dropbar.nvim

IDE-like breadcrumbs, out of the box

A polished, IDE-like, highly-customizable winbar for Neovim
with drop-down menu support and mutiple backends

• Features
• Requirements
• Installation
• Usage
• Configuration
  • Options
    • General
    • Icons
    • Symbol
    • Bar
    • Menu
    • Sources
      • Path
      • Treesitter
      • LSP
      • Markdown
  • API
  • Highlighting
• Developers
  • Architecture
  • Classes
    • dropbar_t
    • dropbar_symbol_t
    • dropbar_menu_t
    • dropbar_menu_entry_t
    • dropbar_menu_hl_info_t
    • dropbar_source_t
  • Making a New Source
    • Making a Source With Drop-Down Menus
    • Default on_click() Callback
    • Lazy-Loading Expensive Fields
• Similar Projects

Features

dropbar-demo-light.mp4

• Opening drop-down menus or go to definition with a single mouse click

  

• Pick mode for quickly selecting a component in the winbar with shortcuts

  

• Automatically truncating long components

  

• Multiple backends that support fall-backs

  dropbar.nvim comes with four builtin sources:

  • lsp: gets symbols from language servers using nvim's builtin LSP framework

  • markdown: a custom incremental parser that gets symbol information about markdown headings

  • path: gets current file path

  • treesitter: gets symbols from treesitter parsers using nvim's builtin treesitter integration

  To make a new source yourself, see making a new source.

  For source fall-backs support, see bar options.

• Zero config & Zero dependency

  dropbar.nvim does not require nvim-lspconfig, nvim-treesitter or any third-party UI libraries to work. As long as the language server or the treesitter parser is installed, it should work just fine.

• Drop-down menu components and winbar symbols that response to mouse/cursor hovering:

  

  • This features requires :h mousemoveevent to be enabled.

• Preview symbols in their source windows when hovering over them in the drop-down menu

  

• Reorient the source window on previewing or after jumping to a symbol

• Add preview for symbols shown in the winbar

• Preview symbols (files) from path source

• Add more actions other than jump and preview, e.g. rename, delete, select, etc.

• Support visual mode selection to select/delete multiple symbols

• Add scrollbar to the menu when the symbol list is too long

• Ability to hide/show the winbar on each window separately

Requirements

• Neovim Nightly (>= 0.10.0-dev)
• Optional
  • nvim-web-devicons, if you want to see icons for different filetypes
  • Working language server installation for the lsp source to work
  • Working treesitter parser installation for the treesitter source to work

Installation

• Using lazy.nvim

  require('lazy').setup({
    { 'Bekaboo/dropbar.nvim' }
  })

• Using packer.nvim

  require('packer').startup(function(use)
    use('Bekaboo/dropbar.nvim')
  end)

• Using native package manager

  mkdir -p ~/.local/share/nvim/site/pack/packages/
  git clone https://github.com/Bekaboo/dropbar.nvim ~/.local/share/nvim/site/pack/packages/start/dropbar.nvim

  Lazy-loading is unneeded as it is already done in plugin/dropbar.lua.

Usage

• Basics
  • Moves the cursor around and see the winbar reflects your current context
• Mouse support
  • Click on a component in the winbar to open a drop-down menu of its siblings
  • Click on an entry in the drop-down menu to go to its location
  • Click on the indicator in the drop-down menu to open a sub-menu of its children
• Pick mode
  • Use require('dropbar.api').pick() to enter interactive pick mode or require('dropbar.api').pick(<idx>) to directly select a component at idx.
  • Inside interactive pick mode, press the corresponding pivot shown before each component to select it
• Default keymaps in drop-down menu
  • <LeftMouse>: call the on_click callback of the symbol at the mouse click
  • <CR>: find the first clickable symbol in the current drop-down menu entry and call its on_click callback
  • To disable, remap or add new keymaps in the drop-down menu, see menu options

Configuration

Options

A full list of all available options and their default values:

---@class dropbar_configs_t
local opts = {
  general = {
    ---@type boolean|fun(buf: integer, win: integer): boolean
    enable = function(buf, win)
      return not vim.api.nvim_win_get_config(win).zindex
        and vim.bo[buf].buftype == ''
        and vim.api.nvim_buf_get_name(buf) ~= ''
        and not vim.wo[win].diff
    end,
    -- Wait for a short time before updating the winbar, if another update
    -- request is received within this time, the previous request will be
    -- cancelled, this improves the performance when the user is holding
    -- down a key (e.g. 'j') to scroll the window, default to 0 ms
    -- If you encounter performance issues when scrolling the window, try
    -- setting this option to a number slightly larger than
    -- 1000 / key_repeat_rate
    update_interval = 0,
    update_events = {
      win = {
        'CursorMoved',
        'CursorMovedI',
        'WinEnter',
        'WinResized',
      },
      buf = {
        'BufModifiedSet',
        'FileChangedShellPost',
        'TextChanged',
        'TextChangedI',
      },
      global = {
        'DirChanged',
        'VimResized',
      },
    },
  },
  icons = {
    enable = true,
    kinds = {
      use_devicons = true,
      symbols = {
        Array = '󰅪 ',
        Boolean = ' ',
        BreakStatement = '󰙧 ',
        Call = '󰃷 ',
        CaseStatement = '󱃙 ',
        Class = ' ',
        Color = '󰏘 ',
        Constant = '󰏿 ',
        Constructor = ' ',
        ContinueStatement = '→ ',
        Copilot = ' ',
        Declaration = '󰙠 ',
        Delete = '󰩺 ',
        DoStatement = '󰑖 ',
        Enum = ' ',
        EnumMember = ' ',
        Event = ' ',
        Field = ' ',
        File = '󰈔 ',
        Folder = '󰉋 ',
        ForStatement = '󰑖 ',
        Function = '󰊕 ',
        Identifier = '󰀫 ',
        IfStatement = '󰇉 ',
        Interface = ' ',
        Keyword = '󰌋 ',
        List = '󰅪 ',
        Log = '󰦪 ',
        Lsp = ' ',
        Macro = '󰁌 ',
        MarkdownH1 = '󰉫 ',
        MarkdownH2 = '󰉬 ',
        MarkdownH3 = '󰉭 ',
        MarkdownH4 = '󰉮 ',
        MarkdownH5 = '󰉯 ',
        MarkdownH6 = '󰉰 ',
        Method = '󰆧 ',
        Module = '󰏗 ',
        Namespace = '󰅩 ',
        Null = '󰢤 ',
        Number = '󰎠 ',
        Object = '󰅩 ',
        Operator = '󰆕 ',
        Package = '󰆦 ',
        Property = ' ',
        Reference = '󰦾 ',
        Regex = ' ',
        Repeat = '󰑖 ',
        Scope = '󰅩 ',
        Snippet = '󰩫 ',
        Specifier = '󰦪 ',
        Statement = '󰅩 ',
        String = '󰉾 ',
        Struct = ' ',
        SwitchStatement = '󰺟 ',
        Text = ' ',
        Type = ' ',
        TypeParameter = '󰆩 ',
        Unit = ' ',
        Value = '󰎠 ',
        Variable = '󰀫 ',
        WhileStatement = '󰑖 ',
      },
    },
    ui = {
      bar = {
        separator = ' ',
        extends = '…',
      },
      menu = {
        separator = ' ',
        indicator = ' ',
      },
    },
  },
  symbol = {
    preview = {
      ---Reorient the preview window on previewing a new symbol
      ---@param _ integer source window id, ignored
      ---@param range {start: {line: integer}, end: {line: integer}} 0-indexed
      reorient = function(_, range)
        local invisible = range['end'].line - vim.fn.line('w$') + 1
        if invisible > 0 then
          local view = vim.fn.winsaveview()
          view.topline = view.topline + invisible
          vim.fn.winrestview(view)
        end
      end,
    },
    jump = {
      ---@param win integer source window id
      ---@param range {start: {line: integer}, end: {line: integer}} 0-indexed
      reorient = function(win, range)
        local view = vim.fn.winsaveview()
        local win_height = vim.api.nvim_win_get_height(win)
        local topline = range.start.line - math.floor(win_height / 4)
        if
          topline > view.topline
          and topline + win_height < vim.fn.line('$')
        then
          view.topline = topline
          vim.fn.winrestview(view)
        end
      end,
    },
  },
  bar = {
    ---@type dropbar_source_t[]|fun(buf: integer, win: integer): dropbar_source_t[]
    sources = function(buf, _)
      local sources = require('dropbar.sources')
        local utils = require('dropbar.utils')
      if vim.bo[buf].ft == 'markdown' then
        return {
          sources.path,
          utils.source.fallback({
            sources.treesitter,
            sources.markdown,
            sources.lsp,
          }),
        }
      end
      return {
        sources.path,
        utils.source.fallback({
          sources.lsp,
          sources.treesitter,
        }),
      }
    end,
    padding = {
      left = 1,
      right = 1,
    },
    pick = {
      pivots = 'abcdefghijklmnopqrstuvwxyz',
    },
    truncate = true,
  },
  menu = {
    -- When on, preview the symbol under the cursor on CursorMoved
    preview = true,
    -- When on, automatically set the cursor to the closest previous/next
    -- clickable component in the direction of cursor movement on CursorMoved
    quick_navigation = true,
    entry = {
      padding = {
        left = 1,
        right = 1,
      },
    },
    ---@type table<string, string|function|table<string, string|function>>
    keymaps = {
      ['<LeftMouse>'] = function()
        local api = require('dropbar.api')
        local menu = api.get_current_dropbar_menu()
        if not menu then
          return
        end
        local mouse = vim.fn.getmousepos()
        if mouse.winid ~= menu.win then
          local prev_menu = api.get_dropbar_menu(mouse.winid)
          if prev_menu and prev_menu.sub_menu then
            prev_menu.sub_menu:close()
          end
          if vim.api.nvim_win_is_valid(mouse.winid) then
            vim.api.nvim_set_current_win(mouse.winid)
          end
          return
        end
        menu:click_at({ mouse.line, mouse.column - 1 }, nil, 1, 'l')
      end,
      ['<CR>'] = function()
        local menu = require('dropbar.api').get_current_dropbar_menu()
        if not menu then
          return
        end
        local cursor = vim.api.nvim_win_get_cursor(menu.win)
        local component = menu.entries[cursor[1]]:first_clickable(cursor[2])
        if component then
          menu:click_on(component, nil, 1, 'l')
        end
      end,
      ['<MouseMove>'] = function()
        local menu = require('dropbar.api').get_current_dropbar_menu()
        if not menu then
          return
        end
        local mouse = vim.fn.getmousepos()
        -- If mouse is not in the menu window or on the border, end preview
        -- and clear hover highlights
        if mouse.winid ~= menu.win or mouse.line <= 0 or mouse.column <= 0 then
          -- Find the root menu
          while menu and menu.prev_menu do
            menu = menu.prev_menu
          end
          if menu then
            menu:finish_preview(true)
            menu:update_hover_hl()
          end
          return
        end
        if M.opts.menu.preview then
          menu:preview_symbol_at({ mouse.line, mouse.column - 1 }, true)
        end
        menu:update_hover_hl({ mouse.line, mouse.column - 1 })
      end,
    },
    ---@alias dropbar_menu_win_config_opts_t any|fun(menu: dropbar_menu_t):any
    ---@type table<string, dropbar_menu_win_config_opts_t>
    ---@see vim.api.nvim_open_win
    win_configs = {
      border = 'none',
      style = 'minimal',
      row = function(menu)
        return menu.prev_menu
            and menu.prev_menu.clicked_at
            and menu.prev_menu.clicked_at[1] - vim.fn.line('w0')
          or 0
      end,
      ---@param menu dropbar_menu_t
      col = function(menu)
        if menu.prev_menu then
          return menu.prev_menu._win_configs.width
        end
        local mouse = vim.fn.getmousepos()
        local bar = require('dropbar.api').get_dropbar(
          vim.api.nvim_win_get_buf(menu.prev_win),
          menu.prev_win
        )
        if not bar then
          return mouse.wincol
        end
        local _, range = bar:get_component_at(math.max(0, mouse.wincol - 1))
        return range and range.start or mouse.wincol
      end,
      relative = 'win',
      win = function(menu)
        return menu.prev_menu and menu.prev_menu.win
          or vim.fn.getmousepos().winid
      end,
      height = function(menu)
        return math.max(
          1,
          math.min(
            #menu.entries,
            vim.go.pumheight ~= 0 and vim.go.pumheight
              or math.ceil(vim.go.lines / 4)
          )
        )
      end,
      width = function(menu)
        local min_width = vim.go.pumwidth ~= 0 and vim.go.pumwidth or 8
        if vim.tbl_isempty(menu.entries) then
          return min_width
        end
        return math.max(
          min_width,
          math.max(unpack(vim.tbl_map(function(entry)
            return entry:displaywidth()
          end, menu.entries)))
        )
      end,
    },
  },
  sources = {
    path = {
      ---@type string|fun(buf: integer): string
      relative_to = function(_)
        return vim.fn.getcwd()
      end,
      ---Can be used to filter out files or directories
      ---based on their name
      ---@type fun(name: string): boolean
      filter = function(_)
        return true
      end,
      ---Last symbol from path source when current buf is modified
      ---@param sym dropbar_symbol_t
      ---@return dropbar_symbol_t
      modified = function(sym)
        return sym
      end,
    },
    treesitter = {
      -- Lua pattern used to extract a short name from the node text
      -- Be aware that the match result must not be nil!
      name_pattern = '[#~%*%w%._%->!@:]+%s*'
        .. string.rep('[#~%*%w%._%->!@:]*', 3, '%s*'),
      -- The order matters! The first match is used as the type
      -- of the treesitter symbol and used to show the icon
      -- Types listed below must have corresponding icons
      -- in the `icons.kinds.symbols` table for the icon to be shown
      valid_types = {
        'array',
        'boolean',
        'break_statement',
        'call',
        'case_statement',
        'class',
        'constant',
        'constructor',
        'continue_statement',
        'delete',
        'do_statement',
        'enum',
        'enum_member',
        'event',
        'for_statement',
        'function',
        'h1_marker',
        'h2_marker',
        'h3_marker',
        'h4_marker',
        'h5_marker',
        'h6_marker',
        'if_statement',
        'interface',
        'keyword',
        'list',
        'macro',
        'method',
        'module',
        'namespace',
        'null',
        'number',
        'operator',
        'package',
        'pair',
        'property',
        'reference',
        'repeat',
        'scope',
        'specifier',
        'string',
        'struct',
        'switch_statement',
        'type',
        'type_parameter',
        'unit',
        'value',
        'variable',
        'while_statement',
        'declaration',
        'field',
        'identifier',
        'object',
        'statement',
        'text',
      },
    },
    lsp = {
      request = {
        -- Times to retry a request before giving up
        ttl_init = 60,
        interval = 1000, -- in ms
      },
    },
    markdown = {
      parse = {
        -- Number of lines to update when cursor moves out of the parsed range
        look_ahead = 200,
      },
    },
  },
}

General

These options live under opts.general and are used to configure the general behavior of the plugin:

• opts.general.enable: boolean|fun(buf: integer, win: integer): boolean
  • Controls whether to enable the plugin for the current buffer and window
  • If a function is provided, it will be called with the current bufnr and winid and should return a boolean
  • Default:

    function(buf, win)
      return not vim.api.nvim_win_get_config(win).zindex
      and vim.bo[buf].buftype == ''
      and vim.api.nvim_buf_get_name(buf) ~= ''
      and not vim.wo[win].diff
    end

• opts.general.update_interval: number
  • Wait for a short time before updating the winbar, if another update request is received within this time, the previous request will be cancelled, this improves the performance when the user is holding down a key (e.g. 'j') to scroll the window
  • If you encounter performance issues when scrolling the window, try setting this option to a number slightly larger than 1000 / key_repeat_rate
  • Default: 0
• opts.general.update_events.win: string[]
  • List of events that should trigger an update on the dropbar attached to a single window
  • Default:

    {
      'CursorMoved',
      'CursorMovedI',
      'WinEnter',
      'WinLeave',
      'WinResized',
    }

• opts.general.update_events.buf: string[]
  • List of events that should trigger an update on all dropbars attached to a buffer
  • Default:

    {
      'BufModifiedSet',
      'FileChangedShellPost',
      'TextChanged',
      'TextChangedI',
    }

• opts.general.update_events.global: string[]
  • List of events that should trigger an update of all dropbars in current nvim session
  • Default:

    {
      'DirChanged',
      'VimResized',
    }

Icons

These options live under opts.icons and are used to configure the icons used by the plugin:

• opts.icons.enable: boolean
  • Whether to enable icons
  • Default: true
• opts.icons.kinds.use_devicons: boolean
  • Whether to use nvim-web-devicons to show icons for different filetypes
  • Default: true
• opts.icons.kinds.symbols: table<string, string>
  • Table mapping the different kinds of symbols to their corresponding icons
  • Default:

    {
      Array = '󰅪 ',
      Boolean = ' ',
      BreakStatement = '󰙧 ',
      Call = '󰃷 ',
      CaseStatement = '󱃙 ',
      Class = ' ',
      Color = '󰏘 ',
      Constant = '󰏿 ',
      Constructor = ' ',
      ContinueStatement = '→ ',
      Copilot = ' ',
      Declaration = '󰙠 ',
      Delete = '󰩺 ',
      DoStatement = '󰑖 ',
      Enum = ' ',
      EnumMember = ' ',
      Event = ' ',
      Field = ' ',
      File = '󰈔 ',
      Folder = '󰉋 ',
      ForStatement = '󰑖 ',
      Function = '󰊕 ',
      Identifier = '󰀫 ',
      IfStatement = '󰇉 ',
      Interface = ' ',
      Keyword = '󰌋 ',
      List = '󰅪 ',
      Log = '󰦪 ',
      Lsp = ' ',
      Macro = '󰁌 ',
      MarkdownH1 = '󰉫 ',
      MarkdownH2 = '󰉬 ',
      MarkdownH3 = '󰉭 ',
      MarkdownH4 = '󰉮 ',
      MarkdownH5 = '󰉯 ',
      MarkdownH6 = '󰉰 ',
      Method = '󰆧 ',
      Module = '󰏗 ',
      Namespace = '󰅩 ',
      Null = '󰢤 ',
      Number = '󰎠 ',
      Object = '󰅩 ',
      Operator = '󰆕 ',
      Package = '󰆦 ',
      Pair = '󰅪 ',
      Property = ' ',
      Reference = '󰦾 ',
      Regex = ' ',
      Repeat = '󰑖 ',
      Scope = '󰅩 ',
      Snippet = '󰩫 ',
      Specifier = '󰦪 ',
      Statement = '󰅩 ',
      String = '󰉾 ',
      Struct = ' ',
      SwitchStatement = '󰺟 ',
      Terminal = ' ',
      Text = ' ',
      Type = ' ',
      TypeParameter = '󰆩 ',
      Unit = ' ',
      Value = '󰎠 ',
      Variable = '󰀫 ',
      WhileStatement = '󰑖 ',
    }

• opts.icons.ui.bar: table<string, string>
  • Controls the icons used in the winbar UI
  • Default:

    {
      separator = ' ',
      extends = '…',
    }

• opts.icons.ui.menu: table<string, string>
  • Controls the icons used in the menu UI
  • Default:

    {
      separator = ' ',
      indicator = ' ',
    }

Symbol

These options live under opts.symbol and are used to control the behavior of the symbols:

• opts.symbol.preview.reorient: fun(win: integer, range: {start: {line: integer, character: integer}, end: {line: integer, character: integer}})
  • Function to reorient the source window when previewing symbol given the source window win and the range of the symbol range
  • Default:

    function(_, range)
      local invisible = range['end'].line - vim.fn.line('w$') + 1
      if invisible > 0 then
        local view = vim.fn.winsaveview()
        view.topline = view.topline + invisible
        vim.fn.winrestview(view)
      end
    end

• opts.symbol.jump.reorient: fun(win: integer, range: {start: {line: integer, character: integer}, end: {line: integer, character: integer}})
  • Function to reorient the source window after jumping to symbol given the source window win and the range of the symbol range
  • Default:

    function(win, range)
      local view = vim.fn.winsaveview()
      local win_height = vim.api.nvim_win_get_height(win)
      local topline = range.start.line - math.floor(win_height / 4)
      if
        topline > view.topline
        and topline + win_height < vim.fn.line('$')
      then
        view.topline = topline
        vim.fn.winrestview(view)
      end
    end,

Bar

These options live under opts.bar and are used to control the behavior of the winbar:

• opts.bar.hover: boolean
  • Whether to highlight the symbol under the cursor
  • This feature requires 'mousemoveevent' to be enabled
  • Default: true
• opts.bar.sources: dropbar_source_t[]|fun(buf: integer, win: integer): dropbar_source_t[]
  • List of sources to show in the winbar
  • If a function is provided, it will be called with the current bufnr and winid and should return a list of sources
  • Default:

    function(buf, _)
      local sources = require('dropbar.sources')
      local utils = require('dropbar.utils')
      if vim.bo[buf].ft == 'markdown' then
        return {
          sources.path,
          utils.source.fallback({
            sources.treesitter,
            sources.markdown,
            sources.lsp,
          }),
        }
      end
      return {
        sources.path,
        utils.source.fallback({
          sources.lsp,
          sources.treesitter,
        }),
      }
    end,

  • For more information about sources, see dropbar_source_t.
• opts.bar.padding: { left: number, right: number }
  • Padding to use between the winbar and the window border
  • Default: { left = 1, right = 1 }
• opts.bar.pick.pivots: string
  • Pivots to use in pick mode
  • Default: 'abcdefghijklmnopqrstuvwxyz'
• opts.bar.truncate: boolean
  • Whether to truncate the winbar if it doesn't fit in the window
  • Default: true

Menu

These options live under opts.menu and are used to control the behavior of the menu:

• opts.menu.quick_navigation: boolean
  • When on, automatically set the cursor to the closest previous/next clickable component in the direction of cursor movement on CursorMoved
  • Default: true
• opts.menu.entry.padding: { left: number, right: number }
  • Padding to use between the menu entry and the menu border
  • Default: { left = 1, right = 1 }
• opts.menu.preview: boolean
  • Whether to enable previewing for menu entries
  • Default: true
• opts.menu.keymaps: table<string, function|string|table<string, function>|table<string, string>>
  • Buffer-local keymaps in the menu
  • Use <key> = <function|string> to map a key in normal mode and visual mode in the menu buffer, or use <key> = table<mode, function|string> to map a key in specific modes.
  • Default:

    {
      ['<LeftMouse>'] = function()
        local api = require('dropbar.api')
        local menu = api.get_current_dropbar_menu()
        if not menu then
          return
        end
        local mouse = vim.fn.getmousepos()
        if mouse.winid ~= menu.win then
          local prev_menu = api.get_dropbar_menu(mouse.winid)
          if prev_menu and prev_menu.sub_menu then
            prev_menu.sub_menu:close()
          end
          if vim.api.nvim_win_is_valid(mouse.winid) then
            vim.api.nvim_set_current_win(mouse.winid)
          end
          return
        end
        menu:click_at({ mouse.line, mouse.column - 1 }, nil, 1, 'l')
      end,
      ['<CR>'] = function()
        local menu = require('dropbar.api').get_current_dropbar_menu()
        if not menu then
          return
        end
        local cursor = vim.api.nvim_win_get_cursor(menu.win)
        local component = menu.entries[cursor[1]]:first_clickable(cursor[2])
        if component then
          menu:click_on(component, nil, 1, 'l')
        end
      end,
      ['<MouseMove>'] = function()
        local menu = require('dropbar.api').get_current_dropbar_menu()
        if not menu then
          return
        end
        local mouse = vim.fn.getmousepos()
        -- If mouse is not in the menu window or on the border, end preview
        -- and clear hover highlights
        if mouse.winid ~= menu.win or mouse.line <= 0 or mouse.column <= 0 then
          -- Find the root menu
          while menu and menu.prev_menu do
            menu = menu.prev_menu
          end
          if menu then
            menu:finish_preview(true)
            menu:update_hover_hl()
          end
          return
        end
        if M.opts.menu.preview then
          menu:preview_symbol_at({ mouse.line, mouse.column - 1 }, true)
        end
        menu:update_hover_hl({ mouse.line, mouse.column - 1 })
      end,
    }

• opts.menu.win_configs: table<string, dropbar_menu_win_config_opts_t>
  • Window configurations for the menu, see :h nvim_open_win()
  • Each config key in opts.menu.win_configs accepts either a plain value which will be passes directly to nvim_open_win(), or a function that takes the current menu (see dropbar_menu_t) as an argument and returns a value to be passed to nvim_open_win().
  • Default:

    {
      border = 'none',
      style = 'minimal',
      row = function(menu)
        return menu.prev_menu
            and menu.prev_menu.clicked_at
            and menu.prev_menu.clicked_at[1] - vim.fn.line('w0')
          or 0
      end,
      ---@param menu dropbar_menu_t
      col = function(menu)
        if menu.prev_menu then
          return menu.prev_menu._win_configs.width
        end
        local mouse = vim.fn.getmousepos()
        local bar = require('dropbar.api').get_dropbar(
          vim.api.nvim_win_get_buf(menu.prev_win),
          menu.prev_win
        )
        if not bar then
          return mouse.wincol
        end
        local _, range = bar:get_component_at(math.max(0, mouse.wincol - 1))
        return range and range.start or mouse.wincol
      end,
      relative = 'win',
      win = function(menu)
        return menu.prev_menu and menu.prev_menu.win
          or vim.fn.getmousepos().winid
      end,
      height = function(menu)
        return math.max(
          1,
          math.min(
            #menu.entries,
            vim.go.pumheight ~= 0 and vim.go.pumheight
              or math.ceil(vim.go.lines / 4)
          )
        )
      end,
      width = function(menu)
        local min_width = vim.go.pumwidth ~= 0 and vim.go.pumwidth or 8
        if vim.tbl_isempty(menu.entries) then
          return min_width
        end
        return math.max(
          min_width,
          math.max(unpack(vim.tbl_map(function(entry)
            return entry:displaywidth()
          end, menu.entries)))
        )
      end,
    }

Sources

These options live under opts.sources and are used to control the behavior of each sources.

Path

• opts.sources.path.relative_to: string|fun(buf: integer): string
  • The path to use as the root of the relative path
  • If a function is provided, it will be called with the current buffer number as an argument and should return a string to use as the root of the relative path
  • Notice: currently does not support .. relative paths
  • Default:

    function(_)
      return vim.fn.getcwd()
    end

• opts.sources.path.filter: function(name: string): boolean
  • A function that takes a file name and returns whether to include it in the results shown in the drop-down menu
  • Default:

    function(_)
      return true
    end

• opts.sources.path.modified: function(sym: dropbar_symbol_t): dropbar_symbol_t
  • A function that takes the last symbol_{dropbar_symbol_t} in the result got from the path source and returns an alternative symbol_{dropbar_symbol_t} to show if the current buffer is modified
  • Default:

    function(sym)
      return sym
    end

  • To set a different icon, name, or highlights when the buffer is modified, you can change the corresponding fields in the returned symbol_{dropbar_symbol_t}

    function(sym)
      return sym:merge({
        name = sym.name .. '[+]',
        icon = ' ',
        name_hl = 'DiffAdded',
        icon_hl = 'DiffAdded',
        -- ...
      })
    end

Treesitter

• opts.sources.treesitter.name_pattern: string
  • Lua pattern used to extract a short name from the node text
  • Be aware! The matching result must not be nil
  • Default: '[#~%*%w%._%->!@:]+%s*' .. string.rep('[#~%*%w%._%->!@:]*', 3, '%s*')
• opts.sources.treesitter.valid_types: string[]
  • A list of treesitter node types to include in the results
  • Default:

    {
      'array',
      'boolean',
      'break_statement',
      'call',
      'case_statement',
      'class',
      'constant',
      'constructor',
      'continue_statement',
      'delete',
      'do_statement',
      'enum',
      'enum_member',
      'event',
      'for_statement',
      'function',
      'h1_marker',
      'h2_marker',
      'h3_marker',
      'h4_marker',
      'h5_marker',
      'h6_marker',
      'if_statement',
      'interface',
      'keyword',
      'list',
      'macro',
      'method',
      'module',
      'namespace',
      'null',
      'number',
      'operator',
      'package',
      'pair',
      'property',
      'reference',
      'repeat',
      'scope',
      'specifier',
      'string',
      'struct',
      'switch_statement',
      'type',
      'type_parameter',
      'unit',
      'value',
      'variable',
      'while_statement',
      'declaration',
      'field',
      'identifier',
      'object',
      'statement',
      'text',
    }

LSP

• opts.sources.lsp.request.ttl_init: number
  • Number of times to retry a request before giving up
  • Default: 60
• opts.sources.lsp.request.interval: number
  • Number of milliseconds to wait between retries
  • Default: 1000

Markdown

• opts.sources.markdown.parse.look_ahead: number
  • Number of lines to update when cursor moves out of the parsed range
  • Default: 200

API

dropbar.nvim exposes a few functions in lua/dropbar/api.lua that can be used to interact with the winbar or the drop-down menu:

• get_dropbar(buf: integer?, win: integer): dropbar_t?
  • Get the dropbar associated with the given buffer and window
  • For more information about the dropbar_t type, see dropbar_t
• get_current_dropbar(): dropbar_t?
  • Get the dropbar associated with the current buffer and window
• get_dropbar_menu(win: integer): dropbar_menu_t?
  • Get the drop-down menu associated with the given window
  • For more information about the dropbar_menu_t type, see dropbar_menu_t
• get_current_dropbr_menu(): dropbar_menu_t?
  • Get the drop-down menu associated with the current window
• goto_context_start(count: integer?)
  • Move the cursor to the start of the current context
  • If count is 0 or nil, go to the start of current context, or the start at previous context if cursor is already at the start of current context
  • If count is positive, goto the start of count previous context
• select_next_context()
  • Open the menu of current context to select the next context
• pick(idx: integer?)
  • Pick a component from current winbar
  • If idx is nil, enter interactive pick mode to select a component
  • If idx is a number, directly pick the component at that index if it exists

Highlighting

dropbar.nvim defines the following highlight groups that, override them in your colorscheme to change the appearance of the drop-down menu, the names should be self-explanatory:

Highlight groups

Highlight group	Attributes
DropBarCurrentContext	{ link = 'Visual' }
DropBarHover	{ link = 'Visual' }
DropBarIconCurrentContext	{ link = 'Visual' }
DropBarIconKindArray	{ link = 'Array' }
DropBarIconKindBoolean	{ link = 'Boolean' }
DropBarIconKindBreakStatement	{ link = 'Error' }
DropBarIconKindCall	{ link = 'Function' }
DropBarIconKindCaseStatement	{ link = 'Conditional' }
DropBarIconKindClass	{ link = 'CmpItemKindClass' }
DropBarIconKindConstant	{ link = 'Constant' }
DropBarIconKindConstructor	{ link = 'CmpItemKindConstructor' }
DropBarIconKindContinueStatement	{ link = 'Repeat' }
DropBarIconKindDeclaration	{ link = 'CmpItemKindSnippet' }
DropBarIconKindDelete	{ link = 'Error' }
DropBarIconKindDoStatement	{ link = 'Repeat' }
DropBarIconKindElseStatement	{ link = 'Conditional' }
DropBarIconKindEnum	{ link = 'CmpItemKindEnum' }
DropBarIconKindEnumMember	{ link = 'CmpItemKindEnumMember' }
DropBarIconKindEvent	{ link = 'CmpItemKindEvent' }
DropBarIconKindField	{ link = 'CmpItemKindField' }
DropBarIconKindFile	{ link = 'NormalFloat' }
DropBarIconKindFolder	{ link = 'Directory' }
DropBarIconKindForStatement	{ link = 'Repeat' }
DropBarIconKindFunction	{ link = 'Function' }
DropBarIconKindH1Marker	{ link = 'markdownH1' }
DropBarIconKindH2Marker	{ link = 'markdownH2' }
DropBarIconKindH3Marker	{ link = 'markdownH3' }
DropBarIconKindH4Marker	{ link = 'markdownH4' }
DropBarIconKindH5Marker	{ link = 'markdownH5' }
DropBarIconKindH6Marker	{ link = 'markdownH6' }
DropBarIconKindIdentifier	{ link = 'CmpItemKindVariable' }
DropBarIconKindIfStatement	{ link = 'Conditional' }
DropBarIconKindInterface	{ link = 'CmpItemKindInterface' }
DropBarIconKindKeyword	{ link = 'Keyword' }
DropBarIconKindList	{ link = 'SpecialChar' }
DropBarIconKindMacro	{ link = 'Macro' }
DropBarIconKindMarkdownH1	{ link = 'markdownH1' }
DropBarIconKindMarkdownH2	{ link = 'markdownH2' }
DropBarIconKindMarkdownH3	{ link = 'markdownH3' }
DropBarIconKindMarkdownH4	{ link = 'markdownH4' }
DropBarIconKindMarkdownH5	{ link = 'markdownH5' }
DropBarIconKindMarkdownH6	{ link = 'markdownH6' }
DropBarIconKindMethod	{ link = 'CmpItemKindMethod' }
DropBarIconKindModule	{ link = 'CmpItemKindModule' }
DropBarIconKindNamespace	{ link = 'NameSpace' }
DropBarIconKindNull	{ link = 'Constant' }
DropBarIconKindNumber	{ link = 'Number' }
DropBarIconKindObject	{ link = 'Statement' }
DropBarIconKindOperator	{ link = 'Operator' }
DropBarIconKindPackage	{ link = 'CmpItemKindModule' }
DropBarIconKindPair	{ link = 'String' }
DropBarIconKindProperty	{ link = 'CmpItemKindProperty' }
DropBarIconKindReference	{ link = 'CmpItemKindReference' }
DropBarIconKindRepeat	{ link = 'Repeat' }
DropBarIconKindScope	{ link = 'NameSpace' }
DropBarIconKindSpecifier	{ link = 'Specifier' }
DropBarIconKindStatement	{ link = 'Statement' }
DropBarIconKindString	{ link = 'String' }
DropBarIconKindStruct	{ link = 'CmpItemKindStruct' }
DropBarIconKindSwitchStatement	{ link = 'Conditional' }
DropBarIconKindType	{ link = 'CmpItemKindClass' }
DropBarIconKindTypeParameter	{ link = 'CmpItemKindTypeParameter' }
DropBarIconKindUnit	{ link = 'CmpItemKindUnit' }
DropBarIconKindValue	{ link = 'Number' }
DropBarIconKindVariable	{ link = 'CmpItemKindVariable' }
DropBarIconKindWhileStatement	{ link = 'Repeat' }
DropBarIconUIIndicator	{ link = 'SpecialChar' }
DropBarIconUIPickPivot	{ link = 'Error' }
DropBarIconUISeparator	{ link = 'SpecialChar' }
DropBarIconUISeparatorMenu	{ link = 'DropBarIconUISeparator' }
DropBarMenuCurrentContext	{ link = 'PmenuSel' }
DropBarMenuFloatBorder	{ link = 'FloatBorder' }
DropBarMenuHoverEntry	{ link = 'Visual' }
DropBarMenuHoverIcon	{ reverse = true }
DropBarMenuHoverSymbol	{ bold = true }
DropBarMenuNormalFloat	{ link = 'NormalFloat' }
DropBarPreview	{ link = 'Visual' }
DropBarKindArray	undefined
DropBarKindBoolean	undefined
DropBarKindBreakStatement	undefined
DropBarKindCall	undefined
DropBarKindCaseStatement	undefined
DropBarKindClass	undefined
DropBarKindConstant	undefined
DropBarKindConstructor	undefined
DropBarKindContinueStatement	undefined
DropBarKindDeclaration	undefined
DropBarKindDelete	undefined
DropBarKindDoStatement	undefined
DropBarKindElseStatement	undefined
DropBarKindEnum	undefined
DropBarKindEnumMember	undefined
DropBarKindEvent	undefined
DropBarKindField	undefined
DropBarKindFile	undefined
DropBarKindFolder	undefined
DropBarKindForStatement	undefined
DropBarKindFunction	undefined
DropBarKindH1Marker	undefined
DropBarKindH2Marker	undefined
DropBarKindH3Marker	undefined
DropBarKindH4Marker	undefined
DropBarKindH5Marker	undefined
DropBarKindH6Marker	undefined
DropBarKindIdentifier	undefined
DropBarKindIfStatement	undefined
DropBarKindInterface	undefined
DropBarKindKeyword	undefined
DropBarKindList	undefined
DropBarKindMacro	undefined
DropBarKindMarkdownH1	undefined
DropBarKindMarkdownH2	undefined
DropBarKindMarkdownH3	undefined
DropBarKindMarkdownH4	undefined
DropBarKindMarkdownH5	undefined
DropBarKindMarkdownH6	undefined
DropBarKindMethod	undefined
DropBarKindModule	undefined
DropBarKindNamespace	undefined
DropBarKindNull	undefined
DropBarKindNumber	undefined
DropBarKindObject	undefined
DropBarKindOperator	undefined
DropBarKindPackage	undefined
DropBarKindProperty	undefined
DropBarKindReference	undefined
DropBarKindRepeat	undefined
DropBarKindScope	undefined
DropBarKindSpecifier	undefined
DropBarKindStatement	undefined
DropBarKindString	undefined
DropBarKindStruct	undefined
DropBarKindSwitchStatement	undefined
DropBarKindType	undefined
DropBarKindTypeParameter	undefined
DropBarKindUnit	undefined
DropBarKindValue	undefined
DropBarKindVariable	undefined
DropBarKindWhileStatement	undefined

Developers

Architecture

                                              ┌──────────────────┐
                                              │winbar at win 1000│ {k}th symbol clicked
                                              │ contaning buf 1  ├──────────────────────┐
                                              └───────┬─▲────────┘                      │
                                                      ▼ │                               │
                                          _G.dropbar.get_dropbar_str()                  │
                                                      │ ▲                               │
    ┌──────────────┐                           ┌──────▼─┴──────┐                        │
    │sources       │                           │_G.dropbar.bars│                        │
    │ ┌───┐        │                           └──────┬─▲──────┘                        │
    │ │lsp│        │                       ┌───────┬──▼─┴──┬───────┐                    │
    │ └───┘        │                     ┌─▼─┐   ┌─┴─┐   ┌─┴─┐    ...                   │
    │ ┌──────────┐ │                     │[1]│   │[2]│   │[3]│                          │
    │ │treesitter│ │                     └─┬─┘   └─┬─┘   └─┬─┘                          │
    │ └──────────┘ │                       │      ...     ...                           │
    │  ...         │                       └──┬─▲─────────────┬──────┐                  │
    └─────┬─▲──────┘                        ┌─▼─┴──┐       ┌──┴───┐ ...                 │
          │ │                               │[1000]│       │[1015]│                     │
          │ │                               └─┬─▲──┘       └──────┘                     │
          │ │                    __tostring() │ │ return string cache                   │
          │ │                             ┌───▼─┴───┐                    ┌──────────────▼──────────────┐
          │ │                             │dropbar_t├────────────────────▶_G.dropbar.on_click_callbacks│
          │ │    On update events         └───┬─▲───┘  register symbol   └──────────────┬──────────────┘
          │ │ get_symbols(1, 1000, <cursor>)  │ │    on_click() callbacks               │
          │ └─────────────────────────────────┘ │                       ┌──────────┬────▼─────┬─────────┐
          └─────────────────────────────────────┘                   ┌───▼────┐ ┌───┴────┐ ┌───┴────┐   ...
      each source returns dropbar_symbol_t[]                        │['buf1']│ │['buf2']│ │['buf3']│
     dropbar_t adds symbols as its components                       └───┬────┘ └───┬────┘ └───┬────┘
          dropbar_t flushes string cache                                │         ...        ...
                                                                        └────────┬───────────────┬─────────┐
                                                                           ┌─────▼─────┐   ┌─────┴─────┐  ...
                                                                           │['win1000']│   │['win1015']│
                                                                           └─────┬─────┘   └─────┬─────┘
                                                                                 │              ...
                                                                  ┌─────────┬────▼────┬─────────┐
                                                              ┌───┴───┐    ...   ┌────┴────┐   ...
                                                              │['fn1']│          │['fn{k}']│
                                                              └───────┘          └────┬────┘
                                                                                      ▼
                                                      invoke _G.dropbar.bars[1][1000].components[k]:on_click()
                                                                                      │
                                                                                      ▼
                                                                     open drop-down menu, goto symbol, etc

Classes

⚠️ Notice

The plugin is still in its early stage, so the names and fields of classes might change in the future without notice.

dropbar_t

Declared and defined in lua/dropbar/bar.lua.

---

dropbar_t is a class that represents a winbar.

It gets symbols_{dropbar_symbol_t[]} from sources_{dropbar_source_t} and renders them to a string. It is also responsible for registering on_click callbacks of each symbol in the global table _G.dropbar.on_click_callbacks so that nvim knows which function to call when a symbol is clicked.

dropbar_t has the following fields:

Field	Type	Description
buf	integer	the buffer the dropbar is attached to
win	integer	the window the dropbar is attached to
sources	dropbar_source_t[]	sourcesdropbar_source_t[] that provide symbols to the dropbar
separator	dropbar_symbol_t	separatordropbar_symbol_t between symbols
padding	{left: integer, right: integer}	padding to use between the winbar and the window border
extends	dropbar_symbol_t	symboldropbar_symbol_t to use when a symbol is truncated
components	dropbar_symbol_t[]	symbolsdropbar_symbol_t[] to render
string_cache	string	string cache of the dropbar
in_pick_mode	boolean?	whether the dropbar is in pick mode
symbol_on_hover	dropbar_symbol_t	The previous symboldropbar_symbol_t[] under mouse hovering in the dropbar
last_update_request_time	float?	timestamp of the last update request in ms, see :h uv.hrtime()

dropbar_t has the following methods:

Method	Description
dropbar_t:new(opts: dropbar_opts_t): dropbar_t	constructor of dropbar_t
dropbar_t:del()	destructor of dropbar_t
dropbar_t:displaywidth(): integer	returns the display width of the dropbar
dropbar_t:truncate()	truncates the dropbar if it exceeds the display width *side effect: changes dropbar componentsdropbar_symbol_t[]
dropbar_t:cat(plain: boolean?): string	concatenates the dropbar components into a string with substrings for highlights and click support if plain is not set; else returns a plain string without substrings for highlights and click support
dropbar_t:redraw()	redraws the dropbar
dropbar_t:update()	update dropbar componentsdropbar_symbol_t[] and redraw the dropbar afterwards
dropbar_t:pick_mode_wrap(fn: fun(...): T?, ...): T?	executes fn with parameters ... in pick mode
dropbar_t:pick(idx: integer?)	pick a component from dropbar in interactive pick mode if idx is not given; else pick the idxth component directly
dropbar_t:update_current_context_hl(bar_idx: integer)	Update the current context highlight hl-DropBarCurrentContext and hl-DropBarIconCurrentContext assuming the bar_idx th symbol is clicked in the winbar
dropbar_t:update_hover_hl(col: integer?)	Highlight the symbol at col as if the mouse is hovering on it
dropbar_t:__tostring(): string	meta method to convert dropbar_t to its string representation

dropbar_symbol_t

Declared and defined in lua/dropbar/bar.lua.

---

dropbar_symbol_t is a class that represents a symbol in a dropbar. It is the basic element of dropbar_t and dropbar_menu_entry_t.

dropbar_symbol_t has the following fields:

Field	Type	Description
name	string	name of the symbol
icon	string	icon of the symbol
name_hl	string?	highlight of the name of the symbol
icon_hl	string?	highlight of the icon of the symbol
win	integer?	the source window the symbol is shown in
buf	integer?	the source buffer the symbol is defined in
view	table?	The original view of the source window, created by winsaveview(), used to restore the view after previewing the symbol
bar	dropbar_t?	the dropbardropbar_t the symbol belongs to, if the symbol is shown inside a winbar
menu	dropbar_menu_t?	menudropbar_menu_t associated with the symbol, if the symbol is shown inside a winbar
entry	dropbar_menu_entry_t?	the dropbar menu entrydropbar_menu_entry_t the symbol belongs to, if the symbol is shown inside a menu
children	dropbar_symbol_t[]?	children of the symbol (e.g. a children of a function symbol can be local variables inside the function)
siblings	dropbar_symbol_t[]?	siblings of the symbol (e.g. a sibling of a symbol that represents a level 4 markdown heading can be other headings with level 4)
bar_idx	integer?	index of the symbol in the dropbardropbar_t
entry_idx	integer?	index of the symbol in the menu entrydropbar_menu_entry_t
sibling_idx	integer?	index of the symbol in the siblings
range	{start: {line: integer, character: integer}, end: {line: integer, character: integer}}	range of the symbol in the source window
on_click	fun(this: dropbar_symbol_t, min_width: integer?, n_clicks: integer?, button: string?, modifiers: string?)|false?	callback to invoke when the symbol is clicked, force disable on_click when the value if set to false
data	table?	any extra data associated with the symbol

dropbar_symbol_t has the following methods:

Method	Description
dropbar_symbol_t:new(opts: dropbar_symbol_t?): dropbar_symbol_t	constructor of dropbar_symbol_t
dropbar_symbol_t:del()	destructor of dropbar_symbol_t
dropbar_symbol_t:merge(opts: dropbar_symbol_t)	create a new dropbar_symbol_t by merging opts into the current dropbar_symbol_t
dropbar_symbol_t:cat(plain: boolean?): string	concatenates the symbol into a string with substrings for highlights and click support if plain is not set; else returns a plain string without substrings for highlights and click support
dropbar_symbol_t:displaywidth(): integer	returns the display width of the symbol
dropbar_symbol_t:bytewidth(): integer	returns the byte width of the symbol
dropbar_symbol_t:jump()	jump to the start of the range of the dropbar symbol
dropbar_symbol_t:preview()	preview the symbol in the source window
dropbar_symbol_t:preview_restore_hl()	clear the preview highlights in the source window
dropbar_symbol_t:preview_restore_view()	restore the view in the source window after previewing the symbol
dropbar_symbol_t:swap_field(field: string, new_val: any)	temporarily change the content of a dropbar symbol
dropbar_symbol_t:restore()	restore the original value of the fields of a dropbar symbol changed in dropbar_symbol_t:swap_field()

dropbar_menu_t

Declared and defined in lua/dropbar/menu.lua.

---

dropbar_menu_t is a class that represents a drop-down menu.

dropbar_menu_t has the following fields:

Field	Type	Description
buf	integer	buffer number of the menu
win	integer	window id of the menu
is_opened	boolean?	whether the menu is currently opened
entries	dropbar_menu_entry_t[]	entries in the menu
win_configs	table	window configuration, value can be a function, see menu configuration options
_win_configs	table?	evaluated window configuration
cursor	integer[]?	initial cursor position
prev_win	integer?	previous window, assigned when calling new() or automatically determined in open()
sub_menu	dropbar_menu_t?	submenu, assigned when calling new() or automatically determined when a new menu opens
prev_menu	dropbar_menu_t?	previous menu, assigned when calling new() or automatically determined in open()
clicked_at	integer[]?	last position where the menu was clicked, 1,0-indexed
prev_cursor	integer[]?	previous cursor position in the menu
symbol_previewed	dropbar_symbol_t?	symbol begin previewed in the menu

dropbar_menu_t has the following methods:

Method	Description
dropbar_menu_t:new(opts: dropbar_menu_t?): dropbar_menu_t	constructor of dropbar_menu_t
dropbar_menu_t:del()	destructor of dropbar_menu_t
dropbar_menu_t:eval_win_configs()	evaluate window configurations dropbar_menu_t.win_configs and store the result in dropbar_menu_t._win_configs
dropbar_menu_t:get_component_at(pos: integer[], look_ahead: boolean?): dropbar_symbol_t?, { start: integer, end: integer }?	get the componentdropbar_symbol_t at position pos and its range it occupies in the entry it belongs to
dropbar_menu_t:click_at(pos: integer[], min_width: integer?, n_clicks: integer?, button: string?, modifiers: string?)	simulate a click at pos in the menu
dropbar_menu_t:click_on(symbol: dropbar_symbol_t, min_width: integer?, n_clicks: integer?, button: string?, modifiers: string?)	simulate a click at the component symboldropbar_symbol_t of the menu
dropbar_menu_t:update_hover_hl(pos: integer[])	update the hover highlights (DropBarMenuHover*) assuming the cursor/mouse is hovering at pos in the menu
dropbar_menu_t:update_current_context_hl(linenr: integer?)	update the current context highlight (hl-DropBarMenuCurrentContext) assuming the cursor is at line linenr in the menu
dropbar_menu_t:add_hl(hl_info: dropbar_menu_hl_info_t[][])	add highlights to the menu buffer
dropbar_menu_t:make_buf()	create the menu buffer from the entriesdropbar_menu_entry_t, must be called after self:eval_win_configs()
dropbar_menu_t:make_win()	open the menu window with self._win_configs and set menu options, must be called after self:make_buf()
dropbar_menu_t:override(opts: dropbar_menu_t?)	override menu options
dropbar_menu_t:preview_symbol_at(pos: integer[], look_ahead: boolean?)	preview the componentdropbar_symbol_t at position pos in the menu
dropbar_menu_t:finish_preview(restore_view: boolean?)	finish previewing the symbol, always clear the preview highlights in the source buffer, restore the original view of the source window if restore_view is true or nil
dropbar_menu_t:quick_navigation(new_cursor: integer[])	nagivate the cursor to the neartest clickable component on the current menu entry in the direction of cursor movement
dropbar_menu_t:open(opts: dropbar_menu_t?)	open the menu with options opts
dropbar_menu_t:close(restore_view: boolean?)	close the menu
dropbar_menu_t:toggle(opts: dropbar_menu_t?)	toggle the menu

dropbar_menu_entry_t

Declared and defined in lua/dropbar/menu.lua.

---

dropbar_menu_entry_t is a class that represents an entry (row) in a drop-down menu. A dropbar_menu_t instance is made up of multiple dropbar_menu_entry_t instances while a dropbar_menu_entry_t instance can contain multiple dropbar_symbol_t instances.

dropbar_menu_entry_t has the following fields:

Field	Type	Description
separator	dropbar_symbol_t	separator to use in the entry
padding	{left: integer, right: integer}	padding to use between the menu entry and the menu border
components	dropbar_symbol_t[]	componentsdropbar_symbol_t[] in the entry
menu	dropbar_menu_t?	the menu the entry belongs to
idx	integer?	the index of the entry in the menu

dropbar_menu_entry_t has the following methods:

Method	Description
dropbar_menu_entry_t:new(opts: dropbar_menu_entry_t?): dropbar_menu_entry_t	constructor of dropbar_menu_entry_t
dropbar_menu_entry_t:del()	destructor of dropbar_menu_entry_t
dropbar_menu_entry_t:cat(): string, dropbar_menu_hl_info_t	concatenate the components into a string, returns the string and highlight infodropbar_menu_hl_info_t
dropbar_menu_entry_t:displaywidth(): integer	calculate the display width of the entry
dropbar_menu_entry_t:bytewidth(): integer	calculate the byte width of the entry
dropbar_menu_entry_t:first_clickable(offset: integer?): dropbar_symbol_t?, { start: integer, end: integer }?	get the first clickable componentdropbar_symbol_t and its range in the dropbar menu entry starting from offset, which defaults to 0
dropbar_menu_entry_t:get_component_at(col: integer, look_ahead: boolean?): dropbar_symbol_t?, { start: integer, end: integer }?	get the componentdropbar_symbol_t at column position col and the range it occupies in the menu entry
dropbar_menu_entry_t:prev_clickable(col: integer): dropbar_symbol_t?, { start: integer, end: integer }?	get the previous clickable componentdropbar_symbol_t and its range in the dropbar menu entry given current column position col
dropbar_menu_entry_t:next_clickable(col: integer): dropbar_symbol_t?, { start: integer, end: integer }?	get the next clickable componentdropbar_symbol_t and its range in the dropbar menu entry given current column position col

dropbar_menu_hl_info_t

Declared and defined in lua/dropbar/menu.lua.

---

dropbar_menu_hl_info_t is a class that represents a highlight range in a single line of a drop-down menu.

dropbar_menu_hl_info_t has the following fields:

Field	Type	Description
start	integer	start column of the higlighted range
end	integer	end column of the higlighted range
hlgroup	string	highlight group to use for the range
ns	integer?	namespace to use for the range, nil if using default namespace

dropbar_source_t

Declared in lua/dropbar/sources/init.lua.

---

dropbar_source_t is a class that represents a source of a drop-down menu.

dropbar_source_t has the following field:

Field	Type	Description
get_symbols	function(buf: integer, win: integer, cursor: integer[]): dropbar_symbol_t[]	returns the symbolsdropbar_symbol_t[] to show in the winbar given buffer number buf and cursor position cursor

Making a New Source

A dropbar_source_t instance is just a table with get_symbols field set to a function that returns an array of dropbar_symbol_t instances given the buffer number, the window id, and the cursor position.

We have seen a simple example of a custom source in the default config of opts.bar.sources where the second source is set to a combination of lsp/treesitter/markdown sources using the utils.source.fallback() factory function, which simply returns a table containing a get_symbols() function where each source passed to utils.source.fallback() is queried and the first non-empty result get from the sources is returned as the result of the combined source.

Here is another example of a custom source that will always return two symbols saying 'Hello' and 'dropbar' with highlights 'hl-Keyword' and 'hl-Title' and a smiling face shown in 'hl-WarningMsg' at the start of the first symbol; clicking on the first symbol will show a notification message saying 'Have you smiled today?', followed by the smiling face icon used in the in dropbar symbol:

local bar = require('dropbar.bar')
local custom_source = {
  get_symbols = function(_, _, _)
    return {
      bar.dropbar_symbol_t:new({
        icon = ' ',
        icon_hl = 'WarningMsg',
        name = 'Hello',
        name_hl = 'Keyword',
        on_click = function(self)
          vim.notify('Have you smiled today? ' .. self.icon)
        end,
      }),
      bar.dropbar_symbol_t:new({
        name = 'dropbar',
        name_hl = 'Title',
      }),
    }
  end,
}

Add this source to opts.bar.sources table to see it in action:

require('dropbar').setup({
  bar = {
    sources = {
      custom_source,
    },
  },
})

Making a Source With Drop-Down Menus

The following example shows how to make a source that returns two symbols with the first symbol having a drop-down menu with a single entry saying 'World':

local bar = require('dropbar.bar')
local menu = require('dropbar.menu')
local custom_source = {
  get_symbols = function(_, _, _)
    return {
      bar.dropbar_symbol_t:new({
        icon = ' ',
        icon_hl = 'WarningMsg',
        name = 'Hello',
        name_hl = 'Keyword',
        on_click = function(self)
          self.menu = menu.dropbar_menu_t:new({
            entries = {
              menu.dropbar_menu_entry_t:new({
                components = {
                  bar.dropbar_symbol_t:new({
                    icon = ' ',
                    icon_hl = 'WarningMsg',
                    name = 'World',
                    name_hl = 'Keyword',
                    on_click = function(sym)
                      vim.notify('Have you smiled today? ' .. sym.icon)
                    end,
                  }),
                },
              }),
            },
          })
          self.menu:toggle()
        end,
      }),
      bar.dropbar_symbol_t:new({
        name = 'dropbar',
        icon = ' ',
        name_hl = 'Special',
        icon_hl = 'Error',
      }),
    }
  end,
}

Default on_click() Callback

dropbar_symbol_t:new() defines a default on_click() callback if non is provided.

The default on_click() callback will look for these fields in the symbol instance and create a drop-down menu accordingly on click, for more information about these fields see dropbar_symbol_t.

For creating the drop-down menu:

• dropbar_symbol_t.siblings
• dropbar_symbol_t.sibling_idx
• dropbar_symbol_t.children

For jumping to the symbol or previewing it:

• dropbar_symbol_t.range
• dropbar_symbol_t.win
• dropbar_symbol_t.buf

The following example shows a source that utilizes the default on_click() callback:

local bar = require('dropbar.bar')
local custom_source = {
  get_symbols = function(buf, win, _)
    return {
      bar.dropbar_symbol_t:new({
        name = 'Section 1',
        name_hl = 'Keyword',
        siblings = {
          bar.dropbar_symbol_t:new({
            name = 'Section 2',
            name_hl = 'WarningMsg',
          }),
          bar.dropbar_symbol_t:new({
            name = 'Section 3',
            name_hl = 'Error',
          }),
          bar.dropbar_symbol_t:new({
            name = 'Section 4',
            name_hl = 'String',
            children = {
              bar.dropbar_symbol_t:new({
                buf = buf,
                win = win,
                name = 'Section 4.1',
                name_hl = 'String',
                -- Will jump to line 3, col 4 (0-indexed) when clicked in the
                -- menu
                range = {
                  start = { line = 3, character = 4 },
                  ['end'] = { line = 5, character = 6 },
                }
              }),
            },
          }),
        },
      }),
    }
  end,
}

To see this source in action add it to opts.bar.sources table:

require('dropbar').setup({
  bar = {
    sources = {
      custom_source,
    },
  },
})

Lazy-Loading Expensive Fields

If the symbol fields siblings or children are expensive to compute, you can use meta-tables to lazy-load them, so that they are only computed when a menu is opened:

local bar = require('dropbar.bar')
local custom_source = {
  get_symbols = function(_, _, _)
    return {
      bar.dropbar_symbol_t:new(setmetatable({
        name = 'Section 1',
        name_hl = 'Keyword',
      }, {
        __index = function(self, key)
          if key == 'siblings' then
            self[siblings] = -- [[ compute siblings ]]
            return self[siblings]
          end
          if key == 'children' then
            self[children] = -- [[ compute children ]]
            return self[children]
          end
          -- ...
        end,
      })),
    }
  end,
}

To see concrete examples of lazy-loading see lua/dropbar/sources.

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