Autocomplete plugin improvements (#1519)

* Add icons support to autocomplete plugin

* Removed redundant flag check

* Added support for non syntax colors

* Assert if color name not in style.syntax

* Autocomplete plugin improvements

* Support suggestion symbols scoping
  - global: all open documents
  - local: current document
  - related: all open documents with same syntax
  - none: language syntax symbols only
* Register style.syntax[] entries as icons
* Other related fixes

data/plugins/autocomplete.lua

@@ -10,6 +10,10 @@ local RootView = require "core.rootview"
 local DocView = require "core.docview"
 local Doc = require "core.doc"
 
+---Symbols cache of all open documents
+---@type table<core.doc, table>
+local cache = setmetatable({}, { __mode = "k" })
+
 config.plugins.autocomplete = common.merge({
   -- Amount of characters that need to be written for autocomplete
   min_len = 3,
@@ -19,8 +23,16 @@ config.plugins.autocomplete = common.merge({
   max_suggestions = 100,
   -- Maximum amount of symbols to cache per document
   max_symbols = 4000,
+  -- Which symbols to show on the suggestions list: global, local, related, none
+  suggestions_scope = "global",
   -- Font size of the description box
   desc_font_size = 12,
+  -- Do not show the icons associated to the suggestions
+  hide_icons = false,
+  -- Position where icons will be displayed on the suggestions list
+  icon_position = "left",
+  -- Do not show the additional information related to a suggestion
+  hide_info = false,
   -- The config specification used by gui generators
   config_spec = {
     name = "Autocomplete",
@@ -60,6 +72,26 @@ config.plugins.autocomplete = common.merge({
       min = 1000,
       max = 10000
     },
+    {
+      label = "Suggestions Scope",
+      description = "Which symbols to show on the suggestions list.",
+      path = "suggestions_scope",
+      type = "selection",
+      default = "global",
+      values = {
+        {"All Documents", "global"},
+        {"Current Document", "local"},
+        {"Related Documents", "related"},
+        {"Known Symbols", "none"}
+      },
+      on_apply = function(value)
+        if value == "global" then
+          for _, doc in ipairs(core.docs) do
+            if cache[doc] then cache[doc] = nil end
+          end
+        end
+      end
+    },
     {
       label = "Description Font Size",
       description = "Font size of the description box.",
@@ -67,6 +99,31 @@ config.plugins.autocomplete = common.merge({
       type = "number",
       default = 12,
       min = 8
+    },
+    {
+      label = "Hide Icons",
+      description = "Do not show icons on the suggestions list.",
+      path = "hide_icons",
+      type = "toggle",
+      default = false
+    },
+    {
+      label = "Icons Position",
+      description = "Position to display icons on the suggestions list.",
+      path = "icon_position",
+      type = "selection",
+      default = "left",
+      values = {
+        {"Left", "left"},
+        {"Right", "Right"}
+      }
+    },
+    {
+      label = "Hide Items Info",
+      description = "Do not show the additional info related to each suggestion.",
+      path = "hide_info",
+      type = "toggle",
+      default = false
     }
   }
 }, config.plugins.autocomplete)
@@ -76,6 +133,7 @@ local autocomplete = {}
 autocomplete.map = {}
 autocomplete.map_manually = {}
 autocomplete.on_close = nil
+autocomplete.icons = {}
 
 -- Flag that indicates if the autocomplete box was manually triggered
 -- with the autocomplete.complete() function to prevent the suggestions
@@ -95,6 +153,7 @@ function autocomplete.add(t, manually_triggered)
           {
             text = text,
             info = info.info,
+            icon = info.icon,          -- Name of icon to show
             desc = info.desc,          -- Description shown on item selected
             onhover = info.onhover,    -- A callback called once when item is hovered
             onselect = info.onselect,  -- A callback called when item is selected
@@ -119,28 +178,35 @@ end
 --
 -- Thread that scans open document symbols and cache them
 --
-local max_symbols = config.plugins.autocomplete.max_symbols
+local global_symbols = {}
 
 core.add_thread(function()
-  local cache = setmetatable({}, { __mode = "k" })
+  local function load_syntax_symbols(doc)
-
+    if doc.syntax and not autocomplete.map["language_"..doc.syntax.name] then
-  local function get_syntax_symbols(symbols, doc)
+      local symbols = {
-    if doc.syntax then
+        name = "language_"..doc.syntax.name,
-      for sym in pairs(doc.syntax.symbols) do
+        files = doc.syntax.files,
-        symbols[sym] = true
+        items = {}
+      }
+      for name, type in pairs(doc.syntax.symbols) do
+        symbols.items[name] = type
       end
+      autocomplete.add(symbols)
+      return symbols.items
     end
+    return {}
   end
 
   local function get_symbols(doc)
     local s = {}
-    get_syntax_symbols(s, doc)
+    local syntax_symbols = load_syntax_symbols(doc)
+    local max_symbols = config.plugins.autocomplete.max_symbols
     if doc.disable_symbols then return s end
     local i = 1
     local symbols_count = 0
     while i <= #doc.lines do
       for sym in doc.lines[i]:gmatch(config.symbol_pattern) do
-        if not s[sym] then
+        if not s[sym] and not syntax_symbols[sym] then
           symbols_count = symbols_count + 1
           if symbols_count > max_symbols then
             s = nil
@@ -186,14 +252,18 @@ core.add_thread(function()
         }
       end
       -- update symbol set with doc's symbol set
+      if config.plugins.autocomplete.suggestions_scope == "global" then
         for sym in pairs(cache[doc].symbols) do
           symbols[sym] = true
         end
+      end
       coroutine.yield()
     end
 
-    -- update symbols list
+    -- update global symbols list
-    autocomplete.add { name = "open-docs", items = symbols }
+    if config.plugins.autocomplete.suggestions_scope == "global" then
+      global_symbols = symbols
+    end
 
     -- wait for next scan
     local valid = true
@@ -240,12 +310,50 @@ local function update_suggestions()
     map = autocomplete.map_manually
   end
 
+  local assigned_sym = {}
+
   -- get all relevant suggestions for given filename
   local items = {}
   for _, v in pairs(map) do
     if common.match_pattern(filename, v.files) then
       for _, item in pairs(v.items) do
         table.insert(items, item)
+        assigned_sym[item.text] = true
+      end
+    end
+  end
+
+  -- Append the global, local or related text symbols if applicable
+  local scope = config.plugins.autocomplete.suggestions_scope
+
+  if not triggered_manually then
+    local text_symbols = nil
+
+    if scope == "global" then
+      text_symbols = global_symbols
+    elseif scope == "local" and cache[doc] and cache[doc].symbols then
+      text_symbols = cache[doc].symbols
+    elseif scope == "related" then
+      for _, d in ipairs(core.docs) do
+        if doc.syntax == d.syntax then
+          if cache[d].symbols then
+            for name in pairs(cache[d].symbols) do
+              if not assigned_sym[name] then
+                table.insert(items, setmetatable(
+                  {text = name, info = "normal"}, mt
+                ))
+              end
+            end
+          end
+        end
+      end
+    end
+
+    if text_symbols then
+      for name in pairs(text_symbols) do
+        if not assigned_sym[name] then
+          table.insert(items, setmetatable({text = name, info = "normal"}, mt))
+        end
       end
     end
   end
@@ -286,13 +394,23 @@ local function get_suggestions_rect(av)
   y = y + av:get_line_height() + style.padding.y
   local font = av:get_font()
   local th = font:get_height()
+  local has_icons = false
+  local hide_info = config.plugins.autocomplete.hide_info
+  local hide_icons = config.plugins.autocomplete.hide_icons
 
   local max_width = 0
   for _, s in ipairs(suggestions) do
     local w = font:get_width(s.text)
-    if s.info then
+    if s.info and not hide_info then
       w = w + style.font:get_width(s.info) + style.padding.x
     end
+    local icon = s.icon or s.info
+    if not hide_icons and icon and autocomplete.icons[icon] then
+      w = w + autocomplete.icons[icon].font:get_width(
+        autocomplete.icons[icon].char
+      ) + (style.padding.x / 2)
+      has_icons = true
+    end
     max_width = math.max(max_width, w)
   end
 
@@ -319,7 +437,8 @@ local function get_suggestions_rect(av)
     x - style.padding.x,
     y - style.padding.y,
     max_width + style.padding.x * 2,
-    max_items * (th + style.padding.y) + style.padding.y
+    max_items * (th + style.padding.y) + style.padding.y,
+    has_icons
 end
 
 local function wrap_line(line, max_chars)
@@ -439,7 +558,7 @@ local function draw_suggestions_box(av)
   local ah = config.plugins.autocomplete.max_height
 
   -- draw background rect
-  local rx, ry, rw, rh = get_suggestions_rect(av)
+  local rx, ry, rw, rh, has_icons = get_suggestions_rect(av)
   renderer.draw_rect(rx, ry, rw, rh, style.background3)
 
   -- draw text
@@ -448,17 +567,52 @@ local function draw_suggestions_box(av)
   local y = ry + style.padding.y / 2
   local show_count = #suggestions <= ah and #suggestions or ah
   local start_index = suggestions_idx > ah and (suggestions_idx-(ah-1)) or 1
+  local hide_info = config.plugins.autocomplete.hide_info
 
   for i=start_index, start_index+show_count-1, 1 do
     if not suggestions[i] then
       break
     end
     local s = suggestions[i]
+
+    local icon_l_padding, icon_r_padding = 0, 0
+
+    if has_icons then
+      local icon = s.icon or s.info
+      if icon and autocomplete.icons[icon] then
+        local ifont = autocomplete.icons[icon].font
+        local itext = autocomplete.icons[icon].char
+        local icolor = autocomplete.icons[icon].color
+        if i == suggestions_idx then
+          icolor = style.accent
+        elseif type(icolor) == "string" then
+          icolor = style.syntax[icolor]
+        end
+        if config.plugins.autocomplete.icon_position == "left" then
+          common.draw_text(
+            ifont, icolor, itext, "left", rx + style.padding.x, y, rw, lh
+          )
+          icon_l_padding = ifont:get_width(itext) + (style.padding.x / 2)
+        else
+          common.draw_text(
+            ifont, icolor, itext, "right", rx, y, rw - style.padding.x, lh
+          )
+          icon_r_padding = ifont:get_width(itext) + (style.padding.x / 2)
+        end
+      end
+    end
+
     local color = (i == suggestions_idx) and style.accent or style.text
-    common.draw_text(font, color, s.text, "left", rx + style.padding.x, y, rw, lh)
+    common.draw_text(
-    if s.info then
+      font, color, s.text, "left",
+      rx + icon_l_padding + style.padding.x, y, rw, lh
+    )
+    if s.info and not hide_info then
       color = (i == suggestions_idx) and style.text or style.dim
-      common.draw_text(style.font, color, s.info, "right", rx, y, rw - style.padding.x, lh)
+      common.draw_text(
+        style.font, color, s.info, "right",
+        rx, y, rw - icon_r_padding - style.padding.x, lh
+      )
     end
     y = y + lh
     if suggestions_idx == i then
@@ -619,6 +773,31 @@ function autocomplete.can_complete()
   return false
 end
 
+---Register a font icon that can be assigned to completion items.
+---@param name string
+---@param character string
+---@param font? renderer.font
+---@param color? string | renderer.color A style.syntax[] name or specific color
+function autocomplete.add_icon(name, character, font, color)
+  local color_type = type(color)
+  assert(
+    not color or color_type == "table"
+      or (color_type == "string" and style.syntax[color]),
+    "invalid icon color given"
+  )
+  autocomplete.icons[name] = {
+    char = character,
+    font = font or style.code_font,
+    color = color or "keyword"
+  }
+end
+
+--
+-- Register built-in syntax symbol types icon
+--
+for name, _ in pairs(style.syntax) do
+  autocomplete.add_icon(name, "M", style.icon_font, name)
+end
 
 --
 -- Commands
@@ -632,7 +811,6 @@ command.add(predicate, {
   ["autocomplete:complete"] = function(dv)
     local doc = dv.doc
     local item = suggestions[suggestions_idx]
-    local text = item.text
     local inserted = false
     if item.onselect then
       inserted = item.onselect(suggestions_idx, item)