feat: option to scroll to closest quickfix item (#23)

lua/quicker/config.lua

@@ -33,6 +33,10 @@ local default_config = {
     -- Load the referenced buffers to apply more accurate highlights (may be slow)
     load_buffers = true,
   },
+  follow = {
+    -- When quickfix window is open, scroll to closest item to the cursor
+    enabled = false,
+  },
   -- Map of quickfix item type to icon
   type_icons = {
     E = "󰅚 ",
@@ -74,6 +78,7 @@ local default_config = {
 ---@field use_default_opts boolean
 ---@field constrain_cursor boolean
 ---@field highlight quicker.HighlightConfig
+---@field follow quicker.FollowConfig
 ---@field edit quicker.EditConfig
 ---@field type_icons table<string, string>
 ---@field borders quicker.Borders
@@ -89,6 +94,7 @@ local M = {}
 ---@field use_default_opts? boolean Set to false to disable the default options in `opts`
 ---@field constrain_cursor? boolean Keep the cursor to the right of the filename and lnum columns
 ---@field highlight? quicker.SetupHighlightConfig Configure syntax highlighting
+---@field follow? quicker.SetupFollowConfig Configure cursor following
 ---@field edit? quicker.SetupEditConfig
 ---@field type_icons? table<string, string> Map of quickfix item type to icon
 ---@field borders? quicker.SetupBorders Characters used for drawing the borders
@@ -157,6 +163,12 @@ end
 ---@field lsp? boolean Use LSP semantic token highlighting
 ---@field load_buffers? boolean Load the referenced buffers to apply more accurate highlights (may be slow)
 
+---@class (exact) quicker.FollowConfig
+---@field enabled boolean
+
+---@class (exact) quicker.SetupFollowConfig
+---@field enabled? boolean
+
 ---@class (exact) quicker.EditConfig
 ---@field enabled boolean
 ---@field autosave boolean|"unmodified"

lua/quicker/follow.lua

@@ -0,0 +1,84 @@
+local util = require("quicker.util")
+local M = {}
+
+M.seek_to_position = function()
+  if util.is_open(0) then
+    local qf_list = vim.fn.getloclist(0, { winid = 0, items = 0 })
+    local new_pos = M.calculate_pos(qf_list.items)
+    if new_pos then
+      M.set_pos(qf_list.winid, new_pos)
+    end
+  end
+
+  if util.is_open() then
+    local qf_list = vim.fn.getqflist({ winid = 0, items = 0 })
+    local new_pos = M.calculate_pos(qf_list.items)
+    if new_pos then
+      M.set_pos(qf_list.winid, new_pos)
+    end
+  end
+end
+
+---Calculate the current buffer/cursor location in the quickfix list
+---@param list QuickFixItem[]
+---@return nil|integer
+M.calculate_pos = function(list)
+  if vim.bo.buftype ~= "" then
+    return
+  end
+  local bufnr = vim.api.nvim_get_current_buf()
+  local cursor = vim.api.nvim_win_get_cursor(0)
+  local lnum, col = cursor[1], cursor[2] + 1
+  local prev_lnum = -1
+  local prev_col = -1
+  local found_buf = false
+  local ret
+  for i, entry in ipairs(list) do
+    if entry.bufnr ~= bufnr then
+      if found_buf then
+        return ret
+      end
+    else
+      found_buf = true
+
+      -- If we detect that the list isn't sorted, bail.
+      if
+        prev_lnum > -1
+        and (entry.lnum < prev_lnum or (entry.lnum == prev_lnum and entry.col <= prev_col))
+      then
+        return
+      end
+
+      if prev_lnum == -1 or lnum > entry.lnum or (lnum == entry.lnum and col >= entry.col) then
+        ret = i
+      end
+      prev_lnum = entry.lnum
+      prev_col = entry.col
+    end
+  end
+
+  return ret
+end
+
+local timers = {}
+---@param winid integer
+---@param pos integer
+M.set_pos = function(winid, pos)
+  local timer = timers[winid]
+  if timer then
+    timer:close()
+  end
+  timer = assert(vim.uv.new_timer())
+  timers[winid] = timer
+  timer:start(10, 0, function()
+    timer:close()
+    timers[winid] = nil
+    vim.schedule(function()
+      if vim.api.nvim_win_is_valid(winid) then
+        pcall(vim.api.nvim_win_set_cursor, winid, { pos, 0 })
+      end
+    end)
+  end)
+end
+
+return M

lua/quicker/init.lua

@@ -45,6 +45,16 @@ local function setup(opts)
       end,
     })
   end
+  if config.follow.enabled then
+    vim.api.nvim_create_autocmd({ "CursorMoved", "BufEnter" }, {
+      desc = "quicker.nvim scroll to nearest location in quickfix",
+      pattern = "*",
+      group = aug,
+      callback = function()
+        require("quicker.follow").seek_to_position()
+      end,
+    })
+  end
 
   vim.o.quickfixtextfunc = "v:lua.require'quicker.display'.quickfixtextfunc"
 
@@ -95,11 +105,7 @@ end
 
 ---@param loclist_win? integer Check if loclist is open for the given window. If nil, check quickfix.
 M.is_open = function(loclist_win)
-  if loclist_win then
-    return vim.fn.getloclist(loclist_win or 0, { winid = 0 }).winid ~= 0
-  else
-    return vim.fn.getqflist({ winid = 0 }).winid ~= 0
-  end
+  return require("quicker.util").is_open(loclist_win)
 end
 
 ---@class quicker.OpenCmdMods: vim.api.keyset.parse_cmd.mods

lua/quicker/util.lua

@@ -10,6 +10,15 @@ function M.buf_find_win(bufnr)
   end
 end
 
+---@param loclist_win? integer Check if loclist is open for the given window. If nil, check quickfix.
+M.is_open = function(loclist_win)
+  if loclist_win then
+    return vim.fn.getloclist(loclist_win or 0, { winid = 0 }).winid ~= 0
+  else
+    return vim.fn.getqflist({ winid = 0 }).winid ~= 0
+  end
+end
+
 ---@param winid nil|integer
 ---@return nil|"c"|"l"
 M.get_win_type = function(winid)