Support outline.nvim (#54)

* feat(plugin): support fork of symbols-outline

The symbols-outline.nvim plugin was archived, and there is a popular
fork that added some nice new features. The fork's filetype is still
"Outline", but the user commands have changed.

ref: https://github.com/hedyhli/outline.nvim

* feat(plugin): separate support for outline.nvim and symbols-outline.nvim

---------

Co-authored-by: Ben Elan <[email protected]>

README.md

@@ -111,6 +111,7 @@ require('possession').setup {
         nvim_tree = true,
         neo_tree = true,
         symbols_outline = true,
+        outline = true,
         tabby = true,
         dap = true,
         dapui = true,

doc/possession.txt

@@ -239,9 +239,10 @@ Currently no configuration options beside enabling/disabling are available.
 Saves neo-tree windows and restores them when loading the session.
 
                                                   *possession-symbols-outline*
+                                                          *possession-outline*
 
-Saves symbols-outline.nvim windows and restores when loading session.
-NOTE: currently this only works for a single outline due to
+Saves symbols-outline.nvim/outline.nvim windows and restores when loading
+session. NOTE: currently this only works for a single outline due to
 symbols-outline.nvim limitations
 
                                                             *possession-tabby*

lua/possession/config.lua

@@ -58,6 +58,7 @@ local function defaults()
             nvim_tree = true,
             neo_tree = true,
             symbols_outline = true,
+            outline = true,
             tabby = true,
             dap = true,
             dapui = true,

lua/possession/plugins/init.lua

@@ -9,6 +9,7 @@ local plugins = {
     'nvim_tree',
     'neo_tree',
     'symbols_outline',
+    'outline',
     'tabby',
     'neotest',
     'dapui',

lua/possession/plugins/outline.lua

@@ -0,0 +1,24 @@
+local plugins = require('possession.plugins')
+local utils = require('possession.utils')
+
+local function buf_is_plugin(buf)
+    return vim.api.nvim_buf_get_option(buf, 'filetype') == 'Outline'
+end
+
+local find_tab_buf = function(tab)
+    return utils.find_tab_buf(tab, buf_is_plugin)
+end
+
+-- NOTE: currently symbols-outline does not really work on per-tab basis so this does not make sense but in
+-- theory symbols-outline could easily work like other file-trees so stick with this implementation for now
+return plugins.implement_file_tree_plugin_hooks('symbols-outline', {
+    has_plugin = 'outline',
+    buf_is_plugin = buf_is_plugin,
+    open_in_tab = function(tab)
+        vim.cmd('OutlineOpen')
+        -- Need to wait for some async stuff
+        vim.wait(100, function()
+            return find_tab_buf(tab) ~= nil
+        end)
+    end,
+})