Recently I switched to Neovim as my go-to text editor, and have been configuring it as an IDE. The flexibility to have it behave exactly the way I want is amazing!

One GUI element of VS Code that I’ve missed is having a sidebar with hotkeys to quickly jump between different views, such as Git and my project’s file tree. Fortunately, there’s a great library by folke that is designed to create and manage sidebars: edgy.nvim. The sidebar config is reminiscent of declarative languages like CSS, so setting up my sidebar felt pretty familiar. To start, I created a side with three neo-tree.nvim views:

1. A file tree (explorer) view
2. A list of my open buffers
3. Git tree view of my modified files

The lazy.nvim edgy config for that looks like this:

return {
	"folke/edgy.nvim",
	event = "VeryLazy",
	init = function()
		vim.opt.laststatus = 3 -- show a single status line at the bottom
		vim.opt.splitkeep = "screen" -- prevents jumping when open/close sidebars
	end,
	opts = {
		right =	{
				title = "Files",
				ft = "neo-tree",
				filter = function(buf)
					return vim.b[buf].neo_tree_source == "filesystem"
				end,
				open = "Neotree filesystem",
				size = { height = 0.5 }, -- 1/2 window height
				pinned = true,
			},
			{
				title = "Buffers",
				ft = "neo-tree",
				filter = function(buf)
					return vim.b[buf].neo_tree_source == "buffers"
				end,
				pinned = true,
				open = "Neotree position=top buffers",
				size = { height = 0.25 },
			},
			{
				title = "Git",
				ft = "neo-tree",
				filter = function(buf)
					return vim.b[buf].neo_tree_source == "git_status"
				end,
				pinned = true,
				open = "Neotree position=left git_status",
				size = { height = 0.25 },
			},
			-- any other neo-tree windows should also be here
			"neo-tree",
		}
	}
}

return {
	"folke/edgy.nvim",
	event = "VeryLazy",
	init = function()
		vim.opt.laststatus = 3 -- show a single status line at the bottom
		vim.opt.splitkeep = "screen" -- prevents jumping when open/close sidebars
	end,
	opts = {
		right =	{
				title = "Files",
				ft = "neo-tree",
				filter = function(buf)
					return vim.b[buf].neo_tree_source == "filesystem"
				end,
				open = "Neotree filesystem",
				size = { height = 0.5 }, -- 1/2 window height
				pinned = true,
			},
			{
				title = "Buffers",
				ft = "neo-tree",
				filter = function(buf)
					return vim.b[buf].neo_tree_source == "buffers"
				end,
				pinned = true,
				open = "Neotree position=top buffers",
				size = { height = 0.25 },
			},
			{
				title = "Git",
				ft = "neo-tree",
				filter = function(buf)
					return vim.b[buf].neo_tree_source == "git_status"
				end,
				pinned = true,
				open = "Neotree position=left git_status",
				size = { height = 0.25 },
			},
			-- any other neo-tree windows should also be here
			"neo-tree",
		}
	}
}

Overall this is great! I get a sidebar with all the panels I want in one place. It has a problem though. Perhaps because the three pinned views of the edgebar are opened in the order I declare them (files -> buffers -> git), my focus always ends up in the git view when I open it. I put it on the bottom because I use it the least, though. What I really want is to default to the Files view getting focus, with a specific binding for each of the views if I want to focus a specific one.

Programmatically focusing a window in Neovim

After a quick search, I found the API for setting focus on a window:

vim.api.nvim_set_current_win(window_id)

vim.api.nvim_set_current_win(window_id)

Super simple and straightforward! Unfortunately, it requires a window ID. I have no idea what my window IDs are. The good news is that Neovim has a similarly simple API for that one, too.

-- integer[]
local window_ids = vim.api.nvim_list_wins()

-- integer[]
local window_ids = vim.api.nvim_list_wins()

I’m going to feel like such a champion calling a function that lists all my wins!

Now I’ve got a list of window IDs and and an API to set my focus to one of them. The only question that remains is: which one is which? I have no hope of figuring out which window_ids integer corresponds to which window. For this one I’m going to need to use the edgy API. The get_win(window?) API looks like what I’m after!

I tried calling it with one of my window IDs, only to have the LSP tell me I’m doing it wrong! Apparently the API takes a window object, not an integer?

What the heck, how am I supposed to get a window object if not via a window ID from the nvim_list_wins() API?

I did some digging which ultimately resulted in me reading the edgy source code for the get_win() function and the short answer is: I’m not supposed to! The function defaults to grabbing the integer window ID for the current window if one isn’t provided. What’s up with that?! After verifying that it is in fact using an integer the whole time, I opened a PR to fix the type annotation for the window parameter. Anyway long story short, the integer window ID works fine, so until that PR gets merged I’m going to just ignore the warning. This is the magic of open source: if you find something wrong, you can make the change and submit a PR to fix it!

That was a bit of a tangent, but it’s always great to contribute to open source. Anyway, I’ve still got a problem: I don’t know the window ID of my neo-tree panes! At this point I was getting comfortable poking around in the edgy codebase, so I looked for where I can find the Title value I set for each of my views. I found a function to select a window, and in the code to open a selector UI it has the following line:

local title = w.view.get_title()

local title = w.view.get_title()

Perfect! That is exactly what I need. It’s all coming together:

1. Channel my inner winner and call nvim_list_wins()
2. With each window ID, get the corresponding edgy Window object
3. Check if the value from Window.view.get_title() matches the name of the window I want
4. If it does, set my focus to that window

With only one major bump along the road, this seems to be going pretty smoothly. I quickly coded up a helper function for this since I want to use it in 4 separate keybindings: One to open the edge bar, and one for each of the three views within that edge bar. Here’s what that looks like:

---@param title string: the edgy title of the window to focus
local focus_window = function(title)
	local all_win_ids = vim.api.nvim_list_wins()
	local edgy = require("edgy") -- owns the window titles
	for _, win_id in ipairs(all_win_ids) do -- loop over all windows
		local win = edgy.get_win(win_id) -- edgy window.view stores the title
		if win and win.view.get_title() == title then
			vim.api.nvim_set_current_win(win_id)
		end
	end
end

---@param title string: the edgy title of the window to focus
local focus_window = function(title)
	local all_win_ids = vim.api.nvim_list_wins()
	local edgy = require("edgy") -- owns the window titles
	for _, win_id in ipairs(all_win_ids) do -- loop over all windows
		local win = edgy.get_win(win_id) -- edgy window.view stores the title
		if win and win.view.get_title() == title then
			vim.api.nvim_set_current_win(win_id)
		end
	end
end

All that’s left is to call this sucker in my keybinds and I’m ready to roll! For brevity, here’s just the keybind to open the edge bar on the right:

return {
	"folke/edgy.nvim",
	-- other configs...
	keys = {
		{
			"<leader>pl", -- the keybinding
			function() -- what happens when I press it
				-- ensure neo-tree is loaded
				require("lazy").load({plugins = {"neo-tree.nvim"}})
				-- Open the right edge bar
				require("edgy").toggle("right")
				focus_window("Files") -- The magic sauce!
			end
		}
	}
}

return {
	"folke/edgy.nvim",
	-- other configs...
	keys = {
		{
			"<leader>pl", -- the keybinding
			function() -- what happens when I press it
				-- ensure neo-tree is loaded
				require("lazy").load({plugins = {"neo-tree.nvim"}})
				-- Open the right edge bar
				require("edgy").toggle("right")
				focus_window("Files") -- The magic sauce!
			end
		}
	}
}

Now that everything is in place, I was ready to feel like a wizard, conjuring up trees and having my cursor arrive precisely where it is meant to. I ran :source % to reload my new edgy config and try it out:

Uh oh. It’s still behaving exactly the same, focusing the Git view in the bottom right corner. Once the pane is opened, my keybinds to jump to a specific named view work correctly. What could cause that? My first thought is that either edgy or neo-tree opens asynchronously to avoid blocking the main thread. I’m by no means an expert in Lua, so I have no idea how the parallelism engine works for the language.

After a bit of research, I found this video by TJ DeVries about the vim scheduler. I found it very interesting, but the TL;DR: here is that neovim lua code has an event loop similar to JavaScript. To queue a function to be executed once the runtime finishes executing everything on the event loop, call vim.schedule() and pass it the function you want it to run. Not too bad! With this change, the function run on keybind looks something like this:

function()
	require("lazy").load({ plugins = { "neo-tree.nvim" } })
	require("edgy").toggle("right")
	vim.schedule( function()
		focus_window("Files")
	end)
end

function()
	require("lazy").load({ plugins = { "neo-tree.nvim" } })
	require("edgy").toggle("right")
	vim.schedule( function()
		focus_window("Files")
	end)
end

Another round of :source % to reload the config, and this time it works how I want! I love that I have so much control over the behavior of my editor in Neovim. You can check out the final edgy.lua config on my GitHub.