feat: add window open/close events, restore focus to prior win on close, closes #476

Author: cseickel

doc/neo-tree.txt

@@ -1061,6 +1061,26 @@ have.
 "neo_tree_popup_buffer_leave"~
 Fired after leaving a neo-tree popup buffer.
 
+"neo_tree_window_before_open"~
+Fired before opening a new Neo-tree window. Called with the following arg:
+                                                     *neo-tree-window-event-args*
+The event argument for all window events is a table with the following keys:
+    `winid`    = the |winid| of the window being opned or closed.
+    `tabnr`    = the tab number that the window is in.
+    `source`   = the name of the source that is in the window, such as "filesystem".
+    `position` = the position of the window, i.e. "left", "bottom", "right".
+
+"neo_tree_window_after_open"~
+Fired after opening a new Neo-tree window. Called with 
+|neo-tree-window-event-args|.
+
+"neo_tree_window_before_close"~
+Fired before closing a Neo-tree window. Called with 
+|neo-tree-window-event-args|.
+
+"neo_tree_window_after_close"~
+Fired after closing a Neo-tree window. Called with 
+|neo-tree-window-event-args|.
 
 NOTE: The following events are used internally and not intended for end user
 usage. You can use them if you want, but beware that they may be debounced, and

lua/neo-tree/defaults.lua

@@ -132,7 +132,31 @@ local config = {
   --    handler = function()
   --      vim.cmd 'highlight! Cursor guibg=#5f87af blend=0'
   --    end
-  --  }
+  --  },
+  -- {
+  --   event = "neo_tree_window_before_open",
+  --   handler = function(args)
+  --     print("neo_tree_window_before_open", vim.inspect(args))
+  --   end
+  -- },
+  -- {
+  --   event = "neo_tree_window_after_open",
+  --   handler = function(args)
+  --     vim.cmd("wincmd =")
+  --   end
+  -- },
+  -- {
+  --   event = "neo_tree_window_before_close",
+  --   handler = function(args)
+  --     print("neo_tree_window_before_close", vim.inspect(args))
+  --   end
+  -- },
+  -- {
+  --   event = "neo_tree_window_after_close",
+  --   handler = function(args)
+  --     vim.cmd("wincmd =")
+  --   end
+  -- }
   --},
   default_component_configs = {
     container = {

lua/neo-tree/events/init.lua

@@ -20,6 +20,10 @@ local M = {
   NEO_TREE_BUFFER_LEAVE = "neo_tree_buffer_leave",
   NEO_TREE_POPUP_BUFFER_ENTER = "neo_tree_popup_buffer_enter",
   NEO_TREE_POPUP_BUFFER_LEAVE = "neo_tree_popup_buffer_leave",
+  NEO_TREE_WINDOW_BEFORE_CLOSE = "neo_tree_window_before_close",
+  NEO_TREE_WINDOW_AFTER_CLOSE = "neo_tree_window_after_close",
+  NEO_TREE_WINDOW_BEFORE_OPEN = "neo_tree_window_before_open",
+  NEO_TREE_WINDOW_AFTER_OPEN = "neo_tree_window_after_open",
   VIM_BUFFER_ADDED = "vim_buffer_added",
   VIM_BUFFER_CHANGED = "vim_buffer_changed",
   VIM_BUFFER_DELETED = "vim_buffer_deleted",

lua/neo-tree/ui/renderer.lua

@@ -90,7 +90,23 @@ M.close = function(state)
         else
           local win_list = vim.api.nvim_tabpage_list_wins(0)
           if #win_list > 1 then
+            local args = {
+              position = state.current_position,
+              source = state.name,
+              winid = state.winid,
+              tabnr = state.tabnr,
+            }
+            events.fire_event(events.NEO_TREE_WINDOW_BEFORE_CLOSE, args)
+            -- focus the prior used window if we are closing the currently focused window
+            local current_winid = vim.api.nvim_get_current_win()
+            if current_winid == state.winid then
+              local pwin = require("neo-tree").get_prior_window()
+              if type(pwin) == "number" and pwin > 0 then
+                pcall(vim.api.nvim_set_current_win, pwin)
+              end
+            end
             vim.api.nvim_win_close(state.winid, true)
+            events.fire_event(events.NEO_TREE_WINDOW_AFTER_CLOSE, args)
           end
         end
       end
@@ -731,6 +747,13 @@ create_window = function(state)
   }
 
   local win
+  local event_args = {
+    position = state.current_position,
+    source = state.name,
+    tabnr = state.tabnr,
+  }
+  events.fire_event(events.NEO_TREE_WINDOW_BEFORE_OPEN, event_args)
+
   if state.current_position == "float" then
     state.force_float = nil
     -- First get the default options for floating windows.
@@ -791,6 +814,8 @@ create_window = function(state)
     state.bufnr = win.bufnr
     vim.api.nvim_buf_set_name(state.bufnr, bufname)
   end
+  event_args.winid = state.winid
+  events.fire_event(events.NEO_TREE_WINDOW_AFTER_OPEN, event_args)
 
   if type(state.bufnr) == "number" then
     vim.api.nvim_buf_set_var(state.bufnr, "neo_tree_source", state.name)