bufferline: add bufferline plugin

plugins/bufferlines/bufferline.nix

@@ -0,0 +1,177 @@
+{ config, pkgs, lib, ... }:
+with lib;
+let
+  cfg = config.programs.nixvim.plugins.bufferline;
+  helpers = import ../helpers.nix { inherit lib; };
+in
+{
+  options = {
+    programs.nixvim.plugins.bufferline = {
+      enable = mkEnableOption "Enable bufferline";
+      numbers = mkOption {
+        type = types.lines;
+        description = "A lua function customizing the styling of numbers.";
+        default = "";
+      };
+      closeCommand = mkOption {
+        type = types.lines;
+        description = "Command or function run when closing a buffer.";
+        default = "";
+      };
+      rightMouseCommand = mkOption {
+        type = types.lines;
+        description = "Command or function run when right clicking on a buffer.";
+        default = "";
+      };
+      leftMouseCommand = mkOption {
+        type = types.lines;
+        description = "Command or function run when clicking on a buffer.";
+        default = "";
+      };
+      middleMouseCommand = mkOption {
+        type = types.lines;
+        description = "Command or function run when middle clicking on a buffer.";
+        default = "";
+      };
+      indicatorIcon = mkOption {
+        type = types.str;
+        description = "The Icon shown as a indicator for buffer. Changing it is NOT recommended, 
+        this is intended to be an escape hatch for people who cannot bear it for whatever reason.";
+      };
+      bufferCloseIcon = mkOption {
+        type = types.str;
+        description = "The close icon for each buffer.";
+      };
+      modifiedIcon = mkOption {
+        type = types.str;
+        description = "The icon indicating a buffer was modified.";
+      };
+      closeIcon = mkOption {
+        type = types.str;
+        description = "The close icon.";
+      };
+      leftTruncMarker = mkOption {
+        type = types.str;
+      };
+      rightTruncMarker = mkOption {
+        type = types.str;
+      };
+      nameFormatter = mkOption {
+        type = types.lines;
+        description = "A lua function that can be used to modify the buffer's lable. The argument 'buf' containing a name, path and bufnr is supplied.";
+        default = "";
+      };
+      maxNameLength = mkOption {
+        type = types.int;
+        description = "Max length of a buffer name.";
+        default = 18;
+      };
+      maxPrefixLength = mkOption {
+        type = types.int;
+        description = "Max length of a buffer prefix (used when a buffer is de-duplicated)";
+        default = 15;
+      };
+      tabSize = mkOption {
+        type = types.int;
+        description = "Size of the tabs";
+        default = 18;
+      };
+      diagnostics = mkOption {
+        type = types.enum [ false "nvim_lsp" "coc" ];
+        default = false;
+      };
+      diagnosticsUpdateInInsert = mkOption {
+        type = types.bool;
+        default = false;
+      };
+      diagnosticsIndicator = mkOption {
+        type = types.lines;
+        default = "";
+      };
+      customFilter = mkOption {
+        type = types.lines;
+        default = "";
+      };
+      showBufferIcons = mkOption {
+        type = types.bool;
+        default = true; 
+      };
+      showBufferCloseIcons = mkOption {
+        type = types.bool;
+        default = true;
+      };
+      showCloseIcon = mkOption {
+        type = types.bool;
+        default = true;
+      };
+      showTabIndicators = mkOption {
+        type = types.bool;
+        default = true;
+      };
+      persistBufferSort = mkOption {
+        type = types.bool;
+        default = true;
+      };
+      separatorStyle = mkOption {
+        type = types.enum [ "slant" "thick" "thin" ];
+      };
+      enforceRegularTabs = mkOption {
+        type = types.bool;
+        default = false;
+      };
+      alwaysShowBufferline = mkOption {
+        type = types.bool;
+        default = true;
+      };
+      sortBy = mkOption {
+        type = types.enum [ "id" "extension" "relative_directory" "directory" "tabs" ];
+      };
+    };
+  };
+
+  config = let 
+    setupOptions = {
+      options = {
+        numbers = cfg.numbers;
+        close_command = cfg.closeCommand;
+        right_mouse_command = cfg.rightMouseCommand;
+        left_mouse_command = cfg.leftMouseCommand;
+        middle_mouse_command = cfg.middleMouseCommand;
+        indicator_icon = cfg.indicatorIcon;
+        buffer_close_icon = cfg.bufferCloseIcon;
+        modified_icon = cfg.modifiedIcon;
+        close_icon = cfg.closeIcon;
+        left_trunc_marker = cfg.leftTruncMarker;
+        right_trunc_marker = cfg.rightTruncMarker;
+        name_formatter = cfg.nameFormatter;
+        max_name_length = cfg.maxNameLength;
+        max_prefix_length = cfg.maxPrefixLength;
+        tab_size = cfg.tabSize;
+        diagnostics = cfg.diagnostics;
+        diagnostics_update_in_insert = cfg.diagnosticsUpdateInInsert;
+        diagnostics_indicator = cfg.diagnosticsIndicator;
+        custom_filter = cfg.customFilter;
+        show_buffer_icons = cfg.showBufferIcons;
+        show_buffer_close_icons = cfg.showBufferCloseIcons;
+        show_close_icon = cfg.showCloseIcon;
+        show_tab_indicators = cfg.showTabIndicators;
+        persist_buffer_sort = cfg.persistBufferSort;
+        separator_style = cfg.separatorStyle;
+        enforce_regular_tabs = cfg.enforceRegularTabs;
+        always_show_bufferline = cfg.alwaysShowBufferline;
+        sort_by = cfg.sortBy;
+      };
+    };
+    in mkIf cfg.enable {
+    programs.nixvim = {
+      extraPlugins = with pkgs.vimPlugins; [
+        bufferline-nvim
+        nvim-web-devicons
+      ];
+      options.termguicolors = true;
+      extraConfigLua = ''
+        require('bufferline').setup{${helpers.toLuaObject setupOptions}}
+      '';
+    };
+  };
+}