Show file lines (#1384)

* Added showing lines of files in NERDTRee.

* Added dynamic binding and documentation

---------

Co-authored-by: Diallo Han <diallo@hpcnt.com>

README.markdown

@@ -188,6 +188,28 @@ let g:NERDTreeDirArrowCollapsible = '?'
 ```
 The preceding values are the non-Windows default arrow symbols. Setting these variables to empty strings will remove the arrows completely and shift the entire tree two character positions to the left. See `:h NERDTreeDirArrowExpandable` for more details.
 
+### How can I show lines of files?
+
+```vim
+let g:NERDTreeFileLines = 1
+```
+
+Lines in the file are displayed as shown below.
+```
+</pack/packer/start/nerdtree/
+▸ autoload/
+▸ doc/
+▸ lib/
+▸ nerdtree_plugin/
+▸ plugin/
+▸ syntax/
+  _config.yml (1)
+  CHANGELOG.md (307)
+  LICENCE (13)
+  README.markdown (234)
+  screenshot.png (219)
+```
+
 ### Can NERDTree access remote files via scp or ftp?
 
 Short answer: No, and there are no plans to add that functionality. However, Vim ships with a plugin that does just that. It's called netrw, and by adding the following lines to your `.vimrc`, you can use it to open files over the `scp:`, `ftp:`, or other protocols, while still using NERDTree for all local files. The function seamlessly makes the decision to open NERDTree or netrw, and other supported protocols can be added to the regular expression.

autoload/nerdtree/ui_glue.vim

@@ -57,6 +57,7 @@ function! nerdtree#ui_glue#createDefaultBindings() abort
     call NERDTreeAddKeyMap({ 'key': g:NERDTreeMapToggleFilters, 'scope': 'all', 'callback': s.'toggleIgnoreFilter' })
     call NERDTreeAddKeyMap({ 'key': g:NERDTreeMapToggleFiles, 'scope': 'all', 'callback': s.'toggleShowFiles' })
     call NERDTreeAddKeyMap({ 'key': g:NERDTreeMapToggleBookmarks, 'scope': 'all', 'callback': s.'toggleShowBookmarks' })
+    call NERDTreeAddKeyMap({ 'key': g:NERDTreeMapToggleFileLines, 'scope': 'all', 'callback': s.'toggleShowFileLines' })
 
     call NERDTreeAddKeyMap({ 'key': g:NERDTreeMapCloseDir, 'scope': 'Node', 'callback': s.'closeCurrentDir' })
     call NERDTreeAddKeyMap({ 'key': g:NERDTreeMapCloseChildren, 'scope': 'DirNode', 'callback': s.'closeChildren' })
@@ -685,6 +686,12 @@ function! s:toggleShowHidden() abort
     call b:NERDTree.ui.toggleShowHidden()
 endfunction
 
+" FUNCTION: s:toggleShowFileLines() {{{1
+" toggles the display of hidden files
+function! s:toggleShowFileLines() abort
+    call b:NERDTree.ui.toggleShowFileLines()
+endfunction
+
 " FUNCTION: s:toggleZoom() {{{1
 function! s:toggleZoom() abort
     call b:NERDTree.ui.toggleZoom()

doc/NERDTree.txt

@@ -287,6 +287,7 @@ I........Toggle whether hidden files displayed......................|NERDTree-I|
 f........Toggle whether the file filters are used...................|NERDTree-f|
 F........Toggle whether files are displayed.........................|NERDTree-F|
 B........Toggle whether the bookmark table is displayed.............|NERDTree-B|
+L........Toggle whether the bookmark table is displayed.............|NERDTree-L|
 
 q........Close the NERDTree window..................................|NERDTree-q|
 A........Zoom (maximize/minimize) the NERDTree window...............|NERDTree-A|
@@ -601,6 +602,14 @@ Applies to: no restrictions.
 
 Toggles whether the bookmarks table is displayed.
 
+------------------------------------------------------------------------------
+                                                                    *NERDTree-L*
+Default key: L
+Map setting: *NERDTreeMapToggleFileLiness*
+Applies to: no restrictions.
+
+Toggles whether the number of lines in files is displayed.
+
 ------------------------------------------------------------------------------
                                                                     *NERDTree-q*
 Default key: q
@@ -1063,6 +1072,20 @@ This setting can be toggled dynamically, per tree, with the |NERDTree-F|
 mapping and is useful for drastically shrinking the tree when you are
 navigating to a different part of the tree.
 
+------------------------------------------------------------------------------
+                                                        *NERDTreeShowFilesLines*
+Values: 0 or 1.
+Default: 0.
+
+If this setting is set to 1 then the NERDTree shows number of lines for each
+file.
+
+This setting can be toggled dynamically, per tree, with the |NERDTree-L|
+mapping.
+Use one of the follow lines for this setting: >
+    let NERDTreeShowFilesLines=0
+    let NERDTreeShowFilesLines=1
+<
 ------------------------------------------------------------------------------
                                                             *NERDTreeShowHidden*
 Values: 0 or 1.

lib/nerdtree/path.vim

@@ -65,6 +65,25 @@ function! s:Path.cacheDisplayString() abort
         let self.cachedDisplayString = self.addDelimiter(self.cachedDisplayString) . ' -> ' . self.symLinkDest
     endif
 
+    if !self.isDirectory && b:NERDTree.ui.getShowFileLines() != 0
+        let l:bufname = self.str({'format': 'Edit'})
+        let l:lines = 0
+        if executable('wc') 
+            let l:lines = split(system('wc -l "'.l:bufname.'"'))[0]
+        elseif nerdtree#runningWindows()
+            let l:lines = substitute(system('type "'.l:bufname.'" | find /c /v ""'), '\n', '', 'g')
+        else 
+            let s:lines = readfile(l:bufname)
+            let l:lines = 0
+            for s:line in s:lines
+                let l:lines += 1
+                if l:lines >= 20000 
+                    break
+                endif
+            endfor
+        endif
+        let self.cachedDisplayString = self.addDelimiter(self.cachedDisplayString) . ' ('.l:lines.')'
+    endif
     if self.isReadOnly
         let self.cachedDisplayString = self.addDelimiter(self.cachedDisplayString) . ' ['.g:NERDTreeGlyphReadOnly.']'
     endif

lib/nerdtree/ui.vim

@@ -103,6 +103,7 @@ function! s:UI._dumpHelp()
         let help .= '" '. g:NERDTreeMapToggleFilters .': file filters (' . (self.isIgnoreFilterEnabled() ? 'on' : 'off') . ")\n"
         let help .= '" '. g:NERDTreeMapToggleFiles .': files (' . (self.getShowFiles() ? 'on' : 'off') . ")\n"
         let help .= '" '. g:NERDTreeMapToggleBookmarks .': bookmarks (' . (self.getShowBookmarks() ? 'on' : 'off') . ")\n"
+        let help .= '" '. g:NERDTreeMapToggleFileLines .': files lines (' . (self.getShowFileLines() ? 'on' : 'off') . ")\n"
 
         " add quickhelp entries for each custom key map
         let help .= "\"\n\" ----------------------------\n"
@@ -147,6 +148,7 @@ function! s:UI.New(nerdtree)
     let newObj._showFiles = g:NERDTreeShowFiles
     let newObj._showHidden = g:NERDTreeShowHidden
     let newObj._showBookmarks = g:NERDTreeShowBookmarks
+    let newObj._showFileLines = g:NERDTreeFileLines
 
     return newObj
 endfunction
@@ -284,6 +286,11 @@ function! s:UI.getShowHidden()
     return self._showHidden
 endfunction
 
+" FUNCTION: s:UI.getShowFileLines() {{{1
+function! s:UI.getShowFileLines()
+    return self._showFileLines
+endfunction
+
 " FUNCTION: s:UI._indentLevelFor(line) {{{1
 function! s:UI._indentLevelFor(line)
     " Replace multi-character DirArrows with a single space so the
@@ -512,6 +519,15 @@ function! s:UI.toggleShowHidden()
     call self.centerView()
 endfunction
 
+" FUNCTION: s:UI.toggleShowFileLines() {{{1
+" toggles the display of file lines
+function! s:UI.toggleShowFileLines()
+    let self._showFileLines = !self._showFileLines
+    call self.nerdtree.root.refresh()
+    call self.renderViewSavingPosition()
+    call self.centerView()
+endfunction
+
 " FUNCTION: s:UI.toggleZoom() {{{1
 " zoom (maximize/minimize) the NERDTree window
 function! s:UI.toggleZoom()

plugin/NERD_tree.vim

@@ -53,6 +53,7 @@ let g:NERDTreeShowFiles             = get(g:, 'NERDTreeShowFiles',             1
 let g:NERDTreeShowHidden            = get(g:, 'NERDTreeShowHidden',            0)
 let g:NERDTreeShowLineNumbers       = get(g:, 'NERDTreeShowLineNumbers',       0)
 let g:NERDTreeSortDirs              = get(g:, 'NERDTreeSortDirs',              1)
+let g:NERDTreeFileLines             = get(g:, 'NERDTreeFileLines',             0)
 
 
 if !nerdtree#runningWindows() && !nerdtree#runningCygwin()
@@ -130,6 +131,7 @@ let g:NERDTreeMapToggleBookmarks = get(g:, 'NERDTreeMapToggleBookmarks', 'B')
 let g:NERDTreeMapToggleFiles     = get(g:, 'NERDTreeMapToggleFiles',     'F')
 let g:NERDTreeMapToggleFilters   = get(g:, 'NERDTreeMapToggleFilters',   'f')
 let g:NERDTreeMapToggleHidden    = get(g:, 'NERDTreeMapToggleHidden',    'I')
+let g:NERDTreeMapToggleFileLines = get(g:, 'NERDTreeMapToggleFileLines', 'L')
 let g:NERDTreeMapToggleZoom      = get(g:, 'NERDTreeMapToggleZoom',      'A')
 let g:NERDTreeMapUpdir           = get(g:, 'NERDTreeMapUpdir',           'u')
 let g:NERDTreeMapUpdirKeepOpen   = get(g:, 'NERDTreeMapUpdirKeepOpen',   'U')
@@ -144,6 +146,7 @@ call nerdtree#loadClassFiles()
 "============================================================
 call nerdtree#ui_glue#setupCommands()
 
+
 " SECTION: Auto commands {{{1
 "============================================================
 augroup NERDTree