Merge pull request #1693 from mrmr1993/current-tabs-visible-experiments

Rework tabline for tabs and buffers

autoload/airline/builder.vim

@@ -22,7 +22,19 @@ function! s:prototype.add_raw(text) dict
   call add(self._sections, ['', a:text])
 endfunction
 
-function! s:get_prev_group(sections, i)
+function! s:prototype.insert_section(group, contents, position) dict
+  call insert(self._sections, [a:group, a:contents], a:position)
+endfunction
+
+function! s:prototype.insert_raw(text, position) dict
+  call insert(self._sections, ['', a:text], a:position)
+endfunction
+
+function! s:prototype.get_position() dict
+  return len(self._sections)
+endfunction
+
+function! airline#builder#get_prev_group(sections, i)
   let x = a:i - 1
   while x >= 0
     let group = a:sections[x][0]
@@ -34,6 +46,19 @@ function! s:get_prev_group(sections, i)
   return ''
 endfunction
 
+function! airline#builder#get_next_group(sections, i)
+  let x = a:i + 1
+  let l = len(a:sections)
+  while x < l
+    let group = a:sections[x][0]
+    if group != '' && group != '|'
+      return group
+    endif
+    let x = x + 1
+  endwhile
+  return ''
+endfunction
+
 function! s:prototype.build() dict
   let side = 1
   let line = ''
@@ -48,7 +73,7 @@ function! s:prototype.build() dict
     let group = section[0]
     let contents = section[1]
     let pgroup = prev_group
-    let prev_group = s:get_prev_group(self._sections, i)
+    let prev_group = airline#builder#get_prev_group(self._sections, i)
     if group ==# 'airline_c' && &buftype ==# 'terminal' && self._context.active
       let group = 'airline_term'
     elseif group ==# 'airline_c' && !self._context.active && has_key(self._context, 'bufnr')
@@ -102,7 +127,7 @@ function! s:prototype.build() dict
   return line
 endfunction
 
-function! s:should_change_group(group1, group2)
+function! airline#builder#should_change_group(group1, group2)
   if a:group1 == a:group2
     return 0
   endif
@@ -132,7 +157,7 @@ function! s:get_transitioned_seperator(self, prev_group, group, side)
 endfunction
 
 function! s:get_seperator(self, prev_group, group, side)
-  if s:should_change_group(a:prev_group, a:group)
+  if airline#builder#should_change_group(a:prev_group, a:group)
     return s:get_transitioned_seperator(a:self, a:prev_group, a:group, a:side)
   else
     return a:side ? a:self._context.left_alt_sep : a:self._context.right_alt_sep

autoload/airline/extensions/tabline.vim

@@ -181,7 +181,7 @@ function! airline#extensions#tabline#new_builder()
     let builder_context.left_alt_sep = get(g:, 'airline#extensions#tabline#left_alt_sep' , '|')
   endif
 
-  return airline#builder#new(builder_context)
+  return airline#extensions#tabline#builder#new(builder_context)
 endfunction
 
 function! airline#extensions#tabline#group_of_bufnr(tab_bufs, bufnr)

autoload/airline/extensions/tabline/buffers.vim

@@ -52,7 +52,7 @@ function! airline#extensions#tabline#buffers#get()
     " no-op
   endtry
   let cur = bufnr('%')
-  if cur == s:current_bufnr
+  if cur == s:current_bufnr && &columns == s:column_width
     if !g:airline_detect_modified || getbufvar(cur, '&modified') == s:current_modified
       return s:current_tabline
     endif
@@ -69,24 +69,45 @@ function! airline#extensions#tabline#buffers#get()
   if show_buf_label_first
     call airline#extensions#tabline#add_label(b, 'buffers')
   endif
-  let pgroup = ''
+
-  for nr in s:get_visible_buffers()
+  let b.tab_bufs = tabpagebuflist(tabpagenr())
-    if nr < 0
+
-      call b.add_raw('%#airline_tabhid#...')
+  let b.overflow_group = 'airline_tabhid'
-      continue
+  let b.buffers = airline#extensions#tabline#buflist#list()
+  if get(g:, 'airline#extensions#tabline#current_first', 0)
+    if index(b.buffers, cur) > -1
+      call remove(b.buffers, index(b.buffers, cur))
     endif
+    let b.buffers = [cur] + b.buffers
+  endif
 
-    let group = airline#extensions#tabline#group_of_bufnr(tab_bufs, nr)
+  function! b.get_group(i) dict
-
+    let bufnum = get(self.buffers, a:i, -1)
-    if nr == cur
+    if bufnum == -1
+      return ''
+    endif
+    let group = airline#extensions#tabline#group_of_bufnr(self.tab_bufs, bufnum)
+    if bufnum == bufnr('%')
       let s:current_modified = (group == 'airline_tabmod') ? 1 : 0
     endif
+    return group
+  endfunction
 
-    " Neovim feature: Have clickable buffers
+  if has("tablineat")
-    if has("tablineat")
+    function! b.get_pretitle(i) dict
-      call b.add_raw('%'.nr.'@airline#extensions#tabline#buffers#clickbuf@')
+      let bufnum = get(self.buffers, a:i, -1)
-    endif
+      return '%'.bufnum.'@airline#extensions#tabline#buffers#clickbuf@'
+    endfunction
 
+    function b.get_posttitle(i) dict
+      return '%X'
+    endfunction
+  endif
+
+  function! b.get_title(i) dict
+    let bufnum = get(self.buffers, a:i, -1)
+    let group = self.get_group(a:i)
+    let pgroup = self.get_group(a:i - 1)
     if get(g:, 'airline_powerline_fonts', 0)
       let space = s:spc
     else
@@ -95,20 +116,18 @@ function! airline#extensions#tabline#buffers#get()
 
     if get(g:, 'airline#extensions#tabline#buffer_idx_mode', 0)
       if len(s:number_map) > 0
-        call b.add_section(group, space. get(s:number_map, index, '') . '%(%{airline#extensions#tabline#get_buffer_name('.nr.')}%)' . s:spc)
+        return space. get(s:number_map, a:i, '') . '%(%{airline#extensions#tabline#get_buffer_name('.bufnum.')}%)' . s:spc
       else
-        call b.add_section(group, '['.index.s:spc.'%(%{airline#extensions#tabline#get_buffer_name('.nr.')}%)'.']')
+        return '['.a:i.s:spc.'%(%{airline#extensions#tabline#get_buffer_name('.bufnum.')}%)'.']'
       endif
-      let index += 1
     else
-      call b.add_section(group, space.'%(%{airline#extensions#tabline#get_buffer_name('.nr.')}%)'.s:spc)
+      return space.'%(%{airline#extensions#tabline#get_buffer_name('.bufnum.')}%)'.s:spc
     endif
+  endfunction
 
-    if has("tablineat")
+  let current_buffer = max([index(b.buffers, cur), 0])
-      call b.add_raw('%X')
+  let last_buffer = len(b.buffers) - 1
-    endif
+  call b.insert_titles(current_buffer, 0, last_buffer)
-    let pgroup=group
-  endfor
 
   call b.add_section('airline_tabfill', '')
   call b.split()
@@ -122,69 +141,18 @@ function! airline#extensions#tabline#buffers#get()
   endif
 
   let s:current_bufnr = cur
+  let s:column_width = &columns
   let s:current_tabline = b.build()
+  let s:current_visible_buffers = copy(b.buffers)
+  if b._right_title <= last_buffer
+    call remove(s:current_visible_buffers, b._right_title, last_buffer)
+  endif
+  if b._left_title > 0
+    call remove(s:current_visible_buffers, 0, b._left_title)
+  endif
   return s:current_tabline
 endfunction
 
-function! s:get_visible_buffers()
-  let buffers = airline#extensions#tabline#buflist#list()
-  let cur = bufnr('%')
-  if get(g:, 'airline#extensions#tabline#current_first', 0)
-    if index(buffers, cur) > -1
-      call remove(buffers, index(buffers, cur))
-    endif
-    let buffers = [cur] + buffers
-  endif
-
-  let total_width = 0
-  let max_width = 0
-
-  for nr in buffers
-    let width = len(airline#extensions#tabline#get_buffer_name(nr)) + 4
-    let total_width += width
-    let max_width = max([max_width, width])
-  endfor
-
-  " only show current and surrounding buffers if there are too many buffers
-  let position  = index(buffers, cur)
-  let vimwidth = &columns
-  if total_width > vimwidth && position > -1
-    let buf_count = len(buffers)
-
-    " determine how many buffers to show based on the longest buffer width,
-    " use one on the right side and put the rest on the left
-    let buf_max   = vimwidth / max_width
-    let buf_right = 1
-    let buf_left  = max([0, buf_max - buf_right])
-
-    let start = max([0, position - buf_left])
-    let end   = min([buf_count, position + buf_right])
-
-    " fill up available space on the right
-    if position < buf_left
-      let end += (buf_left - position)
-    endif
-
-    " fill up available space on the left
-    if end > buf_count - 1 - buf_right
-      let start -= max([0, buf_right - (buf_count - 1 - position)])
-    endif
-
-    let buffers = eval('buffers[' . start . ':' . end . ']')
-
-    if start > 0
-      call insert(buffers, -1, 0)
-    endif
-
-    if end < buf_count - 1
-      call add(buffers, -1)
-    endif
-  endif
-
-  let s:current_visible_buffers = buffers
-  return buffers
-endfunction
-
 function! s:select_tab(buf_index)
   " no-op when called in 'keymap_ignored_filetypes'
   if count(get(g:, 'airline#extensions#tabline#keymap_ignored_filetypes', 

autoload/airline/extensions/tabline/builder.vim

@@ -0,0 +1,232 @@
+" MIT License. Copyright (c) 2013-2018 Bailey Ling et al.
+" vim: et ts=2 sts=2 sw=2
+
+scriptencoding utf-8
+
+let s:prototype = {}
+
+" Set the point in the tabline where the builder should insert the titles.
+"
+" Subsequent calls will overwrite the previous ones, so only the last call
+" determines to location to insert titles.
+"
+" NOTE: The titles are not inserted until |build| is called, so that the
+" remaining contents of the tabline can be taken into account.
+"
+" Callers should define at least |get_title| and |get_group| on the host
+" object before calling |build|.
+function! s:prototype.insert_titles(current, first, last) dict
+  let self._first_title = a:first " lowest index
+  let self._last_title = a:last " highest index
+  let self._left_title = a:current " next index to add on the left
+  let self._right_title = a:current + 1 " next index to add on the right
+  let self._left_position = self.get_position() " left end of titles
+  let self._right_position = self._left_position " right end of the titles
+endfunction
+
+" Insert a title for entry number |index|, of group |group| at position |pos|,
+" if there is space for it. Returns 1 if it is inserted, 0 otherwise
+"
+" |force| inserts the title even if there isn't enough space left for it.
+" |sep_size| adjusts the size change that the title is considered to take up,
+"            to account for changes to the separators
+"
+" The title is defined by |get_title| on the hosting object, called with
+" |index| as its only argument.
+" |get_pretitle| and |get_posttitle| may be defined on the host object to
+" insert some formatting before or after the title. These should be 0-width.
+"
+" This method updates |_right_position| and |_remaining_space| on the host
+" object, if the title is inserted.
+function! s:prototype.try_insert_title(index, group, pos, sep_size, force) dict
+  let title = self.get_title(a:index)
+  let title_size = s:tabline_evaluated_length(title) + a:sep_size
+  if a:force || self._remaining_space >= title_size
+    let pos = a:pos
+    if has_key(self, "get_pretitle")
+      call self.insert_raw(self.get_pretitle(a:index), pos)
+      let self._right_position += 1
+      let pos += 1
+    endif
+
+    call self.insert_section(a:group, title, pos)
+    let self._right_position += 1
+    let pos += 1
+
+    if has_key(self, "get_posttitle")
+      call self.insert_raw(self.get_posttitle(a:index), pos)
+      let self._right_position += 1
+      let pos += 1
+    endif
+
+    let self._remaining_space -= title_size
+    return 1
+  endif
+  return 0
+endfunction
+
+function! s:get_separator_change(new_group, old_group, end_group, sep_size, alt_sep_size)
+  return s:get_separator_change_with_end(a:new_group, a:old_group, a:end_group, a:end_group, a:sep_size, a:alt_sep_size)
+endfunction
+
+" Compute the change in size of the tabline caused by separators
+"
+" This should be kept up-to-date with |s:get_transitioned_seperator| and
+" |s:get_separator| in autoload/airline/builder.vim
+function! s:get_separator_change_with_end(new_group, old_group, new_end_group, old_end_group, sep_size, alt_sep_size)
+  let sep_change = 0
+  if !empty(a:new_end_group) " Separator between title and the end
+    let sep_change += airline#builder#should_change_group(a:new_group, a:new_end_group) ? a:sep_size : a:alt_sep_size
+  endif
+  if !empty(a:old_group) " Separator between the title and the one adjacent
+    let sep_change += airline#builder#should_change_group(a:new_group, a:old_group) ? a:sep_size : a:alt_sep_size
+    if !empty(a:old_end_group) " Remove mis-predicted separator
+      let sep_change -= airline#builder#should_change_group(a:old_group, a:old_end_group) ? a:sep_size : a:alt_sep_size
+    endif
+  endif
+  return sep_change
+endfunction
+
+" This replaces the build function of the |airline#builder#new| object, to
+" insert titles as specified by the last call to |insert_titles| before
+" passing to the original build function.
+"
+" Callers should define at least |get_title| and |get_group| on the host
+" object if |insert_titles| has been called on it.
+function! s:prototype.build() dict
+  if has_key(self, '_left_position') && self._first_title <= self._last_title
+    let self._remaining_space = &columns - s:tabline_evaluated_length(self._build())
+
+    let center_active = get(g:, 'airline#extensions#tabline#center_active', 0)
+
+    let sep_size = s:tabline_evaluated_length(self._context.left_sep)
+    let alt_sep_size = s:tabline_evaluated_length(self._context.left_alt_sep)
+
+    let outer_left_group = airline#builder#get_prev_group(self._sections, self._left_position)
+    let outer_right_group = airline#builder#get_next_group(self._sections, self._right_position)
+
+    let overflow_marker = get(g:, 'airline#extensions#tabline#overflow_marker', g:airline_symbols.ellipsis)
+    let overflow_marker_size = s:tabline_evaluated_length(overflow_marker)
+    " Allow space for the markers before we begin filling in titles.
+    if self._left_title > self._first_title
+      let self._remaining_space -= overflow_marker_size +
+        \ s:get_separator_change(self.overflow_group, "", outer_left_group, sep_size, alt_sep_size)
+    endif
+    if self._left_title < self._last_title
+      let self._remaining_space -= overflow_marker_size +
+        \ s:get_separator_change(self.overflow_group, "", outer_right_group, sep_size, alt_sep_size)
+    endif
+
+    " Add the current title
+    let group = self.get_group(self._left_title)
+    if self._left_title == self._first_title
+      let sep_change = s:get_separator_change(group, "", outer_left_group, sep_size, alt_sep_size)
+    else
+      let sep_change = s:get_separator_change(group, "", self.overflow_group, sep_size, alt_sep_size)
+    endif
+    if self._left_title == self._last_title
+      let sep_change += s:get_separator_change(group, "", outer_right_group, sep_size, alt_sep_size)
+    else
+      let sep_change += s:get_separator_change(group, "", self.overflow_group, sep_size, alt_sep_size)
+    endif
+    let left_group = group
+    let right_group = group
+    let self._left_title -=
+      \ self.try_insert_title(self._left_title, group, self._left_position, sep_change, 1)
+
+    if get(g:, 'airline#extensions#tabline#current_first', 0)
+      " always have current title first
+      let self._left_position += 1
+    endif
+
+    if !center_active && self._right_title <= self._last_title
+      " Add the title to the right
+      let group = self.get_group(self._right_title)
+      if self._right_title == self._last_title
+        let sep_change = s:get_separator_change_with_end(group, right_group, outer_right_group, self.overflow_group, sep_size, alt_sep_size) - overflow_marker_size
+      else
+        let sep_change = s:get_separator_change(group, right_group, self.overflow_group, sep_size, alt_sep_size)
+      endif
+      let right_group = group
+      let self._right_title +=
+      \ self.try_insert_title(self._right_title, group, self._right_position, sep_change, 1)
+    endif
+
+    while self._remaining_space > 0
+      let done = 0
+      if self._left_title >= self._first_title
+        " Insert next title to the left
+        let group = self.get_group(self._left_title)
+        if self._left_title == self._first_title
+          let sep_change = s:get_separator_change_with_end(group, left_group, outer_left_group, self.overflow_group, sep_size, alt_sep_size) - overflow_marker_size
+        else
+          let sep_change = s:get_separator_change(group, left_group, self.overflow_group, sep_size, alt_sep_size)
+        endif
+        let left_group = group
+        let done = self.try_insert_title(self._left_title, group, self._left_position, sep_change, 0)
+        let self._left_title -= done
+      endif
+      " If center_active is set, this |if| operates as an independent |if|,
+      " otherwise as an |elif|.
+      if self._right_title <= self._last_title && (center_active || !done)
+        " Insert next title to the right
+        let group = self.get_group(self._right_title)
+        if self._right_title == self._last_title
+          let sep_change = s:get_separator_change_with_end(group, right_group, outer_right_group, self.overflow_group, sep_size, alt_sep_size) - overflow_marker_size
+        else
+          let sep_change = s:get_separator_change(group, right_group, self.overflow_group, sep_size, alt_sep_size)
+        endif
+        let right_group = group
+        let done = self.try_insert_title(self._right_title, group, self._right_position, sep_change, 0)
+        let self._right_title += done
+      endif
+      if !done
+        break
+      endif
+    endwhile
+
+    if self._left_title >= self._first_title
+      if get(g:, 'airline#extensions#tabline#current_first', 0)
+        let self._left_position -= 1
+      endif
+      call self.insert_section(self.overflow_group, overflow_marker, self._left_position)
+      let self._right_position += 1
+    endif
+
+    if self._right_title <= self._last_title
+      call self.insert_section(self.overflow_group, overflow_marker, self._right_position)
+    endif
+  endif
+
+  return self._build()
+endfunction
+
+let s:prototype.overflow_group = 'airline_tab'
+
+" Extract the text content a tabline will render. (Incomplete).
+"
+" See :help 'statusline' for the list of fields.
+function! s:evaluate_tabline(tabline)
+  let tabline = a:tabline
+  let tabline = substitute(tabline, '%{\([^}]\+\)}', '\=eval(submatch(1))', 'g')
+  let tabline = substitute(tabline, '%#[^#]\+#', '', 'g')
+  let tabline = substitute(tabline, '%(\([^)]\+\)%)', '\1', 'g')
+  let tabline = substitute(tabline, '%\d\+[TX]', '', 'g')
+  let tabline = substitute(tabline, '%=', '', 'g')
+  let tabline = substitute(tabline, '%\d*\*', '', 'g')
+  if has('tablineat')
+    let tabline = substitute(tabline, '%@[^@]\+@', '', 'g')
+  endif
+  return tabline
+endfunction
+
+function! s:tabline_evaluated_length(tabline)
+  return airline#util#strchars(s:evaluate_tabline(a:tabline))
+endfunction
+
+function! airline#extensions#tabline#builder#new(context)
+  let builder = airline#builder#new(a:context)
+  let builder._build = builder.build
+  call extend(builder, s:prototype, 'force')
+  return builder
+endfunction

autoload/airline/extensions/tabline/tabs.vim

@@ -33,45 +33,45 @@ function! airline#extensions#tabline#tabs#get()
   catch
     " no-op
   endtry
-  if curbuf == s:current_bufnr && curtab == s:current_tabnr
+  if curbuf == s:current_bufnr && curtab == s:current_tabnr && &columns == s:column_width
     if !g:airline_detect_modified || getbufvar(curbuf, '&modified') == s:current_modified
       return s:current_tabline
     endif
   endif
 
-  let tab_nr_type = get(g:, 'airline#extensions#tabline#tab_nr_type', 0)
   let b = airline#extensions#tabline#new_builder()
 
   call airline#extensions#tabline#add_label(b, 'tabs')
-  " always have current tabpage first
+
-  let tablist = range(1, tabpagenr('$'))
+  function! b.get_group(i) dict
-  if get(g:, 'airline#extensions#tabline#current_first', 0)
+    let curtab = tabpagenr()
-    if index(tablist, curtab) > -1
+    let group = 'airline_tab'
-      call remove(tablist, index(tablist, curtab))
+    if a:i == curtab
-    endif
-    let tablist = [curtab] + tablist
-  endif
-  for i in tablist
-    if i == curtab
       let group = 'airline_tabsel'
       if g:airline_detect_modified
-        for bi in tabpagebuflist(i)
+        for bi in tabpagebuflist(curtab)
           if getbufvar(bi, '&modified')
             let group = 'airline_tabmod'
           endif
         endfor
       endif
       let s:current_modified = (group == 'airline_tabmod') ? 1 : 0
-    else
-      let group = 'airline_tab'
     endif
+    return group
+  endfunction
+
+  function! b.get_title(i) dict
     let val = '%('
 
     if get(g:, 'airline#extensions#tabline#show_tab_nr', 1)
-      let val .= airline#extensions#tabline#tabs#tabnr_formatter(tab_nr_type, i)
+      let tab_nr_type = get(g:, 'airline#extensions#tabline#tab_nr_type', 0)
+      let val .= airline#extensions#tabline#tabs#tabnr_formatter(tab_nr_type, a:i)
     endif
-    call b.add_section(group, val.'%'.i.'T %{airline#extensions#tabline#title('.i.')} %)')
+
-  endfor
+    return val.'%'.a:i.'T %{airline#extensions#tabline#title('.a:i.')} %)'
+  endfunction
+
+  call b.insert_titles(curtab, 1, tabpagenr('$'))
 
   call b.add_section('airline_tabfill', '')
   call b.split()
@@ -95,6 +95,7 @@ function! airline#extensions#tabline#tabs#get()
 
   let s:current_bufnr = curbuf
   let s:current_tabnr = curtab
+  let s:column_width = &columns
   let s:current_tabline = b.build()
   return s:current_tabline
 endfunction

autoload/airline/init.vim

@@ -70,7 +70,8 @@ function! airline#init#bootstrap()
           \ 'spell': 'SPELL',
           \ 'modified': '+',
           \ 'space': ' ',
-          \ 'keymap': 'Keymap:'
+          \ 'keymap': 'Keymap:',
+          \ 'ellipsis': '...'
           \  }, 'keep')
 
   if get(g:, 'airline_powerline_fonts', 0)

autoload/airline/util.vim

@@ -86,3 +86,13 @@ else
     return 0
   endfunction
 endif
+
+" Compatibility wrapper for strchars, in case this vim version does not
+" have it natively
+function! airline#util#strchars(str)
+  if exists('*strchars')
+    return strchars(a:str)
+  else
+    return strlen(substitute(a:str, '.', 'a', 'g'))
+  endif
+endfunction

doc/airline.txt

@@ -709,6 +709,9 @@ with the middle mouse button to delete that buffer.
 * rename label for tabs (default: 'tabs') (c) >
   let g:airline#extensions#tabline#tabs_label = 't'
 
+* change the symbol for skipped tabs/buffers (default '...') >
+  let g:airline#extensions#tabline#overflow_marker = '…'
+
 * always show current tabpage/buffer first >
   let airline#extensions#tabline#current_first = 1
 <  default: 0