WinEnter

WinEnter is an autocommand event in Vim and Neovim that fires when the focus switches to a different window. It is part of the window-related events that allow per-window customization as users navigate splits, tabs, or other window arrangements.

The event is typically used to adjust window-local options or apply context-specific behavior as the active window changes. Common uses include enabling or adjusting cursorline, line numbers, wrapping, or local formatting settings when entering a window. It can be combined with patterns to limit its scope and is frequently paired with WinLeave for symmetrical behavior when leaving a window.

In Vimscript, you can attach actions to WinEnter with an autocmd. For example:

autocmd WinEnter * setlocal cursorline

autocmd WinEnter * setlocal number

In Neovim, the same can be written in Lua using the API:

vim.api.nvim_create_autocmd("WinEnter", { pattern = "*", callback = function()

vim.opt_local.number = true

end})

WinEnter is commonly used alongside WinLeave, BufWinEnter, and other window events to manage per-window state as users move between windows. While simple demonstrations enable basic options, more advanced configurations might conditionally apply settings based on file type, buffer type, or specific window characteristics.