nvim-tree.lua/lua/nvim-tree/renderer/init.lua

local log = require("nvim-tree.log")
local view = require("nvim-tree.view")
local events = require("nvim-tree.events")

local Class = require("nvim-tree.classic")
local Builder = require("nvim-tree.renderer.builder")

local SIGN_GROUP = "NvimTreeRendererSigns"

local namespace_highlights_id = vim.api.nvim_create_namespace("NvimTreeHighlights")
local namespace_extmarks_id = vim.api.nvim_create_namespace("NvimTreeExtmarks")
local namespace_virtual_lines_id = vim.api.nvim_create_namespace("NvimTreeVirtualLines")

---@class (exact) Renderer: Class
---@field explorer Explorer
local Renderer = Class:extend()

---@class Renderer
---@overload fun(args: RendererArgs): Renderer

---@class (exact) RendererArgs
---@field explorer Explorer

---@protected
---@param args RendererArgs
function Renderer:new(args)
  self.explorer = args.explorer
end

---@private
---@param bufnr number
---@param lines string[]
---@param hl_args AddHighlightArgs[]
---@param signs string[]
---@param extmarks table[] extra marks for right icon placement
---@param virtual_lines table[] virtual lines for hidden count display
function Renderer:_draw(bufnr, lines, hl_args, signs, extmarks, virtual_lines)
  if vim.fn.has("nvim-0.10") == 1 then
    vim.api.nvim_set_option_value("modifiable", true, { buf = bufnr })
  else
    vim.api.nvim_buf_set_option(bufnr, "modifiable", true) ---@diagnostic disable-line: deprecated
  end

  vim.api.nvim_buf_set_lines(bufnr, 0, -1, false, lines)
  self:render_hl(bufnr, hl_args)

  if vim.fn.has("nvim-0.10") == 1 then
    vim.api.nvim_set_option_value("modifiable", false, { buf = bufnr })
  else
    vim.api.nvim_buf_set_option(bufnr, "modifiable", false) ---@diagnostic disable-line: deprecated
  end

  vim.fn.sign_unplace(SIGN_GROUP)
  for i, sign_name in pairs(signs) do
    vim.fn.sign_place(0, SIGN_GROUP, sign_name, bufnr, { lnum = i + 1 })
  end

  vim.api.nvim_buf_clear_namespace(bufnr, namespace_extmarks_id, 0, -1)
  for i, extname in pairs(extmarks) do
    for _, mark in ipairs(extname) do
      vim.api.nvim_buf_set_extmark(bufnr, namespace_extmarks_id, i, -1, {
        virt_text     = { { mark.str, mark.hl } },
        virt_text_pos = "right_align",
        hl_mode       = "combine",
      })
    end
  end

  vim.api.nvim_buf_clear_namespace(bufnr, namespace_virtual_lines_id, 0, -1)
  for line_nr, vlines in pairs(virtual_lines) do
    vim.api.nvim_buf_set_extmark(bufnr, namespace_virtual_lines_id, line_nr, 0, {
      virt_lines         = vlines,
      virt_lines_above   = false,
      virt_lines_leftcol = true,
    })
  end
end

---@private
function Renderer:render_hl(bufnr, hl)
  if not bufnr or not vim.api.nvim_buf_is_loaded(bufnr) then
    return
  end
  vim.api.nvim_buf_clear_namespace(bufnr, namespace_highlights_id, 0, -1)
  for _, data in ipairs(hl) do
    if type(data[1]) == "table" then
      for _, group in ipairs(data[1]) do
        vim.api.nvim_buf_add_highlight(bufnr, namespace_highlights_id, group, data[2], data[3], data[4])
      end
    end
  end
end

function Renderer:draw()
  local bufnr = view.get_bufnr()
  if not bufnr or not vim.api.nvim_buf_is_loaded(bufnr) then
    return
  end

  local profile = log.profile_start("draw")

  local cursor = vim.api.nvim_win_get_cursor(view.get_winnr() or 0)

  local builder = Builder(self.explorer):build()

  self:_draw(bufnr, builder.lines, builder.hl_args, builder.signs, builder.extmarks, builder.virtual_lines)

  if cursor and #builder.lines >= cursor[1] then
    vim.api.nvim_win_set_cursor(view.get_winnr() or 0, cursor)
  end

  view.grow_from_content()

  log.profile_end(profile)

  events._dispatch_on_tree_rendered(bufnr, view.get_winnr())
end

return Renderer