feat(api): Add method to jump to previous window

lua/smart-splits/api.lua

@@ -2,6 +2,7 @@ local lazy = require('smart-splits.lazy')
 local config = lazy.require_on_index('smart-splits.config') --[[@as SmartSplitsConfig]]
 local mux = lazy.require_on_exported_call('smart-splits.mux') --[[@as SmartSplitsMultiplexer]]
 local utils = require('smart-splits.utils')
+local mux_utils = require('smart-splits.mux.utils')
 local types = require('smart-splits.types')
 local Direction = types.Direction
 local AtEdgeBehavior = types.AtEdgeBehavior
@@ -489,4 +490,11 @@ end, {
   Direction.down,
 })
 
+function M.move_cursor_previous_win()
+  local win = mux_utils.get_previous_win()
+  if win then
+    vim.api.nvim_set_current_win(win)
+  end
+end
+
 return M

lua/smart-splits/init.lua

@@ -21,6 +21,8 @@ end, {
   Direction.down,
 })
 
+M.move_cursor_previous_win = lazy.require_on_exported_call('smart-splits.api').move_cursor_previous_win
+
 M.start_resize_mode = function()
   require('smart-splits.resize-mode').start_resize_mode()
 end

lua/smart-splits/mux/utils.lua

@@ -35,11 +35,27 @@ function M.are_we_gui()
   return current_ui ~= nil and not current_ui.stdin_tty and not current_ui.stdout_tty
 end
 
+local prev_win = nil
+
+---Return the buf ID of the previous buffer, if there is one
+---@return number|nil
+function M.get_previous_win()
+  return prev_win
+end
+
 ---Initialization for mux capabilities.
 ---If selected mux has an `on_init` or `on_exit`,
 ---call `on_init` and set up autocmds to call `on_init` on `VimResume`
 ---and `on_exit` on `VimSuspend` and `VimLeavePre`.
 function M.startup()
+  -- buffer tracking for "previous buffer"
+  vim.api.nvim_create_autocmd('WinLeave', {
+    callback = function()
+      prev_win = tonumber(vim.api.nvim_get_current_win())
+    end,
+  })
+
+  -- multiplexer startup/shutdown events
   local mux = require('smart-splits.mux').get()
   if not mux then
     return