Improve dart lang module (#2895)

* Use lsp-dart

* Add hover to +flutter flag

* Update README

* Fixes

modules/lang/dart/README.org

@@ -31,11 +31,12 @@ This module has no dedicated maintainers.
 ** Module Flags
 + =+lsp= Enable LSP server integration.
 + =+flutter= Adds ~flutter~ integration and some sane defaults for Flutter
-  development.
+  development along with ~hover~ for desktop development.
 
 ** Plugins
 + [[https://github.com/bradyt/dart-mode][dart-mode]]
 + [[https://github.com/amake/flutter.el][flutter.el]]
++ [[https://github.com/ericdallo/hover.el][hover.el]]
 
 * Prerequisites
 Make sure that the Dart SDK is on your ~PATH~, and if using Flutter, make sure
@@ -85,8 +86,8 @@ flutter doctor # for Dependency check and further instructions
 ** Dart & Flutter
 On Linux, the installers for Dart and Flutter use the ~/opt~ directory, and this
 module assumes that. However, you may set ~lsp-dart-sdk-dir~ to your Dart
-install directory, if it differs, to make sure LSP can find the language server
+install directory and ~flutter-sdk-path~ to you flutter SDK folder, to make sure
-included with the Dart SDK.
+LSP can find the language server included with the Dart SDK.
 
 Alternatively, these variables shouldn't be necessary if you just include Dart
 and Flutter on your `PATH` variable.

modules/lang/dart/config.el

@@ -6,7 +6,7 @@
   :config
   (when (and (featurep! +flutter) IS-LINUX)
     (when-let (path (doom-glob "/opt/flutter/bin/cache/dart-sdk"))
-      (setq lsp-dart-sdk-dir path))))
+      (setq flutter-sdk-path path))))
 
 
 (use-package! flutter
@@ -16,3 +16,13 @@
   (map! :map dart-mode-map
         :localleader
         "r" #'flutter-run-or-hot-reload))
+
+
+(use-package! hover
+  :when (featurep! +flutter)
+  :defer t
+  :config
+  (map! :map dart-mode-map
+        :localleader
+        "h r" #'hover-run-or-hot-reload
+        "h R" #'hover-run-or-hot-restart))

modules/lang/dart/doctor.el

@@ -6,8 +6,3 @@
 
 (unless (executable-find "dart")
   (warn! "Dart isn't on PATH."))
-
-(when (featurep! +lsp)
-  (require 'dart-mode)
-  (unless (file-readable-p lsp-dart-sdk-dir)
-    (warn! "LSP Mode can't find lsp-dart-sdk-dir.")))

modules/lang/dart/packages.el

@@ -2,5 +2,10 @@
 ;;; lang/dart/packages.el
 
 (package! dart-mode :pin "04fcd649f1")
+
+(when (featurep! +lsp)
+  (package! lsp-dart :pin "064d47bad3"))
+
 (when (featurep! +flutter)
-  (package! flutter :pin "ec92a4df84"))
+  (package! flutter :pin "ec92a4df84")
+  (package! hover :pin "6f9ed1a651"))