plugin/theme: setup optional barbar plugin

default.nix

@@ -11,7 +11,7 @@ let
   plugins = callPlugins [
     ./plugins/syntax
     ./plugins/explorer
-    (import ./plugins/theme { enableTabline = false; })
+    (import ./plugins/theme { enableBarBar = true; })
     ./plugins/lsp
     ./plugins/formatter
   ];

plugins/theme/barbar.lua

@@ -0,0 +1,38 @@
+-- See: https://github.com/romgrk/barbar.nvim
+require("bufferline").setup({
+	auto_hide = false,
+	closable = false,
+	clickable = false,
+	icons = false, -- TODO: add icons (required nvim-web-devicons)
+})
+
+-------------------------------------------------------------------------------
+-- Keybindings
+
+local opts = { silent = true }
+
+vim.keymap.set("n", "gB", "<Cmd>BufferPrevious<CR>", opts)
+vim.keymap.set("n", "gb", "<Cmd>BufferNext<CR>", opts)
+vim.keymap.set("n", "gQ", "<Cmd>BufferClose<CR>", opts)
+
+-------------------------------------------------------------------------------
+-- Integration with nvim-tree
+
+local nvim_tree_events = require("nvim-tree.events")
+local bufferline_state = require("bufferline.state")
+
+local function get_tree_size()
+	return require("nvim-tree.view").View.width
+end
+
+nvim_tree_events.subscribe("TreeOpen", function()
+	bufferline_state.set_offset(get_tree_size())
+end)
+
+nvim_tree_events.subscribe("Resize", function()
+	bufferline_state.set_offset(get_tree_size())
+end)
+
+nvim_tree_events.subscribe("TreeClose", function()
+	bufferline_state.set_offset(0)
+end)

plugins/theme/default.nix

@@ -1,16 +1,27 @@
-{ enableTabline ? false }:
+{ enableTabline ? false
+, enableBarBar ? false
+}:
 
-{ lib, catppuccin-nvim, lualine-nvim, lualine-lsp-progress, tabline-nvim, ... }:
+{ lib
+, catppuccin-nvim
+, lualine-nvim
+, lualine-lsp-progress
+, tabline-nvim
+, barbar-nvim
+, ...
+}:
 
+let
+  lualinePlugins = [ lualine-nvim lualine-lsp-progress ];
+in
 {
   luaConfig = (builtins.readFile ./catppuccin-nvim.lua)
     + (builtins.readFile ./lualine.lua)
-    + (lib.optional enableTabline (builtins.readFile ./tabline.lua));
+    + (lib.optional enableTabline (builtins.readFile ./tabline.lua))
+    + (lib.optional enableBarBar (builtins.readFile ./barbar.lua));
 
-  plugins = [
-    catppuccin-nvim
-
-    lualine-nvim
-    lualine-lsp-progress
-  ] ++ (lib.optional enableTabline [ tabline-nvim ]);
+  plugins = [ catppuccin-nvim ]
+    ++ lualinePlugins
+    ++ (lib.optional enableTabline [ tabline-nvim ])
+    ++ (lib.optional enableBarBar [ barbar-nvim ]);
 }