feat(highlights): support cterm 8-bit colors; fix #36

cookbook.md

@@ -121,6 +121,7 @@ Each component may contain _any_ of the following fields:
     - `bg`: The background color. Type: as above.
     - `sp`: The underline/undercurl color, if any. Type: as above.
     - Style fields supported by `synIDattrstyle()`: Example: `{ bold = true, underline = true }`
+    - `ctermfg`, `ctermbg`, `cterm` fields as described in `:h nvim_set_hl` for 8-bit colors.
     - `force`: Control whether the parent's `hl` fields will override child's hl.
       Type: `bool`.
   - Description: `hl` controls the colors of what is printed by the component's

lua/heirline/highlights.lua

@@ -14,9 +14,9 @@ local function make_hl(hl_name, hl)
     vim.api.nvim_set_hl(0, hl_name, hl)
 end
 
-local function name_hl(hl)
+local function name_rgb_hl(hl)
     local style = vim.tbl_filter(function(value)
-        return not vim.tbl_contains({ "bg", "fg", "sp" }, value)
+        return not vim.tbl_contains({ "bg", "fg", "sp", "ctermbg", "ctermfg", "cterm" }, value)
     end, vim.tbl_keys(hl))
     return "Stl"
         .. (hl.fg and hl.fg:gsub("#", "") or "")
@@ -28,6 +28,18 @@ local function name_hl(hl)
         .. (hl.sp and hl.sp:gsub("#", "") or "")
 end
 
+local function name_cterm_hl(hl)
+    local style = vim.tbl_filter(function(value)
+        return not vim.tbl_contains({ "bg", "fg", "sp", "ctermbg", "ctermfg", "cterm" }, value)
+    end, vim.tbl_keys(hl.cterm or hl))
+    return "Stl"
+        .. (hl.ctermfg or "")
+        .. "_"
+        .. (hl.ctermbg or "")
+        .. "_"
+        .. table.concat(style, "")
+end
+
 local function hex(val)
     if type(val) == "number" then
         return string.format("#%06x", val)
@@ -45,6 +57,8 @@ local function normalize_hl(hl)
     return fixed_hl
 end
 
+
+local name_hl = vim.o.termguicolors and name_rgb_hl or name_cterm_hl
 function M.eval_hl(hl)
     if vim.tbl_isempty(hl) then
         return "", ""

lua/heirline/utils.lua

@@ -1,13 +1,23 @@
 local M = {}
 
+local TERMGUICOLORS = vim.o.termguicolors
+
 function M.get_highlight(name)
-    local hl = vim.api.nvim_get_hl_by_name(name, true)
-    hl.fg = hl.foreground
-    hl.bg = hl.background
-    hl.sp = hl.special
-    hl.foreground = nil
-    hl.backgroung = nil
-    hl.special = nil
+    local hl = vim.api.nvim_get_hl_by_name(name, TERMGUICOLORS)
+    if TERMGUICOLORS then
+        hl.fg = hl.foreground
+        hl.bg = hl.background
+        hl.sp = hl.special
+        hl.foreground = nil
+        hl.backgroung = nil
+        hl.special = nil
+    else
+        hl.ctermfg = hl.foreground
+        hl.ctermbg = hl.background
+        hl.foreground = nil
+        hl.backgroung = nil
+        hl.special = nil
+    end
     return hl
 end