Add support for eglot, make lsp-mode optional

Author: nilclass

README.md

@@ -24,5 +24,7 @@ This is how the "Hello World" example from Slint looks like:
 ## Prerequisites
 
 - Emacs: I've tested this with GNU Emacs 28.2. ymmv. Please file an issue if you run into any problems.
-- [lsp-mode](https://emacs-lsp.github.io/lsp-mode/): Adds LSP support to Emacs. Can be installed via melpa.
 - [slint-lsp](https://github.com/slint-ui/slint/blob/master/tools/lsp/README.md): The slint language server. Follow the link for installation instructions.
+- (*Optional*) [lsp-mode](https://emacs-lsp.github.io/lsp-mode/): LSP support for Emacs (alternative to built-in eglot). Can be installed via melpa.
+
+`slint-mode` should work with both `lsp-mode` and `eglot`.

slint-mode.el

@@ -5,7 +5,7 @@
 ;; Author: Niklas Cathor <[email protected]>
 ;; Keywords: languages
 ;; Version: 0
-;; Package-Requires: ((emacs "24.4") (lsp-mode "6.0"))
+;; Package-Requires: ((emacs "24.4"))
 ;; Homepage: https://github.com/nilclass/slint-mode
 
 ;; This program is free software; you can redistribute it and/or modify
@@ -23,8 +23,6 @@
 
 ;;; Code:
 
-(require 'lsp-mode)
-
 (defgroup slint nil
   "Major mode for Slint UI files."
   :tag "Slint"
@@ -110,13 +108,18 @@
   (set-syntax-table slint-mode-syntax-table)
   (set (make-local-variable 'font-lock-defaults) '(slint-font-lock-keywords)))
 
-(add-to-list 'lsp-language-id-configuration
-             '(slint-mode . "slint"))
+(with-eval-after-load 'lsp-mode
+  (add-to-list 'lsp-language-id-configuration
+               '(slint-mode . "slint"))
+
+  (lsp-register-client
+   (make-lsp-client :new-connection (lsp-stdio-connection "slint-lsp")
+                    :activation-fn (lsp-activate-on "slint")
+                    :server-id 'slint)))
 
-(lsp-register-client
- (make-lsp-client :new-connection (lsp-stdio-connection "slint-lsp")
-                  :activation-fn (lsp-activate-on "slint")
-                  :server-id 'slint))
+(with-eval-after-load 'eglot
+  (add-to-list 'eglot-server-programs
+               '(slint-mode . ("slint-lsp"))))
 
 ;;;###autoload
 (add-to-list 'auto-mode-alist '("\\.slint\\'" . slint-mode))