From 544d5eabc8550265f08ef2c2289b4ea0dacd44ab Mon Sep 17 00:00:00 2001
From: bhagwan <bhagwan@disroot.org>
Date: Mon, 11 Oct 2021 01:23:00 -0700
Subject: [PATCH] new preview scrollbar option and highlights, win|preview
 options rework

---
 README.md                         |  68 +++--
 doc/fzf-lua.txt                   |  68 +++--
 lua/fzf-lua/config.lua            | 154 ++++++++---
 lua/fzf-lua/core.lua              |  24 +-
 lua/fzf-lua/init.lua              |   4 +-
 lua/fzf-lua/previewer/builtin.lua |  25 +-
 lua/fzf-lua/providers/lsp.lua     |   4 +-
 lua/fzf-lua/utils.lua             |  23 +-
 lua/fzf-lua/win.lua               | 420 +++++++++++++++++++++---------
 9 files changed, 538 insertions(+), 252 deletions(-)

diff --git a/README.md b/README.md
index 84b73a3..23f3488 100644
--- a/README.md
+++ b/README.md
@@ -217,16 +217,48 @@ require'fzf-lua'.setup {
                                         -- "aboveleft vnew   : split left
     -- Only valid when using a float window
     -- (i.e. when 'split' is not defined)
-    win_height       = 0.85,            -- window height
-    win_width        = 0.80,            -- window width
-    win_row          = 0.30,            -- window row position (0=top, 1=bottom)
-    win_col          = 0.50,            -- window col position (0=left, 1=right)
-    -- win_border    = false,           -- window border? or borderchars?
-    win_border       = { '╭', '─', '╮', '│', '╯', '─', '╰', '│' },
-    hl_normal        = 'Normal',        -- window normal color
-    hl_border        = 'Normal',        -- change to 'FloatBorder' if exists
+    height           = 0.85,            -- window height
+    width            = 0.80,            -- window width
+    row              = 0.35,            -- window row position (0=top, 1=bottom)
+    col              = 0.50,            -- window col position (0=left, 1=right)
+    -- border argument passthrough to nvim_open_win(), also used
+    -- to manually draw the border characters around the preview
+    -- window, can be set to 'false' to remove all borders or to
+    -- 'none', 'single', 'double' or 'rounded' (default)
+    border           = { '╭', '─', '╮', '│', '╯', '─', '╰', '│' },
     fullscreen       = false,           -- start fullscreen?
-    window_on_create = function()
+    hl = {
+      normal         = 'Normal',        -- window normal color (fg+bg)
+      border         = 'Normal',        -- border color (try 'FloatBorder')
+      -- Only valid with the builtin previewer:
+      cursor         = 'Cursor',        -- cursor highlight (grep/LSP matches)
+      cursorline     = 'CursorLine',    -- cursor line
+      -- title       = 'Normal',        -- preview border title (file/buffer)
+      -- scrollbar_f = 'PmenuThumb',    -- scrollbar "full" section highlight
+      -- scrollbar_e = 'PmenuSbar',     -- scrollbar "empty" section highlight
+    },
+    preview = {
+      -- default     = 'bat',           -- override the default previewer?
+                                        -- default uses the 'builtin' previewer
+      border         = 'border',        -- border|noborder, applies only to
+                                        -- native fzf previewers (bat/cat/git/etc)
+      wrap           = 'nowrap',        -- wrap|nowrap
+      hidden         = 'nohidden',      -- hidden|nohidden
+      vertical       = 'down:45%',      -- up|down:size
+      horizontal     = 'right:60%',     -- right|left:size
+      layout         = 'flex',          -- horizontal|vertical|flex
+      flip_columns   = 120,             -- #cols to switch to horizontal on flex
+      -- Only valid with the builtin previewer:
+      title          = true,            -- preview border title (file/buf)?
+      scrollbar      = 'float',         -- `false` or string:'float|border'
+                                        -- float:  in-window floating border 
+                                        -- border: in-border chars (see below)
+      scrolloff      = '-2',            -- float scrollbar offset from right
+                                        -- applies only when scrollbar = 'float'
+      scrollchars    = {'█', '' },      -- scrollbar chars ({ <full>, <empty> }
+                                        -- applies only when scrollbar = 'border'
+    },
+    on_create = function()
       -- called once upon creation of the fzf main window
       -- can be used to add custom fzf-lua mappings, e.g:
       --   vim.api.nvim_buf_set_keymap(0, "t", "<C-j>", "<Down>",
@@ -296,15 +328,6 @@ require'fzf-lua'.setup {
       ["header"] = { "fg", "Comment" },
       ["gutter"] = { "bg", "Normal" },
   }, ]]
-  preview_border      = 'border',       -- border|noborder
-  preview_wrap        = 'nowrap',       -- wrap|nowrap
-  preview_opts        = 'nohidden',     -- hidden|nohidden
-  preview_vertical    = 'down:45%',     -- up|down:size
-  preview_horizontal  = 'right:60%',    -- right|left:size
-  preview_layout      = 'flex',         -- horizontal|vertical|flex
-  flip_columns        = 120,            -- #cols to switch to horizontal on flex
-  -- default_previewer   = "bat",       -- override the default previewer?
-                                        -- by default uses the builtin previewer
   previewers = {
     cat = {
       cmd             = "cat",
@@ -327,14 +350,9 @@ require'fzf-lua'.setup {
     builtin = {
       delay           = 100,          -- delay(ms) displaying the preview
                                       -- prevents lag on fast scrolling
-      title           = true,         -- preview title?
-      scrollbar       = true,         -- scrollbar?
-      scrollchar      = '█',          -- scrollbar character
       syntax          = true,         -- preview syntax highlight?
       syntax_limit_l  = 0,            -- syntax limit (lines), 0=nolimit
       syntax_limit_b  = 1024*1024,    -- syntax limit (bytes), 0=nolimit
-      hl_cursor       = 'Cursor',     -- cursor highlight
-      hl_cursorline   = 'CursorLine', -- cursor line highlight
     },
   },
   -- provider setup
@@ -469,8 +487,8 @@ require'fzf-lua'.setup {
       ["ctrl-y"]      = function(selected) print(selected[1]) end,
     },
     winopts = {
-      win_height        = 0.55,
-      win_width         = 0.30,
+      height          = 0.55,
+      width           = 0.30,
     },
     post_reset_cb     = function()
       -- reset statusline highlights after
diff --git a/doc/fzf-lua.txt b/doc/fzf-lua.txt
index ad19006..d5143b7 100644
--- a/doc/fzf-lua.txt
+++ b/doc/fzf-lua.txt
@@ -251,16 +251,48 @@ Consult the list below for available settings:
                                             -- "aboveleft vnew   : split left
         -- Only valid when using a float window
         -- (i.e. when 'split' is not defined)
-        win_height       = 0.85,            -- window height
-        win_width        = 0.80,            -- window width
-        win_row          = 0.30,            -- window row position (0=top, 1=bottom)
-        win_col          = 0.50,            -- window col position (0=left, 1=right)
-        -- win_border    = false,           -- window border? or borderchars?
-        win_border       = { '╭', '─', '╮', '│', '╯', '─', '╰', '│' },
-        hl_normal        = 'Normal',        -- window normal color
-        hl_border        = 'Normal',        -- change to 'FloatBorder' if exists
+        height           = 0.85,            -- window height
+        width            = 0.80,            -- window width
+        row              = 0.35,            -- window row position (0=top, 1=bottom)
+        col              = 0.50,            -- window col position (0=left, 1=right)
+        -- border argument passthrough to nvim_open_win(), also used
+        -- to manually draw the border characters around the preview
+        -- window, can be set to 'false' to remove all borders or to
+        -- 'none', 'single', 'double' or 'rounded' (default)
+        border           = { '╭', '─', '╮', '│', '╯', '─', '╰', '│' },
         fullscreen       = false,           -- start fullscreen?
-        window_on_create = function()
+        hl = {
+          normal         = 'Normal',        -- window normal color (fg+bg)
+          border         = 'Normal',        -- border color (try 'FloatBorder')
+          -- Only valid with the builtin previewer:
+          cursor         = 'Cursor',        -- cursor highlight (grep/LSP matches)
+          cursorline     = 'CursorLine',    -- cursor line
+          -- title       = 'Normal',        -- preview border title (file/buffer)
+          -- scrollbar_f = 'PmenuThumb',    -- scrollbar "full" section highlight
+          -- scrollbar_e = 'PmenuSbar',     -- scrollbar "empty" section highlight
+        },
+        preview = {
+          -- default     = 'bat',           -- override the default previewer?
+                                            -- default uses the 'builtin' previewer
+          border         = 'border',        -- border|noborder, applies only to
+                                            -- native fzf previewers (bat/cat/git/etc)
+          wrap           = 'nowrap',        -- wrap|nowrap
+          hidden         = 'nohidden',      -- hidden|nohidden
+          vertical       = 'down:45%',      -- up|down:size
+          horizontal     = 'right:60%',     -- right|left:size
+          layout         = 'flex',          -- horizontal|vertical|flex
+          flip_columns   = 120,             -- #cols to switch to horizontal on flex
+          -- Only valid with the builtin previewer:
+          title          = true,            -- preview border title (file/buf)?
+          scrollbar      = 'float',         -- `false` or string:'float|border'
+                                            -- float:  in-window floating border 
+                                            -- border: in-border chars (see below)
+          scrolloff      = '-2',            -- float scrollbar offset from right
+                                            -- applies only when scrollbar = 'float'
+          scrollchars    = {'█', '' },      -- scrollbar chars ({ <full>, <empty> }
+                                            -- applies only when scrollbar = 'border'
+        },
+        on_create = function()
           -- called once upon creation of the fzf main window
           -- can be used to add custom fzf-lua mappings, e.g:
           --   vim.api.nvim_buf_set_keymap(0, "t", "<C-j>", "<Down>",
@@ -330,15 +362,6 @@ Consult the list below for available settings:
           ["header"] = { "fg", "Comment" },
           ["gutter"] = { "bg", "Normal" },
       }, ]]
-      preview_border      = 'border',       -- border|noborder
-      preview_wrap        = 'nowrap',       -- wrap|nowrap
-      preview_opts        = 'nohidden',     -- hidden|nohidden
-      preview_vertical    = 'down:45%',     -- up|down:size
-      preview_horizontal  = 'right:60%',    -- right|left:size
-      preview_layout      = 'flex',         -- horizontal|vertical|flex
-      flip_columns        = 120,            -- #cols to switch to horizontal on flex
-      -- default_previewer   = "bat",       -- override the default previewer?
-                                            -- by default uses the builtin previewer
       previewers = {
         cat = {
           cmd             = "cat",
@@ -361,14 +384,9 @@ Consult the list below for available settings:
         builtin = {
           delay           = 100,          -- delay(ms) displaying the preview
                                           -- prevents lag on fast scrolling
-          title           = true,         -- preview title?
-          scrollbar       = true,         -- scrollbar?
-          scrollchar      = '█',          -- scrollbar character
           syntax          = true,         -- preview syntax highlight?
           syntax_limit_l  = 0,            -- syntax limit (lines), 0=nolimit
           syntax_limit_b  = 1024*1024,    -- syntax limit (bytes), 0=nolimit
-          hl_cursor       = 'Cursor',     -- cursor highlight
-          hl_cursorline   = 'CursorLine', -- cursor line highlight
         },
       },
       -- provider setup
@@ -503,8 +521,8 @@ Consult the list below for available settings:
           ["ctrl-y"]      = function(selected) print(selected[1]) end,
         },
         winopts = {
-          win_height        = 0.55,
-          win_width         = 0.30,
+          height          = 0.55,
+          width           = 0.30,
         },
         post_reset_cb     = function()
           -- reset statusline highlights after
diff --git a/lua/fzf-lua/config.lua b/lua/fzf-lua/config.lua
index 14186dc..7a6c0ad 100644
--- a/lua/fzf-lua/config.lua
+++ b/lua/fzf-lua/config.lua
@@ -19,18 +19,50 @@ if M._has_devicons and not M._devicons.has_loaded() then
   M._devicons.setup()
 end
 
+function M._default_previewer_fn()
+  return M.globals.default_previewer or M.globals.winopts.preview.default
+end
+
 M.globals = {
   winopts = {
-    win_height          = 0.85,
-    win_width           = 0.80,
-    win_row             = 0.30,
-    win_col             = 0.50,
-    win_border          = true,
-    borderchars         = { '╭', '─', '╮', '│', '╯', '─', '╰', '│' },
-    hl_normal           = 'Normal',
-    hl_border           = 'Normal',
+    height              = 0.85,
+    width               = 0.80,
+    row                 = 0.35,
+    col                 = 0.55,
+    border              = 'rounded',
     fullscreen          = false,
-    window_on_create = function()
+    hl = {
+      normal            = 'Normal',
+      border            = 'Normal',
+      -- builtin preview only
+      cursor            = 'Cursor',
+      cursorline        = 'CursorLine',
+      -- title          = 'Normal',
+      -- scrollbar_f    = 'PmenuThumb',
+      -- scrollbar_e    = 'PmenuSbar',
+    },
+    preview = {
+      default             = "builtin",
+      border              = 'float',
+      wrap                = 'nowrap',
+      hidden              = 'nohidden',
+      vertical            = 'down:45%',
+      horizontal          = 'right:60%',
+      layout              = 'flex',
+      flip_columns        = 120,
+      title               = true,
+      scrollbar           = 'border',
+      scrolloff           = '-2',
+      scrollchar          = '',
+      scrollchars         = {'█', '' },
+    },
+    _borderchars          = {
+      ["none"]            = {' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ' },
+      ["single"]          = {'┌', '─', '┐', '│', '┘', '─', '└', '│' },
+      ["double"]          = {'╔', '═', '╗', '║', '╝', '═', '╚', '║' },
+      ["rounded"]         = {'╭', '─', '╮', '│', '╯', '─', '╰', '│' },
+    },
+    on_create = function()
       -- vim.cmd("set winhl=Normal:Normal,FloatBorder:Normal")
     end,
   },
@@ -69,14 +101,6 @@ M.globals = {
     ['--height']      = '100%',
     ['--layout']      = 'reverse',
   },
-  preview_border      = 'border',
-  preview_wrap        = 'nowrap',
-  preview_opts        = 'nohidden',
-  preview_vertical    = 'down:45%',
-  preview_horizontal  = 'right:60%',
-  preview_layout      = 'flex',
-  flip_columns        = 120,
-  default_previewer   = "builtin",
   previewers = {
     cat = {
       cmd             = "cat",
@@ -110,20 +134,16 @@ M.globals = {
       -- https://github.com/junegunn/fzf/issues/2417#issuecomment-809886535
       delay           = 100,
       title           = true,
-      scrollbar       = true,
-      scrollchar      = '█',
       syntax          = true,
       syntax_delay    = 0,
       syntax_limit_l  = 0,
       syntax_limit_b  = 1024*1024,
-      hl_cursor       = 'Cursor',
-      hl_cursorline   = 'CursorLine',
       _ctor           = previewers.builtin.buffer_or_file,
     },
   },
 }
 M.globals.files = {
-    previewer           = function() return M.globals.default_previewer end,
+    previewer           = M._default_previewer_fn,
     prompt              = '> ',
     cmd                 = nil,  -- default: auto detect find|fd
     file_icons          = true and M._has_devicons,
@@ -149,7 +169,7 @@ M.globals.files = {
 -- so we can reference 'M.globals.files'
 M.globals.git = {
     files = {
-      previewer     = function() return M.globals.default_previewer end,
+      previewer     = M._default_previewer_fn,
       prompt        = 'GitFiles> ',
       cmd           = "git ls-files --exclude-standard",
       file_icons    = true and M._has_devicons,
@@ -203,7 +223,7 @@ M.globals.git = {
     },
   }
 M.globals.grep = {
-    previewer           = function() return M.globals.default_previewer end,
+    previewer           = M._default_previewer_fn,
     prompt              = 'Rg> ',
     input_prompt        = 'Grep For> ',
     cmd                 = nil,  -- default: auto detect rg|grep
@@ -218,7 +238,7 @@ M.globals.grep = {
     glob_separator      = "%s%-%-"    -- query separator pattern (lua): ' --'
   }
 M.globals.args = {
-    previewer           = function() return M.globals.default_previewer end,
+    previewer           = M._default_previewer_fn,
     prompt              = 'Args> ',
     files_only          = true,
     file_icons          = true and M._has_devicons,
@@ -228,7 +248,7 @@ M.globals.args = {
   }
 M.globals.args.actions["ctrl-x"] = actions.arg_del
 M.globals.oldfiles = {
-    previewer           = function() return M.globals.default_previewer end,
+    previewer           = M._default_previewer_fn,
     prompt              = 'History> ',
     file_icons          = true and M._has_devicons,
     color_icons         = true,
@@ -236,7 +256,7 @@ M.globals.oldfiles = {
     actions             = M.globals.files.actions,
   }
 M.globals.quickfix = {
-    previewer           = function() return M.globals.default_previewer end,
+    previewer           = M._default_previewer_fn,
     prompt              = 'Quickfix> ',
     separator           = '▏',
     file_icons          = true and M._has_devicons,
@@ -245,7 +265,7 @@ M.globals.quickfix = {
     actions             = M.globals.files.actions,
   }
 M.globals.loclist = {
-    previewer           = function() return M.globals.default_previewer end,
+    previewer           = M._default_previewer_fn,
     prompt              = 'Locations> ',
     separator           = '▏',
     file_icons          = true and M._has_devicons,
@@ -310,7 +330,7 @@ M.globals.blines = {
     },
   }
 M.globals.tags = {
-    previewer             = function() return M.globals.default_previewer end,
+    previewer             = M._default_previewer_fn,
     prompt                = 'Tags> ',
     ctags_file            = "tags",
     file_icons            = true and M._has_devicons,
@@ -319,7 +339,7 @@ M.globals.tags = {
     actions             = M.globals.files.actions,
   }
 M.globals.btags = {
-    previewer             = function() return M.globals.default_previewer end,
+    previewer             = M._default_previewer_fn,
     prompt                = 'BTags> ',
     ctags_file            = "tags",
     file_icons            = true and M._has_devicons,
@@ -334,8 +354,8 @@ M.globals.colorschemes = {
         ["default"]       = actions.colorscheme,
       },
       winopts = {
-        win_height       = 0.55,
-        win_width        = 0.50,
+        height            = 0.55,
+        width             = 0.50,
       },
   }
 M.globals.helptags = {
@@ -364,7 +384,7 @@ M.globals.manpages = {
       },
   }
 M.globals.lsp = {
-      previewer           = function() return M.globals.default_previewer end,
+      previewer           = M._default_previewer_fn,
       prompt              = '> ',
       file_icons          = true and M._has_devicons,
       color_icons         = true,
@@ -384,8 +404,8 @@ M.globals.lsp = {
 M.globals.builtin = {
       prompt              = 'Builtin> ',
       winopts = {
-        win_height        = 0.65,
-        win_width         = 0.50,
+        height            = 0.65,
+        width             = 0.50,
       },
       actions = {
         ["default"]       = actions.run_builtin,
@@ -516,18 +536,67 @@ else
   }
 end
 
+
 function M.normalize_opts(opts, defaults)
   if not opts then opts = {} end
-  if not opts.fzf_opts then opts.fzf_opts = {} end
+
+  -- First, merge with provider defaults
   opts = vim.tbl_deep_extend("keep", opts, defaults)
-  opts.keymap = vim.tbl_deep_extend("keep", opts.keymap or {}, M.globals.keymap)
-  if defaults.winopts then
-    if not opts.winopts then opts.winopts = {} end
-    opts.winopts = vim.tbl_deep_extend("keep", opts.winopts, defaults.winopts)
+
+  -- Merge required tables from globals
+  for _, k in ipairs({ 'winopts', 'keymap', 'fzf_opts', 'previewers' }) do
+    opts[k] = vim.tbl_deep_extend("keep", opts[k] or {}, M.globals[k] or {})
   end
+
+  -- backward compatibility, rhs overrides lhs
+  -- (rhs being the "old" option)
+  local backward_compat = {
+    ['winopts.row']                   = 'winopts.win_row',
+    ['winopts.col']                   = 'winopts.win_col',
+    ['winopts.width']                 = 'winopts.win_width',
+    ['winopts.height']                = 'winopts.win_height',
+    ['winopts.border']                = 'winopts.win_border',
+    ['winopts.on_create']             = 'winopts.window_on_create',
+    ['winopts.preview.wrap']          = 'preview_wrap',
+    ['winopts.preview.border']        = 'preview_border',
+    ['winopts.preview.hidden']        = 'preview_opts',
+    ['winopts.preview.vertical']      = 'preview_vertical',
+    ['winopts.preview.horizontal']    = 'preview_horizontal',
+    ['winopts.preview.layout']        = 'preview_layout',
+    ['winopts.preview.flip_columns']  = 'flip_columns',
+    ['winopts.preview.default']       = 'default_previewer',
+    ['winopts.hl.normal']             = 'winopts.hl_normal',
+    ['winopts.hl.border']             = 'winopts.hl_border',
+    ['winopts.hl.cursor']             = 'previewers.builtin.hl_cursor',
+    ['winopts.hl.cursorline']         = 'previewers.builtin.hl_cursorline',
+    ['winopts.preview.title']         = 'previewers.builtin.title',
+    ['winopts.preview.scrollbar']     = 'previewers.builtin.scrollbar',
+    ['winopts.preview.scrollchar']    = 'previewers.builtin.scrollchar',
+  }
+
+  -- recursive key loopkup, can also set new value
+  local map_recurse = function(m, s, v, w)
+    local keys = utils.strsplit(s, '.')
+    local val, map = m, nil
+    for i=1,#keys do
+      map = val
+      val = val[keys[i]]
+      if not val then break end
+      if v~=nil and i==#keys then map[keys[i]] = v end
+    end
+    if v and w then utils.warn(w) end
+    return val
+  end
+
+  -- interate backward compat map, retrieve values from opts or globals
+  for k, v in pairs(backward_compat) do
+    map_recurse(opts, k, map_recurse(opts, v) or map_recurse(M.globals, v))
+     -- ,("'%s' is now defined under '%s'"):format(v, k))
+  end
+
   if type(opts.previewer) == 'function' then
     -- we use a function so the user can override
-    -- globals.default_previewer
+    -- globals.winopts.preview.default
     opts.previewer = opts.previewer()
   end
   if type(opts.previewer) == 'table' then
@@ -566,6 +635,9 @@ function M.normalize_opts(opts, defaults)
   -- are we using skim?
   opts._is_skim = opts.fzf_bin:find('sk') ~= nil
 
+  -- mark as normalized
+  opts._normalized = true
+
   return opts
 end
 
diff --git a/lua/fzf-lua/core.lua b/lua/fzf-lua/core.lua
index def924e..0a80f59 100644
--- a/lua/fzf-lua/core.lua
+++ b/lua/fzf-lua/core.lua
@@ -8,6 +8,10 @@ local win = require "fzf-lua.win"
 local M = {}
 
 M.fzf = function(opts, contents)
+  -- normalize with globals if not already normalized
+  if not opts._normalized then
+    opts = config.normalize_opts(opts, {})
+  end
   -- setup the fzf window and preview layout
   local fzf_win = win(opts)
   if not fzf_win then return end
@@ -66,19 +70,17 @@ M.get_devicon = function(file, ext)
   return icon..config.globals.file_icon_padding:gsub(" ", utils.nbsp), hl
 end
 
-M.preview_window = function(opts)
-  local o = vim.tbl_deep_extend("keep", opts, config.globals)
-  local preview_vertical = string.format('%s:%s:%s:%s',
-    o.preview_opts, o.preview_border, o.preview_wrap, o.preview_vertical)
-  local preview_horizontal = string.format('%s:%s:%s:%s',
-    o.preview_opts, o.preview_border, o.preview_wrap, o.preview_horizontal)
-  if o.preview_layout == "vertical" then
-    return preview_vertical
-  elseif o.preview_layout == "flex" then
-    return utils._if(vim.o.columns>o.flip_columns, preview_horizontal, preview_vertical)
+M.preview_window = function(o)
+  local preview_args = ("%s:%s:%s:"):format(
+    o.winopts.preview.hidden, o.winopts.preview.border, o.winopts.preview.wrap)
+  if o.winopts.preview.layout == "horizontal" or
+     o.winopts.preview.layout == "flex" and
+       vim.o.columns>o.winopts.preview.flip_columns then
+    preview_args = preview_args .. o.winopts.preview.horizontal
   else
-    return preview_horizontal
+    preview_args = preview_args .. o.winopts.preview.vertical
   end
+  return preview_args
 end
 
 M.get_color = function(hl_group, what)
diff --git a/lua/fzf-lua/init.lua b/lua/fzf-lua/init.lua
index ab62940..252099e 100644
--- a/lua/fzf-lua/init.lua
+++ b/lua/fzf-lua/init.lua
@@ -31,10 +31,10 @@ function M.setup(opts)
     utils.warn("'previewers.builtin.keymap' moved under 'keymap.builtin', see ':help fzf-lua-customization'")
   end
   if globals.previewers.builtin.wrap ~= nil then
-    utils.warn("'previewers.builtin.wrap' is not longer in use, set 'preview_wrap' to 'wrap' or 'nowrap' instead")
+    utils.warn("'previewers.builtin.wrap' is not longer in use, set 'winopts.preview.wrap' to 'wrap' or 'nowrap' instead")
   end
   if globals.previewers.builtin.hidden ~= nil then
-    utils.warn("'previewers.builtin.hidden' is not longer in use, set 'preview_opts' to 'hidden' or 'nohidden' instead")
+    utils.warn("'previewers.builtin.hidden' is not longer in use, set 'winopts.preview.hidden' to 'hidden' or 'nohidden' instead")
   end
   -- override BAT_CONFIG_PATH to prevent a
   -- conflct with '$XDG_DATA_HOME/bat/config'
diff --git a/lua/fzf-lua/previewer/builtin.lua b/lua/fzf-lua/previewer/builtin.lua
index f01fc15..0e1ec3c 100644
--- a/lua/fzf-lua/previewer/builtin.lua
+++ b/lua/fzf-lua/previewer/builtin.lua
@@ -31,18 +31,11 @@ function Previewer.base:new(o, opts, fzf_win)
   self.type = "builtin"
   self.win = fzf_win
   self.delay = o.delay
-  self.title = o.title
-  self.scrollbar = o.scrollbar
-  if o.scrollchar and type(o.scrollchar) == 'string' then
-    self.win.winopts.scrollchar = o.scrollchar
-  end
+  self.title = self.win.winopts.preview.title
   self.syntax = o.syntax
   self.syntax_delay = o.syntax_delay
   self.syntax_limit_b = o.syntax_limit_b
   self.syntax_limit_l = o.syntax_limit_l
-  self.hl_cursor = o.hl_cursor
-  self.hl_cursorline = o.hl_cursorline
-  self.hl_range = o.hl_range
   self.backups = {}
   return self
 end
@@ -234,9 +227,7 @@ function Previewer.base:scroll(direction)
       end)
     end
   end
-  if self.scrollbar then
-    self.win:update_scrollbar()
-  end
+  self.win:update_scrollbar()
 end
 
 
@@ -373,8 +364,8 @@ local function set_cursor_hl(self, entry)
 
     fn.clearmatches()
 
-    if lnum and lnum > 0 and col and col > 1 then
-      fn.matchaddpos(self.hl_cursor, {{lnum, math.max(1, col)}}, 11)
+    if self.win.winopts.hl.cursor and lnum and lnum > 0 and col and col > 1 then
+      fn.matchaddpos(self.win.winopts.hl.cursor, {{lnum, math.max(1, col)}}, 11)
     end
 end
 
@@ -391,9 +382,7 @@ function Previewer.buffer_or_file:update_border(entry)
     end
     self.win:update_title(title)
   end
-  if self.scrollbar then
-    self.win:update_scrollbar()
-  end
+  self.win:update_scrollbar()
 end
 
 function Previewer.buffer_or_file:preview_buf_post(entry)
@@ -477,9 +466,7 @@ function Previewer.help_tags:populate_preview_buf(entry_str)
   end)
   api.nvim_win_set_buf(self.win.preview_winid, self.preview_bufnr)
   api.nvim_win_set_cursor(self.win.preview_winid, self.orig_pos)
-  if self.scrollbar then
-    self.win:update_scrollbar()
-  end
+  self.win:update_scrollbar()
   if self.prev_help_bufnr ~= self.preview_bufnr and
     -- only delete the help buffer when the help
     -- tag triggers opening a different help file
diff --git a/lua/fzf-lua/providers/lsp.lua b/lua/fzf-lua/providers/lsp.lua
index b5d9b38..3d41054 100644
--- a/lua/fzf-lua/providers/lsp.lua
+++ b/lua/fzf-lua/providers/lsp.lua
@@ -395,7 +395,7 @@ M.diagnostics = function(opts)
   if not opts then return end
 
   local lsp_clients = vim.lsp.buf_get_clients(0)
-  if utils.tbl_length(lsp_clients) == 0 then
+  if utils.tbl_isempty(lsp_clients) then
     utils.info("LSP: no client attached")
     return
   end
@@ -568,7 +568,7 @@ local function check_capabilities(feature)
   if supported_client then
     return true
   else
-    if utils.tbl_length(clients) == 0 then
+    if utils.tbl_isempty(clients) then
       utils.info("LSP: no client attached")
     else
       utils.info("LSP: server does not support " .. feature)
diff --git a/lua/fzf-lua/utils.lua b/lua/fzf-lua/utils.lua
index d1a3ef2..b4e8ace 100644
--- a/lua/fzf-lua/utils.lua
+++ b/lua/fzf-lua/utils.lua
@@ -164,13 +164,9 @@ function M.tbl_length(T)
   return count
 end
 
-function M.tbl_has(table, key)
-  return table[key] ~= nil
-end
-
-function M.tbl_or(key, tbl1, tbl2)
-  if tbl1[key] ~= nil then return tbl1[key]
-  else return tbl2[key] end
+function M.tbl_isempty(T)
+  if not T or not next(T) then return true end
+  return false
 end
 
 function M.tbl_concat(...)
@@ -414,4 +410,17 @@ function M.io_system(cmd, use_lua_io)
   end
 end
 
+function M.fzf_bind_to_neovim(key)
+  local conv_map  = {
+    ['alt'] = 'A',
+    ['ctrl'] = 'C',
+    ['shift'] = 'S',
+  }
+  key = key:lower()
+  for k, v in pairs(conv_map) do
+    key = key:gsub(k, v)
+  end
+  return ("<%s>"):format(key)
+end
+
 return M
diff --git a/lua/fzf-lua/win.lua b/lua/fzf-lua/win.lua
index 49bd4b0..53696b8 100644
--- a/lua/fzf-lua/win.lua
+++ b/lua/fzf-lua/win.lua
@@ -18,6 +18,14 @@ setmetatable(FzfWin, {
 function FzfWin:setup_keybinds()
   if not self:validate() then return end
   if not self.keymap or not self.keymap.builtin then return end
+  -- find the toggle_preview
+  if self.keymap.fzf then
+    for k, v in pairs(self.keymap.fzf) do
+      if v == 'toggle-preview' then
+        self._fzf_toggle_prev_bind = utils.fzf_bind_to_neovim(k)
+      end
+    end
+  end
   local keymap_tbl = {
     ['toggle-fullscreen']   = { module = 'win', fnc = 'toggle_fullscreen()' },
   }
@@ -65,9 +73,12 @@ local generate_layout = function(winopts)
       if winopts.split then
         anchor = 'NW'
         prev_row = 1
+        prev_width = prev_width - 2
         prev_height = prev_height - 1
         if vert_split then
           prev_col = 1
+        else
+          prev_col = prev_col - 1
         end
       else
         anchor = 'SW'
@@ -79,6 +90,7 @@ local generate_layout = function(winopts)
         prev_col = 1
         prev_row = height + padding
         prev_height = prev_height - 1
+        prev_width = prev_width - 2
       else
         prev_row = row + height + 3
       end
@@ -86,34 +98,29 @@ local generate_layout = function(winopts)
   elseif preview_pos == 'left' or preview_pos == 'right' then
     prev_height = height
     prev_width = utils.round(width * preview_size/100)
-    width = width - prev_width
+    width = width - prev_width - 2
     if preview_pos == 'left' then
       anchor = 'NE'
-      col = col + prev_width
-      prev_col = col - padding
+      col = col + prev_width + 2
+      prev_col = col - 1
       if winopts.split then
         prev_row = 1
+        prev_width = prev_width - 1
         prev_height = prev_height - padding
         if vert_split then
           anchor = 'NW'
           prev_col = 1
-          prev_width = prev_width + 1
         else
-          prev_width = prev_width - 1
+          prev_col = col - 3
         end
       end
     else
       anchor = 'NW'
       if winopts.split then
         prev_row = 1
+        prev_col = width + 4
+        prev_width = prev_width - 3
         prev_height = prev_height - padding
-        if vert_split then
-          prev_col = width + 2
-          prev_width = prev_width - 1
-        else
-          prev_col = width + 3
-          prev_width = prev_width - padding
-        end
       else
         prev_col = col + width + 3
       end
@@ -132,72 +139,113 @@ local generate_layout = function(winopts)
   }
 end
 
-local normalize_winopts = function(opts)
-  if not opts then opts = {} end
-  if not opts.winopts then opts.winopts = {} end
-  opts = vim.tbl_deep_extend("keep", opts, config.globals)
-  opts.winopts = vim.tbl_deep_extend("keep", opts.winopts, config.globals.winopts)
+local strip_borderchars_hl = function(border)
+  local default = nil
+  if type(border) == 'string' then
+    default = config.globals.winopts._borderchars[border]
+  end
+  if not default then
+    default = config.globals.winopts._borderchars['rounded']
+  end
+  if not border or type(border) ~= 'table' or #border<8 then
+    return default
+  end
+  local borderchars = {}
+  for i=1, 8 do
+    if type(border[i]) == 'string' then
+      table.insert(borderchars, border[i])
+    elseif type(border[i]) == 'table' and type(border[i][1]) == 'string' then
+      -- can happen when border chars contains a highlight, i.e:
+      -- border = { {'╭', 'NormalFloat'}, {'─', 'NormalFloat'}, ... }
+      table.insert(borderchars, border[i][1])
+    else
+      table.insert(borderchars, default[i])
+    end
+  end
+  -- assert(#borderchars == 8)
+  return borderchars
+end
+
+local normalize_winopts = function(o)
+  -- make a local copy of opts so we
+  -- don't pollute the user's options
+  local opts = o or {}
+  opts.winopts = vim.tbl_deep_extend("keep", opts.winopts or {}, config.globals.winopts)
+  opts.winopts_fn = opts.winopts_fn or config.globals.winopts_fn
   opts.winopts_raw = opts.winopts_raw or config.globals.winopts_raw
 
-  local raw = {}
-  if opts.winopts_raw and type(opts.winopts_raw) == "function" then
-    raw = opts.winopts_raw()
+  local winopts = utils.tbl_deep_clone(opts.winopts)
+
+  if type(opts.winopts_fn) == "function" then
+    winopts = vim.tbl_deep_extend("force", winopts, opts.winopts_fn())
+  end
+  if type(opts.winopts_raw) == "function" then
+    winopts = vim.tbl_deep_extend("force", winopts, opts.winopts_raw())
   end
 
-  local winopts = opts.winopts
-  local height = raw.height or math.floor(vim.o.lines * winopts.win_height)
-  local width = raw.width or math.floor(vim.o.columns * winopts.win_width)
-  local row = raw.row or math.floor((vim.o.lines - height) * winopts.win_row)
-  local col = raw.col or math.floor((vim.o.columns - width) * winopts.win_col)
-  local border = raw.border or winopts.win_border
-  local scrollchar = raw.scrollchar or winopts.scrollchar
-  local hl_normal = raw.hl_normal or winopts.hl_normal
-  local hl_border = raw.hl_border or winopts.hl_border
-  local fullscreen = raw.fullscreen or winopts.fullscreen
+  local max_width = vim.o.columns-2
+  local max_height = vim.o.lines-4
+  winopts.width = math.min(max_width, winopts.width)
+  winopts.height = math.min(max_height, winopts.height)
+  if not winopts.height or winopts.height <= 1 then
+    winopts.height = math.floor(max_height * winopts.height)
+  end
+  if not winopts.width or winopts.width <= 1 then
+    winopts.width = math.floor(max_width * winopts.width)
+  end
+  if not winopts.row or winopts.row < 1 then
+    winopts.row = math.floor((vim.o.lines - winopts.height) * winopts.row)
+  end
+  if not winopts.col or winopts.col < 1 then
+    winopts.col = math.floor((vim.o.columns - winopts.width) * winopts.col)
+  end
+  winopts.col = math.min(winopts.col, max_width-winopts.width)
+  winopts.row = math.min(winopts.row, max_height-winopts.height)
 
   -- normalize border option for nvim_open_win()
-  if border == false then
-    border = {}
-    for i=1, 8 do border[i] = ' ' end
-  elseif border == true or border == nil then
-    border = config.globals.winopts.borderchars
+  if not winopts.border or winopts.border == true then
+    winopts.border = 'rounded'
+  elseif winopts.border == false then
+    winopts.border = 'none'
   end
 
+  -- We only allow 'none|single|double|rounded'
+  if type(winopts.border) == 'string' then
+    winopts.border = config.globals.winopts._borderchars[winopts.border] or
+      config.globals.winopts._borderchars['rounded']
+  end
+
+  -- Store a version of borderchars with no highlights
+  -- to be used in the border drawing functions
+  winopts.nohl_borderchars = strip_borderchars_hl(winopts.border)
 
   -- parse preview options
-  local preview = opts.preview_horizontal
-  if opts.preview_layout == "vertical" then
-    preview = opts.preview_vertical
-  elseif opts.preview_layout == "flex" then
-    preview = utils._if(vim.o.columns>opts.flip_columns, opts.preview_horizontal, opts.preview_vertical)
+  local preview
+  if winopts.preview.layout == "horizontal" or
+     winopts.preview.layout == "flex" and
+       vim.o.columns > winopts.preview.flip_columns then
+    preview = winopts.preview.horizontal
+  else
+    preview = winopts.preview.vertical
   end
 
   -- builtin previewer params
-  local prev_pos = preview:match("[^:]+") or 'right'
-  local prev_size = tonumber(preview:match(":(%d+)%%")) or 50
+  winopts.preview_pos = preview:match("[^:]+") or 'right'
+  winopts.preview_size = tonumber(preview:match(":(%d+)%%")) or 50
 
-  return {
-    height = height, width = width, row = row, col = col, border = border,
-    window_on_create = raw.window_on_create or winopts.window_on_create,
-    split = raw.split or winopts.split,
-    hl_normal = hl_normal, hl_border = hl_border,
-    -- builtin previewer params
-    scrollchar = scrollchar,
-    preview_pos = prev_pos, preview_size = prev_size,
-    fullscreen = fullscreen
-  }
+  return winopts
 end
 
 function FzfWin:reset_win_highlights(win, is_border)
   local hl = ("Normal:%s,FloatBorder:%s"):format(
-    self.winopts.hl_normal, self.winopts.hl_border)
-  if self._previewer and self._previewer.hl_cursorline then
-    hl = hl .. (",CursorLine:%s"):format(self._previewer.hl_cursorline)
+    self.winopts.hl.normal, self.winopts.hl.border)
+  if self._previewer and self.winopts.hl.cursorline then
+    hl = hl .. (",CursorLine:%s"):format(self.winopts.hl.cursorline)
   end
   if is_border then
     -- our border is manuually drawn so we need
     -- to replace Normal with the border color
-    hl = ("Normal:%s"):format(self.winopts.hl_border)
+    hl = ("Normal:%s"):format(self.winopts.hl.border)
   end
   vim.api.nvim_win_set_option(win, 'winhighlight', hl)
 end
@@ -234,7 +282,7 @@ function FzfWin.autoclose()
 end
 
 local function opt_matches(opts, key, str)
-  local opt = opts[key] or config.globals[key]
+  local opt = opts.winopts.preview[key] or config.globals.winopts.preview[key]
   return opt and opt:match(str)
 end
 
@@ -248,8 +296,9 @@ function FzfWin:new(o)
   self = setmetatable({}, { __index = self })
   self.winopts = normalize_winopts(o)
   self.fullscreen = self.winopts.fullscreen
-  self.preview_wrap = not opt_matches(o, 'preview_wrap', 'nowrap')
-  self.preview_hidden = not opt_matches(o, 'preview_opts', 'nohidden')
+  self.preview_wrap = not opt_matches(o, 'wrap', 'nowrap')
+  self.preview_hidden = not opt_matches(o, 'hidden', 'nohidden')
+  self.preview_border = not opt_matches(o, 'border', 'noborder')
   self.keymap = o.keymap
   self.previewer = o.previewer
   self.previewer_type = o.previewer_type
@@ -285,23 +334,25 @@ function FzfWin:fs_preview_layout(fs)
   local height_diff = 0
   local width_diff = 0
   if preview_pos == 'down' or preview_pos == 'up' then
-    width_diff = vim.o.columns - border_winopts.width - 1
+    width_diff = vim.o.columns - border_winopts.width
     if preview_pos == 'down' then
       height_diff = vim.o.lines - border_winopts.row - border_winopts.height - 2
     elseif preview_pos == 'up' then
       height_diff = border_winopts.row - border_winopts.height
     end
-    prev_winopts.col = prev_winopts.col - width_diff/2
-    border_winopts.col = border_winopts.col - width_diff/2
+    border_winopts.col = 0
+    prev_winopts.col = border_winopts.col + 1
   elseif preview_pos == 'left' or preview_pos == 'right' then
     height_diff = vim.o.lines - border_winopts.height - 2
     if preview_pos == 'left' then
+      border_winopts.col = border_winopts.col - 1
+      prev_winopts.col = prev_winopts.col - 1
       width_diff = border_winopts.col - border_winopts.width
     elseif preview_pos == 'right' then
-      width_diff = vim.o.columns - border_winopts.col - border_winopts.width - 1
+      width_diff = vim.o.columns - border_winopts.col - border_winopts.width
     end
-    prev_winopts.row = prev_winopts.row - height_diff/2
-    border_winopts.row = border_winopts.row - height_diff/2
+    border_winopts.row = 0
+    prev_winopts.row = border_winopts.row + 1
   end
 
   prev_winopts.height = prev_winopts.height + height_diff
@@ -340,7 +391,6 @@ function FzfWin:preview_layout()
     local winopts = {relative = 'editor', focusable = false, style = 'minimal'}
     if self.winopts.split then
       winopts = {relative = 'win', win = self.fzf_winid, focusable = false, style = 'minimal'}
-      width = width - 2
     end
     local preview_opts = vim.tbl_extend('force', winopts, {
         anchor = anchor,
@@ -371,35 +421,14 @@ function FzfWin:preview_winids()
     return self.preview_winid, self.border_winid
 end
 
-local strip_border_highlights = function(border)
-  local default = config.globals.winopts.borderchars
-  if not border or type(border) ~= 'table' or #border<8 then
-    return default
-  end
-  local borderchars = {}
-  for i=1, 8 do
-    if type(border[i]) == 'string' then
-      table.insert(borderchars, border[i])
-    elseif type(border[i]) == 'table' and type(border[i][1]) == 'string' then
-      -- can happen when border chars contains a highlight, i.e:
-      -- border = { {'╭', 'NormalFloat'}, {'─', 'NormalFloat'}, ... }
-      table.insert(borderchars, border[i][1])
-    else
-      table.insert(borderchars, default[i])
-    end
-  end
-  -- assert(#borderchars == 8)
-  return borderchars
-end
-
 function FzfWin:update_border_buf()
   local border_buf = self.border_buf
   local border_winopts = self.border_winopts
-  local border_chars = strip_border_highlights(self.winopts.border)
+  local borderchars = self.winopts.nohl_borderchars
   local width, height = border_winopts.width, border_winopts.height
-  local top = border_chars[1] .. border_chars[2]:rep(width - 2) .. border_chars[3]
-  local mid = border_chars[8] .. (' '):rep(width - 2) .. border_chars[4]
-  local bot = border_chars[7] .. border_chars[6]:rep(width - 2) .. border_chars[5]
+  local top = borderchars[1] .. borderchars[2]:rep(width - 2) .. borderchars[3]
+  local mid = borderchars[8] .. (' '):rep(width - 2) .. borderchars[4]
+  local bot = borderchars[7] .. borderchars[6]:rep(width - 2) .. borderchars[5]
   local lines = {top}
   for _ = 1, height - 2 do
     table.insert(lines, mid)
@@ -581,9 +610,9 @@ function FzfWin:create()
 
   self:reset_win_highlights(self.fzf_winid)
 
-  if self.winopts.window_on_create and
-      type(self.winopts.window_on_create) == 'function' then
-    self.winopts.window_on_create()
+  if self.winopts.on_create and
+      type(self.winopts.on_create) == 'function' then
+    self.winopts.on_create()
   end
 
   -- create or redraw the preview win
@@ -614,6 +643,19 @@ function FzfWin:close_preview()
   if self.preview_winid and vim.api.nvim_win_is_valid(self.preview_winid) then
     api.nvim_win_close(self.preview_winid, true)
   end
+  if self._sbuf1 and vim.api.nvim_buf_is_valid(self._sbuf1) then
+    vim.api.nvim_buf_delete(self._sbuf1, {force=true})
+  end
+  if self._swin1 and vim.api.nvim_win_is_valid(self._swin1) then
+    api.nvim_win_close(self._swin1, true)
+  end
+  if self._sbuf2 and vim.api.nvim_buf_is_valid(self._sbuf2) then
+    vim.api.nvim_buf_delete(self._sbuf2, {force=true})
+  end
+  if self._swin2 and vim.api.nvim_win_is_valid(self._swin2) then
+    api.nvim_win_close(self._swin2, true)
+  end
+  self._sbuf1, self._sbuf2, self._swin1, self._swin2 = nil, nil, nil, nil
   self.border_buf = nil
   self.border_winid = nil
   self.preview_winid = nil
@@ -652,43 +694,174 @@ function FzfWin.win_leave()
   _self:close()
 end
 
-function FzfWin:update_scrollbar()
-  if not self:validate_preview() then return end
-  local border_winid = self.border_winid
-  local preview_winid = self.preview_winid
-  local border_chars = strip_border_highlights(self.winopts.border)
-  local scrollchar = self.winopts.scrollchar
-  local buf = api.nvim_win_get_buf(preview_winid)
-  local border_buf = api.nvim_win_get_buf(border_winid)
-  local line_count = api.nvim_buf_line_count(buf)
+function FzfWin:clear_border_highlights()
+  if self.border_winid and vim.api.nvim_win_is_valid(self.border_winid) then
+    vim.fn.clearmatches(self.border_winid)
+  end
+end
 
-  local win_info = fn.getwininfo(preview_winid)[1]
-  local topline, height = win_info.topline, win_info.height
+function FzfWin:set_title_hl()
+  if self.winopts.hl.title and self._title_len and self._title_len>0 then
+    vim.api.nvim_win_call(self.border_winid, function()
+      fn.matchaddpos(self.winopts.hl.title, {{1, 9, self._title_len}}, 11)
+    end)
+  end
+end
+
+function FzfWin:update_scrollbar_border(o)
+
+  -- do not display on files that are fully contained
+  if o.bar_height >= o.line_count then return end
+
+  local borderchars = self.winopts.nohl_borderchars
+  local scrollchars = self.winopts.preview.scrollchars
 
-  local bar_size = math.min(height, math.ceil(height * height / line_count))
+  -- bar_offset starts at 0, first line is 1
+  o.bar_offset = o.bar_offset+1
 
-  local bar_pos = math.ceil(height * topline / line_count)
-  if bar_pos + bar_size > height then
-      bar_pos = height - bar_size + 1
+  -- backward compatibility before 'scrollchar' was a table
+  if type(self.winopts.preview.scrollchar) == 'string' and
+    #self.winopts.preview.scrollchar > 0 then
+    scrollchars[1] = self.winopts.preview.scrollchar
+  end
+  for i=1,2 do
+    if not scrollchars[i] or #scrollchars[i]==0 then
+      scrollchars[i] = borderchars[4]
+    end
   end
 
-  -- only accept a string
-  if not scrollchar or type(scrollchar) ~= 'string' then
-    scrollchar = '█'
+  -- matchaddpos() can't handle more than 8 items at once
+  local add_to_tbl = function(tbl, item)
+    local len = utils.tbl_length(tbl)
+    if len==0 or utils.tbl_length(tbl[len])==8 then
+      table.insert(tbl, {})
+      len = len+1
+    end
+    table.insert(tbl[len], item)
   end
 
-  local lines = api.nvim_buf_get_lines(border_buf, 1, -2, true)
+  local full, empty = {}, {}
+  local lines = api.nvim_buf_get_lines(self.border_buf, 1, -2, true)
   for i = 1, #lines do
+    local line, linew = lines[i], fn.strwidth(lines[i])
     local bar_char
-    if i >= bar_pos and i < bar_pos + bar_size then
-      bar_char = scrollchar
+    if i >= o.bar_offset and i < o.bar_offset + o.bar_height then
+      bar_char = scrollchars[1]
+      add_to_tbl(full, {i+1, linew+2, 1})
+    else
+      bar_char = scrollchars[2]
+      add_to_tbl(empty, {i+1, linew+2, 1})
+    end
+    lines[i] = fn.strcharpart(line, 0, linew - 1) .. bar_char
+  end
+  api.nvim_buf_set_lines(self.border_buf, 1, -2, 0, lines)
+  -- border highlights
+  if self.winopts.hl.scrollbar_f or self.winopts.hl.scrollbar_e then
+    vim.api.nvim_win_call(self.border_winid, function()
+      if self.winopts.hl.scrollbar_f then
+        for i=1,#full do
+          fn.matchaddpos(self.winopts.hl.scrollbar_f, full[i], 11)
+        end
+      end
+      if self.winopts.hl.scrollbar_e then
+        for i=1,#empty do
+          fn.matchaddpos(self.winopts.hl.scrollbar_e, empty[i], 11)
+        end
+      end
+    end)
+  end
+end
+
+local function ensure_tmp_buf(bufnr)
+  if bufnr and vim.api.nvim_buf_is_valid(bufnr) then
+    return bufnr
+  end
+  bufnr = api.nvim_create_buf(false, true)
+  -- running nvim with `-M` will reset modifiable's default value to false
+  vim.bo[bufnr].modifiable = true
+  vim.bo[bufnr].bufhidden = 'wipe'
+  return bufnr
+end
+
+function FzfWin:hide_scrollbar()
+  if self._swin1 and vim.api.nvim_win_is_valid(self._swin1) then
+    vim.api.nvim_win_hide(self._swin1)
+    self._swin1 = nil
+  end
+  if self._swin2 and vim.api.nvim_win_is_valid(self._swin2) then
+    vim.api.nvim_win_hide(self._swin2)
+    self._swin2 = nil
+  end
+end
+
+function FzfWin:update_scrollbar_float(o)
+  -- do not display on files that are fully contained
+  if o.bar_height >= o.line_count then
+    self:hide_scrollbar()
+  else
+    local info = o.wininfo
+    local style1 = {}
+    style1.relative = 'editor'
+    style1.style = 'minimal'
+    style1.width = 1
+    style1.height = info.height
+    style1.row = info.winrow - 1
+    style1.col = info.wincol + info.width +
+      (tonumber(self.winopts.preview.scrolloff) or -2)
+    style1.zindex = info.zindex or 998
+    if self._swin1 and vim.api.nvim_win_is_valid(self._swin1) then
+      vim.api.nvim_win_set_config(self._swin1, style1)
     else
-      bar_char = border_chars[4]
+      style1.noautocmd = true
+      self._sbuf1 = ensure_tmp_buf(self._sbuf1)
+      self._swin1 = vim.api.nvim_open_win(self._sbuf1, false, style1)
+      local hl = self.winopts.hl.scrollbar_e or 'PmenuSbar'
+      vim.api.nvim_win_set_option(self._swin1, 'winhighlight',
+        ('Normal:%s,NormalNC:%s,NormalFloat:%s'):format(hl, hl, hl))
+    end
+    local style2 = utils.tbl_deep_clone(style1)
+    style2.height = o.bar_height
+    style2.row = style1.row + o.bar_offset
+    style2.zindex = style1.zindex + 1
+    if self._swin2 and vim.api.nvim_win_is_valid(self._swin2) then
+      vim.api.nvim_win_set_config(self._swin2, style2)
+    else
+      style2.noautocmd = true
+      self._sbuf2 = ensure_tmp_buf(self._sbuf2)
+      self._swin2 = vim.api.nvim_open_win(self._sbuf2, false, style2)
+      local hl = self.winopts.hl.scrollbar_f or 'PmenuThumb'
+      vim.api.nvim_win_set_option(self._swin2, 'winhighlight',
+        ('Normal:%s,NormalNC:%s,NormalFloat:%s'):format(hl, hl, hl))
     end
-    local line = lines[i]
-    lines[i] = fn.strcharpart(line, 0, fn.strwidth(line) - 1) .. bar_char
   end
-  api.nvim_buf_set_lines(border_buf, 1, -2, 0, lines)
+end
+
+function FzfWin:update_scrollbar()
+  if not self.winopts.preview.scrollbar
+     or self.winopts.preview.scrollbar == 'none'
+     or not self:validate_preview() then
+    return
+   end
+
+  local buf = api.nvim_win_get_buf(self.preview_winid)
+
+  local o = {}
+  o.wininfo = fn.getwininfo(self.preview_winid)[1]
+  o.line_count = api.nvim_buf_line_count(buf)
+
+  local topline, height = o.wininfo.topline, o.wininfo.height
+  o.bar_height = math.min(height, math.ceil(height * height / o.line_count))
+  o.bar_offset = math.min(height - o.bar_height, math.floor(height * topline / o.line_count))
+
+  -- reset highlights before we move the scrollbar
+  self:clear_border_highlights()
+  self:set_title_hl()
+
+  if self.winopts.preview.scrollbar == 'float' then
+    self:update_scrollbar_float(o)
+  else
+    self:update_scrollbar_border(o)
+  end
 end
 
 function FzfWin:update_title(title)
@@ -700,17 +873,21 @@ function FzfWin:update_title(title)
   if #title > width-right_pad then
     title = title:sub(1, width-right_pad) .. " "
   end
+  -- save for set_title_hl
+  self._title_len = #title
   local prefix = fn.strcharpart(top, 0, 3)
   local suffix = fn.strcharpart(top, fn.strwidth(title) + 3, fn.strwidth(top))
   title = ('%s%s%s'):format(prefix, title, suffix)
   api.nvim_buf_set_lines(border_buf, 0, 1, 1, {title})
+  self:set_title_hl()
 end
 
 -- keybind methods below
 function FzfWin.toggle_fullscreen()
-  if not _self then return end
+  if not _self or _self.winopts.split then return end
   local self = _self
   self.fullscreen = not self.fullscreen
+  self:hide_scrollbar()
   if self and self:validate() then
     self:redraw()
   end
@@ -723,6 +900,9 @@ function FzfWin.toggle_preview()
   if not _self then return end
   local self = _self
   self.preview_hidden = not self.preview_hidden
+  if self.winopts.split and self._fzf_toggle_prev_bind then
+    utils.feed_keys_termcodes(self._fzf_toggle_prev_bind)
+  end
   if self.preview_hidden and self:validate_preview() then
     self:close_preview()
     self:redraw()