call add(toReturn, i)
        endif
    endfor

    return toReturn
endfunction

"FUNCTION: MenuController._nextIndexFor(shortcut) {{{3
"get the index to the next menu item with the given shortcut, starts from the
"current cursor location and wraps around to the top again if need be
function! s:MenuController._nextIndexFor(shortcut)
    for i in range(self.selection+1, len(self.menuItems)-1)
        if self.menuItems[i].shortcut == a:shortcut
            return i
        endif
    endfor

    for i in range(0, self.selection)
        if self.menuItems[i].shortcut == a:shortcut
            return i
        endif
    endfor

    return -1
endfunction

"FUNCTION: MenuController._setCmdheight() {{{3
"sets &cmdheight to whatever is needed to display the menu
function! s:MenuController._setCmdheight()
    let &cmdheight = len(self.menuItems) + 3
endfunction

"FUNCTION: MenuController._saveOptions() {{{3
"set any vim options that are required to make the menu work (saving their old
"values)
function! s:MenuController._saveOptions()
    let self._oldLazyredraw = &lazyredraw
    let self._oldCmdheight = &cmdheight
    set nolazyredraw
    call self._setCmdheight()
endfunction

"FUNCTION: MenuController._restoreOptions() {{{3
"restore the options we saved in _saveOptions()
function! s:MenuController._restoreOptions()
    let &cmdheight = self._oldCmdheight
    let &lazyredraw = self._oldLazyredraw
endfunction

"FUNCTION: MenuController._cursorDown() {{{3
"move the cursor to the next menu item, skipping separators
function! s:MenuController._cursorDown()
    let done = 0
    while !done
        if self.selection < len(self.menuItems)-1
            let self.selection += 1
        else
            let self.selection = 0
        endif

        if !self._current().isSeparator()
            let done = 1
        endif
    endwhile
endfunction

"FUNCTION: MenuController._cursorUp() {{{3
"move the cursor to the previous menu item, skipping separators
function! s:MenuController._cursorUp()
    let done = 0
    while !done
        if self.selection > 0
            let self.selection -= 1
        else
            let self.selection = len(self.menuItems)-1
        endif

        if !self._current().isSeparator()
            let done = 1
        endif
    endwhile
endfunction

"CLASS: MenuItem {{{2
"============================================================
let s:MenuItem = {}
"FUNCTION: MenuItem.All() {{{3
"get all top level menu items
function! s:MenuItem.All()
    if !exists("s:menuItems")
        let s:menuItems = []
    endif
    return s:menuItems
endfunction

"FUNCTION: MenuItem.AllEnabled() {{{3
"get all top level menu items that are currently enabled
function! s:MenuItem.AllEnabled()
    let toReturn = []
    for i in s:MenuItem.All()
        if i.enabled()
            call add(toReturn, i)
        endif
    endfor
    return toReturn
endfunction

"FUNCTION: MenuItem.Create(options) {{{3
"make a new menu item and add it to the global list
function! s:MenuItem.Create(options)
    let newMenuItem = copy(self)

    let newMenuItem.text = a:options['text']
    let newMenuItem.shortcut = a:options['shortcut']
    let newMenuItem.children = []

    let newMenuItem.isActiveCallback = -1
    if has_key(a:options, 'isActiveCallback')
        let newMenuItem.isActiveCallback = a:options['isActiveCallback']
    endif

    let newMenuItem.callback = -1
    if has_key(a:options, 'callback')
        let newMenuItem.callback = a:options['callback']
    endif

    if has_key(a:options, 'parent')
        call add(a:options['parent'].children, newMenuItem)
    else
        call add(s:MenuItem.All(), newMenuItem)
    endif

    return newMenuItem
endfunction

"FUNCTION: MenuItem.CreateSeparator(options) {{{3
"make a new separator menu item and add it to the global list
function! s:MenuItem.CreateSeparator(options)
    let standard_options = { 'text': '--------------------',
                \ 'shortcut': -1,
                \ 'callback': -1 }
    let options = extend(a:options, standard_options, "force")

    return s:MenuItem.Create(options)
endfunction

"FUNCTION: MenuItem.CreateSubmenu(options) {{{3
"make a new submenu and add it to global list
function! s:MenuItem.CreateSubmenu(options)
    let standard_options = { 'callback': -1 }
    let options = extend(a:options, standard_options, "force")

    return s:MenuItem.Create(options)
endfunction

"FUNCTION: MenuItem.enabled() {{{3
"return 1 if this menu item should be displayed
"
"delegates off to the isActiveCallback, and defaults to 1 if no callback was
"specified
function! s:MenuItem.enabled()
    if self.isActiveCallback != -1
        return {self.isActiveCallback}()
    endif
    return 1
endfunction

"FUNCTION: MenuItem.execute() {{{3
"perform the action behind this menu item, if this menuitem has children then
"display a new menu for them, otherwise deletegate off to the menuitem's
"callback
function! s:MenuItem.execute()
    if len(self.children)
        let mc = s:MenuController.New(self.children)
        call mc.showMenu()
    else
        if self.callback != -1
            call {self.callback}()
        endif
    endif
endfunction

"FUNCTION: MenuItem.isSeparator() {{{3
"return 1 if this menuitem is a separator
function! s:MenuItem.isSeparator()
    return self.callback == -1 && self.children == []
endfunction

"FUNCTION: MenuItem.isSubmenu() {{{3
"return 1 if this menuitem is a submenu
function! s:MenuItem.isSubmenu()
    return self.callback == -1 && !empty(self.children)
endfunction

"CLASS: TreeFileNode {{{2
"This class is the parent of the TreeDirNode class and constitures the
"'Component' part of the composite design pattern between the treenode
"classes.
"============================================================
let s:TreeFileNode = {}
"FUNCTION: TreeFileNode.activate(forceKeepWinOpen) {{{3
function! s:TreeFileNode.activate(forceKeepWinOpen)
    call self.open()
    if !a:forceKeepWinOpen
        call s:closeTreeIfQuitOnOpen()
    end
endfunction
"FUNCTION: TreeFileNode.bookmark(name) {{{3
"bookmark this node with a:name
function! s:TreeFileNode.bookmark(name)

    "if a bookmark exists with the same name and the node is cached then save
    "it so we can update its display string
    let oldMarkedNode = {}
    try
        let oldMarkedNode = s:Bookmark.GetNodeForName(a:name, 1)
    catch /^NERDTree.BookmarkNotFoundError/
    catch /^NERDTree.BookmarkedNodeNotFoundError/
    endtry

    call s:Bookmark.AddBookmark(a:name, self.path)
    call self.path.cacheDisplayString()
    call s:Bookmark.Write()

    if !empty(oldMarkedNode)
        call oldMarkedNode.path.cacheDisplayString()
    endif
endfunction
"FUNCTION: TreeFileNode.cacheParent() {{{3
"initializes self.parent if it isnt already
function! s:TreeFileNode.cacheParent()
    if empty(self.parent)
        let parentPath = self.path.getParent()
        if parentPath.equals(self.path)
            throw "NERDTree.CannotCacheParentError: already at root"
        endif
        let self.parent = s:TreeFileNode.New(parentPath)
    endif
endfunction
"FUNCTION: TreeFileNode.compareNodes {{{3
"This is supposed to be a class level method but i cant figure out how to
"get func refs to work from a dict..
"
"A class level method that compares two nodes
"
"Args:
"n1, n2: the 2 nodes to compare
function! s:compareNodes(n1, n2)
    return a:n1.path.compareTo(a:n2.path)
endfunction

"FUNCTION: TreeFileNode.clearBoomarks() {{{3
function! s:TreeFileNode.clearBoomarks()
    for i in s:Bookmark.Bookmarks()
        if i.path.equals(self.path)
            call i.delete()
        end
    endfor
    call self.path.cacheDisplayString()
endfunction
"FUNCTION: TreeFileNode.copy(dest) {{{3
function! s:TreeFileNode.copy(dest)
    call self.path.copy(a:dest)
    let newPath = s:Path.New(a:dest)
    let parent = b:NERDTreeRoot.findNode(newPath.getParent())
    if !empty(parent)
        call parent.refresh()
        return parent.findNode(newPath)
    else
        return {}
    endif
endfunction

"FUNCTION: TreeFileNode.delete {{{3
"Removes this node from the tree and calls the Delete method for its path obj
function! s:TreeFileNode.delete()
    call self.path.delete()
    call self.parent.removeChild(self)
endfunction

"FUNCTION: TreeFileNode.displayString() {{{3
"
"Returns a string that specifies how the node should be represented as a
"string
"
"Return:
"a string that can be used in the view to represent this node
function! s:TreeFileNode.displayString()
    return self.path.displayString()
endfunction

"FUNCTION: TreeFileNode.equals(treenode) {{{3
"
"Compares this treenode to the input treenode and returns 1 if they are the
"same node.
"
"Use this method instead of ==  because sometimes when the treenodes contain
"many children, vim seg faults when doing ==
"
"Args:
"treenode: the other treenode to compare to
function! s:TreeFileNode.equals(treenode)
    return self.path.str() ==# a:treenode.path.str()
endfunction

"FUNCTION: TreeFileNode.findNode(path) {{{3
"Returns self if this node.path.Equals the given path.
"Returns {} if not equal.
"
"Args:
"path: the path object to compare against
function! s:TreeFileNode.findNode(path)
    if a:path.equals(self.path)
        return self
    endif
    return {}
endfunction
"FUNCTION: TreeFileNode.findOpenDirSiblingWithVisibleChildren(direction) {{{3
"
"Finds the next sibling for this node in the indicated direction. This sibling
"must be a directory and may/may not have children as specified.
"
"Args:
"direction: 0 if you want to find the previous sibling, 1 for the next sibling
"
"Return:
"a treenode object or {} if no appropriate sibling could be found
function! s:TreeFileNode.findOpenDirSiblingWithVisibleChildren(direction)
    "if we have no parent then we can have no siblings
    if self.parent != {}
        let nextSibling = self.findSibling(a:direction)

        while nextSibling != {}
            if nextSibling.path.isDirectory && nextSibling.hasVisibleChildren() && nextSibling.isOpen
                return nextSibling
            endif
            let nextSibling = nextSibling.findSibling(a:direction)
        endwhile
    endif

    return {}
endfunction
"FUNCTION: TreeFileNode.findSibling(direction) {{{3
"
"Finds the next sibling for this node in the indicated direction
"
"Args:
"direction: 0 if you want to find the previous sibling, 1 for the next sibling
"
"Return:
"a treenode object or {} if no sibling could be found
function! s:TreeFileNode.findSibling(direction)
    "if we have no parent then we can have no siblings
    if self.parent != {}

        "get the index of this node in its parents children
        let siblingIndx = self.parent.getChildIndex(self.path)

        if siblingIndx != -1
            "move a long to the next potential sibling node
            let siblingIndx = a:direction ==# 1 ? siblingIndx+1 : siblingIndx-1

            "keep moving along to the next sibling till we find one that is valid
            let numSiblings = self.parent.getChildCount()
            while siblingIndx >= 0 && siblingIndx < numSiblings

                "if the next node is not an ignored node (i.e. wont show up in the
                "view) then return it
                if self.parent.children[siblingIndx].path.ignore() ==# 0
                    return self.parent.children[siblingIndx]
                endif

                "go to next node
                let siblingIndx = a:direction ==# 1 ? siblingIndx+1 : siblingIndx-1
            endwhile
        endif
    endif

    return {}
endfunction

"FUNCTION: TreeFileNode.getLineNum(){{{3
"returns the line number this node is rendered on, or -1 if it isnt rendered
function! s:TreeFileNode.getLineNum()
    "if the node is the root then return the root line no.
    if self.isRoot()
        return s:TreeFileNode.GetRootLineNum()
    endif

    let totalLines = line("$")

    "the path components we have matched so far
    let pathcomponents = [substitute(b:NERDTreeRoot.path.str({'format': 'UI'}), '/ *$', '', '')]
    "the index of the component we are searching for
    let curPathComponent = 1

    let fullpath = self.path.str({'format': 'UI'})


    let lnum = s:TreeFileNode.GetRootLineNum()
    while lnum > 0
        let lnum = lnum + 1
        "have we reached the bottom of the tree?
        if lnum ==# totalLines+1
            return -1
        endif

        let curLine = getline(lnum)

        let indent = s:indentLevelFor(curLine)
        if indent ==# curPathComponent
            let curLine = s:stripMarkupFromLine(curLine, 1)

            let curPath =  join(pathcomponents, '/') . '/' . curLine
            if stridx(fullpath, curPath, 0) ==# 0
                if fullpath ==# curPath || strpart(fullpath, len(curPath)-1,1) ==# '/'
                    let curLine = substitute(curLine, '/ *$', '', '')
                    call add(pathcomponents, curLine)
                    let curPathComponent = curPathComponent + 1

                    if fullpath ==# curPath
                        return lnum
                    endif
                endif
            endif
        endif
    endwhile
    return -1
endfunction

"FUNCTION: TreeFileNode.GetRootForTab(){{{3
"get the root node for this tab
function! s:TreeFileNode.GetRootForTab()
    if s:treeExistsForTab()
        return getbufvar(t:NERDTreeBufName, 'NERDTreeRoot')
    end
    return {}
endfunction
"FUNCTION: TreeFileNode.GetRootLineNum(){{{3
"gets the line number of the root node
function! s:TreeFileNode.GetRootLineNum()
    let rootLine = 1
    while getline(rootLine) !~# '^\(/\|<\)'
        let rootLine = rootLine + 1
    endwhile
    return rootLine
endfunction

"FUNCTION: TreeFileNode.GetSelected() {{{3
"gets the treenode that the cursor is currently over
function! s:TreeFileNode.GetSelected()
    try
        let path = s:getPath(line("."))
        if path ==# {}
            return {}
        endif
        return b:NERDTreeRoot.findNode(path)
    catch /NERDTree/
        return {}
    endtry
endfunction
"FUNCTION: TreeFileNode.isVisible() {{{3
"returns 1 if this node should be visible according to the tree filters and
"hidden file filters (and their on/off status)
function! s:TreeFileNode.isVisible()
    return !self.path.ignore()
endfunction
"FUNCTION: TreeFileNode.isRoot() {{{3
"returns 1 if this node is b:NERDTreeRoot
function! s:TreeFileNode.isRoot()
    if !s:treeExistsForBuf()
        throw "NERDTree.NoTreeError: No tree exists for the current buffer"
    endif

    return self.equals(b:NERDTreeRoot)
endfunction

"FUNCTION: TreeFileNode.makeRoot() {{{3
"Make this node the root of the tree
function! s:TreeFileNode.makeRoot()
    if self.path.isDirectory
        let b:NERDTreeRoot = self
    else
        call self.cacheParent()
        let b:NERDTreeRoot = self.parent
    endif

    call b:NERDTreeRoot.open()

    "change dir to the dir of the new root if instructed to
    if g:NERDTreeChDirMode ==# 2
        exec "cd " . b:NERDTreeRoot.path.str({'format': 'Edit'})
    endif
endfunction
"FUNCTION: TreeFileNode.New(path) {{{3
"Returns a new TreeNode object with the given path and parent
"
"Args:
"path: a path object representing the full filesystem path to the file/dir that the node represents
function! s:TreeFileNode.New(path)
    if a:path.isDirectory
        return s:TreeDirNode.New(a:path)
    else
        let newTreeNode = copy(self)
        let newTreeNode.path = a:path
        let newTreeNode.parent = {}
        return newTreeNode
    endif
endfunction

"FUNCTION: TreeFileNode.open() {{{3
"Open the file represented by the given node in the current window, splitting
"the window if needed
"
"ARGS:
"treenode: file node to open
function! s:TreeFileNode.open()
    if b:NERDTreeType ==# "secondary"
        exec 'edit ' . self.path.str({'format': 'Edit'})
        return
    endif

    "if the file is already open in this tab then just stick the cursor in it
    let winnr = bufwinnr('^' . self.path.str() . '$')
    if winnr != -1
        call s:exec(winnr . "wincmd w")

    else
        if !s:isWindowUsable(winnr("#")) && s:firstUsableWindow() ==# -1
            call self.openSplit()
        else
            try
                if !s:isWindowUsable(winnr("#"))
                    call s:exec(s:firstUsableWindow() . "wincmd w")
                else
                    call s:exec('wincmd p')
                endif
                exec ("edit " . self.path.str({'format': 'Edit'}))
            catch /^Vim\%((\a\+)\)\=:E37/
                call s:putCursorInTreeWin()
                throw "NERDTree.FileAlreadyOpenAndModifiedError: ". self.path.str() ." is already open and modified."
            catch /^Vim\%((\a\+)\)\=:/
                echo v:exception
            endtry
        endif
    endif
endfunction
"FUNCTION: TreeFileNode.openSplit() {{{3
"Open this node in a new window
function! s:TreeFileNode.openSplit()

    if b:NERDTreeType ==# "secondary"
        exec "split " . self.path.str({'format': 'Edit'})
        return
    endif

    " Save the user's settings for splitbelow and splitright
    let savesplitbelow=&splitbelow
    let savesplitright=&splitright

    " 'there' will be set to a command to move from the split window
    " back to the explorer window
    "
    " 'back' will be set to a command to move from the explorer window
    " back to the newly split window
    "
    " 'right' and 'below' will be set to the settings needed for
    " splitbelow and splitright IF the explorer is the only window.
    "
    let there= g:NERDTreeWinPos ==# "left" ? "wincmd h" : "wincmd l"
    let back = g:NERDTreeWinPos ==# "left" ? "wincmd l" : "wincmd h"
    let right= g:NERDTreeWinPos ==# "left"
    let below=0

    " Attempt to go to adjacent window
    call s:exec(back)

    let onlyOneWin = (winnr("$") ==# 1)

    " If no adjacent window, set splitright and splitbelow appropriately
    if onlyOneWin
        let &splitright=right
        let &splitbelow=below
    else
        " found adjacent window - invert split direction
        let &splitright=!right
        let &splitbelow=!below
    endif

    let splitMode = onlyOneWin ? "vertical" : ""

    " Open the new window
    try
        exec(splitMode." sp " . self.path.str({'format': 'Edit'}))
    catch /^Vim\%((\a\+)\)\=:E37/
        call s:putCursorInTreeWin()
        throw "NERDTree.FileAlreadyOpenAndModifiedError: ". self.path.str() ." is already open and modified."
    catch /^Vim\%((\a\+)\)\=:/
        "do nothing
    endtry

    "resize the tree window if no other window was open before
    if onlyOneWin
        let size = exists("b:NERDTreeOldWindowSize") ? b:NERDTreeOldWindowSize : g:NERDTreeWinSize
        call s:exec(there)
        exec("silent ". splitMode ." resize ". size)
        call s:exec('wincmd p')
    endif

    " Restore splitmode settings
    let &splitbelow=savesplitbelow
    let &splitright=savesplitright
endfunction
"FUNCTION: TreeFileNode.openVSplit() {{{3
"Open this node in a new vertical window
function! s:TreeFileNode.openVSplit()
    if b:NERDTreeType ==# "secondary"
        exec "vnew " . self.path.str({'format': 'Edit'})
        return
    endif

    let winwidth = winwidth(".")
    if winnr("$")==#1
        let winwidth = g:NERDTreeWinSize
    endif

    call s:exec("wincmd p")
    exec "vnew " . self.path.str({'format': 'Edit'})

    "resize the nerd tree back to the original size
    call s:putCursorInTreeWin()
    exec("silent vertical resize ". winwidth)
    call s:exec('wincmd p')
endfunction
"FUNCTION: TreeFileNode.openInNewTab(options) {{{3
function! s:TreeFileNode.openInNewTab(options)
    let currentTab = tabpagenr()

    if !has_key(a:options, 'keepTreeOpen')
        call s:closeTreeIfQuitOnOpen()
    endif

    exec "tabedit " . self.path.str({'format': 'Edit'})

    if has_key(a:options, 'stayInCurrentTab') && a:options['stayInCurrentTab']
        exec "tabnext " . currentTab
    endif

endfunction
"FUNCTION: TreeFileNode.putCursorHere(isJump, recurseUpward){{{3
"Places the cursor on the line number this node is rendered on
"
"Args:
"isJump: 1 if this cursor movement should be counted as a jump by vim
"recurseUpward: try to put the cursor on the parent if the this node isnt
"visible
function! s:TreeFileNode.putCursorHere(isJump, recurseUpward)
    let ln = self.getLineNum()
    if ln != -1
        if a:isJump
            mark '
        endif
        call cursor(ln, col("."))
    else
        if a:recurseUpward
            let node = self
            while node != {} && node.getLineNum() ==# -1
                let node = node.parent
                call node.open()
            endwhile
            call s:renderView()
            call node.putCursorHere(a:isJump, 0)
        endif
    endif
endfunction

"FUNCTION: TreeFileNode.refresh() {{{3
function! s:TreeFileNode.refresh()
    call self.path.refresh()
endfunction
"FUNCTION: TreeFileNode.rename() {{{3
"Calls the rename method for this nodes path obj
function! s:TreeFileNode.rename(newName)
    let newName = substitute(a:newName, '\(\\\|\/\)$', '', '')
    call self.path.rename(newName)
    call self.parent.removeChild(self)

    let parentPath = self.path.getParent()
    let newParent = b:NERDTreeRoot.findNode(parentPath)

    if newParent != {}
        call newParent.createChild(self.path, 1)
        call newParent.refresh()
    endif
endfunction
"FUNCTION: TreeFileNode.renderToString {{{3
"returns a string representation for this tree to be rendered in the view
function! s:TreeFileNode.renderToString()
    return self._renderToString(0, 0, [], self.getChildCount() ==# 1)
endfunction


"Args:
"depth: the current depth in the tree for this call
"drawText: 1 if we should actually draw the line for this node (if 0 then the
"child nodes are rendered only)
"vertMap: a binary array that indicates whether a vertical bar should be draw
"for each depth in the tree
"isLastChild:true if this curNode is the last child of its parent
function! s:TreeFileNode._renderToString(depth, drawText, vertMap, isLastChild)
    let output = ""
    if a:drawText ==# 1

        let treeParts = ''

        "get all the leading spaces and vertical tree parts for this line
        if a:depth > 1
            for j in a:vertMap[0:-2]
                if g:NERDTreeDirArrows
                    let treeParts = treeParts . '  '
                else
                    if j ==# 1
                        let treeParts = treeParts . '| '
                    else
                        let treeParts = treeParts . '  '
                    endif
                endif
            endfor
        endif

        "get the last vertical tree part for this line which will be different
        "if this node is the last child of its parent
        if !g:NERDTreeDirArrows
            if a:isLastChild
                let treeParts = treeParts . '`'
            else
                let treeParts = treeParts . '|'
            endif
        endif

        "smack the appropriate dir/file symbol on the line before the file/dir
        "name itself
        if self.path.isDirectory
            if self.isOpen
                if g:NERDTreeDirArrows
                    let treeParts = treeParts . '▾ '
                else
                    let treeParts = treeParts . '~'
                endif
            else
                if g:NERDTreeDirArrows
                    let treeParts = treeParts . '▸ '
                else
                    let treeParts = treeParts . '+'
                endif
            endif
        else
            if g:NERDTreeDirArrows
                let treeParts = treeParts . '  '
            else
                let treeParts = treeParts . '-'
            endif
        endif
        let line = treeParts . self.displayString()

        let output = output . line . "\n"
    endif

    "if the node is an open dir, draw its children
    if self.path.isDirectory ==# 1 && self.isOpen ==# 1

        let childNodesToDraw = self.getVisibleChildren()
        if len(childNodesToDraw) > 0

            "draw all the nodes children except the last
            let lastIndx = len(childNodesToDraw)-1
            if lastIndx > 0
                for i in childNodesToDraw[0:lastIndx-1]
                    let output = output . i._renderToString(a:depth + 1, 1, add(copy(a:vertMap), 1), 0)
                endfor
            endif

            "draw the last child, indicating that it IS the last
            let output = output . childNodesToDraw[lastIndx]._renderToString(a:depth + 1, 1, add(copy(a:vertMap), 0), 1)
        endif
    endif

    return output
endfunction
"CLASS: TreeDirNode {{{2
"This class is a child of the TreeFileNode class and constitutes the
"'Composite' part of the composite design pattern between the treenode
"classes.
"============================================================
let s:TreeDirNode = copy(s:TreeFileNode)
"FUNCTION: TreeDirNode.AbsoluteTreeRoot(){{{3
"class method that returns the highest cached ancestor of the current root
function! s:TreeDirNode.AbsoluteTreeRoot()
    let currentNode = b:NERDTreeRoot
    while currentNode.parent != {}
        let currentNode = currentNode.parent
    endwhile
    return currentNode
endfunction
"FUNCTION: TreeDirNode.activate(forceKeepWinOpen) {{{3
unlet s:TreeDirNode.activate
function! s:TreeDirNode.activate(forceKeepWinOpen)
    call self.toggleOpen()
    call s:renderView()
    call self.putCursorHere(0, 0)
endfunction
"FUNCTION: TreeDirNode.addChild(treenode, inOrder) {{{3
"Adds the given treenode to the list of children for this node
"
"Args:
"-treenode: the node to add
"-inOrder: 1 if the new node should be inserted in sorted order
function! s:TreeDirNode.addChild(treenode, inOrder)
    call add(self.children, a:treenode)
    let a:treenode.parent = self

    if a:inOrder
        call self.sortChildren()
    endif
endfunction

"FUNCTION: TreeDirNode.close() {{{3
"Closes this directory
function! s:TreeDirNode.close()
    let self.isOpen = 0
endfunction

"FUNCTION: TreeDirNode.closeChildren() {{{3
"Closes all the child dir nodes of this node
function! s:TreeDirNode.closeChildren()
    for i in self.children
        if i.path.isDirectory
            call i.close()
            call i.closeChildren()
        endif
    endfor
endfunction

"FUNCTION: TreeDirNode.createChild(path, inOrder) {{{3
"Instantiates a new child node for this node with the given path. The new
"nodes parent is set to this node.
"
"Args:
"path: a Path object that this node will represent/contain
"inOrder: 1 if the new node should be inserted in sorted order
"
"Returns:
"the newly created node
function! s:TreeDirNode.createChild(path, inOrder)
    let newTreeNode = s:TreeFileNode.New(a:path)
    call self.addChild(newTreeNode, a:inOrder)
    return newTreeNode
endfunction

"FUNCTION: TreeDirNode.findNode(path) {{{3
"Will find one of the children (recursively) that has the given path
"
"Args:
"path: a path object
unlet s:TreeDirNode.findNode
function! s:TreeDirNode.findNode(path)
    if a:path.equals(self.path)
        return self
    endif
    if stridx(a:path.str(), self.path.str(), 0) ==# -1
        return {}
    endif

    if self.path.isDirectory
        for i in self.children
            let retVal = i.findNode(a:path)
            if retVal != {}
                return retVal
            endif
        endfor
    endif
    return {}
endfunction
"FUNCTION: TreeDirNode.getChildCount() {{{3
"Returns the number of children this node has
function! s:TreeDirNode.getChildCount()
    return len(self.children)
endfunction

"FUNCTION: TreeDirNode.getChild(path) {{{3
"Returns child node of this node that has the given path or {} if no such node
"exists.
"
"This function doesnt not recurse into child dir nodes
"
"Args:
"path: a path object
function! s:TreeDirNode.getChild(path)
    if stridx(a:path.str(), self.path.str(), 0) ==# -1
        return {}
    endif

    let index = self.getChildIndex(a:path)
    if index ==# -1
        return {}
    else
        return self.children[index]
    endif

endfunction

"FUNCTION: TreeDirNode.getChildByIndex(indx, visible) {{{3
"returns the child at the given index
"Args:
"indx: the index to get the child from
"visible: 1 if only the visible children array should be used, 0 if all the
"children should be searched.
function! s:TreeDirNode.getChildByIndex(indx, visible)
    let array_to_search = a:visible? self.getVisibleChildren() : self.children
    if a:indx > len(array_to_search)
        throw "NERDTree.InvalidArgumentsError: Index is out of bounds."
    endif
    return array_to_search[a:indx]
endfunction

"FUNCTION: TreeDirNode.getChildIndex(path) {{{3
"Returns the index of the child node of this node that has the given path or
"-1 if no such node exists.
"
"This function doesnt not recurse into child dir nodes
"
"Args:
"path: a path object
function! s:TreeDirNode.getChildIndex(path)
    if stridx(a:path.str(), self.path.str(), 0) ==# -1
        return -1
    endif

    "do a binary search for the child
    let a = 0
    let z = self.getChildCount()
    while a < z
        let mid = (a+z)/2
        let diff = a:path.compareTo(self.children[mid].path)

        if diff ==# -1
            let z = mid
        elseif diff ==# 1
            let a = mid+1
        else
            return mid
        endif
    endwhile
    return -1
endfunction

"FUNCTION: TreeDirNode.GetSelected() {{{3
"Returns the current node if it is a dir node, or else returns the current
"nodes parent
unlet s:TreeDirNode.GetSelected
function! s:TreeDirNode.GetSelected()
    let currentDir = s:TreeFileNode.GetSelected()
    if currentDir != {} && !currentDir.isRoot()
        if currentDir.path.isDirectory ==# 0
            let currentDir = currentDir.parent
        endif
    endif
    return currentDir
endfunction
"FUNCTION: TreeDirNode.getVisibleChildCount() {{{3
"Returns the number of visible children this node has
function! s:TreeDirNode.getVisibleChildCount()
    return len(self.getVisibleChildren())
endfunction

"FUNCTION: TreeDirNode.getVisibleChildren() {{{3
"Returns a list of children to display for this node, in the correct order
"
"Return:
"an array of treenodes
function! s:TreeDirNode.getVisibleChildren()
    let toReturn = []
    for i in self.children
        if i.path.ignore() ==# 0
            call add(toReturn, i)
        endif
    endfor
    return toReturn
endfunction

"FUNCTION: TreeDirNode.hasVisibleChildren() {{{3
"returns 1 if this node has any childre, 0 otherwise..
function! s:TreeDirNode.hasVisibleChildren()
    return self.getVisibleChildCount() != 0
endfunction

"FUNCTION: TreeDirNode._initChildren() {{{3
"Removes all childen from this node and re-reads them
"
"Args:
"silent: 1 if the function should not echo any "please wait" messages for
"large directories
"
"Return: the number of child nodes read
function! s:TreeDirNode._initChildren(silent)
    "remove all the current child nodes
    let self.children = []

    "get an array of all the files in the nodes dir
    let dir = self.path
    let globDir = dir.str({'format': 'Glob'})
    let filesStr = globpath(globDir, '*') . "\n" . globpath(globDir, '.*')
    let files = split(filesStr, "\n")

    if !a:silent && len(files) > g:NERDTreeNotificationThreshold
        call s:echo("Please wait, caching a large dir ...")
    endif

    let invalidFilesFound = 0
    for i in files

        "filter out the .. and . directories
        "Note: we must match .. AND ../ cos sometimes the globpath returns
        "../ for path with strange chars (eg $)
        if i !~# '\/\.\.\/\?$' && i !~# '\/\.\/\?$'

            "put the next file in a new node and attach it
            try
                let path = s:Path.New(i)
                call self.createChild(path, 0)
            catch /^NERDTree.\(InvalidArguments\|InvalidFiletype\)Error/
                let invalidFilesFound += 1
            endtry
        endif
    endfor

    call self.sortChildren()

    if !a:silent && len(files) > g:NERDTreeNotificationThreshold
        call s:echo("Please wait, caching a large dir ... DONE (". self.getChildCount() ." nodes cached).")
    endif

    if invalidFilesFound
        call s:echoWarning(invalidFilesFound . " file(s) could not be loaded into the NERD tree")
    endif
    return self.getChildCount()
endfunction
"FUNCTION: TreeDirNode.New(path) {{{3
"Returns a new TreeNode object with the given path and parent
"
"Args:
"path: a path object representing the full filesystem path to the file/dir that the node represents
unlet s:TreeDirNode.New
function! s:TreeDirNode.New(path)
    if a:path.isDirectory != 1
        throw "NERDTree.InvalidArgumentsError: A TreeDirNode object must be instantiated with a directory Path object."
    endif

    let newTreeNode = copy(self)
    let newTreeNode.path = a:path

    let newTreeNode.isOpen = 0
    let newTreeNode.children = []

    let newTreeNode.parent = {}

    return newTreeNode
endfunction
"FUNCTION: TreeDirNode.open() {{{3
"Reads in all this nodes children
"
"Return: the number of child nodes read
unlet s:TreeDirNode.open
function! s:TreeDirNode.open()
    let self.isOpen = 1
    if self.children ==# []
        return self._initChildren(0)
    else
        return 0
    endif
endfunction

" FUNCTION: TreeDirNode.openExplorer() {{{3
" opens an explorer window for this node in the previous window (could be a
" nerd tree or a netrw)
function! s:TreeDirNode.openExplorer()
    let oldwin = winnr()
    call s:exec('wincmd p')
    if oldwin ==# winnr() || (&modified && s:bufInWindows(winbufnr(winnr())) < 2)
        call s:exec('wincmd p')
        call self.openSplit()
    else
        exec ("silent edit " . self.path.str({'format': 'Edit'}))
    endif
endfunction
"FUNCTION: TreeDirNode.openInNewTab(options) {{{3
unlet s:TreeDirNode.openInNewTab
function! s:TreeDirNode.openInNewTab(options)
    let currentTab = tabpagenr()

    if !has_key(a:options, 'keepTreeOpen') || !a:options['keepTreeOpen']
        call s:closeTreeIfQuitOnOpen()
    endif

    tabnew
    call s:initNerdTree(self.path.str())

    if has_key(a:options, 'stayInCurrentTab') && a:options['stayInCurrentTab']
        exec "tabnext " . currentTab
    endif
endfunction
"FUNCTION: TreeDirNode.openRecursively() {{{3
"Opens this treenode and all of its children whose paths arent 'ignored'
"because of the file filters.
"
"This method is actually a wrapper for the OpenRecursively2 method which does
"the work.
function! s:TreeDirNode.openRecursively()
    call self._openRecursively2(1)
endfunction

"FUNCTION: TreeDirNode._openRecursively2() {{{3
"Opens this all children of this treenode recursively if either:
"   *they arent filtered by file filters
"   *a:forceOpen is 1
"
"Args:
"forceOpen: 1 if this node should be opened regardless of file filters
function! s:TreeDirNode._openRecursively2(forceOpen)
    if self.path.ignore() ==# 0 || a:forceOpen
        let self.isOpen = 1
        if self.children ==# []
            call self._initChildren(1)
        endif

        for i in self.children
            if i.path.isDirectory ==# 1
                call i._openRecursively2(0)
            endif
        endfor
    endif
endfunction

"FUNCTION: TreeDirNode.refresh() {{{3
unlet s:TreeDirNode.refresh
function! s:TreeDirNode.refresh()
    call self.path.refresh()

    "if this node was ever opened, refresh its children
    if self.isOpen || !empty(self.children)
        "go thru all the files/dirs under this node
        let newChildNodes = []
        let invalidFilesFound = 0
        let dir = self.path
        let globDir = dir.str({'format': 'Glob'})
        let filesStr = globpath(globDir, '*') . "\n" . globpath(globDir, '.*')
        let files = split(filesStr, "\n")
        for i in files
            "filter out the .. and . directories
            "Note: we must match .. AND ../ cos sometimes the globpath returns
            "../ for path with strange chars (eg $)
            if i !~# '\/\.\.\/\?$' && i !~# '\/\.\/\?$'

                try
                    "create a new path and see if it exists in this nodes children
                    let path = s:Path.New(i)
                    let newNode = self.getChild(path)
                    if newNode != {}
                        call newNode.refresh()
                        call add(newChildNodes, newNode)

                    "the node doesnt exist so create it
                    else
                        let newNode = s:TreeFileNode.New(path)
                        let newNode.parent = self
                        call add(newChildNodes, newNode)
                    endif


                catch /^NERDTree.InvalidArgumentsError/
                    let invalidFilesFound = 1
                endtry
            endif
        endfor

        "swap this nodes children out for the children we just read/refreshed
        let self.children = newChildNodes
        call self.sortChildren()

        if invalidFilesFound
            call s:echoWarning("some files could not be loaded into the NERD tree")
        endif
    endif
endfunction

"FUNCTION: TreeDirNode.reveal(path) {{{3
"reveal the given path, i.e. cache and open all treenodes needed to display it
"in the UI
function! s:TreeDirNode.reveal(path)
    if !a:path.isUnder(self.path)
        throw "NERDTree.InvalidArgumentsError: " . a:path.str() . " should be under " . self.path.str()
    endif

    call self.open()

    if self.path.equals(a:path.getParent())
        let n = self.findNode(a:path)
        call s:renderView()
        call n.putCursorHere(1,0)
        return
    endif

    let p = a:path
    while !p.getParent().equals(self.path)
        let p = p.getParent()
    endwhile

    let n = self.findNode(p)
    call n.reveal(a:path)
endfunction
"FUNCTION: TreeDirNode.removeChild(treenode) {{{3
"
"Removes the given treenode from this nodes set of children
"
"Args:
"treenode: the node to remove
"
"Throws a NERDTree.ChildNotFoundError if the given treenode is not found
function! s:TreeDirNode.removeChild(treenode)
    for i in range(0, self.getChildCount()-1)
        if self.children[i].equals(a:treenode)
            call remove(self.children, i)
            return
        endif
    endfor

    throw "NERDTree.ChildNotFoundError: child node was not found"
endfunction

"FUNCTION: TreeDirNode.sortChildren() {{{3
"
"Sorts the children of this node according to alphabetical order and the
"directory priority.
"
function! s:TreeDirNode.sortChildren()
    let CompareFunc = function("s:compareNodes")
    call sort(self.children, CompareFunc)
endfunction

"FUNCTION: TreeDirNode.toggleOpen() {{{3
"Opens this directory if it is closed and vice versa
function! s:TreeDirNode.toggleOpen()
    if self.isOpen ==# 1
        call self.close()
    else
        call self.open()
    endif
endfunction

"FUNCTION: TreeDirNode.transplantChild(newNode) {{{3
"Replaces the child of this with the given node (where the child node's full
"path matches a:newNode's fullpath). The search for the matching node is
"non-recursive
"
"Arg:
"newNode: the node to graft into the tree
function! s:TreeDirNode.transplantChild(newNode)
    for i in range(0, self.getChildCount()-1)
        if self.children[i].equals(a:newNode)
            let self.children[i] = a:newNode
            let a:newNode.parent = self
            break
        endif
    endfor
endfunction
"============================================================
"CLASS: Path {{{2
"============================================================
let s:Path = {}
"FUNCTION: Path.AbsolutePathFor(str) {{{3
function! s:Path.AbsolutePathFor(str)
    let prependCWD = 0
    if s:running_windows
        let prependCWD = a:str !~# '^.:\(\\\|\/\)'
    else
        let prependCWD = a:str !~# '^/'
    endif

    let toReturn = a:str
    if prependCWD
        let toReturn = getcwd() . s:Path.Slash() . a:str
    endif

    return toReturn
endfunction
"FUNCTION: Path.bookmarkNames() {{{3
function! s:Path.bookmarkNames()
    if !exists("self._bookmarkNames")
        call self.cacheDisplayString()
    endif
    return self._bookmarkNames
endfunction
"FUNCTION: Path.cacheDisplayString() {{{3
function! s:Path.cacheDisplayString()
    let self.cachedDisplayString = self.getLastPathComponent(1)

    if self.isExecutable
        let self.cachedDisplayString = self.cachedDisplayString . '*'
    endif

    let self._bookmarkNames = []
    for i in s:Bookmark.Bookmarks()
        if i.path.equals(self)
            call add(self._bookmarkNames, i.name)
        endif
    endfor
    if !empty(self._bookmarkNames)
        let self.cachedDisplayString .= ' {' . join(self._bookmarkNames) . '}'
    endif

    if self.isSymLink
        let self.cachedDisplayString .=  ' -> ' . self.symLinkDest
    endif

    if self.isReadOnly
        let self.cachedDisplayString .=  ' [RO]'
    endif
endfunction
"FUNCTION: Path.changeToDir() {{{3
function! s:Path.changeToDir()
    let dir = self.str({'format': 'Cd'})
    if self.isDirectory ==# 0
        let dir = self.getParent().str({'format': 'Cd'})
    endif

    try
        execute "cd " . dir
        call s:echo("CWD is now: " . getcwd())
    catch
        throw "NERDTree.PathChangeError: cannot change CWD to " . dir
    endtry
endfunction

"FUNCTION: Path.compareTo() {{{3
"
"Compares this Path to the given path and returns 0 if they are equal, -1 if
"this Path is "less than" the given path, or 1 if it is "greater".
"
"Args:
"path: the path object to compare this to
"
"Return:
"1, -1 or 0
function! s:Path.compareTo(path)
    let thisPath = self.getLastPathComponent(1)
    let thatPath = a:path.getLastPathComponent(1)

    "if the paths are the same then clearly we return 0
    if thisPath ==# thatPath
        return 0
    endif

    let thisSS = self.getSortOrderIndex()
    let thatSS = a:path.getSortOrderIndex()

    "compare the sort sequences, if they are different then the return
    "value is easy
    if thisSS < thatSS
        return -1
    elseif thisSS > thatSS
        return 1
    else
        "if the sort sequences are the same then compare the paths
        "alphabetically
        let pathCompare = g:NERDTreeCaseSensitiveSort ? thisPath <# thatPath : thisPath <? thatPath
        if pathCompare
            return -1
        else
            return 1
        endif
    endif
endfunction

"FUNCTION: Path.Create(fullpath) {{{3
"
"Factory method.
"
"Creates a path object with the given path. The path is also created on the
"filesystem. If the path already exists, a NERDTree.Path.Exists exception is
"thrown. If any other errors occur, a NERDTree.Path exception is thrown.
"
"Args:
"fullpath: the full filesystem path to the file/dir to create
function! s:Path.Create(fullpath)
    "bail if the a:fullpath already exists
    if isdirectory(a:fullpath) || filereadable(a:fullpath)
        throw "NERDTree.CreatePathError: Directory Exists: '" . a:fullpath . "'"
    endif

    try

        "if it ends with a slash, assume its a dir create it
        if a:fullpath =~# '\(\\\|\/\)$'
            "whack the trailing slash off the end if it exists
            let fullpath = substitute(a:fullpath, '\(\\\|\/\)$', '', '')

            call mkdir(fullpath, 'p')

        "assume its a file and create
        else
            call writefile([], a:fullpath)
        endif
    catch
        throw "NERDTree.CreatePathError: Could not create path: '" . a:fullpath . "'"
    endtry

    return s:Path.New(a:fullpath)
endfunction

"FUNCTION: Path.copy(dest) {{{3
"
"Copies the file/dir represented by this Path to the given location
"
"Args:
"dest: the location to copy this dir/file to
function! s:Path.copy(dest)
    if !s:Path.CopyingSupported()
        throw "NERDTree.CopyingNotSupportedError: Copying is not supported on this OS"
    endif

    let dest = s:Path.WinToUnixPath(a:dest)

    let cmd = g:NERDTreeCopyCmd . " " . escape(self.str(), s:escape_chars) . " " . escape(dest, s:escape_chars)
    let success = system(cmd)
    if success != 0
        throw "NERDTree.CopyError: Could not copy ''". self.str() ."'' to: '" . a:dest . "'"
    endif
endfunction

"FUNCTION: Path.CopyingSupported() {{{3
"
"returns 1 if copying is supported for this OS
function! s:Path.CopyingSupported()
    return exists('g:NERDTreeCopyCmd')
endfunction


"FUNCTION: Path.copyingWillOverwrite(dest) {{{3
"
"returns 1 if copy this path to the given location will cause files to
"overwritten
"
"Args:
"dest: the location this path will be copied to
function! s:Path.copyingWillOverwrite(dest)
    if filereadable(a:dest)
        return 1
    endif

    if isdirectory(a:dest)
        let path = s:Path.JoinPathStrings(a:dest, self.getLastPathComponent(0))
        if filereadable(path)
            return 1
        endif
    endif
endfunction

"FUNCTION: Path.delete() {{{3
"
"Deletes the file represented by this path.
"Deletion of directories is not supported
"
"Throws NERDTree.Path.Deletion exceptions
function! s:Path.delete()
    if self.isDirectory

        let cmd = g:NERDTreeRemoveDirCmd . self.str({'escape': 1})
        let success = system(cmd)

        if v:shell_error != 0
            throw "NERDTree.PathDeletionError: Could not delete directory: '" . self.str() . "'"
        endif
    else
        let success = delete(self.str())
        if success != 0
            throw "NERDTree.PathDeletionError: Could not delete file: '" . self.str() . "'"
        endif
    endif

    "delete all bookmarks for this path
    for i in self.bookmarkNames()
        let bookmark = s:Bookmark.BookmarkFor(i)
        call bookmark.delete()
    endfor
endfunction

"FUNCTION: Path.displayString() {{{3
"
"Returns a string that specifies how the path should be represented as a
"string
function! s:Path.displayString()
    if self.cachedDisplayString ==# ""
        call self.cacheDisplayString()
    endif

    return self.cachedDisplayString
endfunction
"FUNCTION: Path.extractDriveLetter(fullpath) {{{3
"
"If running windows, cache the drive letter for this path
function! s:Path.extractDriveLetter(fullpath)
    if s:running_windows
        let self.drive = substitute(a:fullpath, '\(^[a-zA-Z]:\).*', '\1', '')
    else
        let self.drive = ''
    endif

endfunction
"FUNCTION: Path.exists() {{{3
"return 1 if this path points to a location that is readable or is a directory
function! s:Path.exists()
    let p = self.str()
    return filereadable(p) || isdirectory(p)
endfunction
"FUNCTION: Path.getDir() {{{3
"
"Returns this path if it is a directory, else this paths parent.
"
"Return:
"a Path object
function! s:Path.getDir()
    if self.isDirectory
        return self
    else
        return self.getParent()
    endif
endfunction
"FUNCTION: Path.getParent() {{{3
"
"Returns a new path object for this paths parent
"
"Return:
"a new Path object
function! s:Path.getParent()
    if s:running_windows
        let path = self.drive . '\' . join(self.pathSegments[0:-2], '\')
    else
        let path = '/'. join(self.pathSegments[0:-2], '/')
    endif

    return s:Path.New(path)
endfunction
"FUNCTION: Path.getLastPathComponent(dirSlash) {{{3
"
"Gets the last part of this path.
"
"Args:
"dirSlash: if 1 then a trailing slash will be added to the returned value for
"directory nodes.
function! s:Path.getLastPathComponent(dirSlash)
    if empty(self.pathSegments)
        return ''
    endif
    let toReturn = self.pathSegments[-1]
    if a:dirSlash && self.isDirectory
        let toReturn = toReturn . '/'
    endif
    return toReturn
endfunction

"FUNCTION: Path.getSortOrderIndex() {{{3
"returns the index of the pattern in g:NERDTreeSortOrder that this path matches
function! s:Path.getSortOrderIndex()
    let i = 0
    while i < len(g:NERDTreeSortOrder)
        if  self.getLastPathComponent(1) =~# g:NERDTreeSortOrder[i]
            return i
        endif
        let i = i + 1
    endwhile
    return s:NERDTreeSortStarIndex
endfunction

"FUNCTION: Path.ignore() {{{3
"returns true if this path should be ignored
function! s:Path.ignore()
    let lastPathComponent = self.getLastPathComponent(0)

    "filter out the user specified paths to ignore
    if b:NERDTreeIgnoreEnabled
        for i in g:NERDTreeIgnore
            if lastPathComponent =~# i
                return 1
            endif
        endfor
    endif

    "dont show hidden files unless instructed to
    if b:NERDTreeShowHidden ==# 0 && lastPathComponent =~# '^\.'
        return 1
    endif

    if b:NERDTreeShowFiles ==# 0 && self.isDirectory ==# 0
        return 1
    endif

    return 0
endfunction

"FUNCTION: Path.isUnder(path) {{{3
"return 1 if this path is somewhere under the given path in the filesystem.
"
"a:path should be a dir
function! s:Path.isUnder(path)
    if a:path.isDirectory == 0
        return 0
    endif

    let this = self.str()
    let that = a:path.str()
    return stridx(this, that . s:Path.Slash()) == 0
endfunction

"FUNCTION: Path.JoinPathStrings(...) {{{3
function! s:Path.JoinPathStrings(...)
    let components = []
    for i in a:000
        let components = extend(components, split(i, '/'))
    endfor
    return '/' . join(components, '/')
endfunction

"FUNCTION: Path.equals() {{{3
"
"Determines whether 2 path objects are "equal".
"They are equal if the paths they represent are the same
"
"Args:
"path: the other path obj to compare this with
function! s:Path.equals(path)
    return self.str() ==# a:path.str()
endfunction

"FUNCTION: Path.New() {{{3
"The Constructor for the Path object
function! s:Path.New(path)
    let newPath = copy(self)

    call newPath.readInfoFromDisk(s:Path.AbsolutePathFor(a:path))

    let newPath.cachedDisplayString = ""

    return newPath
endfunction

"FUNCTION: Path.Slash() {{{3
"return the slash to use for the current OS
function! s:Path.Slash()
    return s:running_windows ? '\' : '/'
endfunction

"FUNCTION: Path.readInfoFromDisk(fullpath) {{{3
"
"
"Throws NERDTree.Path.InvalidArguments exception.
function! s:Path.readInfoFromDisk(fullpath)
    call self.extractDriveLetter(a:fullpath)

    let fullpath = s:Path.WinToUnixPath(a:fullpath)

    if getftype(fullpath) ==# "fifo"
        throw "NERDTree.InvalidFiletypeError: Cant handle FIFO files: " . a:fullpath
    endif

    let self.pathSegments = split(fullpath, '/')

    let self.isReadOnly = 0
    if isdirectory(a:fullpath)
        let self.isDirectory = 1
    elseif filereadable(a:fullpath)
        let self.isDirectory = 0
        let self.isReadOnly = filewritable(a:fullpath) ==# 0
    else
        throw "NERDTree.InvalidArgumentsError: Invalid path = " . a:fullpath
    endif

    let self.isExecutable = 0
    if !self.isDirectory
        let self.isExecutable = getfperm(a:fullpath) =~# 'x'
    endif

    "grab the last part of the path (minus the trailing slash)
    let lastPathComponent = self.getLastPathComponent(0)

    "get the path to the new node with the parent dir fully resolved
    let hardPath = resolve(self.strTrunk()) . '/' . lastPathComponent

    "if  the last part of the path is a symlink then flag it as such
    let self.isSymLink = (resolve(hardPath) != hardPath)
    if self.isSymLink
        let self.symLinkDest = resolve(fullpath)

        "if the link is a dir then slap a / on the end of its dest
        if isdirectory(self.symLinkDest)

            "we always wanna treat MS windows shortcuts as files for
            "simplicity
            if hardPath !~# '\.lnk$'

                let self.symLinkDest = self.symLinkDest . '/'
            endif
        endif
    endif
endfunction

"FUNCTION: Path.refresh() {{{3
function! s:Path.refresh()
    call self.readInfoFromDisk(self.str())
    call self.cacheDisplayString()
endfunction

"FUNCTION: Path.rename() {{{3
"
"Renames this node on the filesystem
function! s:Path.rename(newPath)
    if a:newPath ==# ''
        throw "NERDTree.InvalidArgumentsError: Invalid newPath for renaming = ". a:newPath
    endif

    let success =  rename(self.str(), a:newPath)
    if success != 0
        throw "NERDTree.PathRenameError: Could not rename: '" . self.str() . "'" . 'to:' . a:newPath
    endif
    call self.readInfoFromDisk(a:newPath)

    for i in self.bookmarkNames()
        let b = s:Bookmark.BookmarkFor(i)
        call b.setPath(copy(self))
    endfor
    call s:Bookmark.Write()
endfunction

"FUNCTION: Path.str() {{{3
"
"Returns a string representation of this Path
"
"Takes an optional dictionary param to specify how the output should be
"formatted.
"
"The dict may have the following keys:
"  'format'
"  'escape'
"  'truncateTo'
"
"The 'format' key may have a value of:
"  'Cd' - a string to be used with the :cd command
"  'Edit' - a string to be used with :e :sp :new :tabedit etc
"  'UI' - a string used in the NERD tree UI
"
"The 'escape' key, if specified will cause the output to be escaped with
"shellescape()
"
"The 'truncateTo' key causes the resulting string to be truncated to the value
"'truncateTo' maps to. A '<' char will be prepended.
function! s:Path.str(...)
    let options = a:0 ? a:1 : {}
    let toReturn = ""

    if has_key(options, 'format')
        let format = options['format']
        if has_key(self, '_strFor' . format)
            exec 'let toReturn = self._strFor' . format . '()'
        else
            raise 'NERDTree.UnknownFormatError: unknown format "'. format .'"'
        endif
    else
        let toReturn = self._str()
    endif

    if has_key(options, 'escape') && options['escape']
        let toReturn = shellescape(toReturn)
    endif

    if has_key(options, 'truncateTo')
        let limit = options['truncateTo']
        if len(toReturn) > limit
            let toReturn = "<" . strpart(toReturn, len(toReturn) - limit + 1)
        endif
    endif

    return toReturn
endfunction

"FUNCTION: Path._strForUI() {{{3
function! s:Path._strForUI()
    let toReturn = '/' . join(self.pathSegments, '/')
    if self.isDirectory && toReturn != '/'
        let toReturn  = toReturn . '/'
    endif
    return toReturn
endfunction

"FUNCTION: Path._strForCd() {{{3
"
" returns a string that can be used with :cd
function! s:Path._strForCd()
    return escape(self.str(), s:escape_chars)
endfunction
"FUNCTION: Path._strForEdit() {{{3
"
"Return: the string for this path that is suitable to be used with the :edit
"command
function! s:Path._strForEdit()
    let p = self.str({'format': 'UI'})
    let cwd = getcwd()

    if s:running_windows
        let p = tolower(self.str())
        let cwd = tolower(getcwd())
    endif

    let p = escape(p, s:escape_chars)

    let cwd = cwd . s:Path.Slash()

    "return a relative path if we can
    if stridx(p, cwd) ==# 0
        let p = strpart(p, strlen(cwd))
    endif

    if p ==# ''
        let p = '.'
    endif

    return p

endfunction
"FUNCTION: Path._strForGlob() {{{3
function! s:Path._strForGlob()
    let lead = s:Path.Slash()

    "if we are running windows then slap a drive letter on the front
    if s:running_windows
        let lead = self.drive . '\'
    endif

    let toReturn = lead . join(self.pathSegments, s:Path.Slash())

    if !s:running_windows
        let toReturn = escape(toReturn, s:escape_chars)
    endif
    return toReturn
endfunction
"FUNCTION: Path._str() {{{3
"
"Gets the string path for this path object that is appropriate for the OS.
"EG, in windows c:\foo\bar
"    in *nix  /foo/bar
function! s:Path._str()
    let lead = s:Path.Slash()

    "if we are running windows then slap a drive letter on the front
    if s:running_windows
        let lead = self.drive . '\'
    endif

    return lead . join(self.pathSegments, s:Path.Slash())
endfunction

"FUNCTION: Path.strTrunk() {{{3
"Gets the path without the last segment on the end.
function! s:Path.strTrunk()
    return self.drive . '/' . join(self.pathSegments[0:-2], '/')
endfunction

"FUNCTION: Path.WinToUnixPath(pathstr){{{3
"Takes in a windows path and returns the unix equiv
"
"A class level method
"
"Args:
"pathstr: the windows path to convert
function! s:Path.WinToUnixPath(pathstr)
    if !s:running_windows
        return a:pathstr
    endif

    let toReturn = a:pathstr

    "remove the x:\ of the front
    let toReturn = substitute(toReturn, '^.*:\(\\\|/\)\?', '/', "")

    "convert all \ chars to /
    let toReturn = substitute(toReturn, '\', '/', "g")

    return toReturn
endfunction

" SECTION: General Functions {{{1
"============================================================
"FUNCTION: s:bufInWindows(bnum){{{2
"[[STOLEN FROM VTREEEXPLORER.VIM]]
"Determine the number of windows open to this buffer number.
"Care of Yegappan Lakshman.  Thanks!
"
"Args:
"bnum: the subject buffers buffer number
function! s:bufInWindows(bnum)
    let cnt = 0
    let winnum = 1
    while 1
        let bufnum = winbufnr(winnum)
        if bufnum < 0
            break
        endif
        if bufnum ==# a:bnum
            let cnt = cnt + 1
        endif
        let winnum = winnum + 1
    endwhile

    return cnt
endfunction " >>>
"FUNCTION: s:checkForBrowse(dir) {{{2
"inits a secondary nerd tree in the current buffer if appropriate
function! s:checkForBrowse(dir)
    if a:dir != '' && isdirectory(a:dir)
        call s:initNerdTreeInPlace(a:dir)
    endif
endfunction
"FUNCTION: s:compareBookmarks(first, second) {{{2
"Compares two bookmarks
function! s:compareBookmarks(first, second)
    return a:first.compareTo(a:second)
endfunction

" FUNCTION: s:completeBookmarks(A,L,P) {{{2
" completion function for the bookmark commands
function! s:completeBookmarks(A,L,P)
    return filter(s:Bookmark.BookmarkNames(), 'v:val =~# "^' . a:A . '"')
endfunction
" FUNCTION: s:exec(cmd) {{{2
" same as :exec cmd  but eventignore=all is set for the duration
function! s:exec(cmd)
    let old_ei = &ei
    set ei=all
    exec a:cmd
    let &ei = old_ei
endfunction
" FUNCTION: s:findAndRevealPath() {{{2
function! s:findAndRevealPath()
    try
        let p = s:Path.New(expand("%:p"))
    catch /^NERDTree.InvalidArgumentsError/
        call s:echo("no file for the current buffer")
        return
    endtry

    if !s:treeExistsForTab()
        try
            let cwd = s:Path.New(getcwd())
        catch /^NERDTree.InvalidArgumentsError/
            call s:echo("current directory does not exist.")
            let cwd = p.getParent()
        endtry

        if p.isUnder(cwd)
            call s:initNerdTree(cwd.str())
        else
            call s:initNerdTree(p.getParent().str())
        endif
    else
        if !p.isUnder(s:TreeFileNode.GetRootForTab().path)
            call s:initNerdTree(p.getParent().str())
        else
            if !s:isTreeOpen()
                call s:toggle("")
            endif
        endif
    endif
    call s:putCursorInTreeWin()
    call b:NERDTreeRoot.reveal(p)
endfunction
"FUNCTION: s:initNerdTree(name) {{{2
"Initialise the nerd tree for this tab. The tree will start in either the
"given directory, or the directory associated with the given bookmark
"
"Args:
"name: the name of a bookmark or a directory
function! s:initNerdTree(name)
    let path = {}
    if s:Bookmark.BookmarkExistsFor(a:name)
        let path = s:Bookmark.BookmarkFor(a:name).path
    else
        let dir = a:name ==# '' ? getcwd() : a:name

        "hack to get an absolute path if a relative path is given
        if dir =~# '^\.'
            let dir = getcwd() . s:Path.Slash() . dir
        endif
        let dir = resolve(dir)

        try
            let path = s:Path.New(dir)
        catch /^NERDTree.InvalidArgumentsError/
            call s:echo("No bookmark or directory found for: " . a:name)
            return
        endtry
    endif
    if !path.isDirectory
        let path = path.getParent()
    endif

    "if instructed to, then change the vim CWD to the dir the NERDTree is
    "inited in
    if g:NERDTreeChDirMode != 0
        call path.changeToDir()
    endif

    if s:treeExistsForTab()
        if s:isTreeOpen()
            call s:closeTree()
        endif
        unlet t:NERDTreeBufName
    endif

    let newRoot = s:TreeDirNode.New(path)
    call newRoot.open()

    call s:createTreeWin()
    let b:treeShowHelp = 0
    let b:NERDTreeIgnoreEnabled = 1
    let b:NERDTreeShowFiles = g:NERDTreeShowFiles
    let b:NERDTreeShowHidden = g:NERDTreeShowHidden
    let b:NERDTreeShowBookmarks = g:NERDTreeShowBookmarks
    let b:NERDTreeRoot = newRoot

    let b:NERDTreeType = "primary"

    call s:renderView()
    call b:NERDTreeRoot.putCursorHere(0, 0)
endfunction

"FUNCTION: s:initNerdTreeInPlace(dir) {{{2
function! s:initNerdTreeInPlace(dir)
    try
        let path = s:Path.New(a:dir)
    catch /^NERDTree.InvalidArgumentsError/
        call s:echo("Invalid directory name:" . a:name)
        return
    endtry

    "we want the directory buffer to disappear when we do the :edit below
    setlocal bufhidden=wipe

    let previousBuf = expand("#")

    "we need a unique name for each secondary tree buffer to ensure they are
    "all independent
    exec "silent edit " . s:nextBufferName()

    let b:NERDTreePreviousBuf = bufnr(previousBuf)

    let b:NERDTreeRoot = s:TreeDirNode.New(path)
    call b:NERDTreeRoot.open()

    call s:setCommonBufOptions()
    let b:NERDTreeType = "secondary"

    call s:renderView()
endfunction
" FUNCTION: s:initNerdTreeMirror() {{{2
function! s:initNerdTreeMirror()

    "get the names off all the nerd tree buffers
    let treeBufNames = []
    for i in range(1, tabpagenr("$"))
        let nextName = s:tabpagevar(i, 'NERDTreeBufName')
        if nextName != -1 && (!exists("t:NERDTreeBufName") || nextName != t:NERDTreeBufName)
            call add(treeBufNames, nextName)
        endif
    endfor
    let treeBufNames = s:unique(treeBufNames)

    "map the option names (that the user will be prompted with) to the nerd
    "tree buffer names
    let options = {}
    let i = 0
    while i < len(treeBufNames)
        let bufName = treeBufNames[i]
        let treeRoot = getbufvar(bufName, "NERDTreeRoot")
        let options[i+1 . '. ' . treeRoot.path.str() . '  (buf name: ' . bufName . ')'] = bufName
        let i = i + 1
    endwhile

    "work out which tree to mirror, if there is more than 1 then ask the user
    let bufferName = ''
    if len(keys(options)) > 1
        let choices = ["Choose a tree to mirror"]
        let choices = extend(choices, sort(keys(options)))
        let choice = inputlist(choices)
        if choice < 1 || choice > len(options) || choice ==# ''
            return
        endif

        let bufferName = options[sort(keys(options))[choice-1]]
    elseif len(keys(options)) ==# 1
        let bufferName = values(options)[0]
    else
        call s:echo("No trees to mirror")
        return
    endif

    if s:treeExistsForTab() && s:isTreeOpen()
        call s:closeTree()
    endif

    let t:NERDTreeBufName = bufferName
    call s:createTreeWin()
    exec 'buffer ' .  bufferName
    if !&hidden
        call s:renderView()
    endif
endfunction
" FUNCTION: s:nextBufferName() {{{2
" returns the buffer name for the next nerd tree
function! s:nextBufferName()
    let name = s:NERDTreeBufName . s:next_buffer_number
    let s:next_buffer_number += 1
    return name
endfunction
" FUNCTION: s:tabpagevar(tabnr, var) {{{2
function! s:tabpagevar(tabnr, var)
    let currentTab = tabpagenr()
    let old_ei = &ei
    set ei=all

    exec "tabnext " . a:tabnr
    let v = -1
    if exists('t:' . a:var)
        exec 'let v = t:' . a:var
    endif
    exec "tabnext " . currentTab

    let &ei = old_ei

    return v
endfunction
" Function: s:treeExistsForBuffer()   {{{2
" Returns 1 if a nerd tree root exists in the current buffer
function! s:treeExistsForBuf()
    return exists("b:NERDTreeRoot")
endfunction
" Function: s:treeExistsForTab()   {{{2
" Returns 1 if a nerd tree root exists in the current tab
function! s:treeExistsForTab()
    return exists("t:NERDTreeBufName")
endfunction
" Function: s:unique(list)   {{{2
" returns a:list without duplicates
function! s:unique(list)
  let uniqlist = []
  for elem in a:list
    if index(uniqlist, elem) ==# -1
      let uniqlist += [elem]
    endif
  endfor
  return uniqlist
endfunction
" SECTION: Public API {{{1
"============================================================
let g:NERDTreePath = s:Path
let g:NERDTreeDirNode = s:TreeDirNode
let g:NERDTreeFileNode = s:TreeFileNode
let g:NERDTreeBookmark = s:Bookmark

function! NERDTreeAddMenuItem(options)
    call s:MenuItem.Create(a:options)
endfunction

function! NERDTreeAddMenuSeparator(...)
    let opts = a:0 ? a:1 : {}
    call s:MenuItem.CreateSeparator(opts)
endfunction

function! NERDTreeAddSubmenu(options)
    return s:MenuItem.Create(a:options)
endfunction

function! NERDTreeAddKeyMap(options)
    call s:KeyMap.Create(a:options)
endfunction

function! NERDTreeRender()
    call s:renderView()
endfunction

" SECTION: View Functions {{{1
"============================================================
"FUNCTION: s:centerView() {{{2
"centers the nerd tree window around the cursor (provided the nerd tree
"options permit)
function! s:centerView()
    if g:NERDTreeAutoCenter
        let current_line = winline()
        let lines_to_top = current_line
        let lines_to_bottom = winheight(s:getTreeWinNum()) - current_line
        if lines_to_top < g:NERDTreeAutoCenterThreshold || lines_to_bottom < g:NERDTreeAutoCenterThreshold
            normal! zz
        endif
    endif
endfunction
"FUNCTION: s:closeTree() {{{2
"Closes the primary NERD tree window for this tab
function! s:closeTree()
    if !s:isTreeOpen()
        throw "NERDTree.NoTreeFoundError: no NERDTree is open"
    endif

    if winnr("$") != 1
        if winnr() == s:getTreeWinNum()
            wincmd p
            let bufnr = bufnr("")
            wincmd p
        else
            let bufnr = bufnr("")
        endif

        call s:exec(s:getTreeWinNum() . " wincmd w")
        close
        call s:exec(bufwinnr(bufnr) . " wincmd w")
    else
        close
    endif
endfunction

"FUNCTION: s:closeTreeIfOpen() {{{2
"Closes the NERD tree window if it is open
function! s:closeTreeIfOpen()
   if s:isTreeOpen()
      call s:closeTree()
   endif
endfunction
"FUNCTION: s:closeTreeIfQuitOnOpen() {{{2
"Closes the NERD tree window if the close on open option is set
function! s:closeTreeIfQuitOnOpen()
    if g:NERDTreeQuitOnOpen && s:isTreeOpen()
        call s:closeTree()
    endif
endfunction
"FUNCTION: s:createTreeWin() {{{2
"Inits the NERD tree window. ie. opens it, sizes it, sets all the local
"options etc
function! s:createTreeWin()
    "create the nerd tree window
    let splitLocation = g:NERDTreeWinPos ==# "left" ? "topleft " : "botright "
    let splitSize = g:NERDTreeWinSize

    if !exists('t:NERDTreeBufName')
        let t:NERDTreeBufName = s:nextBufferName()
        silent! exec splitLocation . 'vertical ' . splitSize . ' new'
        silent! exec "edit " . t:NERDTreeBufName
    else
        silent! exec splitLocation . 'vertical ' . splitSize . ' split'
        silent! exec "buffer " . t:NERDTreeBufName
    endif

    setlocal winfixwidth
    call s:setCommonBufOptions()
endfunction

"FUNCTION: s:dumpHelp  {{{2
"prints out the quick help
function! s:dumpHelp()
    let old_h = @h
    if b:treeShowHelp ==# 1
        let @h=   "\" NERD tree (" . s:NERD_tree_version . ") quickhelp~\n"
        let @h=@h."\" ============================\n"
        let @h=@h."\" File node mappings~\n"
        let @h=@h."\" ". (g:NERDTreeMouseMode ==# 3 ? "single" : "double") ."-click,\n"
        let @h=@h."\" <CR>,\n"
        if b:NERDTreeType ==# "primary"
            let @h=@h."\" ". g:NERDTreeMapActivateNode .": open in prev window\n"
        else
            let @h=@h."\" ". g:NERDTreeMapActivateNode .": open in current window\n"
        endif
        if b:NERDTreeType ==# "primary"
            let @h=@h."\" ". g:NERDTreeMapPreview .": preview\n"
        endif
        let @h=@h."\" ". g:NERDTreeMapOpenInTab.": open in new tab\n"
        let @h=@h."\" ". g:NERDTreeMapOpenInTabSilent .": open in new tab silently\n"
        let @h=@h."\" middle-click,\n"
        let @h=@h."\" ". g:NERDTreeMapOpenSplit .": open split\n"
        let @h=@h."\" ". g:NERDTreeMapPreviewSplit .": preview split\n"
        let @h=@h."\" ". g:NERDTreeMapOpenVSplit .": open vsplit\n"
        let @h=@h."\" ". g:NERDTreeMapPreviewVSplit .": preview vsplit\n"

        let @h=@h."\"\n\" ----------------------------\n"
        let @h=@h."\" Directory node mappings~\n"
        let @h=@h."\" ". (g:NERDTreeMouseMode ==# 1 ? "double" : "single") ."-click,\n"
        let @h=@h."\" ". g:NERDTreeMapActivateNode .": open & close node\n"
        let @h=@h."\" ". g:NERDTreeMapOpenRecursively .": recursively open node\n"
        let @h=@h."\" ". g:NERDTreeMapCloseDir .": close parent of node\n"
        let @h=@h."\" ". g:NERDTreeMapCloseChildren .": close all child nodes of\n"
        let @h=@h."\"    current node recursively\n"
        let @h=@h."\" middle-click,\n"
        let @h=@h."\" ". g:NERDTreeMapOpenExpl.": explore selected dir\n"

        let @h=@h."\"\n\" ----------------------------\n"
        let @h=@h."\" Bookmark table mappings~\n"
        let @h=@h."\" double-click,\n"
        let @h=@h."\" ". g:NERDTreeMapActivateNode .": open bookmark\n"
        let @h=@h."\" ". g:NERDTreeMapOpenInTab.": open in new tab\n"
        let @h=@h."\" ". g:NERDTreeMapOpenInTabSilent .": open in new tab silently\n"
        let @h=@h."\" ". g:NERDTreeMapDeleteBookmark .": delete bookmark\n"

        let @h=@h."\"\n\" ----------------------------\n"
        let @h=@h."\" Tree navigation mappings~\n"
        let @h=@h."\" ". g:NERDTreeMapJumpRoot .": go to root\n"
        let @h=@h."\" ". g:NERDTreeMapJumpParent .": go to parent\n"
        let @h=@h."\" ". g:NERDTreeMapJumpFirstChild  .": go to first child\n"
        let @h=@h."\" ". g:NERDTreeMapJumpLastChild   .": go to last child\n"
        let @h=@h."\" ". g:NERDTreeMapJumpNextSibling .": go to next sibling\n"
        let @h=@h."\" ". g:NERDTreeMapJumpPrevSibling .": go to prev sibling\n"

        let @h=@h."\"\n\" ----------------------------\n"
        let @h=@h."\" Filesystem mappings~\n"
        let @h=@h."\" ". g:NERDTreeMapChangeRoot .": change tree root to the\n"
        let @h=@h."\"    selected dir\n"
        let @h=@h."\" ". g:NERDTreeMapUpdir .": move tree root up a dir\n"
        let @h=@h."\" ". g:NERDTreeMapUpdirKeepOpen .": move tree root up a dir\n"
        let @h=@h."\"    but leave old root open\n"
        let @h=@h."\" ". g:NERDTreeMapRefresh .": refresh cursor dir\n"
        let @h=@h."\" ". g:NERDTreeMapRefreshRoot .": refresh current root\n"
        let @h=@h."\" ". g:NERDTreeMapMenu .": Show menu\n"
        let @h=@h."\" ". g:NERDTreeMapChdir .":change the CWD to the\n"
        let @h=@h."\"    selected dir\n"

        let @h=@h."\"\n\" ----------------------------\n"
        let @h=@h."\" Tree filtering mappings~\n"
        let @h=@h."\" ". g:NERDTreeMapToggleHidden .": hidden files (" . (b:NERDTreeShowHidden ? "on" : "off") . ")\n"
        let @h=@h."\" ". g:NERDTreeMapToggleFilters .": file filters (" . (b:NERDTreeIgnoreEnabled ? "on" : "off") . ")\n"
        let @h=@h."\" ". g:NERDTreeMapToggleFiles .": files (" . (b:NERDTreeShowFiles ? "on" : "off") . ")\n"
        let @h=@h."\" ". g:NERDTreeMapToggleBookmarks .": bookmarks (" . (b:NERDTreeShowBookmarks ? "on" : "off") . ")\n"

        "add quickhelp entries for each custom key map
        if len(s:KeyMap.All())
            let @h=@h."\"\n\" ----------------------------\n"
            let @h=@h."\" Custom mappings~\n"
            for i in s:KeyMap.All()
                let @h=@h."\" ". i.key .": ". i.quickhelpText ."\n"
            endfor
        endif

        let @h=@h."\"\n\" ----------------------------\n"
        let @h=@h."\" Other mappings~\n"
        let @h=@h."\" ". g:NERDTreeMapQuit .": Close the NERDTree window\n"
        let @h=@h."\" ". g:NERDTreeMapToggleZoom .": Zoom (maximize-minimize)\n"
        let @h=@h."\"    the NERDTree window\n"
        let @h=@h."\" ". g:NERDTreeMapHelp .": toggle help\n"
        let @h=@h."\"\n\" ----------------------------\n"
        let @h=@h."\" Bookmark commands~\n"
        let @h=@h."\" :Bookmark <name>\n"
        let @h=@h."\" :BookmarkToRoot <name>\n"
        let @h=@h."\" :RevealBookmark <name>\n"
        let @h=@h."\" :OpenBookmark <name>\n"
        let @h=@h."\" :ClearBookmarks [<names>]\n"
        let @h=@h."\" :ClearAllBookmarks\n"
        silent! put h
    elseif g:NERDTreeMinimalUI == 0
        let @h="\" Press ". g:NERDTreeMapHelp ." for help\n"
        silent! put h
    endif

    let @h = old_h
endfunction
"FUNCTION: s:echo  {{{2
"A wrapper for :echo. Appends 'NERDTree:' on the front of all messages
"
"Args:
"msg: the message to echo
function! s:echo(msg)
    redraw
    echomsg "NERDTree: " . a:msg
endfunction
"FUNCTION: s:echoWarning {{{2
"Wrapper for s:echo, sets the message type to warningmsg for this message
"Args:
"msg: the message to echo
function! s:echoWarning(msg)
    echohl warningmsg
    call s:echo(a:msg)
    echohl normal
endfunction
"FUNCTION: s:echoError {{{2
"Wrapper for s:echo, sets the message type to errormsg for this message
"Args:
"msg: the message to echo
function! s:echoError(msg)
    echohl errormsg
    call s:echo(a:msg)
    echohl normal
endfunction
"FUNCTION: s:firstUsableWindow(){{{2
"find the window number of the first normal window
function! s:firstUsableWindow()
    let i = 1
    while i <= winnr("$")
        let bnum = winbufnr(i)
        if bnum != -1 && getbufvar(bnum, '&buftype') ==# ''
                    \ && !getwinvar(i, '&previewwindow')
                    \ && (!getbufvar(bnum, '&modified') || &hidden)
            return i
        endif

        let i += 1
    endwhile
    return -1
endfunction
"FUNCTION: s:getPath(ln) {{{2
"Gets the full path to the node that is rendered on the given line number
"
"Args:
"ln: the line number to get the path for
"
"Return:
"A path if a node was selected, {} if nothing is selected.
"If the 'up a dir' line was selected then the path to the parent of the
"current root is returned
function! s:getPath(ln)
    let line = getline(a:ln)

    let rootLine = s:TreeFileNode.GetRootLineNum()

    "check to see if we have the root node
    if a:ln == rootLine
        return b:NERDTreeRoot.path
    endif

    if !g:NERDTreeDirArrows
        " in case called from outside the tree
        if line !~# '^ *[|`▸▾ ]' || line =~# '^$'
            return {}
        endif
    endif

    if line ==# s:tree_up_dir_line
        return b:NERDTreeRoot.path.getParent()
    endif

    let indent = s:indentLevelFor(line)

    "remove the tree parts and the leading space
    let curFile = s:stripMarkupFromLine(line, 0)

    let wasdir = 0
    if curFile =~# '/$'
        let wasdir = 1
        let curFile = substitute(curFile, '/\?$', '/', "")
    endif

    let dir = ""
    let lnum = a:ln
    while lnum > 0
        let lnum = lnum - 1
        let curLine = getline(lnum)
        let curLineStripped = s:stripMarkupFromLine(curLine, 1)

        "have we reached the top of the tree?
        if lnum == rootLine
            let dir = b:NERDTreeRoot.path.str({'format': 'UI'}) . dir
            break
        endif
        if curLineStripped =~# '/$'
            let lpindent = s:indentLevelFor(curLine)
            if lpindent < indent
                let indent = indent - 1

                let dir = substitute (curLineStripped,'^\\', "", "") . dir
                continue
            endif
        endif
    endwhile
    let curFile = b:NERDTreeRoot.path.drive . dir . curFile
    let toReturn = s:Path.New(curFile)
    return toReturn
endfunction

"FUNCTION: s:getTreeWinNum() {{{2
"gets the nerd tree window number for this tab
function! s:getTreeWinNum()
    if exists("t:NERDTreeBufName")
        return bufwinnr(t:NERDTreeBufName)
    else
        return -1
    endif
endfunction
"FUNCTION: s:indentLevelFor(line) {{{2
function! s:indentLevelFor(line)
    let level = match(a:line, '[^ \-+~▸▾`|]') / s:tree_wid
    " check if line includes arrows
    if match(a:line, '[▸▾]') > -1
        " decrement level as arrow uses 3 ascii chars
        let level = level - 1
    endif
    return level
endfunction
"FUNCTION: s:isTreeOpen() {{{2
function! s:isTreeOpen()
    return s:getTreeWinNum() != -1
endfunction
"FUNCTION: s:isWindowUsable(winnumber) {{{2
"Returns 0 if opening a file from the tree in the given window requires it to
"be split, 1 otherwise
"
"Args:
"winnumber: the number of the window in question
function! s:isWindowUsable(winnumber)
    "gotta split if theres only one window (i.e. the NERD tree)
    if winnr("$") ==# 1
        return 0
    endif

    let oldwinnr = winnr()
    call s:exec(a:winnumber . "wincmd p")
    let specialWindow = getbufvar("%", '&buftype') != '' || getwinvar('%', '&previewwindow')
    let modified = &modified
    call s:exec(oldwinnr . "wincmd p")

    "if its a special window e.g. quickfix or another explorer plugin then we
    "have to split
    if specialWindow
        return 0
    endif

    if &hidden
        return 1
    endif

    return !modified || s:bufInWindows(winbufnr(a:winnumber)) >= 2
endfunction

" FUNCTION: s:jumpToChild(direction) {{{2
" Args:
" direction: 0 if going to first child, 1 if going to last
function! s:jumpToChild(direction)
    let currentNode = s:TreeFileNode.GetSelected()
    if currentNode ==# {} || currentNode.isRoot()
        call s:echo("cannot jump to " . (a:direction ? "last" : "first") .  " child")
        return
    end
    let dirNode = currentNode.parent
    let childNodes = dirNode.getVisibleChildren()

    let targetNode = childNodes[0]
    if a:direction
        let targetNode = childNodes[len(childNodes) - 1]
    endif

    if targetNode.equals(currentNode)
        let siblingDir = currentNode.parent.findOpenDirSiblingWithVisibleChildren(a:direction)
        if siblingDir != {}
            let indx = a:direction ? siblingDir.getVisibleChildCount()-1 : 0
            let targetNode = siblingDir.getChildByIndex(indx, 1)
        endif
    endif

    call targetNode.putCursorHere(1, 0)

    call s:centerView()
endfunction


"FUNCTION: s:promptToDelBuffer(bufnum, msg){{{2
"prints out the given msg and, if the user responds by pushing 'y' then the
"buffer with the given bufnum is deleted
"
"Args:
"bufnum: the buffer that may be deleted
"msg: a message that will be echoed to the user asking them if they wish to
"     del the buffer
function! s:promptToDelBuffer(bufnum, msg)
    echo a:msg
    if nr2char(getchar()) ==# 'y'
        exec "silent bdelete! " . a:bufnum
    endif
endfunction

"FUNCTION: s:putCursorOnBookmarkTable(){{{2
"Places the cursor at the top of the bookmarks table
function! s:putCursorOnBookmarkTable()
    if !b:NERDTreeShowBookmarks
        throw "NERDTree.IllegalOperationError: cant find bookmark table, bookmarks arent active"
    endif

    if g:NERDTreeMinimalUI
        return cursor(1, 2)
    endif

    let rootNodeLine = s:TreeFileNode.GetRootLineNum()

    let line = 1
    while getline(line) !~# '^>-\+Bookmarks-\+$'
        let line = line + 1
        if line >= rootNodeLine
            throw "NERDTree.BookmarkTableNotFoundError: didnt find the bookmarks table"
        endif
    endwhile
    call cursor(line, 2)
endfunction

"FUNCTION: s:putCursorInTreeWin(){{{2
"Places the cursor in the nerd tree window
function! s:putCursorInTreeWin()
    if !s:isTreeOpen()
        throw "NERDTree.InvalidOperationError: cant put cursor in NERD tree window, no window exists"
    endif

    call s:exec(s:getTreeWinNum() . "wincmd w")
endfunction

"FUNCTION: s:renderBookmarks {{{2
function! s:renderBookmarks()

    if g:NERDTreeMinimalUI == 0
        call setline(line(".")+1, ">----------Bookmarks----------")
        call cursor(line(".")+1, col("."))
    endif

    for i in s:Bookmark.Bookmarks()
        call setline(line(".")+1, i.str())
        call cursor(line(".")+1, col("."))
    endfor

    call setline(line(".")+1, '')
    call cursor(line(".")+1, col("."))
endfunction
"FUNCTION: s:renderView {{{2
"The entry function for rendering the tree
function! s:renderView()
    setlocal modifiable

    "remember the top line of the buffer and the current line so we can
    "restore the view exactly how it was
    let curLine = line(".")
    let curCol = col(".")
    let topLine = line("w0")

    "delete all lines in the buffer (being careful not to clobber a register)
    silent 1,$delete _

    call s:dumpHelp()

    "delete the blank line before the help and add one after it
    if g:NERDTreeMinimalUI == 0
        call setline(line(".")+1, "")
        call cursor(line(".")+1, col("."))
    endif

    if b:NERDTreeShowBookmarks
        call s:renderBookmarks()
    endif

    "add the 'up a dir' line
    if !g:NERDTreeMinimalUI
        call setline(line(".")+1, s:tree_up_dir_line)
        call cursor(line(".")+1, col("."))
    endif

    "draw the header line
    let header = b:NERDTreeRoot.path.str({'format': 'UI', 'truncateTo': winwidth(0)})
    call setline(line(".")+1, header)
    call cursor(line(".")+1, col("."))

    "draw the tree
    let old_o = @o
    let @o = b:NERDTreeRoot.renderToString()
    silent put o
    let @o = old_o

    "delete the blank line at the top of the buffer
    silent 1,1delete _

    "restore the view
    let old_scrolloff=&scrolloff
    let &scrolloff=0
    call cursor(topLine, 1)
    normal! zt
    call cursor(curLine, curCol)
    let &scrolloff = old_scrolloff

    setlocal nomodifiable
endfunction

"FUNCTION: s:renderViewSavingPosition {{{2
"Renders the tree and ensures the cursor stays on the current node or the
"current nodes parent if it is no longer available upon re-rendering
function! s:renderViewSavingPosition()
    let currentNode = s:TreeFileNode.GetSelected()

    "go up the tree till we find a node that will be visible or till we run
    "out of nodes
    while currentNode != {} && !currentNode.isVisible() && !currentNode.isRoot()
        let currentNode = currentNode.parent
    endwhile

    call s:renderView()

    if currentNode != {}
        call currentNode.putCursorHere(0, 0)
    endif
endfunction
"FUNCTION: s:restoreScreenState() {{{2
"
"Sets the screen state back to what it was when s:saveScreenState was last
"called.
"
"Assumes the cursor is in the NERDTree window
function! s:restoreScreenState()
    if !exists("b:NERDTreeOldTopLine") || !exists("b:NERDTreeOldPos") || !exists("b:NERDTreeOldWindowSize")
        return
    endif
    exec("silent vertical resize ".b:NERDTreeOldWindowSize)

    let old_scrolloff=&scrolloff
    let &scrolloff=0
    call cursor(b:NERDTreeOldTopLine, 0)
    normal! zt
    call setpos(".", b:NERDTreeOldPos)
    let &scrolloff=old_scrolloff
endfunction

"FUNCTION: s:saveScreenState() {{{2
"Saves the current cursor position in the current buffer and the window
"scroll position
function! s:saveScreenState()
    let win = winnr()
    try
        call s:putCursorInTreeWin()
        let b:NERDTreeOldPos = getpos(".")
        let b:NERDTreeOldTopLine = line("w0")
        let b:NERDTreeOldWindowSize = winwidth("")
        call s:exec(win . "wincmd w")
    catch /^NERDTree.InvalidOperationError/
    endtry
endfunction

"FUNCTION: s:setCommonBufOptions() {{{2
function! s:setCommonBufOptions()
    "throwaway buffer options
    setlocal noswapfile
    setlocal buftype=nofile
    setlocal bufhidden=hide
    setlocal nowrap
    setlocal foldcolumn=0
    setlocal nobuflisted
    setlocal nospell
    if g:NERDTreeShowLineNumbers
        setlocal nu
    else
        setlocal nonu
        if v:version >= 703
            setlocal nornu
        endif
    endif

    iabc <buffer>

    if g:NERDTreeHighlightCursorline
        setlocal cursorline
    endif

    call s:setupStatusline()


    let b:treeShowHelp = 0
    let b:NERDTreeIgnoreEnabled = 1
    let b:NERDTreeShowFiles = g:NERDTreeShowFiles
    let b:NERDTreeShowHidden = g:NERDTreeShowHidden
    let b:NERDTreeShowBookmarks = g:NERDTreeShowBookmarks
    setfiletype nerdtree
    call s:bindMappings()
endfunction

"FUNCTION: s:setupStatusline() {{{2
function! s:setupStatusline()
    if g:NERDTreeStatusline != -1
        let &l:statusline = g:NERDTreeStatusline
    endif
endfunction
"FUNCTION: s:stripMarkupFromLine(line, removeLeadingSpaces){{{2
"returns the given line with all the tree parts stripped off
"
"Args:
"line: the subject line
"removeLeadingSpaces: 1 if leading spaces are to be removed (leading spaces =
"any spaces before the actual text of the node)
function! s:stripMarkupFromLine(line, removeLeadingSpaces)
    let line = a:line
    "remove the tree parts and the leading space
    let line = substitute (line, s:tree_markup_reg,"","")

    "strip off any read only flag
    let line = substitute (line, ' \[RO\]', "","")

    "strip off any bookmark flags
    let line = substitute (line, ' {[^}]*}', "","")

    "strip off any executable flags
    let line = substitute (line, '*\ze\($\| \)', "","")

    let wasdir = 0
    if line =~# '/$'
        let wasdir = 1
    endif
    let line = substitute (line,' -> .*',"","") " remove link to
    if wasdir ==# 1
        let line = substitute (line, '/\?$', '/', "")
    endif

    if a:removeLeadingSpaces
        let line = substitute (line, '^ *', '', '')
    endif

    return line
endfunction

"FUNCTION: s:toggle(dir) {{{2
"Toggles the NERD tree. I.e the NERD tree is open, it is closed, if it is
"closed it is restored or initialized (if it doesnt exist)
"
"Args:
"dir: the full path for the root node (is only used if the NERD tree is being
"initialized.
function! s:toggle(dir)
    if s:treeExistsForTab()
        if !s:isTreeOpen()
            call s:createTreeWin()
            if !&hidden
                call s:renderView()
            endif
            call s:restoreScreenState()
        else
            call s:closeTree()
        endif
    else
        call s:initNerdTree(a:dir)
    endif
endfunction
"SECTION: Interface bindings {{{1
"============================================================
"FUNCTION: s:activateNode(forceKeepWindowOpen) {{{2
"If the current node is a file, open it in the previous window (or a new one
"if the previous is modified). If it is a directory then it is opened.
"
"args:
"forceKeepWindowOpen - dont close the window even if NERDTreeQuitOnOpen is set
function! s:activateNode(forceKeepWindowOpen)
    if getline(".") ==# s:tree_up_dir_line
        return s:upDir(0)
    endif

    let treenode = s:TreeFileNode.GetSelected()
    if treenode != {}
        call treenode.activate(a:forceKeepWindowOpen)
    else
        let bookmark = s:Bookmark.GetSelected()
        if !empty(bookmark)
            call bookmark.activate()
        endif
    endif
endfunction

"FUNCTION: s:bindMappings() {{{2
function! s:bindMappings()
    " set up mappings and commands for this buffer
    nnoremap <silent> <buffer> <middlerelease> :call <SID>handleMiddleMouse()<cr>
    nnoremap <silent> <buffer> <leftrelease> <leftrelease>:call <SID>checkForActivate()<cr>
    nnoremap <silent> <buffer> <2-leftmouse> :call <SID>activateNode(0)<cr>

    exec "nnoremap <silent> <buffer> ". g:NERDTreeMapActivateNode . " :call <SID>activateNode(0)<cr>"
    exec "nnoremap <silent> <buffer> ". g:NERDTreeMapOpenSplit ." :call <SID>openEntrySplit(0,0)<cr>"
    exec "nnoremap <silent> <buffer> <cr> :call <SID>activateNode(0)<cr>"

    exec "nnoremap <silent> <buffer> ". g:NERDTreeMapPreview ." :call <SID>previewNode(0)<cr>"
    exec "nnoremap <silent> <buffer> ". g:NERDTreeMapPreviewSplit ." :call <SID>previewNode(1)<cr>"

    exec "nnoremap <silent> <buffer> ". g:NERDTreeMapOpenVSplit ." :call <SID>openEntrySplit(1,0)<cr>"
    exec "nnoremap <silent> <buffer> ". g:NERDTreeMapPreviewVSplit ." :call <SID>previewNode(2)<cr>"

    exec "nnoremap <silent> <buffer> ". g:NERDTreeMapOpenRecursively ." :call <SID>openNodeRecursively()<cr>"

    exec "nnoremap <silent> <buffer> ". g:NERDTreeMapUpdirKeepOpen ." :call <SID>upDir(1)<cr>"
    exec "nnoremap <silent> <buffer> ". g:NERDTreeMapUpdir ." :call <SID>upDir(0)<cr>"
    exec "nnoremap <silent> <buffer> ". g:NERDTreeMapChangeRoot ." :call <SID>chRoot()<cr>"

    exec "nnoremap <silent> <buffer> ". g:NERDTreeMapChdir ." :call <SID>chCwd()<cr>"

    exec "nnoremap <silent> <buffer> ". g:NERDTreeMapQuit ." :call <SID>closeTreeWindow()<cr>"

    exec "nnoremap <silent> <buffer> ". g:NERDTreeMapRefreshRoot ." :call <SID>refreshRoot()<cr>"
    exec "nnoremap <silent> <buffer> ". g:NERDTreeMapRefresh ." :call <SID>refreshCurrent()<cr>"

    exec "nnoremap <silent> <buffer> ". g:NERDTreeMapHelp ." :call <SID>displayHelp()<cr>"
    exec "nnoremap <silent> <buffer> ". g:NERDTreeMapToggleZoom ." :call <SID>toggleZoom()<cr>"
    exec "nnoremap <silent> <buffer> ". g:NERDTreeMapToggleHidden ." :call <SID>toggleShowHidden()<cr>"
    exec "nnoremap <silent> <buffer> ". g:NERDTreeMapToggleFilters ." :call <SID>toggleIgnoreFilter()<cr>"
    exec "nnoremap <silent> <buffer> ". g:NERDTreeMapToggleFiles ." :call <SID>toggleShowFiles()<cr>"
    exec "nnoremap <silent> <buffer> ". g:NERDTreeMapToggleBookmarks ." :call <SID>toggleShowBookmarks()<cr>"

    exec "nnoremap <silent> <buffer> ". g:NERDTreeMapCloseDir ." :call <SID>closeCurrentDir()<cr>"
    exec "nnoremap <silent> <buffer> ". g:NERDTreeMapCloseChildren ." :call <SID>closeChildren()<cr>"

    exec "nnoremap <silent> <buffer> ". g:NERDTreeMapMenu ." :call <SID>showMenu()<cr>"

    exec "nnoremap <silent> <buffer> ". g:NERDTreeMapJumpParent ." :call <SID>jumpToParent()<cr>"
    exec "nnoremap <silent> <buffer> ". g:NERDTreeMapJumpNextSibling ." :call <SID>jumpToSibling(1)<cr>"
    exec "nnoremap <silent> <buffer> ". g:NERDTreeMapJumpPrevSibling ." :call <SID>jumpToSibling(0)<cr>"
    exec "nnoremap <silent> <buffer> ". g:NERDTreeMapJumpFirstChild ." :call <SID>jumpToFirstChild()<cr>"
    exec "nnoremap <silent> <buffer> ". g:NERDTreeMapJumpLastChild ." :call <SID>jumpToLastChild()<cr>"
    exec "nnoremap <silent> <buffer> ". g:NERDTreeMapJumpRoot ." :call <SID>jumpToRoot()<cr>"

    exec "nnoremap <silent> <buffer> ". g:NERDTreeMapOpenInTab ." :call <SID>openInNewTab(0)<cr>"
    exec "nnoremap <silent> <buffer> ". g:NERDTreeMapOpenInTabSilent ." :call <SID>openInNewTab(1)<cr>"

    exec "nnoremap <silent> <buffer> ". g:NERDTreeMapOpenExpl ." :call <SID>openExplorer()<cr>"

    exec "nnoremap <silent> <buffer> ". g:NERDTreeMapDeleteBookmark ." :call <SID>deleteBookmark()<cr>"

    "bind all the user custom maps
    call s:KeyMap.BindAll()

    command! -buffer -nargs=? Bookmark :call <SID>bookmarkNode('<args>')
    command! -buffer -complete=customlist,s:completeBookmarks -nargs=1 RevealBookmark :call <SID>revealBookmark('<args>')
    command! -buffer -complete=customlist,s:completeBookmarks -nargs=1 OpenBookmark :call <SID>openBookmark('<args>')
    command! -buffer -complete=customlist,s:completeBookmarks -nargs=* ClearBookmarks call <SID>clearBookmarks('<args>')
    command! -buffer -complete=customlist,s:completeBookmarks -nargs=+ BookmarkToRoot call s:Bookmark.ToRoot('<args>')
    command! -buffer -nargs=0 ClearAllBookmarks call s:Bookmark.ClearAll() <bar> call <SID>renderView()
    command! -buffer -nargs=0 ReadBookmarks call s:Bookmark.CacheBookmarks(0) <bar> call <SID>renderView()
    command! -buffer -nargs=0 WriteBookmarks call s:Bookmark.Write()
endfunction

" FUNCTION: s:bookmarkNode(name) {{{2
" Associate the current node with the given name
function! s:bookmarkNode(...)
    let currentNode = s:TreeFileNode.GetSelected()
    if currentNode != {}
        let name = a:1
        if empty(name)
            let name = currentNode.path.getLastPathComponent(0)
        endif
        try
            call currentNode.bookmark(name)
            call s:renderView()
        catch /^NERDTree.IllegalBookmarkNameError/
            call s:echo("bookmark names must not contain spaces")
        endtry
    else
        call s:echo("select a node first")
    endif
endfunction
"FUNCTION: s:checkForActivate() {{{2
"Checks if the click should open the current node, if so then activate() is
"called (directories are automatically opened if the symbol beside them is
"clicked)
function! s:checkForActivate()
    let currentNode = s:TreeFileNode.GetSelected()
    if currentNode != {}
        let startToCur = strpart(getline(line(".")), 0, col("."))

        if currentNode.path.isDirectory
            if startToCur =~# s:tree_markup_reg . '$' && startToCur =~# '[+~▾▸]$'
                call s:activateNode(0)
                return
            endif
        endif

        if (g:NERDTreeMouseMode ==# 2 && currentNode.path.isDirectory) || g:NERDTreeMouseMode ==# 3
            let char = strpart(startToCur, strlen(startToCur)-1, 1)
            if char !~# s:tree_markup_reg
                call s:activateNode(0)
                return
            endif
        endif
    endif
endfunction

" FUNCTION: s:chCwd() {{{2
function! s:chCwd()
    let treenode = s:TreeFileNode.GetSelected()
    if treenode ==# {}
        call s:echo("Select a node first")
        return
    endif

    try
        call treenode.path.changeToDir()
    catch /^NERDTree.PathChangeError/
        call s:echoWarning("could not change cwd")
    endtry
endfunction

" FUNCTION: s:chRoot() {{{2
" changes the current root to the selected one
function! s:chRoot()
    let treenode = s:TreeFileNode.GetSelected()
    if treenode ==# {}
        call s:echo("Select a node first")
        return
    endif

    call treenode.makeRoot()
    call s:renderView()
    call b:NERDTreeRoot.putCursorHere(0, 0)
endfunction

" FUNCTION: s:clearBookmarks(bookmarks) {{{2
function! s:clearBookmarks(bookmarks)
    if a:bookmarks ==# ''
        let currentNode = s:TreeFileNode.GetSelected()
        if currentNode != {}
            call currentNode.clearBoomarks()
        endif
    else
        for name in split(a:bookmarks, ' ')
            let bookmark = s:Bookmark.BookmarkFor(name)
            call bookmark.delete()
        endfor
    endif
    call s:renderView()
endfunction
" FUNCTION: s:closeChildren() {{{2
" closes all childnodes of the current node
function! s:closeChildren()
    let currentNode = s:TreeDirNode.GetSelected()
    if currentNode ==# {}
        call s:echo("Select a node first")
        return
    endif

    call currentNode.closeChildren()
    call s:renderView()
    call currentNode.putCursorHere(0, 0)
endfunction
" FUNCTION: s:closeCurrentDir() {{{2
" closes the parent dir of the current node
function! s:closeCurrentDir()
    let treenode = s:TreeFileNode.GetSelected()
    if treenode ==# {}
        call s:echo("Select a node first")
        return
    endif

    let parent = treenode.parent
    if parent ==# {} || parent.isRoot()
        call s:echo("cannot close tree root")
    else
        call treenode.parent.close()
        call s:renderView()
        call treenode.parent.putCursorHere(0, 0)
    endif
endfunction
" FUNCTION: s:closeTreeWindow() {{{2
" close the tree window
function! s:closeTreeWindow()
    if b:NERDTreeType ==# "secondary" && b:NERDTreePreviousBuf != -1
        exec "buffer " . b:NERDTreePreviousBuf
    else
        if winnr("$") > 1
            call s:closeTree()
        else
            call s:echo("Cannot close last window")
        endif
    endif
endfunction
" FUNCTION: s:deleteBookmark() {{{2
" if the cursor is on a bookmark, prompt to delete
function! s:deleteBookmark()
    let bookmark = s:Bookmark.GetSelected()
    if bookmark ==# {}
        call s:echo("Put the cursor on a bookmark")
        return
    endif

    echo  "Are you sure you wish to delete the bookmark:\n\"" . bookmark.name . "\" (yN):"

    if  nr2char(getchar()) ==# 'y'
        try
            call bookmark.delete()
            call s:renderView()
            redraw
        catch /^NERDTree/
            call s:echoWarning("Could not remove bookmark")
        endtry
    else
        call s:echo("delete aborted" )
    endif

endfunction

" FUNCTION: s:displayHelp() {{{2
" toggles the help display
function! s:displayHelp()
    let b:treeShowHelp = b:treeShowHelp ? 0 : 1
    call s:renderView()
    call s:centerView()
endfunction

" FUNCTION: s:handleMiddleMouse() {{{2
function! s:handleMiddleMouse()
    let curNode = s:TreeFileNode.GetSelected()
    if curNode ==# {}
        call s:echo("Put the cursor on a node first" )
        return
    endif

    if curNode.path.isDirectory
        call s:openExplorer()
    else
        call s:openEntrySplit(0,0)
    endif
endfunction


" FUNCTION: s:jumpToFirstChild() {{{2
" wrapper for the jump to child method
function! s:jumpToFirstChild()
    call s:jumpToChild(0)
endfunction

" FUNCTION: s:jumpToLastChild() {{{2
" wrapper for the jump to child method
function! s:jumpToLastChild()
    call s:jumpToChild(1)
endfunction

" FUNCTION: s:jumpToParent() {{{2
" moves the cursor to the parent of the current node
function! s:jumpToParent()
    let currentNode = s:TreeFileNode.GetSelected()
    if !empty(currentNode)
        if !empty(currentNode.parent)
            call currentNode.parent.putCursorHere(1, 0)
            call s:centerView()
        else
            call s:echo("cannot jump to parent")
        endif
    else
        call s:echo("put the cursor on a node first")
    endif
endfunction

" FUNCTION: s:jumpToRoot() {{{2
" moves the cursor to the root node
function! s:jumpToRoot()
    call b:NERDTreeRoot.putCursorHere(1, 0)
    call s:centerView()
endfunction

" FUNCTION: s:jumpToSibling() {{{2
" moves the cursor to the sibling of the current node in the given direction
"
" Args:
" forward: 1 if the cursor should move to the next sibling, 0 if it should
" move back to the previous sibling
function! s:jumpToSibling(forward)
    let currentNode = s:TreeFileNode.GetSelected()
    if !empty(currentNode)
        let sibling = currentNode.findSibling(a:forward)

        if !empty(sibling)
            call sibling.putCursorHere(1, 0)
            call s:centerView()
        endif
    else
        call s:echo("put the cursor on a node first")
    endif
endfunction

" FUNCTION: s:openBookmark(name) {{{2
" put the cursor on the given bookmark and, if its a file, open it
function! s:openBookmark(name)
    try
        let targetNode = s:Bookmark.GetNodeForName(a:name, 0)
        call targetNode.putCursorHere(0, 1)
        redraw!
    catch /^NERDTree.BookmarkedNodeNotFoundError/
        call s:echo("note - target node is not cached")
        let bookmark = s:Bookmark.BookmarkFor(a:name)
        let targetNode = s:TreeFileNode.New(bookmark.path)
    endtry
    if targetNode.path.isDirectory
        call targetNode.openExplorer()
    else
        call targetNode.open()
    endif
endfunction
" FUNCTION: s:openEntrySplit(vertical, forceKeepWindowOpen) {{{2
"Opens the currently selected file from the explorer in a
"new window
"
"args:
"forceKeepWindowOpen - dont close the window even if NERDTreeQuitOnOpen is set
function! s:openEntrySplit(vertical, forceKeepWindowOpen)
    let treenode = s:TreeFileNode.GetSelected()
    if treenode != {}
        if a:vertical
            call treenode.openVSplit()
        else
            call treenode.openSplit()
        endif
        if !a:forceKeepWindowOpen
            call s:closeTreeIfQuitOnOpen()
        endif
    else
        call s:echo("select a node first")
    endif
endfunction

" FUNCTION: s:openExplorer() {{{2
function! s:openExplorer()
    let treenode = s:TreeDirNode.GetSelected()
    if treenode != {}
        call treenode.openExplorer()
    else
        call s:echo("select a node first")
    endif
endfunction

" FUNCTION: s:openInNewTab(stayCurrentTab) {{{2
" Opens the selected node or bookmark in a new tab
" Args:
" stayCurrentTab: if 1 then vim will stay in the current tab, if 0 then vim
" will go to the tab where the new file is opened
function! s:openInNewTab(stayCurrentTab)
    let target = s:TreeFileNode.GetSelected()
    if target == {}
        let target = s:Bookmark.GetSelected()
    endif

    if target != {}
        call target.openInNewTab({'stayInCurrentTab': a:stayCurrentTab})
    endif
endfunction

" FUNCTION: s:openNodeRecursively() {{{2
function! s:openNodeRecursively()
    let treenode = s:TreeFileNode.GetSelected()
    if treenode ==# {} || treenode.path.isDirectory ==# 0
        call s:echo("Select a directory node first" )
    else
        call s:echo("Recursively opening node. Please wait...")
        call treenode.openRecursively()
        call s:renderView()
        redraw
        call s:echo("Recursively opening node. Please wait... DONE")
    endif

endfunction

"FUNCTION: s:previewNode() {{{2
"Args:
"   openNewWin: if 0, use the previous window, if 1 open in new split, if 2
"               open in a vsplit
function! s:previewNode(openNewWin)
    let currentBuf = bufnr("")
    if a:openNewWin > 0
        call s:openEntrySplit(a:openNewWin ==# 2,1)
    else
        call s:activateNode(1)
    end
    call s:exec(bufwinnr(currentBuf) . "wincmd w")
endfunction

" FUNCTION: s:revealBookmark(name) {{{2
" put the cursor on the node associate with the given name
function! s:revealBookmark(name)
    try
        let targetNode = s:Bookmark.GetNodeForName(a:name, 0)
        call targetNode.putCursorHere(0, 1)
    catch /^NERDTree.BookmarkNotFoundError/
        call s:echo("Bookmark isnt cached under the current root")
    endtry
endfunction
" FUNCTION: s:refreshRoot() {{{2
" Reloads the current root. All nodes below this will be lost and the root dir
" will be reloaded.
function! s:refreshRoot()
    call s:echo("Refreshing the root node. This could take a while...")
    call b:NERDTreeRoot.refresh()
    call s:renderView()
    redraw
    call s:echo("Refreshing the root node. This could take a while... DONE")
endfunction

" FUNCTION: s:refreshCurrent() {{{2
" refreshes the root for the current node
function! s:refreshCurrent()
    let treenode = s:TreeDirNode.GetSelected()
    if treenode ==# {}
        call s:echo("Refresh failed. Select a node first")
        return
    endif

    call s:echo("Refreshing node. This could take a while...")
    call treenode.refresh()
    call s:renderView()
    redraw
    call s:echo("Refreshing node. This could take a while... DONE")
endfunction
" FUNCTION: s:showMenu() {{{2
function! s:showMenu()
    let curNode = s:TreeFileNode.GetSelected()
    if curNode ==# {}
        call s:echo("Put the cursor on a node first" )
        return
    endif

    let mc = s:MenuController.New(s:MenuItem.AllEnabled())
    call mc.showMenu()
endfunction

" FUNCTION: s:toggleIgnoreFilter() {{{2
" toggles the use of the NERDTreeIgnore option
function! s:toggleIgnoreFilter()
    let b:NERDTreeIgnoreEnabled = !b:NERDTreeIgnoreEnabled
    call s:renderViewSavingPosition()
    call s:centerView()
endfunction

" FUNCTION: s:toggleShowBookmarks() {{{2
" toggles the display of bookmarks
function! s:toggleShowBookmarks()
    let b:NERDTreeShowBookmarks = !b:NERDTreeShowBookmarks
    if b:NERDTreeShowBookmarks
        call s:renderView()
        call s:putCursorOnBookmarkTable()
    else
        call s:renderViewSavingPosition()
    endif
    call s:centerView()
endfunction
" FUNCTION: s:toggleShowFiles() {{{2
" toggles the display of hidden files
function! s:toggleShowFiles()
    let b:NERDTreeShowFiles = !b:NERDTreeShowFiles
    call s:renderViewSavingPosition()
    call s:centerView()
endfunction

" FUNCTION: s:toggleShowHidden() {{{2
" toggles the display of hidden files
function! s:toggleShowHidden()
    let b:NERDTreeShowHidden = !b:NERDTreeShowHidden
    call s:renderViewSavingPosition()
    call s:centerView()
endfunction

" FUNCTION: s:toggleZoom() {{2
" zoom (maximize/minimize) the NERDTree window
function! s:toggleZoom()
    if exists("b:NERDTreeZoomed") && b:NERDTreeZoomed
        let size = exists("b:NERDTreeOldWindowSize") ? b:NERDTreeOldWindowSize : g:NERDTreeWinSize
        exec "silent vertical resize ". size
        let b:NERDTreeZoomed = 0
    else
        exec "vertical resize"
        let b:NERDTreeZoomed = 1
    endif
endfunction

"FUNCTION: s:upDir(keepState) {{{2
"moves the tree up a level
"
"Args:
"keepState: 1 if the current root should be left open when the tree is
"re-rendered
function! s:upDir(keepState)
    let cwd = b:NERDTreeRoot.path.str({'format': 'UI'})
    if cwd ==# "/" || cwd =~# '^[^/]..$'
        call s:echo("already at top dir")
    else
        if !a:keepState
            call b:NERDTreeRoot.close()
        endif

        let oldRoot = b:NERDTreeRoot

        if empty(b:NERDTreeRoot.parent)
            let path = b:NERDTreeRoot.path.getParent()
            let newRoot = s:TreeDirNode.New(path)
            call newRoot.open()
            call newRoot.transplantChild(b:NERDTreeRoot)
            let b:NERDTreeRoot = newRoot
        else
            let b:NERDTreeRoot = b:NERDTreeRoot.parent
        endif

        if g:NERDTreeChDirMode ==# 2
            call b:NERDTreeRoot.path.changeToDir()
        endif

        call s:renderView()
        call oldRoot.putCursorHere(0, 0)
    endif
endfunction


"reset &cpo back to users setting
let &cpo = s:old_cpo

" vim: set sw=4 sts=4 et fdm=marker: