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

[Alex Bochannek]

Hello!

A while back I turned off `shr-use-fonts' for my HTML email but found
that occasionally proportional fonts are useful when reading my
messages.

I am proposing the below `gnus-article-toggle-fonts' function with a
keybinding of `W D F'.

        New Gnus article washing option to toggle HTML fonts

        * lisp/gnus/gnus-sum.el (gnus-summary-wash-display-map): 
        (gnus-summary-make-menu-bar): Add mode mapping and menu item for
        article HTML font toggle.

        * lisp/gnus/gnus-art.el (gnus-article-toggle-fonts): Toggle
        shr-use-fonts and redisplay message.

        * doc/misc/gnus.texi (Article Washing): Document new HTML font
        toggle function.

diff --git a/doc/misc/gnus.texi b/doc/misc/gnus.texi
index 5f3fba00df..c8aec4eea1 100644
--- a/doc/misc/gnus.texi
+++ b/doc/misc/gnus.texi
@@ -9374,6 +9374,12 @@ Article Washing
 
 @end table
 
+@item W D F
+@kindex W D F @r{(Summary)}
+@findex gnus-article-toggle-fonts
+Toggle proportional fonts for @acronym{HTML} articles.  This temporarily
+changes the @code{shr-use-fonts} variable in the current buffer.
+
 @item W b
 @kindex W b @r{(Summary)}
 @findex gnus-article-add-buttons
diff --git a/lisp/gnus/gnus-art.el b/lisp/gnus/gnus-art.el
index 3c1403e155..7f48191085 100644
--- a/lisp/gnus/gnus-art.el
+++ b/lisp/gnus/gnus-art.el
@@ -2243,6 +2243,19 @@ 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
+          (if (not (local-variable-p 'gnus-article-shr-use-fonts))
+              (setq-local gnus-article-shr-use-fonts shr-use-fonts))
+          (setq-local gnus-article-shr-use-fonts
+                      (not gnus-article-shr-use-fonts))
+          (let ((shr-use-fonts gnus-article-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)
diff --git a/lisp/gnus/gnus-sum.el b/lisp/gnus/gnus-sum.el
index 856e95c0ba..c28e38e315 100644
--- a/lisp/gnus/gnus-sum.el
+++ b/lisp/gnus/gnus-sum.el
@@ -2252,6 +2252,7 @@ gnus-summary-mode-map
   "s" gnus-treat-smiley
   "D" gnus-article-remove-images
   "W" gnus-article-show-images
+  "F" gnus-article-toggle-fonts
   "f" gnus-treat-from-picon
   "m" gnus-treat-mail-picon
   "n" gnus-treat-newsgroups-picon
@@ -2561,6 +2562,7 @@ gnus-summary-make-menu-bar
              ["Unfold headers" gnus-article-treat-unfold-headers t]
              ["Fold newsgroups" gnus-article-treat-fold-newsgroups t]
              ["Html" gnus-article-wash-html t]
+             ["Toggle HTML fonts" gnus-article-toggle-fonts t]
              ["Unsplit URLs" gnus-article-unsplit-urls t]
              ["Verify X-PGP-Sig" gnus-article-verify-x-pgp-sig t]
              ["Decode HZ" gnus-article-decode-HZ t]

-- 
Alex.