Statusline view in search mode or command line mode (#729)

* Search mode horizontal view

Enabled by setting `experimental.horizontal_search = true`

* use stylua

* move to a floating window instead of abusing status line

* pass all tests

* rework

1. rename entries view file and memeber to wildmenu_entries_view
2. move config to config.view.entries
3. support both in insert mode and cmdline
4. make separator configurable by config.view.separator

* rearange wildmenu config

Changed config to:
```lua
  view = {
    entries = {name = 'wildmenu', separator = '|' }
  },
```

* allow view.entries to be either a literal string or a table

lua/cmp/config/default.lua

@@ -123,5 +123,9 @@ return function()
     },
 
     sources = {},
+
+    view = {
+      entries = { name = 'custom' },
+    },
   }
 end

lua/cmp/types/cmp.lua

@@ -81,6 +81,7 @@ cmp.ItemField.Menu = 'menu'
 ---@field public snippet cmp.SnippetConfig
 ---@field public mapping table<string, cmp.Mapping>
 ---@field public sources cmp.SourceConfig[]
+---@field public view cmp.ViewConfig
 ---@field public experimental cmp.ExperimentalConfig
 
 ---@class cmp.CompletionConfig
@@ -129,4 +130,12 @@ cmp.ItemField.Menu = 'menu'
 ---@field public max_item_count number|nil
 ---@field public group_index number|nil
 
+---@class cmp.EntriesConfig
+---@field name string
+---@field separator string|nil
+
+---@class cmp.ViewConfig
+---@field public entries string|cmp.EntriesConfig
+---@field public separator string
+
 return cmp

lua/cmp/view.lua

@@ -4,6 +4,7 @@ local event = require('cmp.utils.event')
 local keymap = require('cmp.utils.keymap')
 local docs_view = require('cmp.view.docs_view')
 local custom_entries_view = require('cmp.view.custom_entries_view')
+local wildmenu_entries_view = require('cmp.view.wildmenu_entries_view')
 local native_entries_view = require('cmp.view.native_entries_view')
 local ghost_text_view = require('cmp.view.ghost_text_view')
 
@@ -12,6 +13,7 @@ local ghost_text_view = require('cmp.view.ghost_text_view')
 ---@field private resolve_dedup cmp.AsyncDedup
 ---@field private native_entries_view cmp.NativeEntriesView
 ---@field private custom_entries_view cmp.CustomEntriesView
+---@field private wildmenu_entries_view cmp.CustomEntriesView
 ---@field private change_dedup cmp.AsyncDedup
 ---@field private docs_view cmp.DocsView
 ---@field private ghost_text_view cmp.GhostTextView
@@ -23,6 +25,7 @@ view.new = function()
   self.resolve_dedup = async.dedup()
   self.custom_entries_view = custom_entries_view.new()
   self.native_entries_view = native_entries_view.new()
+  self.wildmenu_entries_view = wildmenu_entries_view.new()
   self.docs_view = docs_view.new()
   self.ghost_text_view = ghost_text_view.new()
   self.event = event.new()
@@ -181,19 +184,19 @@ end
 view._get_entries_view = function(self)
   self.native_entries_view.event:clear()
   self.custom_entries_view.event:clear()
+  self.wildmenu_entries_view.event:clear()
 
   local c = config.get()
-  if c.experimental.native_menu then
+  local v = self.custom_entries_view
-    self.native_entries_view.event:on('change', function()
+  if (c.view and c.view.entries and (c.view.entries.name or c.view.entries)) == 'wildmenu' then
-      self:on_entry_change()
+    v = self.wildmenu_entries_view
-    end)
+  elseif (c.view and c.view.entries and (c.view.entries.name or c.view.entries)) == 'native' then
-    return self.native_entries_view
+    v = self.native_entries_view
-  else
-    self.custom_entries_view.event:on('change', function()
-      self:on_entry_change()
-    end)
-    return self.custom_entries_view
   end
+  v.event:on('change', function()
+    self:on_entry_change()
+  end)
+  return v
 end
 
 ---On entry change

lua/cmp/view/wildmenu_entries_view.lua

@@ -0,0 +1,301 @@
+local event = require('cmp.utils.event')
+local autocmd = require('cmp.utils.autocmd')
+local feedkeys = require('cmp.utils.feedkeys')
+local config = require('cmp.config')
+local window = require('cmp.utils.window')
+local types = require('cmp.types')
+local keymap = require('cmp.utils.keymap')
+local misc = require('cmp.utils.misc')
+local api = require('cmp.utils.api')
+
+---@class cmp.CustomEntriesView
+---@field private offset number
+---@field private entries_win cmp.Window
+---@field private active boolean
+---@field private entries cmp.Entry[]
+---@field public event cmp.Event
+local statusline_entries_view = {}
+
+local function get_separator()
+  local c = config.get()
+  return (c and c.view and c.view.entries and c.view.entries.separator) or '  '
+end
+
+statusline_entries_view.ns = vim.api.nvim_create_namespace('cmp.view.statusline_entries_view')
+
+statusline_entries_view.init = function(self)
+  self.event = event.new()
+  self.offset = -1
+  self.active = false
+  self.entries = {}
+  self.selected_index = nil
+  self.last_displayed_indices = {}
+  self.moving_forwards = nil
+end
+
+statusline_entries_view.new = function()
+  local self = setmetatable({}, { __index = statusline_entries_view })
+  self:init()
+
+  self.entries_win = window.new()
+  self.entries_win:option('conceallevel', 2)
+  self.entries_win:option('concealcursor', 'n')
+  self.entries_win:option('cursorlineopt', 'line')
+  self.entries_win:option('foldenable', false)
+  self.entries_win:option('wrap', false)
+  self.entries_win:option('scrolloff', 0)
+  self.entries_win:option('winhighlight', 'Normal:Pmenu,FloatBorder:Pmenu,CursorLine:PmenuSel,Search:None')
+  self.entries_win:buffer_option('tabstop', 1)
+
+  vim.api.nvim_set_decoration_provider(statusline_entries_view.ns, {
+    on_win = function(_, win, buf, _, _)
+      if win ~= self.entries_win.win or buf ~= self.entries_win:get_buffer() then
+        return
+      end
+
+      local location = 0
+      for _, i in ipairs(self.last_displayed_indices) do
+        local e = self.entries[i]
+        if e then
+          local view = e:get_view(self.offset, buf)
+          vim.api.nvim_buf_set_extmark(buf, statusline_entries_view.ns, 0, location, {
+            end_line = 0,
+            end_col = location + view['abbr'].bytes,
+            hl_group = view['abbr'].hl_group,
+            hl_mode = 'combine',
+            ephemeral = true,
+          })
+
+          if i == self.selected_index then
+            vim.api.nvim_buf_set_extmark(buf, statusline_entries_view.ns, 0, location, {
+              end_line = 0,
+              end_col = location + view['abbr'].bytes,
+              hl_group = 'PmenuSel',
+              hl_mode = 'combine',
+              ephemeral = true,
+            })
+          end
+
+          for _, m in ipairs(e.matches or {}) do
+            vim.api.nvim_buf_set_extmark(buf, statusline_entries_view.ns, 0, location + m.word_match_start - 1, {
+              end_line = 0,
+              end_col = location + m.word_match_end,
+              hl_group = m.fuzzy and 'CmpItemAbbrMatchFuzzy' or 'CmpItemAbbrMatch',
+              hl_mode = 'combine',
+              ephemeral = true,
+            })
+          end
+
+          location = location + view['abbr'].bytes + get_separator():len()
+        end
+      end
+    end,
+  })
+
+  autocmd.subscribe(
+    'CompleteChanged',
+    vim.schedule_wrap(function()
+      if self:visible() and vim.fn.pumvisible() == 1 then
+        self:close()
+      end
+    end)
+  )
+  return self
+end
+
+statusline_entries_view.close = function(self)
+  self.entries_win:close()
+  self:init()
+end
+
+statusline_entries_view.ready = function()
+  return vim.fn.pumvisible() == 0
+end
+
+statusline_entries_view.on_change = function(self)
+  self.active = false
+end
+
+statusline_entries_view.open = function(self, offset, entries)
+  self.offset = offset
+  self.entries = {}
+  self.last_displayed_indices = {}
+
+  -- Apply window options (that might be changed) on the custom completion menu.
+  self.entries_win:option('winblend', vim.o.pumblend)
+
+  -- local entries_buf = self.entries_win:get_buffer()
+  local dedup = {}
+  local preselect = 0
+  local i = 1
+  for _, e in ipairs(entries) do
+    local view = e:get_view(offset, 0)
+    if view.dup == 1 or not dedup[e.completion_item.label] then
+      dedup[e.completion_item.label] = true
+      table.insert(self.entries, e)
+      if preselect == 0 and e.completion_item.preselect then
+        preselect = i
+      end
+      i = i + 1
+    end
+  end
+
+  self.entries_win:open({
+    relative = 'editor',
+    style = 'minimal',
+    row = vim.api.nvim_win_get_height(0),
+    col = 0,
+    width = vim.api.nvim_win_get_width(0),
+    height = 1,
+    zindex = 1001,
+  })
+  if preselect > 0 and config.get().preselect == types.cmp.PreselectMode.Item then
+    self:_select(preselect, { behavior = types.cmp.SelectBehavior.Select })
+  elseif not string.match(config.get().completion.completeopt, 'noselect') then
+    self:_select(1, { behavior = types.cmp.SelectBehavior.Select })
+  else
+    self:_select(nil, { behavior = types.cmp.SelectBehavior.Select })
+  end
+end
+
+statusline_entries_view.abort = function(self)
+  feedkeys.call('', 'n', function()
+    self:close()
+  end)
+end
+
+statusline_entries_view.draw = function(self)
+  local entries_buf = self.entries_win:get_buffer()
+  local texts = {}
+  local lengths = {}
+  for _, e in ipairs(self.entries) do
+    if e then
+      local view = e:get_view(self.offset, entries_buf)
+      -- add 1 to lengths, to account for the added separator
+      table.insert(lengths, view['abbr'].bytes + get_separator():len())
+      table.insert(texts, view['abbr'].text)
+    end
+  end
+
+  local selected_index = (self.selected_index or 1)
+  local start_index = (self.selected_index or 1)
+  local lst_dspl_ind = self.last_displayed_indices
+  if #lst_dspl_ind == 0 then
+    start_index = start_index
+  elseif vim.tbl_contains(lst_dspl_ind, selected_index) then
+    start_index = lst_dspl_ind[1]
+  elseif self.moving_forwards then
+    local needed_length = lengths[selected_index]
+    start_index = lst_dspl_ind[1]
+    while needed_length > 0 and vim.tbl_contains(lst_dspl_ind, start_index) do
+      needed_length = needed_length - lengths[start_index]
+      start_index = start_index + 1
+    end
+  else -- we need to scroll back
+    local needed_length = lengths[selected_index]
+    start_index = lst_dspl_ind[1]
+    while needed_length > 0 and vim.tbl_contains(lst_dspl_ind, start_index) do
+      needed_length = needed_length - lengths[start_index]
+      start_index = start_index - 1
+      if start_index <= 0 then
+        start_index = #self.entries
+      end
+    end
+  end
+  local statusline = {}
+  local total_length = 0
+  local displayed_indices = {}
+  for index = start_index, #self.entries * 2 do
+    if index > #self.entries then
+      index = index - #self.entries
+    end
+    if total_length + lengths[index] < vim.api.nvim_win_get_width(self.entries_win.win) then
+      if total_length ~= 0 and index == start_index then
+        break
+      end
+      table.insert(statusline, texts[index])
+      table.insert(displayed_indices, index)
+      total_length = total_length + lengths[index]
+    else
+      -- always add the last entry
+      table.insert(statusline, texts[index])
+      break
+    end
+  end
+
+  statusline = table.concat(statusline, get_separator())
+  self.last_displayed_indices = displayed_indices
+
+  vim.api.nvim_buf_set_lines(entries_buf, 0, 1, false, { statusline })
+  vim.api.nvim_buf_set_option(entries_buf, 'modified', false)
+
+  vim.api.nvim_win_call(0, function()
+    misc.redraw()
+  end)
+end
+
+statusline_entries_view.visible = function(self)
+  return self.entries_win:visible()
+end
+
+statusline_entries_view.info = function(self)
+  return self.entries_win:info()
+end
+
+statusline_entries_view.select_next_item = function(self, option)
+  if self:visible() then
+    self.moving_forwards = true
+    if self.selected_index == nil or self.selected_index == #self.entries then
+      self:_select(1, option)
+    else
+      self:_select(self.selected_index + 1, option)
+    end
+  end
+end
+
+statusline_entries_view.select_prev_item = function(self, option)
+  if self:visible() then
+    self.moving_forwards = false
+    if self.selected_index == nil or self.selected_index <= 1 then
+      self:_select(#self.entries, option)
+    else
+      self:_select(self.selected_index - 1, option)
+    end
+  end
+end
+
+statusline_entries_view.get_first_entry = function(self)
+  if self:visible() then
+    return self.entries[1]
+  end
+end
+
+statusline_entries_view.get_selected_entry = function(self)
+  if self:visible() and self.active then
+    return self.entries[self.selected_index]
+  end
+end
+
+statusline_entries_view.get_active_entry = function(self)
+  if self:visible() and self.active then
+    return self:get_selected_entry()
+  end
+end
+
+statusline_entries_view._select = function(self, selected_index, _)
+  self.selected_index = selected_index
+  self.active = (selected_index ~= nil)
+
+  if self.active then
+    local cursor = api.get_cursor()
+    local word = self:get_active_entry():get_vim_item(self.offset).word
+    local length = vim.fn.strchars(string.sub(api.get_current_line(), self.offset, cursor[2]), true)
+    vim.api.nvim_feedkeys(keymap.backspace(length) .. word, 'int', true)
+  end
+
+  self.entries_win:update()
+  self:draw()
+  self.event:emit('change')
+end
+
+return statusline_entries_view