From f0cb4f1fff0004ca0b89b4ce4a5ed7b6952d62ac Mon Sep 17 00:00:00 2001
From: Luuk van Baal <luukvbaal@gmail.com>
Date: Thu, 1 Feb 2024 01:55:12 +0100
Subject: [PATCH] feat: add foldclosed option for sign segments

When set to true, show signs from lines in a closed fold on the
first line of that closed fold.
---
 README.md         |  1 +
 lua/statuscol.lua | 13 +++++++++++++
 2 files changed, 14 insertions(+)

diff --git a/README.md b/README.md
index 802df8e..1efb0e7 100644
--- a/README.md
+++ b/README.md
@@ -124,6 +124,7 @@ Each segment can contain the following elements:
                          -- virtual or wrapped part of a line (when v:virtnum != 0).
     fillchar = " ",      -- character used to fill a segment with less signs than maxwidth
     fillcharhl = nil,    -- highlight group used for fillchar (SignColumn/CursorLineSign if omitted)
+    foldclosed = false,  -- when true, show signs from lines in a closed fold on the first line
   }
 }
 ```
diff --git a/lua/statuscol.lua b/lua/statuscol.lua
index ceb5cc8..42ded9d 100644
--- a/lua/statuscol.lua
+++ b/lua/statuscol.lua
@@ -141,19 +141,31 @@ end
 
 --- Place signs with sign text in sign segments.
 local function place_signs(win, signs)
+  local lines = {}
   for i = 1, #signs do
     local s = signs[i][4]
     if not s.sign_text then goto nextsign end
+
     local name = s.sign_name or s.sign_text
     if not s.sign_hl_group then s.sign_hl_group = "NoTexthl" end
     if not s.sign_name then name = name..s.sign_hl_group end
     if not sign_cache[name] then sign_cache_add(win, s, name) end
     local sign = sign_cache[name]
     if not sign.segment then goto nextsign end
+
     local ss = signsegments[sign.segment]
     local wss = ss.wins[win]
     local sss = wss.signs
     local lnum = signs[i][2] + 1
+
+    if ss.foldclosed then
+      if not lines[lnum] then lines[lnum] = f.foldclosed(lnum) end
+      if lines[lnum] > 0 then
+        lnum = lines[lnum]
+        for j = lnum, f.foldclosedend(lnum) do lines[j] = lnum end
+      end
+    end
+
     if not sss[lnum] then sss[lnum] = {} end
     -- Insert by priority. Potentially remove when nvim_buf_get_extmarks() can return sorted list.
     for j = 1, ss.maxwidth do
@@ -323,6 +335,7 @@ function M.setup(user)
       ss.maxwidth = ss.maxwidth or 1
       ss.colwidth = ss.colwidth or 2
       ss.fillchar = ss.fillchar or " "
+      ss.foldclosed = ss.foldclosed or false
       if ss.fillcharhl then ss.fillcharhl = "%#"..ss.fillcharhl.."#" end
       if setscl ~= false then setscl = true end
       if not segment.text then segment.text = {builtin.signfunc} end