feat: Add folding

lua/symbols-outline.lua

@@ -5,11 +5,12 @@ local writer = require 'symbols-outline.writer'
 local config = require 'symbols-outline.config'
 local utils = require 'symbols-outline.utils.init'
 local View = require 'symbols-outline.view'
+local folding = require 'symbols-outline.folding'
 
 local M = {}
 
 local function setup_global_autocmd()
-  if config.options.highlight_hovered_item then
+  if config.options.highlight_hovered_item or config.options.auto_unfold_hover then
     vim.api.nvim_create_autocmd('CursorHold', {
       pattern = '*',
       callback = function()
@@ -63,6 +64,15 @@ local function wipe_state()
   M.state = { outline_items = {}, flattened_outline_items = {}, code_win = 0 }
 end
 
+local function _update_lines()
+  M.state.flattened_outline_items = parser.flatten(M.state.outline_items)
+  writer.parse_and_write(M.view.bufnr, M.state.flattened_outline_items)
+end
+
+local function _merge_items(items)
+  utils.merge_items_rec({ children = items }, { children = M.state.outline_items })
+end
+
 local function __refresh()
   if M.view:is_open() then
     local function refresh_handler(response)
@@ -71,12 +81,11 @@ local function __refresh()
       end
 
       local items = parser.parse(response)
+      _merge_items(items)
 
       M.state.code_win = vim.api.nvim_get_current_win()
-      M.state.outline_items = items
-      M.state.flattened_outline_items = parser.flatten(items)
 
-      writer.parse_and_write(M.view.bufnr, M.state.flattened_outline_items)
+      _update_lines()
     end
 
     providers.request_symbols(refresh_handler)
@@ -85,9 +94,13 @@ end
 
 M._refresh = utils.debounce(__refresh, 100)
 
-local function goto_location(change_focus)
+function M._current_node()
   local current_line = vim.api.nvim_win_get_cursor(M.view.winnr)[1]
-  local node = M.state.flattened_outline_items[current_line]
+  return M.state.flattened_outline_items[current_line]
+end
+
+local function goto_location(change_focus)
+  local node = M._current_node()
   vim.api.nvim_win_set_cursor(
     M.state.code_win,
     { node.line + 1, node.character }
@@ -100,6 +113,53 @@ local function goto_location(change_focus)
   end
 end
 
+function M._set_folded(folded, move_cursor, node_index)
+  local node = M.state.flattened_outline_items[node_index] or M._current_node()
+  local changed = (folded ~= folding.is_folded(node))
+
+  if folding.is_foldable(node) and changed then
+    node.folded = folded
+
+    if move_cursor then
+      vim.api.nvim_win_set_cursor(M.view.winnr, { node_index, 0 })
+    end
+
+    _update_lines()
+  elseif node.parent then
+    for i, n in ipairs(M.state.flattened_outline_items) do
+      if n == node.parent then
+        M._set_folded(folded, not node.parent.folded and folded, i)
+      end
+    end
+  end
+end
+
+function M._set_all_folded(folded, nodes)
+  local is_root_exec = not nodes
+  nodes = nodes or M.state.outline_items
+
+  for _, node in ipairs(nodes) do
+    node.folded = folded
+    if node.children then
+      M._set_all_folded(folded, node.children)
+    end
+  end
+
+  _update_lines()
+end
+
+local function _items_dfs(callback, children)
+  children = children or M.state.outline_items
+
+  for _, val in ipairs(children) do
+    callback(val)
+
+    if val.children then
+      _items_dfs(callback, val.children)
+    end
+  end
+end
+
 function M._highlight_current_item(winnr)
   local has_provider = providers.has_provider()
 
@@ -127,26 +187,28 @@ function M._highlight_current_item(winnr)
 
   local hovered_line = vim.api.nvim_win_get_cursor(win)[1] - 1
 
-  local nodes = {}
-  for index, value in ipairs(M.state.flattened_outline_items) do
-    if
-      value.line == hovered_line
-      or (hovered_line > value.range_start and hovered_line < value.range_end)
-    then
-      value.line_in_outline = index
-      table.insert(nodes, value)
+  local leaf_node = nil
+
+  local cb = function(value)
+    value.hovered = nil
+
+    if value.line == hovered_line or (hovered_line > value.range_start and hovered_line < value.range_end) then
+      value.hovered = true
+      leaf_node = value
     end
   end
 
-  -- clear old highlight
-  ui.clear_hover_highlight(M.view.bufnr)
-  for _, value in ipairs(nodes) do
-    ui.add_hover_highlight(
-      M.view.bufnr,
-      value.line_in_outline - 1,
-      value.depth * 2
-    )
-    vim.api.nvim_win_set_cursor(M.view.winnr, { value.line_in_outline, 1 })
+  _items_dfs(cb)
+
+  _update_lines()
+
+  if leaf_node then
+    for index, node in ipairs(M.state.flattened_outline_items) do
+      if node == leaf_node then
+          vim.api.nvim_win_set_cursor(M.view.winnr, { index, 1 })
+          break
+      end
+    end
   end
 end
 
@@ -188,6 +250,26 @@ local function setup_keymaps(bufnr)
   map(config.options.keymaps.close, function()
     M.view:close()
   end)
+  -- fold selection
+  map( config.options.keymaps.fold, function ()
+    M._set_folded(true)
+  end)
+  -- unfold selection
+  map(config.options.keymaps.unfold, function ()
+    M._set_folded(false)
+  end)
+  -- fold all
+  map(config.options.keymaps.fold_all, function ()
+    M._set_all_folded(true)
+  end)
+  -- unfold all
+  map(config.options.keymaps.unfold_all, function ()
+    M._set_all_folded(false)
+  end)
+  -- fold reset
+  map(config.options.keymaps.fold_reset,function ()
+    M._set_all_folded(nil)
+  end)
 end
 
 local function handler(response)