[emacs] Enhance epub reading

* emacs/.emacs.d/init/ycp-markup.el: set text-width to be a bit less
than my-org-focus-write width (76 vs 80); increase
next-screen-context-lines in nov mode; set left text margin to 2 in
nov mode
* emacs/.emacs.d/init/ycp-org.el: Add keybindings to nov-mode when
org-remark is available. Unfortunately org-remark-nov-mode is a global
minor mode
* emacs/.emacs.d/lisp/my/my-buffer.el: update my-toggle-focus-write to
use empty buffers on both sides
* emacs/.emacs.d/lisp/my/my-nov.el: a function to set left margin in
nov mode
* emacs/.emacs.d/lisp/my/my-org-remark.el: a convenience function to
org-remark to mark or open depending on active mark

Also use my custom nov.el repo

4 files changed, 79 insertions, 5 deletions

diff --git a/emacs/.emacs.d/lisp/my/my-buffer.el b/emacs/.emacs.d/lisp/my/my-buffer.el
index f06956f..c17e765 100644
--- a/emacs/.emacs.d/lisp/my/my-buffer.el
+++ b/emacs/.emacs.d/lisp/my/my-buffer.el
@@ -239,24 +239,54 @@ that point."
       (setq buffer temp-buffer))
     (set-window-buffer first-window buffer)))
 
+(defun my-set-left-buffer ()
+  "Generate and switch to an empty buffer."
+  (interactive)
+  (set-window-buffer
+   (window-left (get-buffer-window))
+   (with-current-buffer (get-buffer-create "*my-left*")
+     (read-only-mode t)
+     (current-buffer))))
+
+(defun my-set-right-buffer ()
+  "Generate and switch to an empty buffer."
+  (interactive)
+  (set-window-buffer
+   (window-right (get-buffer-window))
+   (with-current-buffer (get-buffer-create "*my-right*")
+     (read-only-mode t)
+     (current-buffer))))
+
 (defun my-toggle-focus-write ()
   "Toggle focus write mode.
 
 Focus write: make the current window the only one centered with
-width 80. If in org-mode, also narrow to current subtree."
+width 80. If in org-mode, also narrow to current subtree. Make
+buffers on both sides empty read-only buffers."
   (interactive)
   ;; Only one window in the current frame indicates we are in focus
   ;; write mode.
-  (if (length= (window-list) 1)
+  (if (and (equal
+            (buffer-name
+             (window-buffer (window-left (get-buffer-window))))
+            "*my-left*")
+           (equal
+            (buffer-name
+             (window-buffer (window-right (get-buffer-window))))
+            "*my-right*"))
       (progn
         (winner-undo)
         (when (derived-mode-p 'org-mode)
           (widen)))
     (when (derived-mode-p 'org-mode)
       (org-narrow-to-subtree))
-    (delete-other-windows)
-    (let ((margin (/ (- (window-width) 80) 2)))
-      (set-window-margins nil margin margin))))
+    (my-set-left-buffer)
+    (my-set-right-buffer)
+    (let ((margin (/ (- 80 (window-width)) 2)))
+      (enlarge-window margin t)
+      (windmove-left)
+      (enlarge-window (- margin) t)
+      (windmove-right))))
 
 (defun my-select-new-window-matching-mode (mode)
   "Select a new window."
@@ -415,6 +445,11 @@ for the given MAJOR-MODE, any text is appended to it."
       (4 (my-buffer-scratch-setup region default-mode))
       (_ (my-buffer-scratch-setup region)))))
 
+(defun my-new-empty-buffer ()
+  "Generate and switch to an empty buffer."
+  (interactive)
+  (switch-to-buffer (generate-new-buffer "empty")))
+
 (defcustom my-scratch-buffer-default-mode 'org-mode
   "Default major mode for `my-buffer-create-scratch'."
   :type 'symbol
diff --git a/emacs/.emacs.d/lisp/my/my-nov.el b/emacs/.emacs.d/lisp/my/my-nov.el
index 4e2f60a..d893017 100644
--- a/emacs/.emacs.d/lisp/my/my-nov.el
+++ b/emacs/.emacs.d/lisp/my/my-nov.el
@@ -64,5 +64,8 @@ chapter title."
     (my-copy-file-with-staging
      nov-file-name dest staging)))
 
+(defun my-nov-set-left-margin ()
+  (set-left-margin (point-min) (point-max) 2))
+
 (provide 'my-nov)
 ;;; my-nov.el ends here
diff --git a/emacs/.emacs.d/lisp/my/my-org-remark.el b/emacs/.emacs.d/lisp/my/my-org-remark.el
new file mode 100644
index 0000000..3e0ef0a
--- /dev/null
+++ b/emacs/.emacs.d/lisp/my/my-org-remark.el
@@ -0,0 +1,36 @@
+;;; my-org-remark.el -- customization to org-remark -*- lexical-binding: t -*-
+
+;; Copyright (C) 2025  Free Software Foundation, Inc.
+
+;; Author: Yuchen Pei <id@ypei.org>
+;; Package-Requires: ((emacs "29.4"))
+
+;; This file is part of dotted.
+
+;; dotted is free software: you can redistribute it and/or modify it under
+;; the terms of the GNU Affero General Public License as published by
+;; the Free Software Foundation, either version 3 of the License, or
+;; (at your option) any later version.
+
+;; dotted 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 Affero General
+;; Public License for more details.
+
+;; You should have received a copy of the GNU Affero General Public
+;; License along with dotted.  If not, see <https://www.gnu.org/licenses/>.
+
+;;; Commentary:
+
+;; customization to org-remark.
+
+;;; Code:
+
+(defun my-org-remark-open-or-create ()
+  (interactive)
+  (if mark-active
+      (call-interactively 'org-remark-mark)
+    (call-interactively 'org-remark-open)))
+
+(provide 'my-org-remark)
+;;; my-org-remark.el ends here
diff --git a/emacs/.emacs.d/lisp/nov.el b/emacs/.emacs.d/lisp/nov.el
-Subproject bbb5c60bfd6b09cffe0406a56930105335f0788
+Subproject c0d30da504fb0b68d8c28ff61a5e0095acda7f5