feat(menu): add scrollbar

docs/config.norg

@@ -112,13 +112,16 @@ version: 1.1.1
    ---@class neocomplete.config.ui.menu
    @end
 
-   It includes some basic window properties like the border and the maximum height of the window.
+   It includes some basic window properties like the border and the maximum height of the window. It
+   also has a field to define the character used for the scrollbar.
    #tangle
    @code lua
    --- Maximum height of the menu
    ---@field max_height integer
    --- The border of the completion menu
    ---@field border string|string[]|string[][]
+   --- Character used for the scrollbar
+   ---@field scrollbar string
    @end
 
 ** Position
@@ -171,13 +174,16 @@ version: 1.1.1
    --- Configuration of the completion menu of neocomplete.nvim
    ---@class neocomplete.config.ui.docs
    @end
-   It consists of window properties like the border and the maximum height of the window.
+   It consists of some basic window properties like the border and the maximum height of the window.
+   It also has a field to define the character used for the scrollbar.
    #tangle
    @code lua
    --- Maximum height of the documentation view
    ---@field max_height integer
    --- The border of the documentation view
    ---@field border string|string[]|string[][]
+   --- Character used for the scrollbar
+   ---@field scrollbar string
    @end
 
 ** Type Icons

docs/menu.norg

@@ -9,7 +9,7 @@ categories: [
     types
 ]
 created: 2024-05-29T11:30:25+0100
-updated: 2024-06-18T19:31:41+0100
+updated: 2024-06-19T21:37:01+0100
 tangle: {
     languages: {
         lua: ../lua/neocomplete/types/menu.lua
@@ -196,3 +196,15 @@ version: 1.1.1
    --- Index of selected item
    ---@field index integer
    @end
+
+** Scrollbar
+   This field is used to store some data for drawing the scrollbar.
+   #tangle
+   @code lua
+   --- Data for the scrollbar
+   ---@field scrollbar neocomplete.scrollbar_data
+
+   ---@class neocomplete.scrollbar_data
+   ---@field buf integer
+   ---@field win integer
+   @end

lua/neocomplete/config.lua

@@ -22,11 +22,13 @@ config.defaults = {
                     { { type_icons[entry_kind] or "", ("@neocomplete.type.%s"):format(entry_kind) } },
                 }
             end,
+            scrollbar = "█",
             alignment = {},
         },
         docs_view = {
             max_height = 7,
             border = "rounded",
+            scrollbar = "█",
         },
         type_icons = {
             Class = "  ",

lua/neocomplete/highlights.lua

@@ -16,4 +16,5 @@ hl("@neocomplete.type", { link = "Normal", default = true })
 hl("@neocomplete.selected", { link = "Visual", default = true })
 hl("@neocomplete.match", { link = "Special", default = true })
 hl("@neocomplete.menu", { link = "NormalFloat", default = true })
+hl("@neocomplete.scrollbar", { link = "PmenuSbar", default = true })
 hl("@neocomplete.entry", { italic = true })

lua/neocomplete/menu/draw.lua

@@ -40,6 +40,7 @@ return function(self)
     local aligned_table = format_utils.get_align_tables(self.entries)
     local column = 0
     vim.api.nvim_buf_clear_namespace(self.buf, self.ns, 0, -1)
+    vim.api.nvim_buf_clear_namespace(self.scrollbar.buf, self.ns, 0, -1)
     local spaces = {}
     for _ = 1, #self.entries do
         table.insert(spaces, (" "):rep(width))
@@ -93,4 +94,18 @@ return function(self)
             vim.api.nvim_buf_add_highlight(self.buf, self.ns, "@neocomplete.match", line - 1, idx - 1, idx)
         end
     end
+
+    local top_visible = vim.fn.line("w0", self.winnr)
+    local bottom_visible = vim.fn.line("w$", self.winnr)
+    local visible_entries = bottom_visible - top_visible + 1
+    local scrollbar_height =
+        math.max(math.min(math.floor(visible_entries * (visible_entries / #self.entries) + 0.5), visible_entries), 1)
+    vim.api.nvim_buf_set_lines(self.scrollbar.buf, 0, -1, false, vim.split(string.rep(" ", visible_entries + 1), ""))
+    local scrollbar_offset = math.max(math.floor(visible_entries * (top_visible / #self.entries)), 1)
+    for i = scrollbar_offset, scrollbar_offset + scrollbar_height do
+        vim.api.nvim_buf_set_extmark(self.scrollbar.buf, self.ns, i - 1, 0, {
+            virt_text = { { self.config.ui.menu.scrollbar, "PmenuSbar" } },
+            virt_text_pos = "overlay",
+        })
+    end
 end

lua/neocomplete/menu/init.lua

@@ -13,6 +13,9 @@ function Menu.new()
     self.buf = vim.api.nvim_create_buf(false, true)
     self.winnr = nil
     self.index = 0
+    self.scrollbar = {}
+    self.scrollbar.win = nil
+    self.scrollbar.buf = vim.api.nvim_create_buf(false, true)
     return self
 end
 
@@ -54,13 +57,26 @@ function Menu:open_win(offset)
         border = self.config.ui.menu.border,
         row = position == "below" and 1 or -(height + 2),
         col = -offset,
+        zindex = 1000,
     })
     vim.wo[self.winnr][self.buf].scrolloff = 0
+
+    self.scrollbar.win = vim.api.nvim_open_win(self.scrollbar.buf, false, {
+        height = height,
+        relative = "cursor",
+        col = -offset + width,
+        row = position == "below" and 2 or -(height + 2) + 1,
+        width = 1,
+        style = "minimal",
+        border = "none",
+        zindex = 2000,
+    })
 end
 
 function Menu:close()
     -- TODO: reset more things?
     pcall(vim.api.nvim_win_close, self.winnr, true)
+    pcall(vim.api.nvim_win_close, self.scrollbar.win, true)
     Menu.winnr = nil
 end
 

lua/neocomplete/types/config.lua

@@ -22,6 +22,8 @@
 ---@field max_height integer
 --- The border of the completion menu
 ---@field border string|string[]|string[][]
+--- Character used for the scrollbar
+---@field scrollbar string
 --- Position of the menu
 ---@field position "auto"|"bottom"|"top"
 --- How an entry should be formatted
@@ -34,5 +36,7 @@
 ---@field max_height integer
 --- The border of the documentation view
 ---@field border string|string[]|string[][]
+--- Character used for the scrollbar
+---@field scrollbar string
 --- The icons used for the different completion item types
 ---@alias neocomplete.config.ui.type_icons table<string, string>

lua/neocomplete/types/menu.lua

@@ -35,4 +35,10 @@
 --- Window of menu
 ---@field winnr integer?
 --- Index of selected item
----@field index integer
+---@field index integer
+--- Data for the scrollbar
+---@field scrollbar neocomplete.scrollbar_data
+
+---@class neocomplete.scrollbar_data
+---@field buf integer
+---@field win integer