feat: telescope preview

1. Remove deprecated function `vim.api.nvim_buf_add_highlight`, add a
   helper buf builder.
2. Add missing annotation style.
2. Use a global variable _G.__fidget_telescope_config is not a good
   design, and we do not need either.
3. Not need a option `use_previewer`, a option in `previewer = false` in
telescope config will just work. Which allow you disable previewer by
default, but you can still toggle previewer window.

eg:
disable preview by default.
```lua
require("telescope").setup({
  extensions = {
    fidget = {
      previewer = false,
    },
  },
})

```

or in lua api
```lua
require("telescope").extensions.fidget.fidget({ previewer = false })
```

Author: xieyonn

lua/fidget/buf.lua

@@ -0,0 +1,156 @@
+---@class fidget.buf
+local M = {}
+
+---@class fidget.buf.BuilderOpts
+
+---@class fidget.buf.Builder
+---@field lines string[]
+---@field row number
+---@field col number
+---@field opts fidget.buf.BuilderOpts
+---@field hls table[]
+local Builder = {}
+Builder.__index = Builder
+
+---Write content
+---@param text string
+---@param hl_group? string | number | vim.api.keyset.highlight
+---@return fidget.buf.Builder
+function Builder:write(text, hl_group)
+  local row, col = self.row, self.col
+  local parts = vim.split(text, "\n", { plain = true })
+
+  for i, part in ipairs(parts) do
+    local line = self.lines[row + 1] or ""
+    self.lines[row + 1] = line .. part
+    col = col + #part
+
+    -- new line
+    if i < #parts then
+      row = row + 1
+      col = 0
+    end
+  end
+
+  if hl_group then
+    table.insert(self.hls, {
+      row = self.row,
+      col = self.col,
+      end_row = row,
+      end_col = col,
+      hl_group = hl_group,
+    })
+  end
+
+  self.row = row
+  self.col = col
+
+  return self
+end
+
+---Write new line.
+---@param n? number
+---@return fidget.buf.Builder
+function Builder:ln(n)
+  n = n or 1
+  for _ = 1, n do
+    -- check first line is empty, because row is 0-base, self.lines is a 1-base array
+    if self.row == 0 and self.lines[1] == nil then
+      self.lines[1] = ""
+    end
+
+    self.row = self.row + 1
+    self.lines[self.row + 1] = ""
+  end
+  self.col = 0
+
+  return self
+end
+
+---Write {n} spaces
+---@param n? number
+---@return fidget.buf.Builder
+function Builder:space(n)
+  return self:write(string.rep(" ", n or 1))
+end
+
+function Builder:separator(sep, hl_group)
+  sep = sep or require("config.icons").icons.sep
+  hl_group = hl_group or "WinSeparator"
+
+  if self.col ~= 0 then
+    -- new line
+    self:ln()
+  end
+  local row = self.row
+
+  table.insert(self.hls, function(bufnr, ns)
+    vim.api.nvim_buf_set_extmark(bufnr, ns, row, 0, {
+      virt_text = { { sep:rep(200), hl_group } },
+      virt_text_pos = "overlay",
+      virt_text_win_col = 0,
+    })
+  end)
+
+  self:ln()
+
+  return self
+end
+
+---Render content, set extmarks.
+---@param bufnr number
+---@param ns? number namespace
+function Builder:render(bufnr, ns)
+  if #self.lines == 0 then
+    return
+  end
+
+  ns = ns
+    or vim.api.nvim_create_namespace(string.format("content_builder_%s", bufnr))
+
+  vim.api.nvim_buf_set_lines(bufnr, 0, -1, false, self.lines)
+
+  local id = 0
+  local set_extmark = function(hl)
+    if type(hl) == "function" then
+      hl(bufnr, ns)
+
+      return
+    end
+
+    local hl_name = hl.hl_group
+    if type(hl_name) == "table" then
+      hl_name = vim.api.nvim_set_hl(
+        ns,
+        string.format("NS_%s_HL_%s", ns, id),
+        hl.hl_group
+      )
+      id = id + 1
+    end
+
+    vim.api.nvim_buf_set_extmark(bufnr, ns, hl.row, hl.col, {
+      end_row = hl.end_row,
+      end_col = hl.end_col,
+      hl_group = hl_name,
+    })
+  end
+
+  for _, hl in ipairs(self.hls) do
+    set_extmark(hl)
+  end
+end
+
+---Create a buf content builder.
+---@param opts? fidget.buf.BuilderOpts
+---@return fidget.buf.Builder
+function M.new_builder(opts)
+  return setmetatable({
+    row = 0,
+    col = 0,
+    lines = {},
+    hls = {},
+    opts = opts,
+  }, Builder)
+end
+
+return M

lua/telescope/_extensions/fidget.lua

@@ -7,6 +7,7 @@ local notification = require("fidget.notification")
 local pickers = require("telescope.pickers")
 local telescope = require("telescope")
 local previewers = require("telescope.previewers")
+local buf = require("fidget.buf")
 
 --- Format HistoryItem, used in Telescope or Neovim messages.
 ---
@@ -36,56 +37,22 @@ local format_entry = function(entry)
   return chunks
 end
 
-local notification_previewer = function()
+local function previewer()
   return previewers.new_buffer_previewer({
     title = "Notification Details",
-    define_preview = function(self, entry, _)
-      local notification_entry = entry.value
+    define_preview = function(self, entry)
+      local data = entry.value
       local bufnr = self.state.bufnr
 
-      vim.api.nvim_buf_set_lines(bufnr, 0, -1, false, {})
-
-      local lines = {
-        "Timestamp: " .. vim.fn.strftime("%c", notification_entry.last_updated),
-        "Group: " .. (notification_entry.group_name or ""),
-        "Annotation: " .. (notification_entry.annote or ""),
-        "Style: " .. (notification_entry.style or ""),
-        "",
-        "Message:",
-        "--------",
-        "",
-      }
-
-      local message_lines = vim.split(notification_entry.message, "\n")
-      for _, line in ipairs(message_lines) do
-        table.insert(lines, line)
-      end
-
-      vim.api.nvim_buf_set_lines(bufnr, 0, -1, false, lines)
-
-      vim.api.nvim_buf_set_option(bufnr, "filetype", "markdown")
-
-      local ns_id = vim.api.nvim_create_namespace("fidget_preview")
-
-      vim.api.nvim_buf_add_highlight(bufnr, ns_id, "Title", 0, 0, 10)
-      vim.api.nvim_buf_add_highlight(bufnr, ns_id, "Title", 1, 0, 6)
-      vim.api.nvim_buf_add_highlight(bufnr, ns_id, "Title", 2, 0, 11)
-      vim.api.nvim_buf_add_highlight(bufnr, ns_id, "Title", 3, 0, 6)
-
-      vim.api.nvim_buf_add_highlight(bufnr, ns_id, "Identifier", 0, 11, -1)
-      vim.api.nvim_buf_add_highlight(bufnr, ns_id, "Special", 1, 7, -1)
-      vim.api.nvim_buf_add_highlight(bufnr, ns_id, "String", 2, 12, -1)
-      vim.api.nvim_buf_add_highlight(bufnr, ns_id, "Comment", 3, 7, -1)
-
-      vim.api.nvim_buf_add_highlight(bufnr, ns_id, "Title", 5, 0, -1)
-      vim.api.nvim_buf_add_highlight(bufnr, ns_id, "Comment", 6, 0, -1)
-
-      if notification_entry.style then
-        local hl_group = notification_entry.style
-        for i = 8, #lines do
-          vim.api.nvim_buf_add_highlight(bufnr, ns_id, hl_group, i - 1, 0, -1)
-        end
-      end
+      buf
+        .new_builder()
+        :write(string.format(" %s ", data.annote or " "), data.style)
+        :write(vim.fn.strftime("%c", data.last_updated), "Comment")
+        :space(1)
+        :write(data.group_name or "", "Special")
+        :separator()
+        :write(data.message or "")
+        :render(bufnr)
     end,
   })
 end
@@ -124,29 +91,24 @@ local create_entry_maker = function(wrap)
   end
 end
 
-local fidget_picker = function(opts)
-  opts = opts or {}
-
-  local default_config = {
-    wrap_text = false,
-    use_previewer = true,
-  }
+local default_config = {
+  wrap_text = false,
+  previewer = true,
+}
 
-  local config = vim.tbl_deep_extend("force", default_config, opts)
+local fidget_picker = function(opts)
+  opts = vim.tbl_extend("force", default_config, opts or {})
 
   local picker_opts = {
     prompt_title = "Notifications",
     finder = finders.new_table({
       results = notification.get_history(),
-      entry_maker = create_entry_maker(config.wrap_text),
+      entry_maker = create_entry_maker(opts.wrap_text),
     }),
     sorter = conf.generic_sorter(opts),
+    previewer = previewer(),
   }
 
-  if config.use_previewer then
-    picker_opts.previewer = notification_previewer()
-  end
-
   picker_opts.attach_mappings = function(prompt_bufnr, _)
     actions.select_default:replace(function()
       actions.close(prompt_bufnr)
@@ -179,16 +141,9 @@ end
 
 return telescope.register_extension({
   setup = function(ext_config)
-    _G.__fidget_telescope_config = ext_config or {}
+    default_config = vim.tbl_extend("force", default_config, ext_config or {})
   end,
   exports = {
-    fidget = function(opts)
-      local config = vim.tbl_deep_extend(
-        "force",
-        _G.__fidget_telescope_config or {},
-        opts or {}
-      )
-      fidget_picker(config)
-    end,
+    fidget = fidget_picker,
   },
 })