refactor(#2826): split global View and instance Window

lua/nvim-tree/actions/tree/open.lua

@@ -1,5 +1,6 @@
 local core = require("nvim-tree.core")
 local lib = require("nvim-tree.lib")
+local view = require("nvim-tree.view")
 local finders_find_file = require("nvim-tree.actions.finders.find-file")
 
 local M = {}
@@ -25,7 +26,7 @@ function M.fn(opts)
 
   local explorer = core.get_explorer()
 
-  if explorer and explorer.window:is_visible() then
+  if explorer and view.is_visible() then
     -- focus
     lib.set_target_win()
     explorer.window:focus()