BufExplorer/plugin/bufexplorer.vim

"============================================================================
"    Copyright: Copyright (c) 2001-2025, Jeff Lanzarotta
"               All rights reserved.
"
"               Redistribution and use in source and binary forms, with or
"               without modification, are permitted provided that the
"               following conditions are met:
"
"               * Redistributions of source code must retain the above
"                 copyright notice, this list of conditions and the following
"                 disclaimer.
"
"               * Redistributions in binary form must reproduce the above
"                 copyright notice, this list of conditions and the following
"                 disclaimer in the documentation and/or other materials
"                 provided with the distribution.
"
"               * Neither the name of the {organization} nor the names of its
"                 contributors may be used to endorse or promote products
"                 derived from this software without specific prior written
"                 permission.
"
"               THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
"               CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
"               INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
"               MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
"               DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR
"               CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
"               SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
"               NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
"               LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
"               HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
"               CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
"               OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
"               EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
" Name Of File: bufexplorer.vim
"  Description: Buffer Explorer Vim Plugin
"   Maintainer: Jeff Lanzarotta (my name at gmail dot com)
" Last Changed: Wednesday, 05 March 2025
"      Version: See g:bufexplorer_version for version number.
"        Usage: This file should reside in the plugin directory and be
"               automatically sourced.
"
"               You may use the default keymappings of
"
"                 <Leader>be  - Opens BufExplorer
"                 <Leader>bt  - Toggles BufExplorer open or closed
"                 <Leader>bs  - Opens horizontally split window BufExplorer
"                 <Leader>bv  - Opens vertically split window BufExplorer
"
"               Or you can override the defaults and define your own mapping
"               in your vimrc file, for example:
"
"                   nnoremap <silent> <F11> :BufExplorer<CR>
"                   nnoremap <silent> <s-F11> :ToggleBufExplorer<CR>
"                   nnoremap <silent> <m-F11> :BufExplorerHorizontalSplit<CR>
"                   nnoremap <silent> <c-F11> :BufExplorerVerticalSplit<CR>
"
"               Or you can use
"
"                 ":BufExplorer"                - Opens BufExplorer
"                 ":ToggleBufExplorer"          - Opens/Closes BufExplorer
"                 ":BufExplorerHorizontalSplit" - Opens horizontally window BufExplorer
"                 ":BufExplorerVerticalSplit"   - Opens vertically split window BufExplorer
"
"               For more help see supplied documentation.
"      History: See supplied documentation.
"=============================================================================

" Exit quickly if already running or when 'compatible' is set. {{{1
if exists("g:bufexplorer_version") || &cp
    finish
endif
"1}}}

" Version number.
let g:bufexplorer_version = "7.8.0"

" Plugin Code {{{1
" Check for Vim version {{{2
if !exists("g:bufExplorerVersionWarn")
    let g:bufExplorerVersionWarn = 1
endif

" Make sure we are using the correct version of Vim. If not, do not load the
" plugin.
if v:version < 704
    if g:bufExplorerVersionWarn
        echohl WarningMsg
        echo "Sorry, bufexplorer ".g:bufexplorer_version." required Vim 7.4 or greater."
        echohl None
    endif
    finish
endif

" Create commands {{{2
command! BufExplorer :call BufExplorer()
command! ToggleBufExplorer :call ToggleBufExplorer()
command! BufExplorerHorizontalSplit :call BufExplorerHorizontalSplit()
command! BufExplorerVerticalSplit :call BufExplorerVerticalSplit()

" Set {{{2
function! s:Set(var, default)
    if !exists(a:var)
        if type(a:default)
            execute "let" a:var "=" string(a:default)
        else
            execute "let" a:var "=" a:default
        endif

        return 1
    endif

    return 0
endfunction

" Script variables {{{2
let s:MRU_Exclude_List = ["[BufExplorer]","__MRU_Files__","[Buf\ List]"]
let s:name = '[BufExplorer]'
let s:originBuffer = 0
" Buffer number of the BufExplorer window.
let s:bufExplorerBuffer = 0
let s:running = 0
let s:sort_by = ["number", "name", "fullpath", "mru", "extension"]
let s:splitMode = ""
let s:didSplit = 0
let s:types = ["fullname", "homename", "path", "relativename", "relativepath", "shortname"]

" Setup the autocommands that handle stuff. {{{2
augroup BufExplorer
    autocmd!
    autocmd WinEnter        * call s:DoWinEnter()
    autocmd BufEnter        * call s:DoBufEnter()
    autocmd BufDelete       * call s:DoBufDelete()
    if exists('##TabClosed')
        autocmd TabClosed      * call s:DoTabClosed()
    endif
    autocmd BufWinEnter \[BufExplorer\] call s:Initialize()
    autocmd BufWinLeave \[BufExplorer\] call s:Cleanup()
augroup END

" AssignTabId {{{2
" Assign a `tabId` to the given tab.
function! s:AssignTabId(tabNbr)
    " Create a unique `tabId` based on the current time and an incrementing
    " counter value that helps ensure uniqueness.
    let tabId = reltimestr(reltime()) . ':' . s:tabIdCounter
    call settabvar(a:tabNbr, 'bufexp_tabId', tabId)
    let s:tabIdCounter = (s:tabIdCounter + 1) % 1000000000
    return tabId
endfunction

let s:tabIdCounter = 0

" GetTabId {{{2
" Retrieve the `tabId` for the given tab (or '' if the tab has no `tabId`).
function! s:GetTabId(tabNbr)
    return gettabvar(a:tabNbr, 'bufexp_tabId', '')
endfunction

" MRU data structure {{{2
" An MRU data structure is a dictionary that holds a circular doubly linked list
" of `item` values.  The dictionary contains three keys:
"   'head': a sentinel `item` representing the head of the list.
"   'next': a dictionary mapping an `item` to the next `item` in the list.
"   'prev': a dictionary mapping an `item` to the previous `item` in the list.
" E.g., an MRU holding buffer numbers will use `0` (an invalid buffer number) as
" `head`.  With the buffer numbers `1`, `2`, and `3`, an example MRU would be:
"
"           +--<---------<---------<---------<---------<+
"  `next`   |                                           |
"           +--> +---+ --> +---+ --> +---+ --> +---+ -->+
"  `head`        | 0 |     | 1 |     | 2 |     | 3 |
"           +<-- +---+ <-- +---+ <-- +---+ <-- +---+ <--+
"  `prev`   |                                           |
"           +->-------->--------->--------->--------->--+
"
" `head` allows the chosen sentinel item to differ in value and type; for
" example, `head` could be the string '.', allowing an MRU of strings (such as
" for `TabId` values).
"
" Note that dictionary keys are always strings.  Integers may be used, but they
" are converted to strings when used (and `keys(theDictionary)` will be a
" list of strings, not of integers).

" MRUNew {{{2
function! s:MRUNew(head)
    let [next, prev] = [{}, {}]
    let next[a:head] = a:head
    let prev[a:head] = a:head
    return { 'head': a:head, 'next': next, 'prev': prev }
endfunction

" MRULen {{{2
function! s:MRULen(mru)
    " Do not include the always-present `mru.head` item.
    return len(a:mru.next) - 1
endfunction

" MRURemoveMustExist {{{2
"   `item` must exist in `mru`.
function! s:MRURemoveMustExist(mru, item)
    let [next, prev] = [a:mru.next, a:mru.prev]
    let prevItem = prev[a:item]
    let nextItem = next[a:item]
    let next[prevItem] = nextItem
    let prev[nextItem] = prevItem
    unlet next[a:item]
    unlet prev[a:item]
endfunction

" MRURemove {{{2
"   `item` need not exist in `mru`.
function! s:MRURemove(mru, item)
    if has_key(a:mru.next, a:item)
        call s:MRURemoveMustExist(a:mru, a:item)
    endif
endfunction

" MRUAdd {{{2
function! s:MRUAdd(mru, item)
    let [next, prev] = [a:mru.next, a:mru.prev]
    let prevItem = a:mru.head
    let nextItem = next[prevItem]
    if a:item != nextItem
        call s:MRURemove(a:mru, a:item)
        let next[a:item] = nextItem
        let prev[a:item] = prevItem
        let next[prevItem] = a:item
        let prev[nextItem] = a:item
    endif
endfunction

" MRUGetItems {{{2
"   Return list of up to `maxItems` items in MRU order.
"   `maxItems == 0` => unlimited.
function! s:MRUGetItems(mru, maxItems)
    let [head, next] = [a:mru.head, a:mru.next]
    let items = []
    let item = next[head]
    while item != head
        if a:maxItems > 0 && len(items) >= a:maxItems
            break
        endif
        call add(items, item)
        let item = next[item]
    endwhile
    return items
endfunction

" MRUGetOrdering {{{2
"   Return dictionary mapping up to `maxItems` from `item` to MRU order.
"   `maxItems == 0` => unlimited.
function! s:MRUGetOrdering(mru, maxItems)
    let [head, next] = [a:mru.head, a:mru.next]
    let items = {}
    let order = 0
    let item = next[head]
    while item != head
        if a:maxItems > 0 && order >= a:maxItems
            break
        endif
        let items[item] = order
        let order = order + 1
        let item = next[item]
    endwhile
    return items
endfunction

" MRU trackers {{{2
" `.head` value for tab MRU:
let s:tabIdHead = '.'

" Track MRU buffers globally (independent of tabs).
let s:bufMru = s:MRUNew(0)

" Track MRU buffers for each tab, indexed by `tabId`.
"   `s:bufMruByTab[tabId] -> MRU structure`.
let s:bufMruByTab = {}

" Track MRU tabs for each buffer, indexed by `bufNbr`.
"   `s:tabMruByBuf[burNbr] -> MRU structure`.
let s:tabMruByBuf = {}

" MRURemoveBuf {{{2
function! s:MRURemoveBuf(bufNbr)
    call s:MRURemove(s:bufMru, a:bufNbr)
    if has_key(s:tabMruByBuf, a:bufNbr)
        let mru = s:tabMruByBuf[a:bufNbr]
        let [head, next] = [mru.head, mru.next]
        let tabId = next[head]
        while tabId != head
            call s:MRURemoveMustExist(s:bufMruByTab[tabId], a:bufNbr)
            let tabId = next[tabId]
        endwhile
        unlet s:tabMruByBuf[a:bufNbr]
    endif
endfunction

" MRURemoveTab {{{2
function! s:MRURemoveTab(tabId)
    if has_key(s:bufMruByTab, a:tabId)
        let mru = s:bufMruByTab[a:tabId]
        let [head, next] = [mru.head, mru.next]
        let bufNbr = next[head]
        while bufNbr != head
            call s:MRURemoveMustExist(s:tabMruByBuf[bufNbr], a:tabId)
            let bufNbr = next[bufNbr]
        endwhile
        unlet s:bufMruByTab[a:tabId]
    endif
endfunction

" MRUAddBufTab {{{2
function! s:MRUAddBufTab(bufNbr, tabId)
    if s:ShouldIgnore(a:bufNbr)
        return
    endif
    call s:MRUAdd(s:bufMru, a:bufNbr)
    if !has_key(s:bufMruByTab, a:tabId)
        let s:bufMruByTab[a:tabId] = s:MRUNew(0)
    endif
    let bufMru = s:bufMruByTab[a:tabId]
    call s:MRUAdd(bufMru, a:bufNbr)
    if !has_key(s:tabMruByBuf, a:bufNbr)
        let s:tabMruByBuf[a:bufNbr] = s:MRUNew(s:tabIdHead)
    endif
    let tabMru = s:tabMruByBuf[a:bufNbr]
    call s:MRUAdd(tabMru, a:tabId)
endfunction

" MRUTabForBuf {{{2
"   Return `tabId` most recently used by `bufNbr`.
"   If no `tabId` is found for `bufNbr`, return `s:tabIdHead`.
function! s:MRUTabForBuf(bufNbr)
    let tabMru = get(s:tabMruByBuf, a:bufNbr, s:alwaysEmptyTabMru)
    return tabMru.next[tabMru.head]
endfunction

" An always-empty MRU for tabs as a default when looking up
" `s:tabMruByBuf[bufNbr]` for an unknown `bufNbr`.
let s:alwaysEmptyTabMru = s:MRUNew(s:tabIdHead)

" MRUTabHasSeenBuf {{{2
"   Return true if `tabId` has ever seen `bufNbr`.
function! s:MRUTabHasSeenBuf(tabId, bufNbr)
    let mru = get(s:bufMruByTab, a:tabId, s:alwaysEmptyBufMru)
    return has_key(mru.next, a:bufNbr)
endfunction

" MRUTabShouldShowBuf {{{2
"   Return true if `tabId` should show `bufNbr`.
"   This is a function of current display modes.
function! s:MRUTabShouldShowBuf(tabId, bufNbr)
    if !g:bufExplorerShowTabBuffer
        " We are showing buffers from all tabs.
        return 1
    elseif g:bufExplorerOnlyOneTab
        " We are showing buffers that were most recently seen in this tab.
        return s:MRUTabForBuf(a:bufNbr) == a:tabId
    else
        " We are showing buffers that have ever been seen in this tab.
        return s:MRUTabHasSeenBuf(a:tabId, a:bufNbr)
    endif
endfunction

" MRUListedBuffersForTab {{{2
"   Return list of up to `maxBuffers` listed buffers in MRU order for the tab.
"   `maxBuffers == 0` => unlimited.
function! s:MRUListedBuffersForTab(tabId, maxBuffers)
    let bufNbrs = []
    let mru = get(s:bufMruByTab, a:tabId, s:alwaysEmptyBufMru)
    let [head, next] = [mru.head, mru.next]
    let bufNbr = next[head]
    while bufNbr != head
        if a:maxBuffers > 0 && len(bufNbrs) >= a:maxBuffers
            break
        endif
        if buflisted(bufNbr) && s:MRUTabShouldShowBuf(a:tabId, bufNbr)
            call add(bufNbrs, bufNbr)
        endif
        let bufNbr = next[bufNbr]
    endwhile
    return bufNbrs
endfunction

" An always-empty MRU for buffers as a default when looking up
" `s:bufMruByTab[tabId]` for an unknown `tabId`.
let s:alwaysEmptyBufMru = s:MRUNew(0)

" MRUOrderForBuf {{{2
" Return the position of `bufNbr` in the current MRU ordering.
" This is a function of the current display mode.  When showing buffers from all
" tabs, it's the global MRU order; otherwise, it the MRU order for the tab at
" BufExplorer launch.  The latter includes all buffers seen in this tab, which
" is sufficient whether `g:bufExplorerOnlyOneTab` is true or false.
function! s:MRUOrderForBuf(bufNbr)
    if !exists('s:mruOrder')
        if g:bufExplorerShowTabBuffer
            let mru = get(s:bufMruByTab, s:tabIdAtLaunch, s:alwaysEmptyBufMru)
        else
            let mru = s:bufMru
        endif
        let s:mruOrder = s:MRUGetOrdering(mru, 0)
    endif
    return get(s:mruOrder, a:bufNbr, len(s:mruOrder))
endfunction

" MRUEnsureTabId {{{2
function! s:MRUEnsureTabId(tabNbr)
    let tabId = s:GetTabId(a:tabNbr)
    if tabId == ''
        let tabId = s:AssignTabId(a:tabNbr)
        for bufNbr in tabpagebuflist(a:tabNbr)
            call s:MRUAddBufTab(bufNbr, tabId)
        endfor
    endif
    return tabId
endfunction

" MRUGarbageCollectBufs {{{2
"   Requires `s:raw_buffer_listing`.
function! s:MRUGarbageCollectBufs()
    for bufNbr in values(s:bufMru.next)
        if bufNbr != 0 && !has_key(s:raw_buffer_listing, bufNbr)
            call s:MRURemoveBuf(bufNbr)
        endif
    endfor
endfunction

" MRUGarbageCollectTabs {{{2
function! s:MRUGarbageCollectTabs()
    let numTabs = tabpagenr('$')
    let liveTabIds = {}
    for tabNbr in range(1, numTabs)
        let tabId = s:GetTabId(tabNbr)
        if tabId != ''
            let liveTabIds[tabId] = 1
        endif
    endfor
    for tabId in keys(s:bufMruByTab)
        if tabId != s:tabIdHead && !has_key(liveTabIds, tabId)
            call s:MRURemoveTab(tabId)
        endif
    endfor
endfunction

" DoWinEnter {{{2
function! s:DoWinEnter()
    let bufNbr = str2nr(expand("<abuf>"))
    let tabNbr = tabpagenr()
    let tabId = s:GetTabId(tabNbr)
    " Ignore `WinEnter` for a newly created tab; this event comes when creating
    " a new tab, and the buffer at that moment is one that is about to be
    " replaced by the buffer to which we are switching; this latter buffer will
    " be handled by the forthcoming `BufEnter` event.
    if tabId != ''
        call s:MRUAddBufTab(bufNbr, tabId)
    endif
endfunction

" DoBufEnter {{{2
function! s:DoBufEnter()
    let bufNbr = str2nr(expand("<abuf>"))
    let tabNbr = tabpagenr()
    let tabId = s:MRUEnsureTabId(tabNbr)
    call s:MRUAddBufTab(bufNbr, tabId)
endfunction

" DoBufDelete {{{2
function! s:DoBufDelete()
    let bufNbr = str2nr(expand("<abuf>"))
    call s:MRURemoveBuf(bufNbr)
endfunction

" DoTabClosed {{{2
function! s:DoTabClosed()
    call s:MRUGarbageCollectTabs()
endfunction

" ShouldIgnore {{{2
function! s:ShouldIgnore(buf)
    " Ignore temporary buffers with buftype set.
    if empty(getbufvar(a:buf, "&buftype")) == 0
        return 1
    endif

    " Ignore buffers with no name.
    if empty(bufname(a:buf)) == 1
        return 1
    endif

    " Ignore the BufExplorer buffer.
    if fnamemodify(bufname(a:buf), ":t") == s:name
        return 1
    endif

    " Ignore any buffers in the exclude list.
    if index(s:MRU_Exclude_List, bufname(a:buf)) >= 0
        return 1
    endif

    " Else return 0 to indicate that the buffer was not ignored.
    return 0
endfunction

" Initialize {{{2
function! s:Initialize()
    call s:SetLocalSettings()
    let s:running = 1
endfunction

" Cleanup {{{2
function! s:Cleanup()
    if exists("s:_insertmode")
        let &insertmode = s:_insertmode
    endif

    if exists("s:_showcmd")
        let &showcmd = s:_showcmd
    endif

    if exists("s:_cpo")
        let &cpo = s:_cpo
    endif

    if exists("s:_report")
        let &report = s:_report
    endif

    let s:running = 0
    let s:splitMode = ""
    let s:didSplit = 0

    delmarks!
endfunction

" SetLocalSettings {{{2
function! s:SetLocalSettings()
    let s:_insertmode = &insertmode
    set noinsertmode

    let s:_showcmd = &showcmd
    set noshowcmd

    let s:_cpo = &cpo
    set cpo&vim

    let s:_report = &report
    let &report = 10000

    setlocal nonumber
    setlocal foldcolumn=0
    setlocal nofoldenable
    setlocal cursorline
    setlocal nospell
    setlocal nobuflisted
    setlocal filetype=bufexplorer
endfunction

" BufExplorerHorizontalSplit {{{2
function! BufExplorerHorizontalSplit()
    let s:splitMode = "sp"
    execute "BufExplorer"
    let s:splitMode = ""
endfunction

" BufExplorerVerticalSplit {{{2
function! BufExplorerVerticalSplit()
    let s:splitMode = "vsp"
    execute "BufExplorer"
    let s:splitMode = ""
endfunction

" ToggleBufExplorer {{{2
function! ToggleBufExplorer()
    if exists("s:running") && s:running == 1 && bufname(winbufnr(0)) == s:name
        call s:Close()
    else
        call BufExplorer()
    endif
endfunction

" BufExplorer {{{2
function! BufExplorer()
    let name = s:name

    if !has("win32")
        " On non-Windows boxes, escape the name so that is shows up correctly.
        let name = escape(name, "[]")
    endif

    " Make sure there is only one explorer open at a time.
    if s:running == 1
        " Go to the open buffer.
        if has("gui")
            execute "drop" name
        endif

        return
    endif

    " Add zero to ensure the variable is treated as a number.
    let s:originBuffer = bufnr("%") + 0
    let s:tabIdAtLaunch = s:MRUEnsureTabId(tabpagenr())

    " Forget any cached MRU ordering from previous invocations.
    unlet! s:mruOrder

    let s:raw_buffer_listing = s:GetBufferInfo(0)

    call s:MRUGarbageCollectBufs()
    call s:MRUGarbageCollectTabs()

    " We may have to split the current window.
    if s:splitMode != ""
        " Save off the original settings.
        let [_splitbelow, _splitright] = [&splitbelow, &splitright]

        " Set the setting to ours.
        let [&splitbelow, &splitright] = [g:bufExplorerSplitBelow, g:bufExplorerSplitRight]
        let _size = (s:splitMode == "sp") ? g:bufExplorerSplitHorzSize : g:bufExplorerSplitVertSize

        " Split the window either horizontally or vertically.
        if _size <= 0
            execute 'keepalt ' . s:splitMode
        else
            execute 'keepalt ' . _size . s:splitMode
        endif

        " Restore the original settings.
        let [&splitbelow, &splitright] = [_splitbelow, _splitright]

        " Remember that a split was triggered
        let s:didSplit = 1
    endif

    if !exists("b:displayMode") || b:displayMode != "winmanager"
        " Do not use keepalt when opening bufexplorer to allow the buffer that
        " we are leaving to become the new alternate buffer
        execute "silent keepjumps hide edit".name
    endif

    " Record BufExplorer's buffer number.
    let s:bufExplorerBuffer = bufnr('%')

    call s:DisplayBufferList()

    " Position the cursor in the newly displayed list on the line representing
    " the active buffer.  The active buffer is the line with the '%' character
    " in it.
    execute search("%")

    if exists('#User#BufExplorer_Started')
        " Notify that BufExplorer has started.  This is an opportunity to make
        " custom buffer-local mappings and the like.
        doautocmd User BufExplorer_Started
    endif
endfunction

" Tracks `tabId` at BufExplorer launch.
let s:tabIdAtLaunch = ''

" DisplayBufferList {{{2
function! s:DisplayBufferList()
    setlocal buftype=nofile
    setlocal modifiable
    setlocal noreadonly
    setlocal noswapfile
    setlocal nowrap
    setlocal bufhidden=wipe

    call s:SetupSyntax()
    call s:MapKeys()

    " Wipe out any existing lines in case BufExplorer buffer exists and the
    " user had changed any global settings that might reduce the number of
    " lines needed in the buffer.
    silent keepjumps 1,$d _

    call setline(1, s:CreateHelp())
    call s:BuildBufferList()
    call cursor(s:firstBufferLine, 1)

    if !g:bufExplorerResize
        normal! zz
    endif

    setlocal nomodifiable
endfunction

" RedisplayBufferList {{{2
function! s:RedisplayBufferList()
    call s:RebuildBufferList()
    call s:UpdateHelpStatus()
endfunction

" MapKeys {{{2
function! s:MapKeys()

    nnoremap <silent> <buffer> <Plug>(BufExplorer_BufferDelete)             :call <SID>RemoveBuffer("delete")<CR>
    nnoremap <silent> <buffer> <Plug>(BufExplorer_BufferDeleteForced)       :call <SID>RemoveBuffer("force_delete")<CR>
    nnoremap <silent> <buffer> <Plug>(BufExplorer_BufferWipe)               :call <SID>RemoveBuffer("wipe")<CR>
    nnoremap <silent> <buffer> <Plug>(BufExplorer_BufferWipeForced)         :call <SID>RemoveBuffer("force_wipe")<CR>
    nnoremap <silent> <buffer> <Plug>(BufExplorer_Close)                    :call <SID>Close()<CR>
    nnoremap <silent> <buffer> <Plug>(BufExplorer_OpenBuffer)               :call <SID>SelectBuffer()<CR>
    nnoremap <silent> <buffer> <Plug>(BufExplorer_OpenBufferAsk)            :call <SID>SelectBuffer("ask")<CR>
    nnoremap <silent> <buffer> <Plug>(BufExplorer_OpenBufferSplitAbove)     :call <SID>SelectBuffer("split", "st")<CR>
    nnoremap <silent> <buffer> <Plug>(BufExplorer_OpenBufferSplitBelow)     :call <SID>SelectBuffer("split", "sb")<CR>
    nnoremap <silent> <buffer> <Plug>(BufExplorer_OpenBufferSplitLeft)      :call <SID>SelectBuffer("split", "vl")<CR>
    nnoremap <silent> <buffer> <Plug>(BufExplorer_OpenBufferSplitRight)     :call <SID>SelectBuffer("split", "vr")<CR>
    nnoremap <silent> <buffer> <Plug>(BufExplorer_OpenBufferTab)            :call <SID>SelectBuffer("tab")<CR>
    nnoremap <silent> <buffer> <Plug>(BufExplorer_SortByNext)               :call <SID>SortSelect()<CR>
    nnoremap <silent> <buffer> <Plug>(BufExplorer_SortByPrev)               :call <SID>ReverseSortSelect()<CR>
    nnoremap <silent> <buffer> <Plug>(BufExplorer_ToggleFindActive)         :call <SID>ToggleFindActive()<CR>
    nnoremap <silent> <buffer> <Plug>(BufExplorer_ToggleHelp)               :call <SID>ToggleHelp()<CR>
    nnoremap <silent> <buffer> <Plug>(BufExplorer_ToggleOnlyOneTab)         :call <SID>ToggleOnlyOneTab()<CR>
    nnoremap <silent> <buffer> <Plug>(BufExplorer_ToggleReverseSort)        :call <SID>SortReverse()<CR>
    nnoremap <silent> <buffer> <Plug>(BufExplorer_ToggleShowRelativePath)   :call <SID>ToggleShowRelativePath()<CR>
    nnoremap <silent> <buffer> <Plug>(BufExplorer_ToggleShowTabBuffer)      :call <SID>ToggleShowTabBuffer()<CR>
    nnoremap <silent> <buffer> <Plug>(BufExplorer_ToggleShowTerminal)       :call <SID>ToggleShowTerminal()<CR>
    nnoremap <silent> <buffer> <Plug>(BufExplorer_ToggleShowUnlisted)       :call <SID>ToggleShowUnlisted()<CR>
    nnoremap <silent> <buffer> <Plug>(BufExplorer_ToggleSplitOutPathName)   :call <SID>ToggleSplitOutPathName()<CR>

    if exists("b:displayMode") && b:displayMode == "winmanager"
        nnoremap <buffer> <silent> <tab> :call <SID>SelectBuffer()<CR>
    endif

    nmap <nowait> <buffer> <2-leftmouse>    <Plug>(BufExplorer_OpenBuffer)
    nmap <nowait> <buffer> <CR>             <Plug>(BufExplorer_OpenBuffer)
    nmap <nowait> <buffer> <F1>             <Plug>(BufExplorer_ToggleHelp)
    nmap <nowait> <buffer> <s-cr>           <Plug>(BufExplorer_OpenBufferTab)
    nmap <nowait> <buffer> a                <Plug>(BufExplorer_ToggleFindActive)
    nmap <nowait> <buffer> b                <Plug>(BufExplorer_OpenBufferAsk)
    nmap <nowait> <buffer> B                <Plug>(BufExplorer_ToggleOnlyOneTab)
    nmap <nowait> <buffer> d                <Plug>(BufExplorer_BufferDelete)
    nmap <nowait> <buffer> D                <Plug>(BufExplorer_BufferWipe)
    nmap <nowait> <buffer> f                <Plug>(BufExplorer_OpenBufferSplitBelow)
    nmap <nowait> <buffer> F                <Plug>(BufExplorer_OpenBufferSplitAbove)
    nmap <nowait> <buffer> o                <Plug>(BufExplorer_OpenBuffer)
    nmap <nowait> <buffer> p                <Plug>(BufExplorer_ToggleSplitOutPathName)
    nmap <nowait> <buffer> q                <Plug>(BufExplorer_Close)
    nmap <nowait> <buffer> r                <Plug>(BufExplorer_ToggleReverseSort)
    nmap <nowait> <buffer> R                <Plug>(BufExplorer_ToggleShowRelativePath)
    nmap <nowait> <buffer> s                <Plug>(BufExplorer_SortByNext)
    nmap <nowait> <buffer> S                <Plug>(BufExplorer_SortByPrev)
    nmap <nowait> <buffer> t                <Plug>(BufExplorer_OpenBufferTab)
    nmap <nowait> <buffer> T                <Plug>(BufExplorer_ToggleShowTabBuffer)
    nmap <nowait> <buffer> u                <Plug>(BufExplorer_ToggleShowUnlisted)
    nmap <nowait> <buffer> v                <Plug>(BufExplorer_OpenBufferSplitRight)
    nmap <nowait> <buffer> V                <Plug>(BufExplorer_OpenBufferSplitLeft)
    nmap <nowait> <buffer> X                <Plug>(BufExplorer_ToggleShowTerminal)


    for k in ["G", "n", "N", "L", "M", "H"]
        execute "nnoremap <buffer> <silent>" k ":keepjumps normal!" k."<CR>"
    endfor
endfunction

" SetupSyntax {{{2
function! s:SetupSyntax()
    if has("syntax")
        syn match bufExplorerHelp     "^\".*" contains=bufExplorerSortBy,bufExplorerMapping,bufExplorerTitle,bufExplorerSortType,bufExplorerToggleSplit,bufExplorerToggleOpen
        syn match bufExplorerOpenIn   "Open in \w\+ window" contained
        syn match bufExplorerSplit    "\w\+ split" contained
        syn match bufExplorerSortBy   "Sorted by .*" contained contains=bufExplorerOpenIn,bufExplorerSplit
        syn match bufExplorerMapping  "\" \zs.\+\ze :" contained
        syn match bufExplorerTitle    "Buffer Explorer.*" contained
        syn match bufExplorerSortType "'\w\{-}'" contained
        syn match bufExplorerBufNbr   /^\s*\d\+/
        syn match bufExplorerToggleSplit  "toggle split type" contained
        syn match bufExplorerToggleOpen   "toggle open mode" contained

        syn match bufExplorerModBuf    /^\s*\d\+.\{4}+.*/
        syn match bufExplorerLockedBuf /^\s*\d\+.\{3}[\-=].*/
        syn match bufExplorerHidBuf    /^\s*\d\+.\{2}h.*/
        syn match bufExplorerActBuf    /^\s*\d\+.\{2}a.*/
        syn match bufExplorerCurBuf    /^\s*\d\+.%.*/
        syn match bufExplorerAltBuf    /^\s*\d\+.#.*/
        syn match bufExplorerUnlBuf    /^\s*\d\+u.*/
        syn match bufExplorerInactBuf  /^\s*\d\+ \{7}.*/

        hi def link bufExplorerBufNbr Number
        hi def link bufExplorerMapping NonText
        hi def link bufExplorerHelp Special
        hi def link bufExplorerOpenIn Identifier
        hi def link bufExplorerSortBy String
        hi def link bufExplorerSplit NonText
        hi def link bufExplorerTitle NonText
        hi def link bufExplorerSortType bufExplorerSortBy
        hi def link bufExplorerToggleSplit bufExplorerSplit
        hi def link bufExplorerToggleOpen bufExplorerOpenIn

        hi def link bufExplorerActBuf Identifier
        hi def link bufExplorerAltBuf String
        hi def link bufExplorerCurBuf Type
        hi def link bufExplorerHidBuf Constant
        hi def link bufExplorerLockedBuf Special
        hi def link bufExplorerModBuf Exception
        hi def link bufExplorerUnlBuf Comment
        hi def link bufExplorerInactBuf Comment
    endif
endfunction

" ToggleHelp {{{2
function! s:ToggleHelp()
    let g:bufExplorerDetailedHelp = !g:bufExplorerDetailedHelp

    setlocal modifiable

    " Save position.
    normal! ma

    " Remove old header.
    if s:firstBufferLine > 1
        execute "keepjumps 1,".(s:firstBufferLine - 1) "d _"
    endif

    call append(0, s:CreateHelp())

    silent! normal! g`a
    delmarks a

    setlocal nomodifiable

    if exists("b:displayMode") && b:displayMode == "winmanager"
        call WinManagerForceReSize("BufExplorer")
    endif
endfunction

" GetHelpStatus {{{2
function! s:GetHelpStatus()
    let ret = '" Sorted by '.((g:bufExplorerReverseSort == 1) ? "reverse " : "").g:bufExplorerSortBy
    let ret .= ' | '.((g:bufExplorerFindActive == 0) ? "Don't " : "")."Locate buffer"
    let ret .= ((g:bufExplorerShowUnlisted == 0) ? "" : " | Show unlisted")
    let ret .= ((g:bufExplorerShowTabBuffer == 0) ? "" : " | Show buffers/tab")
    let ret .= ((g:bufExplorerOnlyOneTab == 0) ? "" : " | One tab/buffer")
    let ret .= ' | '.((g:bufExplorerShowRelativePath == 0) ? "Absolute" : "Relative")
    let ret .= ' '.((g:bufExplorerSplitOutPathName == 0) ? "Full" : "Split")." path"
    let ret .= ((g:bufExplorerShowTerminal == 0) ? "" : " | Show terminal")

    return ret
endfunction

" CreateHelp {{{2
function! s:CreateHelp()
    if g:bufExplorerDefaultHelp == 0 && g:bufExplorerDetailedHelp == 0
        let s:firstBufferLine = 1
        return []
    endif

    let header = []

    if g:bufExplorerDetailedHelp == 1
        call add(header, '" Buffer Explorer ('.g:bufexplorer_version.')')
        call add(header, '" --------------------------')
        call add(header, '" <F1> : toggle this help')
        call add(header, '" <enter> or o or Mouse-Double-Click : open buffer under cursor')
        call add(header, '" <shift-enter> or t : open buffer in another tab')
        call add(header, '" a : toggle find active buffer')
        call add(header, '" b : Fast buffer switching with b<any bufnum>')
        call add(header, '" B : toggle showing buffers only on their MRU tabs')
        call add(header, '" d : delete buffer')
        call add(header, '" D : wipe buffer')
        call add(header, '" F : open buffer in another window above the current')
        call add(header, '" f : open buffer in another window below the current')
        call add(header, '" p : toggle splitting of file and path name')
        call add(header, '" q : quit')
        call add(header, '" r : reverse sort')
        call add(header, '" R : toggle showing relative or full paths')
        call add(header, '" s : cycle thru "sort by" fields '.string(s:sort_by).'')
        call add(header, '" S : reverse cycle thru "sort by" fields')
        call add(header, '" T : toggle showing all buffers/only buffers used on this tab')
        call add(header, '" u : toggle showing unlisted buffers')
        call add(header, '" V : open buffer in another window on the left of the current')
        call add(header, '" v : open buffer in another window on the right of the current')
        call add(header, '" X : toggle showing terminal buffers')
    else
        call add(header, '" Press <F1> for Help')
    endif

    if (!exists("b:displayMode") || b:displayMode != "winmanager") || (b:displayMode == "winmanager" && g:bufExplorerDetailedHelp == 1)
        call add(header, s:GetHelpStatus())
        call add(header, '"=')
    endif

    let s:firstBufferLine = len(header) + 1

    return header
endfunction

" CalculateBufferDetails {{{2
" Calculate `buf`-related details.
" Only these fields of `buf` must be defined on entry:
" - `._bufnr`
" - `.attributes`
" - `.line`
function! s:CalculateBufferDetails(buf)
    let buf = a:buf
    let name = bufname(buf._bufnr)
    let buf["hasNoName"] = empty(name)
    if buf.hasNoName
        let name = "[No Name]"
    endif
    let buf.isterminal = getbufvar(buf._bufnr, '&buftype') == 'terminal'
    if buf.isterminal
        " Neovim uses paths with `term://` prefix, where the provided path
        " is the current working directory when the terminal was launched, e.g.:
        " - Unix:
        "   term://~/tmp/sort//1464953:/bin/bash
        " - Windows:
        "   term://C:\apps\nvim-win64\bin//6408:C:\Windows\system32\cmd.exe
        " Vim uses paths starting with `!`, with no provided path, e.g.:
        " - Unix:
        "   !/bin/bash
        " - Windows:
        "   !C:\Windows\system32\cmd.exe

        " Use the terminal's current working directory as the `path`.
        " For `shortname`, use `!PID:shellName`, prefixed with `!` as Vim does,
        " and without the shell's path for brevity, e.g.:
        "   `/bin/bash` -> `!bash`
        "   `1464953:/bin/bash` -> `!1464953:bash`
        "   `C:\Windows\system32\cmd.exe` -> `!cmd.exe`
        "   `6408:C:\Windows\system32\cmd.exe` -> `!6408:cmd.exe`

        " Neovim-style name format:
        "   term://(cwd)//(pid):(shellPath)
        " e.g.:
        "   term://~/tmp/sort//1464953:/bin/bash
        " `cwd` is the directory at terminal launch.
        let termNameParts = matchlist(name, '\v\c^term://(.*)//(\d+):(.*)$')
        if len(termNameParts) > 0
            let [cwd, pidStr, shellPath] = termNameParts[1:3]
            let pid = str2nr(pidStr)
            let shellName = fnamemodify(shellPath, ':t')
        else
            " Default to Vim's current working directory.
            let cwd = '.'
            let shellName = fnamemodify(name, ':t')
            let pid = -1
            if exists('*term_getjob') && exists('*job_info')
                let job = term_getjob(buf._bufnr)
                if job != v:null
                    let pid = job_info(job).process
                endif
            endif
        endif

        if pid < 0
            let shortname = '!' . shellName
        else
            let shortname = '!' . pid . ':' . shellName
            " On some systems having a `/proc` filesystem (e.g., Linux, *BSD,
            " Solaris), each process has a `cwd` symlink for the current working
            " directory.  `resolve()` will return the actual current working
            " directory if possible; otherwise, it will return the symlink path
            " unchanged.
            let cwd_symlink = '/proc/' . pid . '/cwd'
            let resolved_cwd = resolve(cwd_symlink)
            if resolved_cwd != cwd_symlink
                let cwd = resolved_cwd
            endif
        endif

        let slashed_path = fnamemodify(cwd, ':p')
        let buf.fullname = slashed_path . shortname
        let buf.shortname = shortname
        let homepath = fnamemodify(slashed_path, ':~:h')
        let buf.path = homepath
        let buf.homename = fnamemodify(buf.fullname, ':~')
        let buf.relativepath = fnamemodify(slashed_path, ':~:.:h')
        let buf.relativename = fnamemodify(buf.fullname, ':~:.')
        return
    endif

    let buf.fullname = simplify(fnamemodify(name, ':p'))
    let buf.isdir = getftype(buf.fullname) == "dir"
    if buf.isdir
        " `buf.fullname` ends with a path separator; this will be
        " removed via the first `:h` applied to `buf.fullname` (except
        " for the root directory, where the path separator will remain).
        let parent = fnamemodify(buf.fullname, ':h:h')
        let buf.shortname = fnamemodify(buf.fullname, ':h:t')
        " Special case for root directory: fnamemodify('/', ':h:t') == ''
        if buf.shortname == ''
            let buf.shortname = '.'
        endif
        " Must perform shortening (`:~`, `:.`) before `:h`.
        let buf.homename = fnamemodify(buf.fullname, ':~:h')
        let buf.relativename = fnamemodify(buf.fullname, ':~:.:h')
    else
        let parent = fnamemodify(buf.fullname, ':h')
        let buf.shortname = fnamemodify(buf.fullname, ':t')
        let buf.homename = fnamemodify(buf.fullname, ':~')
        let buf.relativename = fnamemodify(buf.fullname, ':~:.')
    endif
    " `:p` on `parent` adds back the path separator which permits more
    " effective shortening (`:~`, `:.`), but `:h` is required afterward
    " to trim this separator.
    let buf.path = fnamemodify(parent, ':p:~:h')
    let buf.relativepath = fnamemodify(parent, ':p:~:.:h')
endfunction

" GetBufferInfo {{{2
" Return dictionary `{ bufNbr : buf }`.
" - If `onlyBufNbr > 0`, dictionary will contain at most that buffer.
" On return, only these fields are set for each `buf`:
" - `._bufnr`
" - `.attributes`
" - `.line`
" Other fields will be populated by `s:CalculateBufferDetails()`.
function! s:GetBufferInfo(onlyBufNbr)
    redir => bufoutput

    " Below, `:silent buffers` allows capturing the output via `:redir` but
    " prevents display to the user.

    if a:onlyBufNbr > 0 && buflisted(a:onlyBufNbr)
        " We care only about the listed buffer `a:onlyBufNbr`, so no need to
        " enumerate unlisted buffers.
        silent buffers
    else
        " Use `!` to show all buffers including the unlisted ones.
        silent buffers!
    endif
    redir END

    if a:onlyBufNbr > 0
        " Since we are only interested in this specified buffer remove the
        " other buffers listed.
        " Use a very-magic pattern starting with a newline and a run of zero or
        " more spaces/tabs:
        let onlyLinePattern = '\v\n\s*'
        " Continue with the buffer number followed by a non-digit character
        " (which will be a buffer attribute character such as `u` or ` `).
        let onlyLinePattern .= a:onlyBufNbr . '\D'
        " Finish with a run of zero or more non-newline characters plus newline:
        let onlyLinePattern .= '[^\n]*\n'
        let bufoutput = matchstr("\n" . bufoutput . "\n", onlyLinePattern)
    endif

    let all = {}

    " Loop over each line in the buffer.
    for line in split(bufoutput, '\n')
        let bits = split(line, '"')

        " Use first and last components after the split on '"', in case a
        " filename with an embedded '"' is present.
        let buf = {"attributes": bits[0], "line": substitute(bits[-1], '\s*', '', '')}
        let buf._bufnr = str2nr(buf.attributes)
        let all[buf._bufnr] = buf
    endfor

    return all
endfunction

" BuildBufferList {{{2
function! s:BuildBufferList()
    let table = []

    " Loop through every buffer.
    for buf in values(s:raw_buffer_listing)
        " `buf.attributes` must exist, but we defer the expensive work of
        " calculating other buffer details (e.g., `buf.fullname`) until we know
        " the user wants to view this buffer.

        " Skip BufExplorer's buffer.
        if buf._bufnr == s:bufExplorerBuffer
            continue
        endif

        " Skip unlisted buffers if we are not to show them.
        if !g:bufExplorerShowUnlisted && buf.attributes =~ "u"
            " Skip unlisted buffers if we are not to show them.
            continue
        endif

        " Ensure buffer details are computed for this buffer.
        if !has_key(buf, 'fullname')
            call s:CalculateBufferDetails(buf)
        endif

        " Skip 'No Name' buffers if we are not to show them.
        if g:bufExplorerShowNoName == 0 && buf.hasNoName
            continue
        endif

        " Should we show this buffer in this tab?
        if !s:MRUTabShouldShowBuf(s:tabIdAtLaunch, buf._bufnr)
            continue
        endif

        " Skip terminal buffers if we are not to show them.
        if !g:bufExplorerShowTerminal && buf.isterminal
            continue
        endif

        " Skip directory buffers if we are not to show them.
        if !g:bufExplorerShowDirectories && buf.isdir
            continue
        endif

        let row = [buf.attributes]

        if exists("g:loaded_webdevicons")
            let row += [WebDevIconsGetFileTypeSymbol(buf.fullname, buf.isdir)]
        endif

        " Are we to split the path and file name?
        if g:bufExplorerSplitOutPathName
            let type = (g:bufExplorerShowRelativePath) ? "relativepath" : "path"
            let row += [buf.shortname, buf[type]]
        else
            let type = (g:bufExplorerShowRelativePath) ? "relativename" : "homename"
            let row += [buf[type]]
        endif
        let row += [buf.line]
        call add(table, row)
    endfor

    let lines = s:MakeLines(table)
    call setline(s:firstBufferLine, lines)
    let firstMissingLine = s:firstBufferLine + len(lines)
    if line('$') >= firstMissingLine
        " Clear excess lines starting with `firstMissingLine`.
        execute "silent keepjumps ".firstMissingLine.',$d _'
    endif
    call s:SortListing()
endfunction

" MakeLines {{{2
function! s:MakeLines(table)
    if len(a:table) == 0
        return []
    endif
    let lines = []
    " To avoid trailing whitespace, do not pad the final column.
    let numColumnsToPad = len(a:table[0]) - 1
    let maxWidths = repeat([0], numColumnsToPad)
    for row in a:table
        let i = 0
        while i < numColumnsToPad
            let maxWidths[i] = max([maxWidths[i], s:StringWidth(row[i])])
            let i = i + 1
        endwhile
    endfor

    let pads = []
    for w in maxWidths
        call add(pads, repeat(' ', w))
    endfor

    for row in a:table
        let i = 0
        while i < numColumnsToPad
            let row[i] .= strpart(pads[i], s:StringWidth(row[i]))
            let i = i + 1
        endwhile
        call add(lines, join(row, ' '))
    endfor
    return lines
endfunction

" SelectBuffer {{{2
function! s:SelectBuffer(...)
    " Sometimes messages are not cleared when we get here so it looks like an
    " error has occurred when it really has not.
    "echo ""

    let _bufNbr = -1

    if (a:0 == 1) && (a:1 == "ask")
        " Ask the user for input.
        call inputsave()
        let cmd = input("Enter buffer number to switch to: ")
        call inputrestore()

        " Clear the message area from the previous prompt.
        redraw | echo

        if strlen(cmd) > 0
            let _bufNbr = str2nr(cmd)
        else
            call s:Error("Invalid buffer number, try again.")
            return
        endif
    else
        " Are we on a line with a file name?
        if line('.') < s:firstBufferLine
            execute "normal! \<CR>"
            return
        endif

        let _bufNbr = str2nr(getline('.'))

        " Check and see if we are running BufferExplorer via WinManager.
        if exists("b:displayMode") && b:displayMode == "winmanager"
            let _bufName = expand("#"._bufNbr.":p")

            if (a:0 == 1) && (a:1 == "tab")
                call WinManagerFileEdit(_bufName, 1)
            else
                call WinManagerFileEdit(_bufName, 0)
            endif

            return
        endif
    endif

    if bufexists(_bufNbr)
        " Get the tab number where this buffer is located in.
        let tabNbr = s:GetTabNbr(_bufNbr)
        if exists("g:bufExplorerChgWin") && g:bufExplorerChgWin <=winnr("$")
            execute g:bufExplorerChgWin."wincmd w"
            execute "keepjumps keepalt silent b!" _bufNbr

        " Are we supposed to open the selected buffer in a tab?
        elseif (a:0 == 1) && (a:1 == "tab")
            call s:Close()

            " Open a new tab with the selected buffer in it.
            if v:version > 704 || ( v:version == 704 && has('patch2237') )
                " new syntax for last tab as of 7.4.2237
                execute "$tab split +buffer" . _bufNbr
            else
                execute "999tab split +buffer" . _bufNbr
            endif
        " Are we supposed to open the selected buffer in a split?
        elseif (a:0 == 2) && (a:1 == "split")
            call s:Close()
            if (a:2 == "vl")
                execute "vert topleft sb "._bufNbr
            elseif (a:2 == "vr")
                execute "vert belowright sb "._bufNbr
            elseif (a:2 == "st")
                execute "topleft sb "._bufNbr
            else " = sb
                execute "belowright sb "._bufNbr
            endif
        else
            " Request to open in current (BufExplorer) window.
            if g:bufExplorerFindActive && tabNbr > 0
                " Close BufExplorer window and switch to existing tab/window.
                call s:Close()
                execute tabNbr . "tabnext"
                execute bufwinnr(_bufNbr) . "wincmd w"
            else
                " Use BufExplorer window for the buffer.
                execute "keepjumps keepalt silent b!" _bufNbr
            endif
        endif

        " Make the buffer 'listed' again.
        call setbufvar(_bufNbr, "&buflisted", "1")

        " Call any associated function references. g:bufExplorerFuncRef may be
        " an individual function reference or it may be a list containing
        " function references. It will ignore anything that's not a function
        " reference.
        "
        " See  :help FuncRef  for more on function references.
        if exists("g:BufExplorerFuncRef")
            if type(g:BufExplorerFuncRef) == 2
                keepj call g:BufExplorerFuncRef()
            elseif type(g:BufExplorerFuncRef) == 3
                for FncRef in g:BufExplorerFuncRef
                    if type(FncRef) == 2
                        keepj call FncRef()
                    endif
                endfor
            endif
        endif
    else
        call s:Error("Sorry, that buffer no longer exists, please select another")
        call s:DeleteBuffer(_bufNbr, "wipe")
    endif
endfunction

" RemoveBuffer {{{2
" Valid `mode` values:
" - "delete"
" - "force_delete"
" - "wipe"
" - "force_wipe"
function! s:RemoveBuffer(mode)
    " Are we on a line with a file name?
    if line('.') < s:firstBufferLine
        return
    endif

    let mode = a:mode
    let forced = mode =~# '^force_'

    " These commands are to temporarily suspend the activity of winmanager.
    if exists("b:displayMode") && b:displayMode == "winmanager"
        call WinManagerSuspendAUs()
    end

    let bufNbr = str2nr(getline('.'))
    let buf = s:raw_buffer_listing[bufNbr]

    if !forced && (buf.isterminal || getbufvar(bufNbr, '&modified'))
        if buf.isterminal
            let msg = "Buffer " . bufNbr . " is a terminal"
        else
            let msg = "No write since last change for buffer " . bufNbr
        endif
        " Calling confirm() requires Vim built with dialog option.
        if !has("dialog_con") && !has("dialog_gui")
            call s:Error(msg . "; cannot remove without 'force'")
            return
        endif

        let answer = confirm(msg . "; Remove anyway?", "&Yes\n&No", 2)

        if answer == 1
            let mode = 'force_' . mode
        else
            return
        endif

    endif

    " Okay, everything is good, delete or wipe the buffer.
    call s:DeleteBuffer(bufNbr, mode)

    " Reactivate winmanager autocommand activity.
    if exists("b:displayMode") && b:displayMode == "winmanager"
        call WinManagerForceReSize("BufExplorer")
        call WinManagerResumeAUs()
    end
endfunction

" DeleteBuffer {{{2
" Valid `mode` values:
" - "delete"
" - "force_delete"
" - "wipe"
" - "force_wipe"
function! s:DeleteBuffer(bufNbr, mode)
    " This routine assumes that the buffer to be removed is on the current line.
    if a:mode =~# 'delete$' && bufexists(a:bufNbr) && !buflisted(a:bufNbr)
        call s:Error('Buffer ' . a:bufNbr
                \ . ' is unlisted; must `wipe` to remove')
        return
    endif
    try
        " Wipe/Delete buffer from Vim.
        if a:mode == "wipe"
            execute "silent bwipe" a:bufNbr
        elseif a:mode == "force_wipe"
            execute "silent bwipe!" a:bufNbr
        elseif a:mode == "force_delete"
            execute "silent bdelete!" a:bufNbr
        else
            execute "silent bdelete" a:bufNbr
        endif
    catch
        call s:Error(v:exception)
    endtry

    if bufexists(a:bufNbr)
        " Buffer is still present.  We may have failed to wipe it, or it may
        " have changed attributes (as `:bd` only makes a buffer unlisted).
        " Regather information on this buffer, update the buffer list, and
        " redisplay.
        let info = s:GetBufferInfo(a:bufNbr)
        let s:raw_buffer_listing[a:bufNbr] = info[a:bufNbr]
        call s:RedisplayBufferList()
    else
        " Delete the buffer from the list on screen.
        setlocal modifiable
        normal! "_dd
        setlocal nomodifiable

        " Delete the buffer from the raw buffer list.
        unlet s:raw_buffer_listing[a:bufNbr]
    endif
endfunction

" Close {{{2
function! s:Close()
    " Get only the listed buffers associated with the current tab (up to 2).
    let listed = s:MRUListedBuffersForTab(s:tabIdAtLaunch, 2)

    " If we needed to split the main window, close the split one.
    if s:didSplit
        execute "wincmd c"
    endif

    " Check to see if there are anymore buffers listed.
    if len(listed) == 0
        " Since there are no buffers left to switch to, open a new empty
        " buffers.
        execute "enew"
    else
        " Since there are buffers left to switch to, switch to the previous and
        " then the current.
        for b in reverse(listed[0:1])
            execute "keepjumps silent b ".b
        endfor
    endif

    " Clear any messages.
    echo
endfunction

" ToggleShowTerminal {{{2
function! s:ToggleShowTerminal()
    let g:bufExplorerShowTerminal = !g:bufExplorerShowTerminal
    call s:RedisplayBufferList()
endfunction

" ToggleSplitOutPathName {{{2
function! s:ToggleSplitOutPathName()
    let g:bufExplorerSplitOutPathName = !g:bufExplorerSplitOutPathName
    call s:RedisplayBufferList()
endfunction

" ToggleShowRelativePath {{{2
function! s:ToggleShowRelativePath()
    let g:bufExplorerShowRelativePath = !g:bufExplorerShowRelativePath
    call s:RedisplayBufferList()
endfunction

" ToggleShowTabBuffer {{{2
function! s:ToggleShowTabBuffer()
    " Forget any cached MRU ordering, as it depends on
    " `g:bufExplorerShowTabBuffer`.
    unlet! s:mruOrder
    let g:bufExplorerShowTabBuffer = !g:bufExplorerShowTabBuffer
    call s:RedisplayBufferList()
endfunction

" ToggleOnlyOneTab {{{2
function! s:ToggleOnlyOneTab()
    let g:bufExplorerOnlyOneTab = !g:bufExplorerOnlyOneTab
    call s:RedisplayBufferList()
endfunction

" ToggleShowUnlisted {{{2
function! s:ToggleShowUnlisted()
    let g:bufExplorerShowUnlisted = !g:bufExplorerShowUnlisted
    call s:RedisplayBufferList()
endfunction

" ToggleFindActive {{{2
function! s:ToggleFindActive()
    let g:bufExplorerFindActive = !g:bufExplorerFindActive
    call s:UpdateHelpStatus()
endfunction

" RebuildBufferList {{{2
function! s:RebuildBufferList()
    setlocal modifiable

    let curPos = getpos('.')

    let num_bufs = s:BuildBufferList()

    call setpos('.', curPos)

    setlocal nomodifiable

    return num_bufs
endfunction

" UpdateHelpStatus {{{2
function! s:UpdateHelpStatus()
    setlocal modifiable

    let text = s:GetHelpStatus()
    call setline(s:firstBufferLine - 2, text)

    setlocal nomodifiable
endfunction

" Key_number {{{2
function! s:Key_number(line)
    let _bufnr = str2nr(a:line)
    let key = [printf('%9d', _bufnr)]
    return key
endfunction

" Key_name {{{2
function! s:Key_name(line)
    let _bufnr = str2nr(a:line)
    let buf = s:raw_buffer_listing[_bufnr]
    let key = [buf.shortname, buf.fullname]
    return key
endfunction

" Key_fullpath {{{2
function! s:Key_fullpath(line)
    let _bufnr = str2nr(a:line)
    let buf = s:raw_buffer_listing[_bufnr]
    let key = [buf.fullname]
    return key
endfunction

" Key_extension {{{2
function! s:Key_extension(line)
    let _bufnr = str2nr(a:line)
    let buf = s:raw_buffer_listing[_bufnr]
    let extension = fnamemodify(buf.shortname, ':e')
    let key = [extension, buf.shortname, buf.fullname]
    return key
endfunction

" Key_mru {{{2
function! s:Key_mru(line)
    let _bufnr = str2nr(a:line)
    let buf = s:raw_buffer_listing[_bufnr]
    let pos = s:MRUOrderForBuf(_bufnr)
    return [printf('%9d', pos), buf.fullname]
endfunction

" SortByKeyFunc {{{2
function! s:SortByKeyFunc(keyFunc)
    let keyedLines = []
    for line in getline(s:firstBufferLine, "$")
        let key = eval(a:keyFunc . '(line)')
        call add(keyedLines, join(key + [line], "\1"))
    endfor

    " Ignore case when sorting by passing `1`:
    call sort(keyedLines, 1)

    if g:bufExplorerReverseSort
        call reverse(keyedLines)
    endif

    let lines = []
    for keyedLine in keyedLines
        call add(lines, split(keyedLine, "\1")[-1])
    endfor

    call setline(s:firstBufferLine, lines)
endfunction

" SortReverse {{{2
function! s:SortReverse()
    let g:bufExplorerReverseSort = !g:bufExplorerReverseSort
    call s:ReSortListing()
endfunction

" SortSelect {{{2
function! s:SortSelect()
    let g:bufExplorerSortBy = get(s:sort_by, index(s:sort_by, g:bufExplorerSortBy) + 1, s:sort_by[0])
    call s:ReSortListing()
endfunction

" ReverseSortSelect {{{2
function! s:ReverseSortSelect()
    let g:bufExplorerSortBy = get(s:sort_by, index(s:sort_by, g:bufExplorerSortBy) - 1, s:sort_by[-1])
    call s:ReSortListing()
endfunction

" ReSortListing {{{2
function! s:ReSortListing()
    setlocal modifiable

    let curPos = getpos('.')

    call s:SortListing()
    call s:UpdateHelpStatus()

    call setpos('.', curPos)

    setlocal nomodifiable
endfunction

" SortListing {{{2
function! s:SortListing()
    call s:SortByKeyFunc("<SID>Key_" . g:bufExplorerSortBy)
endfunction

" Error {{{2
" Display a message using ErrorMsg highlight group.
function! s:Error(msg)
    echohl ErrorMsg
    echomsg a:msg
    echohl None
endfunction

" Warning {{{2
" Display a message using WarningMsg highlight group.
function! s:Warning(msg)
    echohl WarningMsg
    echomsg a:msg
    echohl None
endfunction

" GetTabNbr {{{2
function! s:GetTabNbr(bufNbr)
    " Prefer current tab.
    if bufwinnr(a:bufNbr) > 0
        return tabpagenr()
    endif
    " Searching buffer bufno, in tabs.
    for i in range(tabpagenr("$"))
        if index(tabpagebuflist(i + 1), a:bufNbr) != -1
            return i + 1
        endif
    endfor

    return 0
endfunction

" GetWinNbr" {{{2
function! s:GetWinNbr(tabNbr, bufNbr)
    " window number in tabpage.
    let tablist = tabpagebuflist(a:tabNbr)
    " Number:     0
    " String:     1
    " Funcref:    2
    " List:       3
    " Dictionary: 4
    " Float:      5
    if type(tablist) == 3
        return index(tabpagebuflist(a:tabNbr), a:bufNbr) + 1
    else
        return 1
    endif
endfunction

" StringWidth" {{{2
if exists('*strwidth')
    function s:StringWidth(s)
        return strwidth(a:s)
    endfunction
else
    function s:StringWidth(s)
        return len(a:s)
    endfunction
endif

" Winmanager Integration {{{2
let g:BufExplorer_title = "\[Buf\ List\]"
call s:Set("g:bufExplorerResize", 1)
call s:Set("g:bufExplorerMaxHeight", 25) " Handles dynamic resizing of the window.

" Evaluate a Vimscript expression in the context of this file.
" This enables debugging of script-local variables and functions from outside
" the plugin, e.g.:
"   :echo BufExplorer_eval('s:bufMru')
function! BufExplorer_eval(expr)
    return eval(a:expr)
endfunction

" Execute a Vimscript statement in the context of this file.
" This enables setting script-local variables from outside the plugin, e.g.:
"   :call BufExplorer_execute('let s:bufMru = s:MRUNew(0)')
function! BufExplorer_execute(statement)
    execute a:statement
endfunction

" function! to start display. Set the mode to 'winmanager' for this buffer.
" This is to figure out how this plugin was called. In a standalone fashion
" or by winmanager.
function! BufExplorer_Start()
    let b:displayMode = "winmanager"
    call s:SetLocalSettings()
    call BufExplorer()
endfunction

" Returns whether the display is okay or not.
function! BufExplorer_IsValid()
    return 0
endfunction

" Handles dynamic refreshing of the window.
function! BufExplorer_Refresh()
    let b:displayMode = "winmanager"
    call s:SetLocalSettings()
    call BufExplorer()
endfunction

function! BufExplorer_ReSize()
    if !g:bufExplorerResize
        return
    end

    let nlines = min([line("$"), g:bufExplorerMaxHeight])

    execute nlines." wincmd _"

    " The following lines restore the layout so that the last file line is also
    " the last window line. Sometimes, when a line is deleted, although the
    " window size is exactly equal to the number of lines in the file, some of
    " the lines are pushed up and we see some lagging '~'s.
    let pres = getpos(".")

    normal! $

    let _scr = &scrolloff
    let &scrolloff = 0

    normal! z-

    let &scrolloff = _scr

    call setpos(".", pres)
endfunction

" Default values {{{2
call s:Set("g:bufExplorerDisableDefaultKeyMapping", 0)  " Do not disable default key mappings.
call s:Set("g:bufExplorerDefaultHelp", 1)               " Show default help?
call s:Set("g:bufExplorerDetailedHelp", 0)              " Show detailed help?
call s:Set("g:bufExplorerFindActive", 1)                " When selecting an active buffer, take you to the window where it is active?
call s:Set("g:bufExplorerOnlyOneTab", 1)                " Show buffer only on MRU tab? (Applies when `g:bufExplorerShowTabBuffer` is true.)
call s:Set("g:bufExplorerReverseSort", 0)               " Sort in reverse order by default?
call s:Set("g:bufExplorerShowDirectories", 1)           " (Dir's are added by commands like ':e .')
call s:Set("g:bufExplorerShowRelativePath", 0)          " Show listings with relative or absolute paths?
call s:Set("g:bufExplorerShowTabBuffer", 0)             " Show only buffer(s) for this tab?
call s:Set("g:bufExplorerShowUnlisted", 0)              " Show unlisted buffers?
call s:Set("g:bufExplorerShowNoName", 0)                " Show 'No Name' buffers?
call s:Set("g:bufExplorerSortBy", "mru")                " Sorting methods are in s:sort_by:
call s:Set("g:bufExplorerSplitBelow", &splitbelow)      " Should horizontal splits be below or above current window?
call s:Set("g:bufExplorerSplitOutPathName", 1)          " Split out path and file name?
call s:Set("g:bufExplorerSplitRight", &splitright)      " Should vertical splits be on the right or left of current window?
call s:Set("g:bufExplorerSplitVertSize", 0)             " Height for a vertical split. If <=0, default Vim size is used.
call s:Set("g:bufExplorerSplitHorzSize", 0)             " Height for a horizontal split. If <=0, default Vim size is used.
call s:Set("g:bufExplorerShowTerminal", 1)              " Show terminal buffers?

" Default key mapping {{{2
if !hasmapto('BufExplorer') && g:bufExplorerDisableDefaultKeyMapping == 0
    nnoremap <script> <silent> <unique> <Leader>be :BufExplorer<CR>
endif

if !hasmapto('ToggleBufExplorer') && g:bufExplorerDisableDefaultKeyMapping == 0
    nnoremap <script> <silent> <unique> <Leader>bt :ToggleBufExplorer<CR>
endif

if !hasmapto('BufExplorerHorizontalSplit') && g:bufExplorerDisableDefaultKeyMapping == 0
    nnoremap <script> <silent> <unique> <Leader>bs :BufExplorerHorizontalSplit<CR>
endif

if !hasmapto('BufExplorerVerticalSplit') && g:bufExplorerDisableDefaultKeyMapping == 0
    nnoremap <script> <silent> <unique> <Leader>bv :BufExplorerVerticalSplit<CR>
endif

" vim:ft=vim foldmethod=marker sw=4