Make the behavior of window splits consistent (#1035)

* add option to spawn split from previous window

* Update some comments and remove debugging statement.

* Simplify the code, and make it respect NERDTreeWinPos and 'splitbelow'.

* Better logic for getting NERDTree window number when not active window.

* Use common functions for splitting windows. Make splitting respect user.

The placement of split windows now respects the user's choices for the
splitright and splitbelow settings, and the g:NERDTreeWinPos variable.

* Update version number in change log.

CHANGELOG.md

@@ -1,5 +1,7 @@
 # Change Log
 
+#### 6.0...
+- **.0**: Make the behavior of window splits consistent [#1035](https://github.com/scrooloose/nerdtree/pull/1035)
 #### 5.3...
 - **.3**: Fix (p)ath not displaying in the minimal menu [#1038](https://github.com/scrooloose/nerdtree/pull/1038)
 - **.2**: Enable events when closing NerdTree window. [#1037](https://github.com/scrooloose/nerdtree/pull/1037)

autoload/nerdtree.vim

@@ -4,6 +4,11 @@ endif
 let g:loaded_nerdtree_autoload = 1
 
 let s:rootNERDTreePath = resolve(expand("<sfile>:p:h:h"))
+
+"FUNCTION: nerdtree#version(...) {{{1
+"  If any value is given as an argument, the entire line of text from the
+"  change log is shown for the current version; otherwise, only the version
+"  number is shown.
 function! nerdtree#version(...)
     let l:changelog = readfile(join([s:rootNERDTreePath, "CHANGELOG.md"], nerdtree#slash()))
     let l:text = 'Unknown'
@@ -22,6 +27,7 @@ endfunction
 " SECTION: General Functions {{{1
 "============================================================
 
+"FUNCTION: nerdtree#slash() {{{2
 function! nerdtree#slash()
 
     if nerdtree#runningWindows()
@@ -49,7 +55,6 @@ function! nerdtree#and(x,y)
             if (l:x % 2) && (l:y % 2)
                 let l:result += float2nr(pow(2, l:n))
             endif
-            echomsg l:x . ", " . l:y . " => " l:result
             let l:x = float2nr(l:x / 2)
             let l:y = float2nr(l:y / 2)
             let l:n += 1

lib/nerdtree/nerdtree.vim

@@ -148,12 +148,19 @@ function! s:NERDTree.GetWinNum()
         return bufwinnr(t:NERDTreeBufName)
     endif
 
+    " If WindowTree, there is no t:NERDTreeBufName variable. Search all windows.
+    for w in range(1,winnr('$'))
+        if bufname(winbufnr(w)) =~# '^' . g:NERDTreeCreator.BufNamePrefix() . '\d\+$'
+            return w
+        endif
+    endfor
+
     return -1
 endfunction
 
 "FUNCTION: s:NERDTree.IsOpen() {{{1
 function! s:NERDTree.IsOpen()
-    return s:NERDTree.GetWinNum() != -1 || bufname('%') =~# '^' . g:NERDTreeCreator.BufNamePrefix() . '\d\+$'
+    return s:NERDTree.GetWinNum() != -1
 endfunction
 
 "FUNCTION: s:NERDTree.isTabTree() {{{1

lib/nerdtree/opener.vim

@@ -71,9 +71,9 @@ endfunction
 function! s:Opener._gotoTargetWin()
     if b:NERDTree.isWinTree()
         if self._where == 'v'
-            vsplit
+            call self._newVSplit()
         elseif self._where == 'h'
-            split
+            call self._newSplit()
         elseif self._where == 't'
             tabnew
         endif
@@ -153,44 +153,17 @@ endfunction
 
 " FUNCTION: Opener._newSplit() {{{1
 function! s:Opener._newSplit()
-    " 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 nerdtree#exec(back, 1)
-
     let onlyOneWin = (winnr("$") ==# 1)
-
+    let savesplitright = &splitright
-    " If no adjacent window, set splitright and splitbelow appropriately
     if onlyOneWin
-        let &splitright=right
+        let &splitright = (g:NERDTreeWinPos ==# "left")
-        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 ")
+        call nerdtree#exec('wincmd p', 1)
+        " If only one window (ie. NERDTree), split vertically instead.
+        call nerdtree#exec(onlyOneWin ? "vertical split" : "split",1)
     catch /^Vim\%((\a\+)\)\=:E37/
         call g:NERDTree.CursorToTreeWin()
         throw "NERDTree.FileAlreadyOpenAndModifiedError: ". self._path.str() ." is already open and modified."
@@ -200,14 +173,12 @@ function! s:Opener._newSplit()
 
     "resize the tree window if no other window was open before
     if onlyOneWin
-        let size = exists("b:NERDTreeOldWindowSize") ? b:NERDTreeOldWindowSize : g:NERDTreeWinSize
+        let size = exists('b:NERDTreeOldWindowSize') ? b:NERDTreeOldWindowSize : g:NERDTreeWinSize
-        call nerdtree#exec(there, 1)
+        call nerdtree#exec('wincmd p', 1)
-        exec("silent ". splitMode ." resize ". size)
+        call nerdtree#exec('silent '. splitMode .' resize '. size, 1)
         call nerdtree#exec('wincmd p', 0)
     endif
 
-    " Restore splitmode settings
-    let &splitbelow=savesplitbelow
     let &splitright=savesplitright
 endfunction
 
@@ -215,7 +186,10 @@ endfunction
 function! s:Opener._newVSplit()
     let l:winwidth = winwidth('.')
 
-    if winnr('$') == 1
+    let onlyOneWin = (winnr("$") ==# 1)
+    let savesplitright = &splitright
+    if onlyOneWin
+        let &splitright = (g:NERDTreeWinPos ==# "left")
         let l:winwidth = g:NERDTreeWinSize
     endif
 
@@ -229,6 +203,7 @@ function! s:Opener._newVSplit()
     execute 'silent vertical resize ' . l:winwidth
 
     call nerdtree#exec(l:currentWindowNumber . 'wincmd w', 0)
+    let &splitright=savesplitright
 endfunction
 
 " FUNCTION: Opener.open(target) {{{1