feat: add new "split" window.position, acts like netrw, closes #23

Author: cseickel

lua/neo-tree.lua

@@ -245,12 +245,19 @@ M.buffer_enter_event = function(args)
   end
 
   -- For all others, make sure another buffer is not hijacking our window
+  -- ..but not if the position is "split"
   local prior_buf = vim.fn.bufnr("#")
   if prior_buf < 1 then
     return
   end
   local prior_type = vim.api.nvim_buf_get_option(prior_buf, "filetype")
   if prior_type == "neo-tree" then
+    local position = vim.api.nvim_buf_get_var(prior_buf, "neo_tree_position")
+    if position == "split" then
+      -- nothing to do here, files are supposed to open in same window
+      return
+    end
+
     local current_tabnr = vim.api.nvim_get_current_tabpage()
     local neo_tree_tabnr = vim.api.nvim_buf_get_var(prior_buf, "neo_tree_tabnr")
     if neo_tree_tabnr ~= current_tabnr then
@@ -276,7 +283,7 @@ M.buffer_enter_event = function(args)
       pcall(vim.cmd, "bdelete " .. bufname)
       local fake_state = {
         window = {
-          position = "left",
+          position = position,
         },
       }
       utils.open_file(fake_state, bufname)

lua/neo-tree/ui/renderer.lua

@@ -7,6 +7,8 @@ local utils = require("neo-tree.utils")
 local highlights = require("neo-tree.ui.highlights")
 local popups = require("neo-tree.ui.popups")
 local events = require("neo-tree.events")
+local keymap = require("nui.utils.keymap")
+local autocmd = require("nui.utils.autocmd")
 local log = require("neo-tree.log")
 
 local M = {}
@@ -357,6 +359,7 @@ local enable_auto_close_floats = function()
 end
 
 create_window = function(state)
+  local bufname = string.format("neo-tree %s [%s]", state.name, state.tabnr)
   local win_options = {
     size = utils.resolve_config_option(state, "window.width", "40"),
     position = utils.resolve_config_option(state, "window.position", "left"),
@@ -400,39 +403,61 @@ create_window = function(state)
         win:unmount()
       end)
     end, { once = true })
+    state.winid = win.winid
+    state.bufnr = win.bufnr
+    vim.api.nvim_buf_set_name(state.bufnr, bufname)
 
     -- why is this necessary?
     vim.api.nvim_set_current_win(win.winid)
     enable_auto_close_floats()
+  elseif win_options.position == "split" then
+    local winid = vim.api.nvim_get_current_win()
+    local bufnr = vim.fn.bufnr(bufname)
+    if bufnr < 1 then
+      bufnr = vim.api.nvim_create_buf(false, false)
+      vim.api.nvim_buf_set_name(bufnr, bufname)
+    end
+    state.winid = winid
+    state.bufnr = bufnr
+    vim.api.nvim_buf_set_option(bufnr, "buftype", "nofile")
+    vim.api.nvim_buf_set_option(bufnr, "swapfile", false)
+    vim.api.nvim_buf_set_option(bufnr, "filetype", "neo-tree")
+    vim.api.nvim_buf_set_option(bufnr, "modifiable", false)
+    vim.api.nvim_win_set_buf(winid, bufnr)
   else
     win = NuiSplit(win_options)
     win:mount()
+    state.winid = win.winid
+    state.bufnr = win.bufnr
+    vim.api.nvim_buf_set_name(state.bufnr, bufname)
   end
 
-  state.winid = win.winid
-  state.bufnr = win.bufnr
-
   if type(state.bufnr) == "number" then
-    local bufname = string.format("neo-tree %s [%s]", state.name, state.tabnr)
-    vim.api.nvim_buf_set_name(state.bufnr, bufname)
     vim.api.nvim_buf_set_var(state.bufnr, "neo_tree_source", state.name)
-    vim.api.nvim_buf_set_var(state.bufnr, "neo_tree_winid", state.winid)
     vim.api.nvim_buf_set_var(state.bufnr, "neo_tree_tabnr", state.tabnr)
+    vim.api.nvim_buf_set_var(state.bufnr, "neo_tree_position", state.window.position)
+    vim.api.nvim_buf_set_var(state.bufnr, "neo_tree_winid", state.winid)
   end
 
-  -- Used to track the position of the cursor within the tree as it gains and loses focus
-  --
-  -- Note `WinEnter` is often too early to restore the cursor position so we do not set
-  -- that up here, and instead trigger those events manually after drawing the tree (not
-  -- to mention that it would be too late to register `WinEnter` here for the first
-  -- iteration of that event on the tree window)
-  win:on({ "WinLeave" }, function()
-    state.position.save()
-  end)
+  if win == nil then
+    autocmd.buf.define(state.bufnr, "WinLeave", function()
+      state.position.save()
+    end)
+  else
+    -- Used to track the position of the cursor within the tree as it gains and loses focus
+    --
+    -- Note `WinEnter` is often too early to restore the cursor position so we do not set
+    -- that up here, and instead trigger those events manually after drawing the tree (not
+    -- to mention that it would be too late to register `WinEnter` here for the first
+    -- iteration of that event on the tree window)
+    win:on({ "WinLeave" }, function()
+      state.position.save()
+    end)
 
-  win:on({ "BufDelete" }, function()
-    win:unmount()
-  end, { once = true })
+    win:on({ "BufDelete" }, function()
+      win:unmount()
+    end, { once = true })
+  end
 
   local skip_this_mapping = {
     ["none"] = true,
@@ -452,7 +477,7 @@ create_window = function(state)
           func = state.commands[func]
         end
         if type(func) == "function" then
-          win:map("n", cmd, function()
+          keymap.set(state.bufnr, "n", cmd, function()
             func(state)
           end, map_options)
         else
@@ -483,14 +508,21 @@ end
 ---@return boolean True if the window exists and is valid, false otherwise.
 M.window_exists = function(state)
   local window_exists
-  if state.winid == nil then
+  local winid = utils.get_value(state, "winid", 0, true)
+  local bufnr = utils.get_value(state, "bufnr", 0, true)
+  local position = utils.get_value(state, "window.position", "left", true)
+
+  if winid == 0 then
     window_exists = false
+  elseif position == "split" then
+    window_exists = vim.api.nvim_win_is_valid(winid)
+      and vim.api.nvim_buf_is_valid(bufnr)
+      and vim.api.nvim_win_get_buf(winid) == bufnr
   else
-    local isvalid = M.is_window_valid(state.winid)
-    window_exists = isvalid and (vim.api.nvim_win_get_number(state.winid) > 0)
+    local isvalid = M.is_window_valid(winid)
+    window_exists = isvalid and (vim.api.nvim_win_get_number(winid) > 0)
     if not window_exists then
       state.winid = nil
-      local bufnr = utils.get_value(state, "bufnr", 0, true)
       if bufnr > 0 and vim.api.nvim_buf_is_valid(bufnr) then
         state.bufnr = nil
         local success, err = pcall(vim.api.nvim_buf_delete, bufnr, { force = true })
@@ -525,13 +557,17 @@ draw = function(nodes, state, parent_id)
   end
 
   -- Create the tree if it doesn't exist.
-  if not M.window_exists(state) then
+  if not parent_id and not M.window_exists(state) then
     create_window(state)
     create_tree(state)
   end
 
   -- draw the given nodes
-  state.tree:set_nodes(nodes, parent_id)
+  local success, msg = pcall(state.tree.set_nodes, state.tree, nodes, parent_id)
+  if not success then
+    log.error("Error setting nodes: ", msg)
+    log.error(vim.inspect(state.tree:get_nodes()))
+  end
   if parent_id ~= nil then
     -- this is a dynamic fetch of children that were not previously loaded
     local node = state.tree:get_node(parent_id)
@@ -558,8 +594,10 @@ M.show_nodes = function(sourceItems, state, parentId)
     events.fire_event(events.BEFORE_RENDER, state)
     local level = 0
     if parentId ~= nil then
-      local parent = state.tree:get_node(parentId)
-      level = parent:get_depth()
+      local success, parent = pcall(state.tree.get_node, state.tree, parentId)
+      if success then
+        level = parent:get_depth()
+      end
     end
     local nodes = create_nodes(sourceItems, state, level)
     draw(nodes, state, parentId)

lua/neo-tree/utils.lua

@@ -215,40 +215,44 @@ M.open_file = function(state, path, open_cmd)
       events.fire_event(events.FILE_OPENED, path)
       return
     end
-    -- use last window if possible
-    local suitable_window_found = false
-    local nt = require("neo-tree")
-    if nt.config.open_files_in_last_window then
-      local prior_window = nt.get_prior_window()
-      if prior_window > 0 then
-        local success = pcall(vim.api.nvim_set_current_win, prior_window)
-        if success then
-          suitable_window_found = true
+    if state.window.position == "split" then
+      vim.cmd(open_cmd .. " " .. path)
+    else
+      -- use last window if possible
+      local suitable_window_found = false
+      local nt = require("neo-tree")
+      if nt.config.open_files_in_last_window then
+        local prior_window = nt.get_prior_window()
+        if prior_window > 0 then
+          local success = pcall(vim.api.nvim_set_current_win, prior_window)
+          if success then
+            suitable_window_found = true
+          end
         end
       end
-    end
-    -- find a suitable window to open the file in
-    if not suitable_window_found then
-      if state.window.position == "right" then
-        vim.cmd("wincmd t")
-      else
+      -- find a suitable window to open the file in
+      if not suitable_window_found then
+        if state.window.position == "right" then
+          vim.cmd("wincmd t")
+        else
+          vim.cmd("wincmd w")
+        end
+      end
+      local attempts = 0
+      while attempts < 4 and vim.bo.filetype == "neo-tree" do
+        attempts = attempts + 1
         vim.cmd("wincmd w")
       end
-    end
-    local attempts = 0
-    while attempts < 4 and vim.bo.filetype == "neo-tree" do
-      attempts = attempts + 1
-      vim.cmd("wincmd w")
-    end
-    -- TODO: make this configurable, see issue #43
-    if vim.bo.filetype == "neo-tree" then
-      -- Neo-tree must be the only window, restore it's status as a sidebar
-      local winid = vim.api.nvim_get_current_win()
-      local width = M.get_value(state, "window.width", 40)
-      vim.cmd("vsplit " .. path)
-      vim.api.nvim_win_set_width(winid, width)
-    else
-      vim.cmd(open_cmd .. " " .. path)
+      -- TODO: make this configurable, see issue #43
+      if vim.bo.filetype == "neo-tree" then
+        -- Neo-tree must be the only window, restore it's status as a sidebar
+        local winid = vim.api.nvim_get_current_win()
+        local width = M.get_value(state, "window.width", 40)
+        vim.cmd("vsplit " .. path)
+        vim.api.nvim_win_set_width(winid, width)
+      else
+        vim.cmd(open_cmd .. " " .. path)
+      end
     end
     events.fire_event(events.FILE_OPENED, path)
   end