From db2dc67e47b3e06c4498192b8b94b93540bade87 Mon Sep 17 00:00:00 2001
From: Andrea Ciceri <andrea.ciceri@autistici.org>
Date: Thu, 9 Jan 2025 11:17:38 +0100
Subject: [PATCH] Add `ultra-scroll` to Emacs

---
 hmModules/emacs/init.el     | 11 +++++++----
 packages/emacs/packages.nix | 10 ++++++++++
 2 files changed, 17 insertions(+), 4 deletions(-)

diff --git a/hmModules/emacs/init.el b/hmModules/emacs/init.el
index 68ba3d2..25a8175 100644
--- a/hmModules/emacs/init.el
+++ b/hmModules/emacs/init.el
@@ -48,8 +48,6 @@
   (native-comp-async-report-warnings-errors nil)
   (inhibit-startup-message t)
   (visible-bell t)
-  (scroll-conservatively 101) ;; more than 100 => redisplay doesn't recenter point)
-  (scroll-margin 3)
   (temporary-file-directory "~/.emacs-saves/")
   (backup-directory-alist `(("." . ,temporary-file-directory)))
   (auto-save-files-name-transforms `((".*" ,temporary-file-directory t)))
@@ -84,6 +82,13 @@
       (async-shell-command (format "sudo nixos-rebuild --flake fleet %s -L" operation) buffer-name)))
   )
 
+(use-package ultra-scroll
+  :init
+  (setq scroll-conservatively 101 ; important!
+        scroll-margin 0)
+  :config
+  (ultra-scroll-mode 1))
+
 (use-package doc-view
   :custom
   (doc-view-scale-internally nil)
@@ -628,7 +633,6 @@
   (add-to-list 'eat-semi-char-non-bound-keys '[?\e 108]) ; M-l
   (eat-update-semi-char-mode-map)
   (eat-reload)
-  :hook (eat-mode . (lambda () (setq-local scroll-margin 0)))
   :bind (("C-c o t" . eat-project))
   ;; FIXME doesn't work well
   ;; ((eat-mode . compilation-shell-minor-mode))
@@ -666,7 +670,6 @@
 	  (defalias (car alias) (cdr alias)))
 	ccr/eshell-aliases)
 
-  :hook (eshell-mode . (lambda () (setq-local scroll-margin 0)))
   :bind (("C-c o e" . project-eshell)
 	 :map eshell-mode-map
 	 ("C-r" . eshell-atuin-history))) ;; i.e. just C-r in semi-char-mode
diff --git a/packages/emacs/packages.nix b/packages/emacs/packages.nix
index a3d9f0d..fde9e30 100644
--- a/packages/emacs/packages.nix
+++ b/packages/emacs/packages.nix
@@ -88,6 +88,16 @@ let
       };
       deps = [ ];
     };
+    ultra-scroll = buildEmacsPackage {
+      name = "ultra-scroll";
+      src = pkgs.fetchFromGitHub {
+        owner = "jdtsmith";
+        repo = "ultra-scroll";
+        rev = "78ab497c6568e4a99f34a84b4c9bfe87d1a71d8c";
+        hash = "sha256-q/LGP69GRtEEbSpXi9JUoZjr/UV1QMVjQw96M6qxsZU=";
+      };
+      deps = [ ];
+    };
   };
 
   # *List* containing emacs packages from (M)ELPA