From 6bd3f685b4602aa478b5e987899e7215af20f25e Mon Sep 17 00:00:00 2001
Message-Id: <6bd3f685b4602aa478b5e987899e7215af20f25e.1634295379.git.info@protesilaos.com>
From: Protesilaos Stavrou <info@protesilaos.com>
Date: Fri, 15 Oct 2021 13:55:44 +0300
Subject: [PATCH] Implement auto-renaming scheme for EWW buffers

* etc/NEWS: Document the new user options.

* lisp/net/eww.el (eww-auto-rename-buffer-function)
(eww-auto-rename-buffer): Add user options.
(eww--rename-buffer): Introduce new function that performs the
renaming of buffers.
(eww--after-page-change): Add new wrapper function which calls
'eww-update-header-line-format' and 'eww-auto-rename-buffer-function'.
(eww, eww-render, eww-tag-title, eww-readable, eww-restore-history):
Include eww--after-page-change.

Fix bug#51176.

Co-authored-by: Abhiseck Paira <abhiseckpaira@disroot.org>
Co-authored-by: Protesilaos Stavrou <info@protesilaos.com>
---
 etc/NEWS        |  8 ++++++++
 lisp/net/eww.el | 39 ++++++++++++++++++++++++++++++++++-----
 2 files changed, 42 insertions(+), 5 deletions(-)

diff --git a/etc/NEWS b/etc/NEWS
index 7dd4d14274..906ff4e6ae 100644
--- a/etc/NEWS
+++ b/etc/NEWS
@@ -89,6 +89,14 @@
 
 * Changes in Specialized Modes and Packages in Emacs 29.1
 
+** eww
+
+---
+*** New user option to automatically rename EWW buffers
+When 'eww-auto-rename-buffer' is set to a non-nil value, it will make
+all buffers use either the title or the URL of the rendered web page.
+The rendering scheme is handled by 'eww-auto-rename-buffer-function'.
+
 ** image-dired
 
 ---
diff --git a/lisp/net/eww.el b/lisp/net/eww.el
index 24c6335210..14cf207e59 100644
--- a/lisp/net/eww.el
+++ b/lisp/net/eww.el
@@ -178,6 +178,21 @@
   :group 'eww
   :type 'hook)
 
+(defcustom eww-auto-rename-buffer-function #'eww--rename-buffer
+  "Function to rename EWW buffer.
+The function is called just before the `eww-after-render-hook' if
+`eww-auto-rename-buffer' is non-nil."
+  :version "29.1"
+  :group 'eww
+  :type 'function)
+
+(defcustom eww-auto-rename-buffer nil
+  "When non-nil rename EWW buffers after they are rendered.
+Renaming is controlled by `eww-auto-rename-buffer-function'."
+  :version "29.1"
+  :group 'eww
+  :type 'boolean)
+
 (defcustom eww-form-checkbox-selected-symbol "[X]"
   "Symbol used to represent a selected checkbox.
 See also `eww-form-checkbox-symbol'."
@@ -353,7 +368,7 @@
     (setq url (url-recreate-url parsed)))
   (plist-put eww-data :url url)
   (plist-put eww-data :title "")
-  (eww-update-header-line-format)
+  (eww--after-page-change)
   (let ((inhibit-read-only t))
     (insert (format "Loading %s..." url))
     (goto-char (point-min)))
@@ -502,6 +517,15 @@
   (member content-type '("text/html"
 			 "application/xhtml+xml")))
 
+(defun eww--rename-buffer ()
+  "Rename the current EWW buffer.
+Use the page's title or URL as an identifier."
+  (when (eq major-mode 'eww-mode)
+    (when-let ((title (or (plist-get eww-data :title)
+                          (plist-get eww-data :url))))
+      (rename-buffer
+       (format "*%s # eww*" (truncate-string-to-width title 40)) t))))
+
 (defun eww-render (status url &optional point buffer encode)
   (let* ((headers (eww-parse-headers))
 	 (content-type
@@ -552,7 +576,7 @@
 	    (eww-display-raw buffer (or encode charset 'utf-8))))
 	  (with-current-buffer buffer
 	    (plist-put eww-data :url url)
-	    (eww-update-header-line-format)
+	    (eww--after-page-change)
 	    (setq eww-history-position 0)
 	    (and last-coding-system-used
 		 (set-buffer-file-coding-system last-coding-system-used))
@@ -796,12 +820,17 @@
 		 `((?u . ,(or url ""))
 		   (?t . ,title))))))))
 
+(defun eww--after-page-change ()
+  (eww-update-header-line-format)
+  (when eww-auto-rename-buffer
+    (funcall eww-auto-rename-buffer-function)))
+
 (defun eww-tag-title (dom)
   (plist-put eww-data :title
 	     (replace-regexp-in-string
 	      "^ \\| $" ""
 	      (replace-regexp-in-string "[ \t\r\n]+" " " (dom-text dom))))
-  (eww-update-header-line-format))
+  (eww--after-page-change))
 
 (defun eww-display-raw (buffer &optional encode)
   (let ((data (buffer-substring (point) (point-max))))
@@ -929,7 +958,7 @@
 		      nil (current-buffer))
     (dolist (elem '(:source :url :title :next :previous :up))
       (plist-put eww-data elem (plist-get old-data elem)))
-    (eww-update-header-line-format)))
+    (eww--after-page-change)))
 
 (defun eww-score-readability (node)
   (let ((score -1))
@@ -1161,7 +1190,7 @@
       (goto-char (plist-get elem :point))
       ;; Make buffer listings more informative.
       (setq list-buffers-directory (plist-get elem :url))
-      (eww-update-header-line-format))))
+      (eww--after-page-change))))
 
 (defun eww-next-url ()
   "Go to the page marked `next'.
-- 
2.33.0