feat: do not close preview when switching dirs (#277)

* feat: do not close preview when cd into dir

* refactor: add helper method to run function after oil buffer loads

* Keep preview window open

* Remove some test logic

* Use `run_after_load` when moving to parent directory

* Remove unnecessary update of current window

* refactor: create helper function for updating preview

---------

Co-authored-by: Steven Arcangeli <stevearc@stevearc.com>

lua/oil/init.lua

@@ -366,6 +366,23 @@ M.toggle_float = function(dir)
   end
 end
 
+---@param oil_bufnr? integer
+local function update_preview_window(oil_bufnr)
+  oil_bufnr = oil_bufnr or 0
+  local util = require("oil.util")
+  util.run_after_load(oil_bufnr, function()
+    local cursor_entry = M.get_cursor_entry()
+    if cursor_entry then
+      local preview_win_id = util.get_preview_win()
+      if preview_win_id then
+        if cursor_entry.id ~= vim.w[preview_win_id].oil_entry_id then
+          M.select({ preview = true })
+        end
+      end
+    end
+  end)
+end
+
 ---Open oil browser for a directory
 ---@param dir nil|string When nil, open the parent of the current buffer, or the cwd if current buffer is not a file
 M.open = function(dir)
@@ -384,6 +401,9 @@ M.open = function(dir)
   if config.buf_options.buflisted ~= nil then
     vim.api.nvim_buf_set_option(0, "buflisted", config.buf_options.buflisted)
   end
+
+  -- If preview window exists, update its content
+  update_preview_window()
 end
 
 ---Restore the buffer that was present when oil was opened
@@ -523,11 +543,7 @@ M.select = function(opts, callback)
     end
   end
 
-  -- Close the preview window if we're not previewing the selection
   local preview_win = util.get_preview_win()
-  if not opts.preview and preview_win then
-    vim.api.nvim_win_close(preview_win, true)
-  end
   local prev_win = vim.api.nvim_get_current_win()
 
   local scheme, dir = util.parse_url(bufname)
@@ -588,15 +604,16 @@ M.select = function(opts, callback)
         emsg_silent = true,
       }
       local filebufnr = vim.fn.bufadd(normalized_url)
+      local entry_is_file = not vim.endswith(normalized_url, "/")
 
       if opts.preview then
         -- If we're previewing a file that hasn't been opened yet, make sure it gets deleted after
         -- we close the window
-        if not vim.endswith(normalized_url, "/") and vim.fn.bufloaded(filebufnr) == 0 then
+        if entry_is_file and vim.fn.bufloaded(filebufnr) == 0 then
           vim.bo[filebufnr].bufhidden = "wipe"
           vim.b[filebufnr].oil_preview_buffer = true
         end
-      elseif not vim.endswith(normalized_url, "/") then
+      elseif entry_is_file then
         -- The :buffer command doesn't set buflisted=true
         -- So do that for non-diretory-buffers
         vim.bo[filebufnr].buflisted = true
@@ -621,6 +638,11 @@ M.select = function(opts, callback)
         args = { filebufnr },
         mods = mods,
       })
+
+      if not opts.preview and preview_win and entry_is_file then
+        vim.api.nvim_win_close(preview_win, true)
+      end
+
       if opts.preview then
         vim.api.nvim_set_option_value("previewwindow", true, { scope = "local", win = 0 })
         vim.w.oil_entry_id = entry.id
@@ -643,6 +665,9 @@ M.select = function(opts, callback)
         M.close()
       end)
     end
+
+    update_preview_window()
+
     finish()
   end)
 end

lua/oil/util.lua

@@ -774,4 +774,26 @@ M.get_visual_range = function()
   return { start_lnum = start_lnum, end_lnum = end_lnum }
 end
 
+---@param bufnr integer
+---@param callback fun()
+M.run_after_load = function(bufnr, callback)
+  if bufnr == 0 then
+    bufnr = vim.api.nvim_get_current_buf()
+  end
+  if vim.b[bufnr].oil_ready then
+    callback()
+  else
+    local autocmd_id
+    autocmd_id = vim.api.nvim_create_autocmd("User", {
+      pattern = "OilEnter",
+      callback = function(args)
+        if args.data.buf == bufnr then
+          callback()
+          vim.api.nvim_del_autocmd(autocmd_id)
+        end
+      end,
+    })
+  end
+end
+
 return M