feat(fzf-tmux): default to using "--tmux"

Replaces `fzf_bin = "fzf-tmux"` as "--tmux" is the preferred method
for both fzf and skim.

Fixed getting the correct width from tmux window/pane for accurate
"flex" layout calculation based on % in setting (default to 50%).

This commit also perpares us better for the upcoming "--popup" option
in fzf in order to support zellij popups.

Ref: junegunn/fzf#4145

README.md

@@ -568,7 +568,10 @@ fzf_opts = {
 -- popup 80% width, 80% height (note `-p` requires tmux > 3.2)
 -- and removes the sides margin added by `fzf-tmux` (fzf#3162)
 -- for more options run `fzf-tmux --help`
-fzf_tmux_opts       = { ["-p"] = "80%,80%", ["--margin"] = "0,0" },
+-- NOTE: since fzf v0.53 / sk v0.15 it is recommended to use
+-- native tmux integration by adding the below to `fzf_opts`
+-- fzf_opts = { ["--tmux"] = "center,80%,60%" }
+fzf_tmux_opts = { ["-p"] = "80%,80%", ["--margin"] = "0,0" },
 ```
 
 </details>

lua/fzf-lua/config.lua

@@ -279,18 +279,6 @@ function M.normalize_opts(opts, globals, __resume_key)
     end
   end
 
-  -- prioritize fzf-tmux split pane flags over the
-  -- popup flag `-p` from fzf-lua defaults (#865)
-  opts._is_fzf_tmux_popup = true
-  if type(opts.fzf_tmux_opts) == "table" then
-    for _, flag in ipairs({ "-u", "-d", "-l", "-r" }) do
-      if opts.fzf_tmux_opts[flag] then
-        opts._is_fzf_tmux_popup = false
-        opts.fzf_tmux_opts["-p"] = nil
-      end
-    end
-  end
-
   -- Merge `winopts` with outputs from `winopts_fn`
   local winopts_fn = opts.winopts_fn or M.globals.winopts_fn
   if type(winopts_fn) == "function" then
@@ -648,6 +636,7 @@ function M.normalize_opts(opts, globals, __resume_key)
               ["--highlight-line"] = true,
             }
           },
+          ["0.53"] = { fzf_opts = { ["--tmux"] = true } },
           ["0.52"] = { fzf_opts = { ["--highlight-line"] = true } },
           ["0.42"] = {
             fzf_opts = {
@@ -720,22 +709,27 @@ function M.normalize_opts(opts, globals, __resume_key)
   end
 
   -- Are we using fzf-tmux? if so get available columns
-  opts._is_fzf_tmux = vim.env.TMUX
-      -- pre fzf v0.53 uses the fzf-tmux script
-      and opts.fzf_bin:match("fzf%-tmux$") and 1
-      -- fzf v0.53 added native tmux integration
-      or utils.has(opts, "fzf", { 0, 53 }) and opts.fzf_opts["--tmux"] and 2
-      -- skim v0.15.5 added native tmux integration
-      or utils.has(opts, "sk", { 0, 15, 5 }) and opts.fzf_opts["--tmux"] and 2
-  if opts._is_fzf_tmux then
-    local out = utils.io_system({ "tmux", "display-message", "-p", "#{window_width}" })
-    opts._tmux_columns = tonumber(out:match("%d+"))
-    opts.winopts.split = nil
-    if opts._is_fzf_tmux == 2 then
-      -- native tmux integration is implemented using tmux popups
-      opts._is_fzf_tmux_popup = true
+  opts._is_fzf_tmux = (function()
+    if not vim.env.TMUX then return end
+    local is_tmux =
+        (opts.fzf_bin:match("fzf%-tmux$") or opts.fzf_bin:match("sk%-tmux$")) and 1
+        -- fzf v0.53 added native tmux integration
+        or utils.has(opts, "fzf", { 0, 53 }) and opts.fzf_opts["--tmux"] and 2
+        -- skim v0.15.5 added native tmux integration
+        or utils.has(opts, "sk", { 0, 15, 5 }) and opts.fzf_opts["--tmux"] and 2
+    if is_tmux == 1 then
+      -- backward compat when using the `fzf-tmux` script: prioritize fzf-tmux
+      -- split pane flags over the popup flag `-p` from fzf-lua defaults (#865)
+      if type(opts.fzf_tmux_opts) == "table" then
+        for _, flag in ipairs({ "-u", "-d", "-l", "-r" }) do
+          if opts.fzf_tmux_opts[flag] then
+            opts.fzf_tmux_opts["-p"] = nil
+          end
+        end
+      end
     end
-  end
+    return is_tmux
+  end)()
 
   -- refresh highlights if background/colorscheme changed (#1092)
   if not M.__HLS_STATE

lua/fzf-lua/profiles/fzf-tmux.lua

@@ -1,8 +1,6 @@
 return {
   desc = "fzf-native run inside a tmux popup",
-  fzf_bin = "fzf-tmux",
-  fzf_opts = { ["--border"] = "rounded" },
-  fzf_tmux_opts = { ["-p"] = "80%,60%" },
+  fzf_opts = { ["--border"] = "rounded", ["--tmux"] = "center,80%,60%" },
   winopts = { preview = { default = "bat" } },
   manpages = { previewer = "man_native" },
   helptags = { previewer = "help_native" },

lua/fzf-lua/win.lua

@@ -266,13 +266,49 @@ local strip_borderchars_hl = function(border)
   return borderchars
 end
 
+function FzfWin:tmux_columns()
+  local is_popup, is_hsplit, opt_val = (function()
+    -- Backward compat using "fzf-tmux" script
+    if self._o._is_fzf_tmux == 1 then
+      for _, flag in ipairs({ "-l", "-r" }) do
+        if self._o.fzf_tmux_opts[flag] then
+          -- left/right split, not a popup, is an hsplit
+          return false, true, self._o.fzf_tmux_opts[flag]
+        end
+      end
+      for _, flag in ipairs({ "-u", "-d" }) do
+        if self._o.fzf_tmux_opts[flag] then
+          -- up/down split, not a popup, not an hsplit
+          return false, false, self._o.fzf_tmux_opts[flag]
+        end
+      end
+      -- Default is a popup with "-p" or without
+      return true, false, self._o.fzf_tmux_opts["-p"]
+    else
+      return true, false, self._o.fzf_opts["--tmux"]
+    end
+  end)()
+  local out = utils.io_system({
+    "tmux", "display-message", "-p",
+    is_popup and "#{window_width}" or "#{pane_width}"
+  })
+  local cols = tonumber(out:match("%d+"))
+  -- Calc the correct width when using tmux popup or left|right splits
+  -- fzf's defaults to "--tmux" is "center,50%" or "50%" for splits
+  if is_popup or is_hsplit then
+    local percent = type(opt_val) == "string" and tonumber(opt_val:match("(%d+)%%")) or 50
+    cols = math.floor(cols * percent / 100)
+  end
+  return cols
+end
+
 function FzfWin:columns(no_fullscreen)
   assert(self.winopts)
   -- When called from `core.preview_window` we need to get the no-fullscreen columns
   -- in order to get an accurate alternate layout trigger that will also be consistent
   -- when starting with `winopts.fullscreen == true`
   local winopts = no_fullscreen and self:normalize_winopts(false) or self.winopts
-  return self._o._is_fzf_tmux and self._o._is_fzf_tmux_popup and self._o._tmux_columns
+  return self._o._is_fzf_tmux and self:tmux_columns()
       or winopts.split and vim.api.nvim_win_get_width(self.fzf_winid or 0)
       or winopts.width
 end