feat: handler for lazy-loading colorschemes

lua/lz/n/handler/colorscheme.lua

@@ -0,0 +1,53 @@
+local loader = require("lz.n.loader")
+
+---@class lz.n.ColorschemeHandler: lz.n.Handler
+---@field augroup? integer
+
+---@type lz.n.ColorschemeHandler
+local M = {
+    pending = {},
+    type = "colorscheme",
+    augroup = nil,
+}
+
+---@param plugin lz.n.Plugin
+function M.del(plugin)
+    for _, plugins in pairs(M.pending) do
+        plugins[plugin.name] = nil
+    end
+end
+
+---@param name string
+local function on_colorscheme(name)
+    if vim.tbl_contains(vim.fn.getcompletion("", "color"), name) then
+        return
+    end
+    loader.load(vim.tbl_values(M.pending[name]))
+end
+
+local function init()
+    if M.augroup then
+        return
+    end
+    M.augroup = vim.api.nvim_create_augroup("lz_n_handler_colorscheme", { clear = true })
+    vim.api.nvim_create_autocmd("ColorSchemePre", {
+        callback = function(event)
+            on_colorscheme(event.match)
+        end,
+        group = M.augroup,
+    })
+end
+
+---@param plugin lz.n.Plugin
+function M.add(plugin)
+    if not plugin.colorscheme then
+        return
+    end
+    init()
+    for _, colorscheme in pairs(plugin.colorscheme) do
+        M.pending[colorscheme] = M.pending[colorscheme] or {}
+        M.pending[colorscheme][plugin.name] = plugin.name
+    end
+end
+
+return M

lua/lz/n/handler/init.lua

@@ -12,6 +12,7 @@ M.types = {
     event = "event",
     ft = "ft",
     keys = "keys",
+    colorscheme = "colorscheme",
 }
 
 local handlers = {
@@ -19,6 +20,7 @@ local handlers = {
     event = require("lz.n.handler.event"),
     ft = require("lz.n.handler.ft"),
     keys = require("lz.n.handler.keys"),
+    colorscheme = require("lz.n.handler.colorscheme"),
 }
 
 ---@param plugin lz.n.Plugin

lua/lz/n/meta.lua

@@ -22,6 +22,7 @@ error("Cannot import a meta module")
 --- @field event? lz.n.Event[]
 --- @field keys? lz.n.Keys[]
 --- @field cmd? string[]
+--- @field colorscheme? string[]
 
 --- @class lz.n.PluginSpecHandlers
 ---
@@ -36,6 +37,9 @@ error("Cannot import a meta module")
 ---
 --- Load a plugin on one or more |key-mapping|s.
 --- @field keys? string|string[]|lz.n.KeysSpec[]
+---
+--- Load a plugin on one or more |colorscheme| events.
+--- @field colorscheme? string[]|string
 
 --- @class lz.n.KeysBase: vim.keymap.set.Opts
 --- @field desc? string

lua/lz/n/spec.lua

@@ -104,7 +104,22 @@ local function parse(spec)
             table.insert(result.cmd, _cmd_spec)
         end
     end
-    result.lazy = result.lazy or result.event ~= nil or result.keys ~= nil or result.cmd ~= nil
+    local colorscheme_spec = spec.colorscheme
+    if colorscheme_spec then
+        result.colorscheme = {}
+    end
+    if type(colorscheme_spec) == "string" then
+        table.insert(result.colorscheme, colorscheme_spec)
+    elseif type(colorscheme_spec) == "table" then
+        for _, _colorscheme_spec in pairs(colorscheme_spec) do
+            table.insert(result.cmd, _colorscheme_spec)
+        end
+    end
+    result.lazy = result.lazy
+        or result.event ~= nil
+        or result.keys ~= nil
+        or result.cmd ~= nil
+        or result.colorscheme ~= nil
     return result
 end