feat(picker.icons): make it easier to add custom icon sources

lua/snacks/picker/config/sources.lua

@@ -535,9 +535,14 @@ M.highlights = {
 }
 
 ---@class snacks.picker.icons.Config: snacks.picker.Config
----@field icon_sources? string[]
+---@field icon_sources? string[] list of sources to use
+--- Custom icon sources can be added here. The key is the source name,
+--- and the value is the file path or URL to load icons from.
+--- The file should be a JSON array of:
+--- `{[1]:string, [2]:string}|{icon:string, name:string, category:string}`
+--- The format is compatible with https://github.com/nvim-telescope/telescope-symbols.nvim
+---@field custom_sources? table<string,string> additional icon sources `table<source,file|url>`
 M.icons = {
-  icon_sources = { "nerd_fonts", "emoji" },
   main = { current = true },
   finder = "icons",
   format = "icon",

lua/snacks/picker/format.lua

@@ -709,7 +709,8 @@ function M.icon(item, picker)
   ---@cast item snacks.picker.Icon
   local ret = {} ---@type snacks.picker.Highlight[]
 
-  ret[#ret + 1] = { a(item.icon, 2), "SnacksPickerIcon" }
+  local icon_width = vim.api.nvim_strwidth(item.icon)
+  ret[#ret + 1] = { a(item.icon, icon_width > 3 and 15 or 3), "SnacksPickerIcon" }
   ret[#ret + 1] = { " " }
   ret[#ret + 1] = { a(item.source, 10), "SnacksPickerIconSource" }
   ret[#ret + 1] = { " " }

lua/snacks/picker/source/icons.lua

@@ -1,5 +1,13 @@
 local M = {}
 
+---@class snacks.picker.icons.Source
+---@field url string
+---@field v? number
+---@field priority? number
+---@field build fun(data:table):snacks.picker.Icon[]
+
+---@alias snacks.picker.icons.source.Item {[1]:string, [2]:string}|{icon:string, name:string, category:string}
+
 local NERDFONTS_SETS = {
   cod = "Codicons",
   dev = "Devicons",
@@ -16,9 +24,32 @@ local NERDFONTS_SETS = {
   md = "Material Design Icons",
 }
 
----@type table<string, {url: string, v?:number, build: fun(data:table):snacks.picker.Icon[]}>
+---@param source string
+local function custom_source(source, url)
+  ---@type snacks.picker.icons.Source
+  return {
+    v = 3,
+    url = url,
+    build = function(data)
+      ---@cast data snacks.picker.icons.source.Item[]
+      local ret = {} ---@type snacks.picker.Icon[]
+      for _, info in ipairs(data) do
+        table.insert(ret, {
+          name = vim.trim(info.name or info[2] or ""),
+          icon = vim.trim(info.icon or info[1] or ""),
+          category = info.category,
+          source = source,
+        })
+      end
+      return ret
+    end,
+  }
+end
+
+---@type table<string, snacks.picker.icons.Source>
 M.sources = {
   nerd_fonts = {
+    priority = 10,
     url = "https://github.com/ryanoasis/nerd-fonts/raw/refs/heads/master/glyphnames.json",
     v = 4,
     build = function(data)
@@ -43,6 +74,7 @@ M.sources = {
   },
   emoji = {
     url = "https://raw.githubusercontent.com/muan/unicode-emoji-json/refs/heads/main/data-by-emoji.json",
+    priority = 20,
     v = 4,
     build = function(data)
       ---@cast data table<string, {name:string, slug:string, group:string}>
@@ -70,7 +102,21 @@ M.sources = {
 ---@param source_name string
 local function load(source_name)
   local source = M.sources[source_name]
-  local file = vim.fn.stdpath("cache") .. "/snacks/picker/icons/" .. source_name .. "-v" .. (source.v or 1) .. ".json"
+  if not source then
+    Snacks.notify.error("Unknown icon source: " .. source_name)
+    return {}
+  end
+
+  -- Load from local file if not a URL
+  if not source.url:find("^https?://") then
+    local fd = assert(io.open(source.url, "r"))
+    local data = fd:read("*a")
+    fd:close()
+    return source.build(vim.json.decode(data))
+  end
+
+  local parts = { source_name, "v" .. (source.v or 1), "-", vim.fn.sha256(source.url):sub(1, 8), ".json" }
+  local file = vim.fn.stdpath("cache") .. "/snacks/picker/icons/" .. table.concat(parts, "")
   vim.fn.mkdir(vim.fn.fnamemodify(file, ":h"), "p")
   if vim.fn.filereadable(file) == 1 then
     local fd = assert(io.open(file, "r"))
@@ -100,7 +146,19 @@ end
 ---@type snacks.picker.finder
 function M.icons(opts)
   local ret = {} ---@type snacks.picker.Icon[]
-  for _, source in ipairs(opts.icon_sources or { "nerd_fonts", "emoji" }) do
+
+  for source, url in pairs(opts.custom_sources or {}) do
+    M.sources[source] = custom_source(source, url)
+  end
+
+  local sources = opts.icon_sources or vim.tbl_keys(M.sources)
+  table.sort(sources, function(a, b)
+    local sa = M.sources[a] and M.sources[a].priority or 0
+    local sb = M.sources[b] and M.sources[b].priority or 0
+    return sa > sb
+  end)
+
+  for _, source in ipairs(sources) do
     vim.list_extend(ret, load(source))
   end
   for _, icon in ipairs(ret) do