feat: max_height for completion window (#2202)

Author: dvimaaniye

doc/cmp.txt

@@ -787,6 +787,13 @@ window.completion.scrollbar~
   `boolean`
   Whether the scrollbar should be enabled if there are more items that fit
 
+                                     *cmp-config.window.completion.max_height*
+window.completion.max_height~
+  `number | nil`
+  The completion window's max height, can be set to 0 to use all available
+  space. To use `vim.o.pumheight` set this to `nil`.
+  See |'pumheight'|.
+
                                      *cmp-config.window.documentation.max_width*
 window.documentation.max_width~
   `number`

lua/cmp/config/window.lua

@@ -10,6 +10,7 @@ window.bordered = function(opts)
     col_offset = opts.col_offset or 0,
     side_padding = opts.side_padding or 1,
     scrollbar = opts.scrollbar == nil and true or opts.scrollbar,
+    max_height = opts.max_height or nil,
   }
 end
 

lua/cmp/types/cmp.lua

@@ -131,6 +131,7 @@ cmp.ItemField = {
 ---@field public col_offset? integer|nil
 ---@field public side_padding? integer|nil
 ---@field public scrollbar? boolean|true
+---@field public max_height? integer|nil
 
 ---@class cmp.DocumentationWindowOptions: cmp.WindowOptions
 ---@field public max_height? integer|nil

lua/cmp/view/custom_entries_view.lua

@@ -174,7 +174,7 @@ custom_entries_view.open = function(self, offset, entries)
   width = width + self.column_width.kind + (self.column_width.menu > 0 and 1 or 0)
   width = width + self.column_width.menu + 1
 
-  local height = vim.api.nvim_get_option_value('pumheight', {})
+  local height = completion.max_height or vim.api.nvim_get_option_value('pumheight', {})
   height = height ~= 0 and height or #self.entries
   height = math.min(height, #self.entries)