Feat: Allow transitional separators to be set on component basis

README.md

@@ -264,7 +264,13 @@ sections = {
     {
       'mode',
       icon = nil, -- displays icon in front of the component
-      separator = nil, -- overwrites component_separators for component
+      separator = nil, -- Determines what separator to use for the component.
+                       -- when a string is given it's treated as component_separator.
+                       -- When a table is given it's treated as section_separator.
+                       -- This options can be used to set colored separators
+                       -- arround component. Option need to be set like `separator = {'', ''}`.
+                       -- Where first element is left_separator and 2nd element is right separator.
+                       -- Passing empty string disables that separator
       condition = nil, -- condition function, component is loaded when function returns true
       -- custom color for component in format
       -- color = {fg = '#rrggbb', bg= '#rrggbb', gui='style'}

doc/lualine.txt

@@ -203,7 +203,13 @@ Local options~
       {
         'mode',
         icon = nil, -- displays icon in front of the component
-        separator = nil, -- overwrites component_separators for component
+      separator = nil, -- Determines what separator to use for the component.
+                       -- when a string is given it's treated as component_separator.
+                       -- When a table is given it's treated as section_separator.
+                       -- This options can be used to set colored separators
+                       -- arround component. Option need to be set like `separator = {'', ''}`.
+                       -- Where first element is left_separator and 2nd element is right separator.
+                       -- Passing empty string disables that separator
         condition = nil, -- condition function, component is loaded when function returns true
         -- custom color for component in format
         -- color = {fg = '#rrggbb', bg= '#rrggbb', gui='style'}

lua/lualine/component.lua

@@ -1,3 +1,5 @@
+-- Copyright (c) 2020-2021 shadmansaleh
+-- MIT license, see LICENSE for more details.
 local highlight = require 'lualine.highlight'
 
 -- Used to provide a unique id for each component
@@ -24,7 +26,7 @@ local Component = {
   end,
 
   set_separator = function(self)
-    if type(self.options.separator) ~= 'string' then
+    if self.options.separator == nil then
       if self.options.component_separators then
         if self.options.self.section < 'lualine_x' then
           self.options.separator = self.options.component_separators[1]
@@ -99,18 +101,41 @@ local Component = {
   -- Apply separator at end of component only when
   -- custom highlights haven't affected background
   apply_separator = function(self)
-    if self.options.separator and #self.options.separator > 0 then
-      self.status = self.status .. self.options.separator
-      self.applied_separator = self.options.separator
+    local separator = self.options.separator
+    if type(separator) == 'table' then
+      if self.options.separator[2] == '' then
+        if self.options.self.section < 'lualine_x' then
+          separator = self.options.component_separators[1]
+        else
+          separator = self.options.component_separators[2]
+        end
+      else
+        return
+      end
+    end
+    if separator and #separator > 0 then
+      self.status = self.status .. separator
+      self.applied_separator = separator
     end
   end,
 
-  strip_separator = function(self, default_highlight)
-    if not default_highlight then default_highlight = '' end
+  apply_section_separators = function(self)
+    if type(self.options.separator) ~= 'table' then return end
+    if self.options.separator[1] ~= '' then
+      self.status = string.format('%%s{%s}%s', self.options.separator[1],
+                                  self.status)
+      self.strip_previous_separator = true
+    end
+    if self.options.separator[2] ~= '' then
+      self.status = string.format('%s%%S{%s}', self.status,
+                                  self.options.separator[2])
+    end
+  end,
+
+  strip_separator = function(self)
     if not self.applied_separator then self.applied_separator = '' end
     self.status = self.status:sub(1, (#self.status -
-                                      (#self.applied_separator +
-                                          #default_highlight)))
+                                      (#self.applied_separator)))
     self.applied_separator = nil
     return self.status
   end,
@@ -135,6 +160,7 @@ local Component = {
       self:apply_icon()
       self:apply_case()
       self:apply_padding()
+      self:apply_section_separators()
       self:apply_highlights(default_highlight)
       self:apply_separator()
     end

lua/lualine/highlight.lua

@@ -170,7 +170,7 @@ function M.get_transitional_highlights(left_section_data, right_section_data,
   -- Grab the last highlighter of left section
   if left_section_data then
     -- extract highlight_name from .....%#highlight_name#
-    left_highlight_name = left_section_data:match('.*%%#(.-)#')
+    left_highlight_name = left_section_data:match('.*%%#(.-)#.-')
   else
     -- When right section us unavailable default to lualine_c
     left_highlight_name = append_mode('lualine_c')
@@ -180,7 +180,7 @@ function M.get_transitional_highlights(left_section_data, right_section_data,
   end
   if right_section_data then
     -- extract highlight_name from %#highlight_name#....
-    right_highlight_name = right_section_data:match('%%#(.-)#.*')
+    right_highlight_name = right_section_data:match('.-%%#(.-)#.*')
   else
     -- When right section us unavailable default to lualine_c
     right_highlight_name = append_mode('lualine_c')
@@ -210,6 +210,7 @@ function M.get_transitional_highlights(left_section_data, right_section_data,
     -- be placed before section
     if reverse then fg, bg = bg, fg end
     if not fg or not bg then return '' end -- Color retrieval failed
+    if bg == fg then return '' end -- Separatoe won't be visible anyway
     M.highlight(highlight_name, fg, bg)
   end
   return '%#' .. highlight_name .. '#'

lua/lualine/init.lua

@@ -7,30 +7,97 @@ local config_module = require('lualine.config')
 
 local config = config_module.config
 
+local function apply_transitional_separators(previous_section, current_section,
+                                             next_section)
+
+  local function fill_section_separator(prev, next, sep, reverse)
+    if #sep == 0 then return 0 end
+    local transitional_highlight = highlight.get_transitional_highlights(prev,
+                                                                         next,
+                                                                         reverse)
+    if transitional_highlight and #transitional_highlight > 0 then
+      return transitional_highlight .. sep
+    else
+      return ''
+    end
+  end
+
+  -- variable to track separators position
+  local sep_pos = 1
+
+  -- %s{sep} is marker for left separator and
+  -- %S{sep} is marker for right separator
+  -- Apply left separator
+  while sep_pos do
+    -- get what the separator char
+    local sep = current_section.data:match('%%s{(.-)}', sep_pos)
+    -- Get where separator starts from
+    sep_pos = current_section.data:find('%%s{.-}', sep_pos)
+    if not sep or not sep_pos then break end
+    -- part of section before separator . -1 since we don't want the %
+    local prev = current_section.data:sub(1, sep_pos - 1)
+    -- part of section after separator. 4 is length of "%s{}"
+    local nxt = current_section.data:sub(sep_pos + 4 + #sep)
+    -- prev might not exist when separator is the first element of section
+    -- use previous section as prev
+    if not prev or #prev == 0 or sep_pos == 1 then
+      prev = previous_section.data
+    end
+    if prev ~= previous_section.data then
+      -- Since the section isn't suppose to be highlighted with separators
+      -- separators highlight extract the last highlight and place it between
+      -- separator and section
+      local last_hl = prev:match('.*(%%#.-#).-')
+      current_section.data = prev ..
+                                 fill_section_separator(prev, nxt, sep, false) ..
+                                 last_hl .. nxt
+    else
+      current_section.data = fill_section_separator(prev, nxt, sep, true) .. nxt
+    end
+  end
+
+  -- Reset pos for right separator
+  sep_pos = 1
+  -- Apply right separator
+  while sep_pos do
+    local sep = current_section.data:match('%%S{(.-)}', sep_pos)
+    sep_pos = current_section.data:find('%%S{.-}', sep_pos)
+    if not sep or not sep_pos then break end
+    local prev = current_section.data:sub(1, sep_pos - 1)
+    local nxt = current_section.data:sub(sep_pos + 4 + #sep)
+    if not nxt or #nxt == 0 or sep_pos == #current_section.data then
+      nxt = next_section.data
+    end
+    if nxt ~= next_section.data then
+      current_section.data = prev ..
+                                 fill_section_separator(prev, nxt, sep, false) ..
+                                 nxt
+    else
+      current_section.data = prev ..
+                                 fill_section_separator(prev, nxt, sep, false)
+    end
+    sep_pos = sep_pos + 4 + #sep
+  end
+  return current_section.data
+end
+
 local function statusline(sections, is_focused)
-  local function create_status_builder()
-    -- The sequence sections should maintain
-    local section_sequence = {'a', 'b', 'c', 'x', 'y', 'z'}
-    local status_builder = {}
-    for _, section_name in ipairs(section_sequence) do
-      if sections['lualine_' .. section_name] then
-        -- insert highlight+components of this section to status_builder
-        local section_highlight = highlight.format_highlight(is_focused,
-                                                             'lualine_' ..
-                                                                 section_name)
-        local section_data = utils_section.draw_section(
-                                 sections['lualine_' .. section_name],
-                                 section_highlight)
-        if #section_data > 0 then
-          table.insert(status_builder,
-                       {name = section_name, data = section_data})
-        end
+
+  -- status_builder stores statusline without section_separators
+  -- The sequence sections should maintain
+  local section_sequence = {'a', 'b', 'c', 'x', 'y', 'z'}
+  local status_builder = {}
+  for _, section_name in ipairs(section_sequence) do
+    if sections['lualine_' .. section_name] then
+      -- insert highlight+components of this section to status_builder
+      local section_data = utils_section.draw_section(
+                               sections['lualine_' .. section_name],
+                               section_name, is_focused)
+      if #section_data > 0 then
+        table.insert(status_builder, {name = section_name, data = section_data})
       end
     end
-    return status_builder
   end
-  -- status_builder stores statusline without section_separators
-  local status_builder = create_status_builder()
 
   -- Actual statusline
   local status = {}
@@ -42,44 +109,16 @@ local function statusline(sections, is_focused)
                    highlight.format_highlight(is_focused, 'lualine_c') .. '%=')
       half_passed = true
     end
-    -- provide section_separators when statusline is in focus
-    if is_focused then
-      -- component separator needs to have fg = current_section.bg
-      -- and bg = adjacent_section.bg
-      local previous_section = status_builder[i - 1] or {}
-      local current_section = status_builder[i]
-      local next_section = status_builder[i + 1] or {}
-      -- For 2nd half we need to show separator before section
-      if current_section.name > 'x' and config.options.section_separators[2] ~=
-          '' then
-        local transitional_highlight = highlight.get_transitional_highlights(
-                                           previous_section.data,
-                                           current_section.data, true)
-        if transitional_highlight and config.options.section_separators and
-            config.options.section_separators[2] then
-          table.insert(status, transitional_highlight ..
-                           config.options.section_separators[2])
-        end
-      end
+    -- component separator needs to have fg = current_section.bg
+    -- and bg = adjacent_section.bg
+    local previous_section = status_builder[i - 1] or {}
+    local current_section = status_builder[i]
+    local next_section = status_builder[i + 1] or {}
 
-      -- **( insert the actual section in the middle )** --
-      table.insert(status, status_builder[i].data)
+    local section = apply_transitional_separators(previous_section,
+                                                  current_section, next_section)
 
-      -- For 1st half we need to show separator after section
-      if current_section.name < 'c' and config.options.section_separators[1] ~=
-          '' then
-        local transitional_highlight = highlight.get_transitional_highlights(
-                                           current_section.data,
-                                           next_section.data)
-        if transitional_highlight and config.options.section_separators and
-            config.options.section_separators[1] then
-          table.insert(status, transitional_highlight ..
-                           config.options.section_separators[1])
-        end
-      end
-    else -- when not in focus
-      table.insert(status, status_builder[i].data)
-    end
+    table.insert(status, section)
   end
   -- incase none of x,y,z was configured lets not fill whole statusline with a,b,c section
   if not half_passed then

lua/lualine/utils/section.lua

@@ -2,8 +2,12 @@
 -- MIT license, see LICENSE for more details.
 local M = {}
 local utils = require('lualine.utils.utils')
+local highlight = require('lualine.highlight')
 -- Returns formated string for a section
-function M.draw_section(section, highlight_name)
+function M.draw_section(section, section_name, is_focused)
+  local highlight_name = highlight.format_highlight(is_focused,
+                                                    'lualine_' .. section_name)
+
   local status = {}
   for _, component in pairs(section) do
     -- load components into status table
@@ -15,29 +19,51 @@ function M.draw_section(section, highlight_name)
   end
 
   -- Flags required for knowing when to remove component separator
-  local next_component_colored = false
+  local strip_next_component = false
   local last_component_found = false
+  local first_component_no = #section
 
   -- Check through components to see when component separator need to be removed
   for component_no = #section, 1, -1 do
+    if #status[component_no] > 0 then first_component_no = component_no end
     -- Remove component separator with highlight for last component
     if not last_component_found and #status[component_no] > 0 then
       last_component_found = true
-      status[component_no] = section[component_no]:strip_separator(
-                                 highlight_name)
+      status[component_no] = section[component_no]:strip_separator()
+      if section_name < 'c' then
+        if type(section[first_component_no].options.separator) ~= 'table' and
+            section[1].options.section_separators[1] ~= '' then
+          status[component_no] = string.format('%s%%S{%s}',
+                                               status[component_no], section[1]
+                                                   .options.section_separators[1])
+        end
+      end
     end
     -- Remove component separator when color option is used in next component
-    if next_component_colored then
-      next_component_colored = false
+    if strip_next_component then
+      strip_next_component = false
       status[component_no] = section[component_no]:strip_separator()
     end
     -- Remove component separator when color option is used to color background
     if (type(section[component_no].options.color) == 'table' and
         section[component_no].options.color.bg) or
         type(section[component_no].options.color) == 'string' then
-      next_component_colored = true
+      strip_next_component = true
       status[component_no] = section[component_no]:strip_separator()
     end
+
+    if (section[component_no].strip_previous_separator == true) then
+      strip_next_component = true
+    end
+  end
+
+  local left_sparator_string = ''
+  if section_name > 'x' and section[first_component_no] and
+      type(section[first_component_no].options.separator) ~= 'table' and
+      section[1].options.section_separators[2] ~= '' then
+    left_sparator_string = string.format('%%s{%s}',
+                           section[first_component_no].options.ls_separator or
+                               section[1].options.section_separators[2])
   end
 
   -- Remove empty strings from status
@@ -47,7 +73,7 @@ function M.draw_section(section, highlight_name)
     -- Don't prepend with old highlight when the component changes it imidiately
     return status_str
   else
-    return highlight_name .. status_str
+    return left_sparator_string .. highlight_name .. status_str
   end
 end
 

lua/tests/spec/utils_spec.lua

@@ -71,19 +71,29 @@ end)
 describe('Section genarator', function()
   local sec = require 'lualine.utils.section'
   it('can draw', function()
-    local opts = build_component_opts()
+    local opts = build_component_opts({section_separators = {'', ''}})
     local section = {
       require('lualine.components.special.function_component'):new(opts),
       require('lualine.components.special.function_component'):new(opts)
     }
-    eq('%#MyHl# test %#MyHl# test ', sec.draw_section(section, '%#MyHl#'))
+    eq(
+        '%#lualine_MySection_normal# test %#lualine_MySection_normal# test %#lualine_MySection_normal#',
+        sec.draw_section(section, 'MySection'))
   end)
 
   it('can remove separators from component with custom colors', function()
-    local opts = build_component_opts()
+    local opts = build_component_opts({section_separators = {'', ''}})
     local opts_colored = build_component_opts({color = 'MyColor'})
-    local opts_colored2 = build_component_opts({color = {bg = '#223344'}})
-    local opts_colored3 = build_component_opts({color = {fg = '#223344'}})
+    local opts_colored2 = build_component_opts(
+                              {
+          color = {bg = '#223344'},
+          section_separators = {'', ''}
+        })
+    local opts_colored3 = build_component_opts(
+                              {
+          color = {fg = '#223344'},
+          section_separators = {'', ''}
+        })
     require'lualine.highlight'.create_highlight_groups(
         require 'lualine.themes.gruvbox')
     local section = {
@@ -92,21 +102,29 @@ describe('Section genarator', function()
       require('lualine.components.special.function_component'):new(opts)
     }
     -- Removes separator on string color
-    eq('%#MyHl# test %#MyHl#%#MyColor# test %#MyHl# test ',
-       sec.draw_section(section, '%#MyHl#'))
-    section[2] = require('lualine.components.special.function_component'):new(
-                     opts_colored2)
+    eq(
+        '%#lualine_MySection_normal# test %#lualine_MySection_normal#%#MyColor#'
+        .. ' test %#lualine_MySection_normal# test %#lualine_MySection_normal#',
+        sec.draw_section(section, 'MySection'))
+    section[2] =
+        require('lua.lualine.components.special.function_component'):new(
+            opts_colored2)
     local highlight_name =
         '%#lualine_c_' .. section[2].options.component_name .. '_normal#'
     -- Removes separator on color with bg
-    eq('%#MyHl# test %#MyHl#' .. highlight_name .. ' test %#MyHl# test ',
-       sec.draw_section(section, '%#MyHl#'))
-    section[2] = require('lualine.components.special.function_component'):new(
-                     opts_colored3)
+    eq('%#lualine_MySection_normal# test %#lualine_MySection_normal#' ..
+           highlight_name ..
+           ' test %#lualine_MySection_normal# test %#lualine_MySection_normal#',
+       sec.draw_section(section, 'MySection'))
+    section[2] =
+        require('lua.lualine.components.special.function_component'):new(
+            opts_colored3)
     local highlight_name2 =
         '%#lualine_c_' .. section[2].options.component_name .. '_normal#'
     -- Doesn't remove separator on color without bg
-    eq('%#MyHl# test %#MyHl#' .. highlight_name2 .. ' test %#MyHl# test ',
-       sec.draw_section(section, '%#MyHl#'))
+    eq('%#lualine_MySection_normal# test %#lualine_MySection_normal#' ..
+           highlight_name2 ..
+           ' test %#lualine_MySection_normal# test %#lualine_MySection_normal#',
+       sec.draw_section(section, 'MySection'))
   end)
 end)