feat(previewer): **BETA** display nvim-treesitter-context

lua/fzf-lua/previewer/builtin.lua

@@ -757,6 +757,32 @@ function Previewer.base:update_render_markdown()
   end
 end
 
+function Previewer.base:update_ts_context(close)
+  -- excerpt from nvim-treesitter-context `update_single_context`
+  if not package.loaded["treesitter-context"] then return end
+  local bufnr, winid = self.preview_bufnr, self.win.preview_winid
+  if close then
+    -- Original cursorline (match) out of bounds, hide ts-context
+    require("treesitter-context.render").close(winid)
+    return
+  end
+  -- Temporarily set "zindex" higher than fzf-lua
+  local config = require("treesitter-context.config")
+  local saved_zindex = config.zindex
+  config.zindex = self.win._o.winopts.zindex + 20
+  require("treesitter-context.render").close_leaked_contexts()
+  local context_ranges, context_lines = require("treesitter-context.context").get(bufnr, winid)
+  if not context_ranges or #context_ranges == 0 then
+    require("treesitter-context.render").close(winid)
+  else
+    assert(context_lines)
+    require("treesitter-context.render").open(bufnr, winid, context_ranges, context_lines)
+    -- _G.dump("ts", bufnr, winid, context_ranges, context_lines)
+  end
+  -- Restore saved "zindex"
+  config.zindex = saved_zindex
+end
+
 function Previewer.buffer_or_file:do_syntax(entry)
   if not self.preview_bufnr then return end
   if not entry or not entry.path then return end
@@ -848,7 +874,6 @@ function Previewer.buffer_or_file:do_syntax(entry)
 end
 
 function Previewer.buffer_or_file:maybe_set_cursorline(win, pos)
-  if not self.winopts.cursorline then return end
   local wininfo = utils.getwininfo(win)
   if wininfo
       and pos[1] >= wininfo.topline
@@ -857,9 +882,11 @@ function Previewer.buffer_or_file:maybe_set_cursorline(win, pos)
     -- reset cursor pos even when it's already there, no bigggie
     -- local curpos = vim.api.nvim_win_get_cursor(win)
     vim.api.nvim_win_set_cursor(win, pos)
-    vim.wo[win].cursorline = true
+    vim.wo[win].cursorline = self.winopts.cursorline
+    self:update_ts_context()
   else
     vim.wo[win].cursorline = false
+    self:update_ts_context(true)
   end
 end