From 7a73598f762942e9e59d64412142f872a90b5f96 Mon Sep 17 00:00:00 2001
From: Fernando Schauenburg <dev@schauenburg.me>
Date: Sun, 13 Aug 2023 01:52:26 +0200
Subject: [PATCH] vim/lualine: add trailing whitespace

---
 config/nvim/lua/fschauen/lualine.lua         | 18 ++++++++++++++++++
 config/nvim/lua/fschauen/plugins/lualine.lua |  8 +++++++-
 2 files changed, 25 insertions(+), 1 deletion(-)

diff --git a/config/nvim/lua/fschauen/lualine.lua b/config/nvim/lua/fschauen/lualine.lua
index efc2aee..e6a80ad 100644
--- a/config/nvim/lua/fschauen/lualine.lua
+++ b/config/nvim/lua/fschauen/lualine.lua
@@ -65,6 +65,23 @@ function mode:update_status(is_focused)
   return ' 󰒲 '
 end
 
+local trailing_whitespace = function()
+  local pattern = [[\s\+$]]
+  local lineno = vim.fn.search(pattern, 'nwc')
+  if lineno == 0 then
+    return ''
+  end
+
+  local result = '·' .. lineno
+
+  local info = vim.fn.searchcount { pattern = pattern }
+  if info.total then
+    result = result .. string.format(' Σ%d', info.total)
+  end
+
+  return result
+end
+
 local colored_if_focused = function(component)
   if type(component) == 'string' then
     local c = require('lualine.components.' .. component):extend()
@@ -96,5 +113,6 @@ return {
   colored_if_focused = colored_if_focused,
   filename = filename,
   mode = mode,
+  trailing_whitespace = trailing_whitespace,
 }
 
diff --git a/config/nvim/lua/fschauen/plugins/lualine.lua b/config/nvim/lua/fschauen/plugins/lualine.lua
index a88ba58..4b88619 100644
--- a/config/nvim/lua/fschauen/plugins/lualine.lua
+++ b/config/nvim/lua/fschauen/plugins/lualine.lua
@@ -56,6 +56,12 @@ return {
           fg = '#f9f5d7',
         },
       },
+      trailing_whitespace = {
+        colored_if_focused(require('fschauen.lualine').trailing_whitespace),
+        color = {
+          bg = orange,
+        },
+      }
     }
 
     local sections = {
@@ -64,7 +70,7 @@ return {
       lualine_c = { C.filename, C.status },
       lualine_x = { C.diagnostics, C.filetype },
       lualine_y = { C.fileformat, 'progress' },
-      lualine_z = { 'location' },
+      lualine_z = { 'location', C.trailing_whitespace },
     }
 
     require('lualine').setup {