Subject: Re: bug#50383: 28.0.50; [PATCH] Feature suggestion, gnus-article-toggle-fonts to toggle fonts for HTML articles

From: Alex Bochannek <[email-masked]>
Date: Sun, 05 Sep 2021 22:22:35 -0700

Lars Ingebrigtsen <[email-masked]> writes:

> Alex Bochannek <[email-masked]> writes:
>
>> I am proposing the below `gnus-article-toggle-fonts' function with a
>> keybinding of `W D F'.
>
> Sounds good to me.
>
>
> [...]
>
>> +          (setq-local gnus-article-shr-use-fonts
>> +                      (not gnus-article-shr-use-fonts))
>
> [...]
>
>> The patch did not keep the fonts toggled when selecting the next message
>> or reloading the current one. I am proposing the below change. I am not
>> sure how you feel about buffer-local Gnus variables in `mm-decode.el',
>> so please let me know if an alternative approach would be better.
>
> Yeah, it would be best to avoid doing that.  How about changing the
> patch to have a buffer-local `shr-use-fonts' in the Gnus article buffer
> and use that instead?

Just like this then?
diff --git a/lisp/gnus/gnus-art.el b/lisp/gnus/gnus-art.el
index 3c1403e155..05d0be8ca2 100644
--- a/lisp/gnus/gnus-art.el
+++ b/lisp/gnus/gnus-art.el
@@ -2243,6 +2243,15 @@ gnus-article-show-images
 	    (funcall function (get-text-property start 'image-url)
 		     start end)))))))
 
+(defun gnus-article-toggle-fonts ()
+  "Toggle the use of proportional fonts for HTML articles."
+  (interactive nil gnus-article-mode gnus-summary-mode)
+  (gnus-with-article-buffer
+    (if (eq mm-text-html-renderer 'shr)
+        (progn
+          (setq-local shr-use-fonts (not shr-use-fonts))
+          (gnus-summary-show-article)))))
+
 (defun gnus-article-treat-fold-newsgroups ()
   "Fold the Newsgroups and Followup-To message headers."
   (interactive nil gnus-article-mode gnus-summary-mode)
@@ -4494,6 +4503,8 @@ gnus-article-mode
   (setq-local nobreak-char-display nil)
   ;; Enable `gnus-article-remove-images' to delete images shr.el renders.
   (setq-local shr-put-image-function #'gnus-shr-put-image)
+  ;; Shadow global shr-use-fonts to support font toggling.
+  (setq-local shr-use-fonts shr-use-fonts)
   (unless gnus-article-show-cursor
     (setq cursor-in-non-selected-windows nil))
   (gnus-set-default-directory)
-- 
Alex.