add event API (#265)

.editorconfig

@@ -0,0 +1,9 @@
+root = true
+
+[*]
+insert_final_newline = true
+end_of_line = lf
+
+[*.lua]
+indent_style = space
+indent_size = 2

doc/nvim-tree-lua.txt

@@ -1,6 +1,6 @@
 *nvim-tree.lua* A file explorer written in lua
 
-Minimum version of neovim: 0.4.0
+Minimum version of neovim: 0.5.0
 
 Author: Yazdani Kiyan <yazdani.kiyan@protonmail.com>
 
@@ -404,3 +404,75 @@ NvimTreeFileNew
 NvimTreeFileDeleted
 
  vim:tw=78:ts=8:noet:ft=help:norl:
+
+==============================================================================
+EVENTS                                                 *nvim-tree-events*
+
+|nvim_tree_events|                                     *nvim_tree_events*
+
+nvim-tree will dispatch events whenever an action is made. These events can be
+subscribed to through handler functions. This allows for even further
+customization of nvim-tree.
+
+A handler for an event is just a function which receives one argument -
+the payload of the event. The payload is different for each event type. Refer
+to |nvim_tree_registering_handlers| for more information.
+<
+
+|nvim_tree_registering_handlers|                *nvim_tree_registering_handlers*
+
+Handlers are registered by calling the `on_*` functions available in the
+`require('nvim-tree.events')` module. See |nvim-tree.events|.
+
+
+For example, registering a handler for when a node is renamed is done like this: >
+
+    local events = require('nvim-tree.events')
+
+    events.on_node_renamed(function(data)
+        print("Node renamed from " .. data.old_name .. " to " ..  data.new_name)
+    end)
+
+==============================================================================
+Lua module: nvim-tree.events                           *nvim-tree.events*
+
+                                     *nvim-tree.events.on_node_renamed()*
+on_node_renamed({handler})
+                Registers a handler for when a node is renamed.
+                • Note: A node can either be a file or a directory.
+
+                Parameters: ~
+                    {handler}    (function) Handler function, with the
+                                 signature `function(payload)`.
+
+                                     *nvim-tree.events.on_file_created()*
+on_file_created({handler})
+                Registers a handler for when a file is created.
+
+                Parameters: ~
+                    {handler}    (function) Handler function, with the
+                                 signature `function(payload)`.
+
+                                     *nvim-tree.events.on_file_removed()*
+on_file_removed({handler})
+                Registers a handler for when a file is removed.
+
+                Parameters: ~
+                    {handler}    (function) Handler function, with the
+                                 signature `function(payload)`.
+
+                                   *nvim-tree.events.on_folder_created()*
+on_folder_created({handler})
+                Registers a handler for when a folder is created.
+
+                Parameters: ~
+                    {handler}    (function) Handler function, with the
+                                 signature `function(payload)`.
+
+                                   *nvim-tree.events.on_folder_removed()*
+on_folder_removed({handler})
+                Registers a handler for when a folder is removed.
+
+                Parameters: ~
+                    {handler}    (function) Handler function, with the
+                                 signature `function(payload)`.

lua/nvim-tree/events.lua

@@ -0,0 +1,94 @@
+local M = {}
+
+local global_handlers = {}
+
+local Event = {
+  NodeRenamed = 'NodeRenamed',
+  FileCreated = 'FileCreated',
+  FileRemoved = 'FileRemoved',
+  FolderCreated = 'FolderCreated',
+  FolderRemoved = 'FolderRemoved',
+}
+
+local function get_handlers(event_name)
+  return global_handlers[event_name] or {}
+end
+
+local function register_handler(event_name, handler)
+  local handlers = get_handlers(event_name)
+  table.insert(handlers, handler)
+  global_handlers[event_name] = handlers
+end
+
+
+local function dispatch(event_name, payload)
+  for _, handler in pairs(get_handlers(event_name)) do
+    local success, error = pcall(handler, payload)
+    if not success then
+      vim.api.nvim_err_writeln('Handler for event ' .. event_name .. ' errored. ' .. vim.inspect(error))
+    end
+  end
+end
+
+--@private
+function M._dispatch_node_renamed(old_name, new_name)
+  dispatch(Event.NodeRenamed, {old_name=old_name, new_name=new_name})
+end
+
+--@private
+function M._dispatch_file_removed(fname)
+  dispatch(Event.FileRemoved, {fname=fname})
+end
+
+--@private
+function M._dispatch_file_created(fname)
+  dispatch(Event.FileCreated, {fname=fname})
+end
+
+--@private
+function M._dispatch_folder_created(folder_name)
+  dispatch(Event.FolderCreated, {folder_name=folder_name})
+end
+
+--@private
+function M._dispatch_folder_removed(folder_name)
+  dispatch(Event.FolderRemoved, {folder_name=folder_name})
+end
+
+--Registers a handler for the NodeRenamed event.
+--@param handler (function) Handler with the signature function(payload), where payload is a table containing:
+--  - old_name (string) Absolute path to the old node location.
+--  - new_name (string) Absolute path to the new node location.
+function M.on_node_renamed(handler)
+  register_handler(Event.NodeRenamed, handler)
+end
+
+--Registers a handler for the FileCreated event.
+--@param handler (function) Handler with the signature function(payload), where payload is a table containing:
+--  - fname (string) Absolute path to the created file.
+function M.on_file_created(handler)
+  register_handler(Event.FileCreated, handler)
+end
+
+--Registers a handler for the FileRemoved event.
+--@param handler (function) Handler with the signature function(payload), where payload is a table containing:
+--  - fname (string) Absolute path to the removed file.
+function M.on_file_removed(handler)
+  register_handler(Event.FileRemoved, handler)
+end
+
+--Registers a handler for the FolderCreated event.
+--@param handler (function) Handler with the signature function(payload), where payload is a table containing:
+--  - folder_name (string) Absolute path to the created folder.
+function M.on_folder_created(handler)
+  register_handler(Event.FolderCreated, handler)
+end
+
+--Registers a handler for the FolderRemoved event.
+--@param handler (function) Handler with the signature function(payload), where payload is a table containing:
+--  - folder_name (string) Absolute path to the removed folder.
+function M.on_folder_removed(handler)
+  register_handler(Event.FolderRemoved, handler)
+end
+
+return M

lua/nvim-tree/fs.lua

@@ -4,6 +4,7 @@ local open_mode = luv.constants.O_CREAT + luv.constants.O_WRONLY + luv.constants
 
 local utils = require'nvim-tree.utils'
 local lib = require'nvim-tree.lib'
+local events = require'nvim-tree.events'
 local M = {}
 local clipboard = {
   move = {},
@@ -34,6 +35,7 @@ local function create_file(file)
       -- this is why we need to chmod to default file permissions
       luv.fs_chmod(file, 420)
       luv.fs_close(fd)
+      events._dispatch_file_created(file)
       api.nvim_out_write('File '..file..' was properly created\n')
       refresh_tree()
     end
@@ -88,6 +90,7 @@ function M.create(node)
         return
       end
       if idx == num_entries then
+        events._dispatch_folder_created(add_into..relpath)
         api.nvim_out_write('Folder '..add_into..relpath..' was properly created\n')
         refresh_tree()
       end
@@ -242,12 +245,14 @@ function M.remove(node)
       if not success then
         return api.nvim_err_writeln('Could not remove '..node.name)
       end
+      events._dispatch_folder_removed(node.absolute_path)
       api.nvim_out_write(node.name..' has been removed\n')
     else
       local success = luv.fs_unlink(node.absolute_path)
       if not success then
         return api.nvim_err_writeln('Could not remove '..node.name)
       end
+      events._dispatch_file_removed(node.absolute_path)
       api.nvim_out_write(node.name..' has been removed\n')
       clear_buffer(node.absolute_path)
     end
@@ -280,6 +285,7 @@ function M.rename(with_sub)
         end
       end
     end
+    events._dispatch_node_renamed(abs_path, new_name)
     refresh_tree()
   end
 end