Add selectioncount formatting options

README.md

@@ -658,6 +658,26 @@ sections = {
 }
 ```
 
+#### selectioncount component options
+
+```lua
+sections = {
+  lualine_a = {
+    {
+      'selectioncount',
+      format = {
+        -- `%b`: bytes, `%c`: chars, `%l`: lines
+        single_line_no_multibyte = '[%c]',
+        single_line_multibyte = '[%c-%b]',
+        multi_line_no_multibyte = '[%c / %l]',
+        multi_line_multibyte = '[%c-%b / %l]',
+        visual_block_mode = '[%cx%l]',
+      }
+    }
+  }
+}
+```
+
 #### searchcount component options
 
 ```lua

lua/lualine/components/selectioncount.lua

@@ -1,16 +1,68 @@
-local function selectioncount()
-  local mode = vim.fn.mode(true)
-  local line_start, col_start = vim.fn.line('v'), vim.fn.col('v')
-  local line_end, col_end = vim.fn.line('.'), vim.fn.col('.')
-  if mode:match('') then
-    return string.format('%dx%d', math.abs(line_start - line_end) + 1, math.abs(col_start - col_end) + 1)
-  elseif mode:match('V') or line_start ~= line_end then
-    return math.abs(line_start - line_end) + 1
-  elseif mode:match('v') then
-    return math.abs(col_start - col_end) + 1
+local M = require('lualine.component'):extend()
+
+local default_format = {
+  single_line_no_multibyte = '[%c]',
+  single_line_multibyte = '[%c-%b]',
+  multi_line_no_multibyte = '[%c / %l]',
+  multi_line_multibyte = '[%c-%b / %l]',
+  visual_block_mode = '[%cx%l]',
+}
+
+function M:init(options)
+  M.super.init(self, options)
+  self.format = vim.tbl_extend('keep', self.options.format or {}, default_format)
+end
+
+function M:update_status()
+  local mode = vim.fn.mode()
+  local lines = math.abs(vim.fn.line('v') - vim.fn.line('.')) + 1
+  if mode == 'v' or mode == 'V' then
+    local wc = vim.fn.wordcount()
+    local is_multibyte = wc.visual_chars ~= wc.visual_bytes
+    local is_multiline = lines > 1
+    local chars = wc.visual_chars
+    if is_multiline then
+      if is_multibyte then
+        local bytes = wc.visual_bytes
+        return self.format.multi_line_multibyte
+          :gsub("^%%b", bytes):gsub("([^%%])%%b", "%1"..bytes)
+          :gsub("^%%c", chars):gsub("([^%%])%%c", "%1"..chars)
+          :gsub("^%%l", lines):gsub("([^%%])%%l", "%1"..lines)
+      else
+        return self.format.multi_line_no_multibyte
+          :gsub("^%%c", chars):gsub("([^%%])%%c", "%1"..chars)
+          :gsub("^%%l", lines):gsub("([^%%])%%l", "%1"..lines)
+      end
+    else
+      if is_multibyte then
+        local bytes = wc.visual_bytes
+        return self.format.single_line_multibyte
+          :gsub("^%%b", bytes):gsub("([^%%])%%b", "%1"..bytes)
+          :gsub("^%%c", chars):gsub("([^%%])%%c", "%1"..chars)
+      else
+        return self.format.single_line_no_multibyte
+          :gsub("^%%c", chars):gsub("([^%%])%%c", "%1"..chars)
+      end
+    end
+  elseif mode == '' then
+    local cols = vim.fn.virtcol('.') - vim.fn.virtcol('v')
+    local line, col
+    if cols >= 0 then
+      line = vim.fn.getline('v')
+      col = vim.fn.charcol('v') - 1
+    else
+      line = vim.fn.getline('.')
+      col = vim.fn.charcol('.') - 1
+      cols = -cols
+    end
+    local char1width = vim.fn.strwidth(vim.fn.strcharpart(line, col, 1))
+    local chars = cols+char1width
+    return self.format.visual_block_mode
+      :gsub("^%%c", chars):gsub("([^%%])%%c", "%1"..chars)
+      :gsub("^%%l", lines):gsub("([^%%])%%l", "%1"..lines)
   else
     return ''
   end
 end
 
-return selectioncount
+return M