Add scroll-lock (#358)

2 files changed, 88 insertions, 0 deletions

diff --git a/evil-collection.el b/evil-collection.el
index e960af1..57b8844 100644
--- a/evil-collection.el
+++ b/evil-collection.el
@@ -241,6 +241,7 @@ through removing their entry from `evil-collection-mode-list'."
     robe
     rtags
     ruby-mode
+    scroll-lock
     sh-script
     ,@(when (>= emacs-major-version 28) '(shortdoc))
     simple
diff --git a/modes/scroll-lock/evil-collection-scroll-lock.el b/modes/scroll-lock/evil-collection-scroll-lock.el
new file mode 100644
index 0000000..a0ff549
--- /dev/null
+++ b/modes/scroll-lock/evil-collection-scroll-lock.el
@@ -0,0 +1,87 @@
+;;; evil-collection-scroll-lock.el --- Bindings for `scroll-lock' -*- lexical-binding: t -*-
+
+;; Copyright (C) 2021 James Nguyen
+
+;; Author: James Nguyen <james@jojojames.com>
+;; Maintainer: James Nguyen <james@jojojames.com>
+;; URL: https://github.com/emacs-evil/evil-collection
+;; Version: 0.0.1
+;; Package-Requires: ((emacs "25.1"))
+;; Keywords: evil, elisp, lisp
+
+;; This program is free software; you can redistribute it and/or modify
+;; it under the terms of the GNU General Public License as published by
+;; the Free Software Foundation, either version 3 of the License, or
+;; (at your option) any later version.
+
+;; This program is distributed in the hope that it will be useful,
+;; but WITHOUT ANY WARRANTY; without even the implied warranty of
+;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+;; GNU General Public License for more details.
+
+;; You should have received a copy of the GNU General Public License
+;; along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+;;; Commentary:
+;;; Bindings for `scroll-lock'.
+
+;;; Code:
+(require 'scroll-lock)
+(require 'evil-collection)
+
+(declare-function scroll-lock-next-line "scroll-lock")
+(declare-function scroll-lock-previous-line "scroll-lock")
+(declare-function scroll-lock-forward-paragraph "scroll-lock")
+(declare-function scroll-lock-backward-paragraph "scroll-lock")
+
+(defconst evil-collection-scroll-lock-maps '(scroll-lock-mode-map))
+
+(evil-define-motion evil-collection-scroll-lock-next-line (count)
+  "Scroll down COUNT lines keeping point fixed."
+  :type line
+  (let (line-move-visual)
+    (scroll-lock-next-line (or count 1))))
+
+(evil-define-motion evil-collection-scroll-lock-previous-line (count)
+  "Scroll up COUNT lines keeping point fixed."
+  :type line
+  (let (line-move-visual)
+    (scroll-lock-previous-line (or count 1))))
+
+(evil-define-motion evil-collection-scroll-lock-forward-paragraph (count)
+  "Scroll down COUNT paragraphs keeping point fixed."
+  :jump t
+  :type exclusive
+  (evil-signal-at-bob-or-eob count)
+  (scroll-lock-forward-paragraph count)
+  (unless (eobp) (forward-line)))
+
+(evil-define-motion evil-collection-scroll-lock-backward-paragraph (count)
+  "Scroll up COUNT paragraphs keeping point fixed."
+  :jump t
+  :type exclusive
+  (evil-signal-at-bob-or-eob (- (or count 1)))
+  (unless (eobp) (forward-line))
+  (scroll-lock-backward-paragraph count)
+  (unless (bobp) (forward-line -1)))
+
+;;;###autoload
+(defun evil-collection-scroll-lock-setup ()
+  "Set up `evil' bindings for `scroll-lock'."
+  (evil-collection-define-key 'normal 'scroll-lock-mode-map
+    [remap evil-next-line] 'evil-collection-scroll-lock-next-line
+    [remap evil-previous-line] 'evil-collection-scroll-lock-previous-line
+    [remap evil-forward-paragraph]
+    'evil-collection-scroll-lock-forward-paragraph
+    [remap evil-backward-paragraph]
+    'evil-collection-scroll-lock-backward-paragraph)
+
+  (evil-add-command-properties
+   #'evil-collection-scroll-lock-forward-paragraph :jump t)
+  (evil-add-command-properties
+   #'evil-collection-scroll-lock-backward-paragraph :jump t)
+
+  (add-hook 'scroll-lock-mode-hook 'evil-normalize-keymaps))
+
+(provide 'evil-collection-scroll-lock)
+;;; evil-collection-scroll-lock.el ends here