branch: externals/doc-view-follow
commit dbb037d2851e6f4cee03c7c664da903ce91e3aa8
Author: Paul Nelson <63298781+ultron...@users.noreply.github.com>
Commit: GitHub <nore...@github.com>
Add files via upload
---
doc-dual-view.el | 139 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 139 insertions(+)
diff --git a/doc-dual-view.el b/doc-dual-view.el
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+;;; doc-dual-view.el --- Sync two windows showing the same document -*-
lexical-binding: t; -*-
+
+;; Copyright (C) 2024 Paul D. Nelson
+
+;; Author: Paul D. Nelson <nelson.paul.da...@gmail.com>
+;; Keywords: convenience
+
+;; 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 <https://www.gnu.org/licenses/>.
+
+;;; Commentary:
+
+;; This package provides a minor mode, `doc-dual-view-mode', that
+;; synchronizes page navigation between two windows displaying the
+;; same document, making it so that when you navigate to a page in one
+;; window, the other window will navigate to a neighboring page, so
+;; that the second window is always one page ahead of the first.
+
+;; Supports `doc-view-mode' and `pdf-view-mode'. You can customize
+;; the `doc-dual-view-modes' variable to add support for additional
+;; document viewing modes or modify the behavior for existing modes.
+
+;;; Code:
+
+(require 'timer)
+
+(defgroup doc-dual-view nil
+ "Synchronize pages between two windows displaying the same document."
+ :group 'convenience)
+
+(defcustom doc-dual-view-modes
+ '((pdf-view-mode
+ (pdf-view-goto-page
+ pdf-view-next-page-command
+ pdf-view-previous-page-command)
+ (lambda () (pdf-view-current-page))
+ (lambda () (pdf-cache-number-of-pages))
+ pdf-view-redisplay)
+ (doc-view-mode
+ (doc-view-goto-page
+ doc-view-next-page
+ doc-view-previous-page)
+ (lambda () (doc-view-current-page))
+ (lambda () (doc-view-last-page-number))
+ doc-view-goto-page))
+ "Alist for supported modes.
+Given by (major-mode (goto-funcs) current-page-func max-page-func
+redisplay-func)."
+ :type '(repeat (list (symbol :tag "Major Mode")
+ (repeat :tag "Goto Page Functions" symbol)
+ (function :tag "Current Page Function")
+ (function :tag "Max Page Function")
+ (function :tag "Redisplay Function")))
+ :group 'doc-dual-view)
+
+(defvar-local doc-dual-view--redisplay-timer nil
+ "Timer for delayed redisplay.")
+
+(defun doc-dual-view--order-windows (windows)
+ "Order WINDOWS based on their position, leftmost (or topmost if equal)
first."
+ (sort windows (lambda (a b)
+ (let ((edges-a (window-edges a))
+ (edges-b (window-edges b)))
+ (or (< (car edges-a) (car edges-b))
+ (and (= (car edges-a) (car edges-b))
+ (< (cadr edges-a) (cadr edges-b))))))))
+
+(defun doc-dual-view--sync-pages (&rest _args)
+ "Sync pages between two windows showing the same document."
+ (let* ((mode-funcs (assoc major-mode doc-dual-view-modes))
+ (goto-funcs (nth 1 mode-funcs))
+ (current-page-func (nth 2 mode-funcs))
+ (max-page-func (nth 3 mode-funcs))
+ (redisplay-func (nth 4 mode-funcs)))
+ (when mode-funcs
+ (let ((windows (doc-dual-view--order-windows
+ (get-buffer-window-list nil nil nil))))
+ (when (= (length windows) 2)
+ (let* ((first-window (car windows))
+ (second-window (cadr windows))
+ (current-page (funcall current-page-func))
+ (max-page (funcall max-page-func))
+ (target-page (if (eq (selected-window) first-window)
+ (min (1+ current-page) max-page)
+ (max (1- current-page) 1))))
+ (with-selected-window (if (eq (selected-window) first-window)
+ second-window
+ first-window)
+ (let ((other-current-page (funcall current-page-func)))
+ (when (not (= other-current-page target-page))
+ ;; Temporarily remove advice to prevent recursion
+ (dolist (func goto-funcs)
+ (advice-remove func #'doc-dual-view--sync-pages))
+ (unwind-protect
+ (progn
+ (funcall (car goto-funcs) target-page)
+ ;; Use timer for redisplay
+ (when doc-dual-view--redisplay-timer
+ (cancel-timer doc-dual-view--redisplay-timer))
+ (setq doc-dual-view--redisplay-timer
+ (run-with-idle-timer
+ 0.001 nil
+ (lambda (win)
+ (when (window-live-p win)
+ (with-selected-window win
+ (funcall redisplay-func))))
+ (selected-window))))
+ ;; Re-add advice after execution
+ (dolist (func goto-funcs)
+ (advice-add
+ func :after #'doc-dual-view--sync-pages))))))))))))
+
+;;;###autoload
+(define-minor-mode doc-dual-view-mode
+ "Minor mode to sync pages between two windows showing the same document."
+ :global nil
+ (dolist (mode-funcs doc-dual-view-modes)
+ (let ((goto-funcs (cadr mode-funcs)))
+ (dolist (goto-func goto-funcs)
+ (if doc-dual-view-mode
+ (advice-add goto-func :after #'doc-dual-view--sync-pages)
+ (advice-remove goto-func #'doc-dual-view--sync-pages)))))
+ (when (not doc-dual-view-mode)
+ (when doc-dual-view--redisplay-timer
+ (cancel-timer doc-dual-view--redisplay-timer)
+ (setq doc-dual-view--redisplay-timer nil))))
+
+(provide 'doc-dual-view)
+;;; doc-dual-view.el ends here
