Mu4e: further improve org-msg

- stylistic tweaks
- make accent colour easily user-settable
- scale LaTeX fragments appropriately
- make it easy to toggle org-msg-mode for one-off messages

modules/email/mu4e/README.org

@@ -18,6 +18,7 @@
   - [[#offlineimap][offlineimap]]
   - [[#mbsync][mbsync]]
   - [[#mu-and-mu4e][mu and mu4e]]
+  - [[#orgmsg][OrgMsg]]
 - [[#troubleshooting][Troubleshooting]]
   - [[#no-such-file-or-directory-mu4e][=No such file or directory, mu4e=]]
   - [[#void-function-org-time-add-error-on-gentoo][~(void-function org-time-add)~ error on Gentoo]]
@@ -168,6 +169,15 @@ Then configure Emacs to use your email address:
     (mu4e-compose-signature . "---\nHenrik Lissner"))
   t)
 #+END_SRC
+** OrgMsg
+By default, ~org-msg-mode~ is enabled before composing the first message.
+To disable ~org-msg-mode~ by default, simply
+#+BEGIN_SRC emacs-lisp :tangle no
+(setq mu4e-compose--org-msg-toggle-next nil)
+#+END_SRC
+
+To toggle org-msg for a single message, just apply the universal argument to the
+compose or reply command (=SPC u= with ~evil~, =C-u= otherwise).
 
 * Troubleshooting
 ** =No such file or directory, mu4e=

modules/email/mu4e/autoload/email.el

@@ -189,18 +189,18 @@ is tomorrow.  With two prefixes, select the deadline."
 
 ;;;###autoload
 (defun my-mu4e-set-account ()
-    "Set the account for composing a message. If a 'To' header is present,
+  "Set the account for composing a message. If a 'To' header is present,
 and correspands to an email account, this account will be selected.
 Otherwise, the user is prompted for the account they wish to use."
-    (unless (and mu4e-compose-parent-message
+  (unless (and mu4e-compose-parent-message
-                 (let ((to (cdr (car (mu4e-message-field mu4e-compose-parent-message :to))))
+               (let ((to (cdr (car (mu4e-message-field mu4e-compose-parent-message :to))))
-                       (from (cdr (car (mu4e-message-field mu4e-compose-parent-message :from)))))
+                     (from (cdr (car (mu4e-message-field mu4e-compose-parent-message :from)))))
-                   (if (member to (plist-get mu4e~server-props :personal-addresses))
+                 (if (member to (plist-get mu4e~server-props :personal-addresses))
-                       (setq user-mail-address to)
+                     (setq user-mail-address to)
-                     (if (member from (plist-get mu4e~server-props :personal-addresses))
+                   (if (member from (plist-get mu4e~server-props :personal-addresses))
-                         (setq user-mail-address from)
+                       (setq user-mail-address from)
-                       nil))))
+                     nil))))
-      (ivy-read "Account: " (plist-get mu4e~server-props :personal-addresses) :action (lambda (candidate) (setq user-mail-address candidate)))))
+    (ivy-read "Account: " (plist-get mu4e~server-props :personal-addresses) :action (lambda (candidate) (setq user-mail-address candidate)))))
 
 ;;;###autoload
 (defun mu4e~main-action-prettier-str (str &optional func-or-shortcut)
@@ -245,3 +245,91 @@ clicked."
    (+mu4e--old-wconf
     (set-window-configuration +mu4e--old-wconf)
     (setq +mu4e--old-wconf nil))))
+
+;; org-msg hooks
+
+;;;###autoload
+(defun +org-msg-img-scale-css (img-uri)
+  "For a given IMG-URI, use imagemagik to find its width."
+  (if org-msg-currently-exporting
+      (list :width
+            (format "%.1fpx"
+                    (/ (string-to-number
+                        (shell-command-to-string
+                         (format "identify -format %%w %s"
+                                 (substring img-uri 7)))) ; 7=(length "file://")
+                       (plist-get org-format-latex-options :scale))))
+    (list :style (format "transform: scale(%.3f)"
+                         (/ 1.0 (plist-get org-format-latex-options :scale))))))
+
+(defun org-html-latex-fragment-scaled (latex-fragment _contents info)
+  "Transcode a LATEX-FRAGMENT object from Org to HTML.
+CONTENTS is nil.  INFO is a plist holding contextual information.
+
+This differs from `org-html-latex-fragment' in that it uses the LaTeX fragment
+as a meaningful alt value, applies a class to indicate what sort of fragment it is
+(latex-fragment-inline or latex-fragment-block), and (on Linux) scales the image to
+account for the value of :scale in `org-format-latex-options'."
+  (let ((latex-frag (org-element-property :value latex-fragment))
+        (processing-type (plist-get info :with-latex)))
+    (cond
+     ((memq processing-type '(t mathjax))
+      (org-html-format-latex latex-frag 'mathjax info))
+     ((memq processing-type '(t html))
+      (org-html-format-latex latex-frag 'html info))
+     ((assq processing-type org-preview-latex-process-alist)
+      (let ((formula-link
+             (org-html-format-latex latex-frag processing-type info)))
+        (when (and formula-link (string-match "file:\\([^]]*\\)" formula-link))
+          (let ((source (org-export-file-uri (match-string 1 formula-link)))
+                (attributes (list :alt latex-frag
+                                  :class (concat "latex-fragment-"
+                                                 (if (equal "\\(" (substring latex-frag 0 2))
+                                                     "inline" "block")))))
+            (when (and (memq processing-type '(dvipng convert)) IS-LINUX)
+              (apply #'plist-put attributes (+org-msg-img-scale-css source)))
+            (org-html--format-image source attributes info)))))
+     (t latex-frag))))
+
+(defun org-html-latex-environment-scaled (latex-environment _contents info)
+  "Transcode a LATEX-ENVIRONMENT element from Org to HTML.
+CONTENTS is nil.  INFO is a plist holding contextual information.
+
+This differs from `org-html-latex-environment' in that (on Linux) it
+scales the image to account for the value of :scale in `org-format-latex-options'."
+  (let ((processing-type (plist-get info :with-latex))
+        (latex-frag (org-remove-indentation
+                     (org-element-property :value latex-environment)))
+        (attributes (org-export-read-attribute :attr_html latex-environment))
+        (label (and (org-element-property :name latex-environment)
+                    (org-export-get-reference latex-environment info)))
+        (caption (and (org-html--latex-environment-numbered-p latex-environment)
+                      (number-to-string
+                       (org-export-get-ordinal
+                        latex-environment info nil
+                        (lambda (l _)
+                          (and (org-html--math-environment-p l)
+                               (org-html--latex-environment-numbered-p l))))))))
+    (plist-put attributes :class "latex-environment")
+    (cond
+     ((memq processing-type '(t mathjax))
+      (org-html-format-latex
+       (if (org-string-nw-p label)
+           (replace-regexp-in-string "\\`.*"
+                                     (format "\\&\n\\\\label{%s}" label)
+                                     latex-frag)
+         latex-frag)
+       'mathjax info))
+     ((assq processing-type org-preview-latex-process-alist)
+      (let ((formula-link
+             (org-html-format-latex
+              (org-html--unlabel-latex-environment latex-frag)
+              processing-type info)))
+        (when (and formula-link (string-match "file:\\([^]]*\\)" formula-link))
+          (let ((source (org-export-file-uri (match-string 1 formula-link))))
+            (when (and (memq processing-type '(dvipng convert)) IS-LINUX)
+              (apply #'plist-put attributes (+org-msg-img-scale-css source)))
+            (org-html--wrap-latex-environment
+             (org-html--format-image source attributes info)
+             info caption label)))))
+     (t (org-html--wrap-latex-environment latex-frag info caption label)))))

modules/email/mu4e/config.el

@@ -172,7 +172,7 @@
 
 (when (featurep! :lang org)
   (use-package! org-msg
-    :hook (org-load . org-msg-mode)
+    :after (mu4e org)
     :config
     (setq org-msg-options "html-postamble:nil H:5 num:nil ^:{} toc:nil author:nil email:nil \\n:t tex:dvipng"
           org-msg-startup "hidestars indent inlineimages"
@@ -190,6 +190,27 @@ Usefull for affecting HTML export config.")
       :after #'org-msg-org-to-xml
       (setq org-msg-currently-exporting nil))
 
+    (advice-add #'org-html-latex-fragment    :override #'org-html-latex-fragment-scaled)
+    (advice-add #'org-html-latex-environment :override #'org-html-latex-environment-scaled)
+
+    (defvar mu4e-compose--org-msg-toggle-next t ; t to initialise org-msg
+      "Whether to toggle ")
+    (defun mu4e-compose-org-msg-handle-toggle (toggle-p)
+      (when (xor toggle-p mu4e-compose--org-msg-toggle-next)
+        (org-msg-mode (if org-msg-mode -1 1))
+        (setq mu4e-compose--org-msg-toggle-next
+              (not mu4e-compose--org-msg-toggle-next))))
+
+    (defadvice! mu4e-maybe-toggle-org-msg (orig-fn toggle-p)
+      :around #'mu4e-compose-new
+      :around #'mu4e-compose-reply
+      (interactive "p")
+      (mu4e-compose-org-msg-handle-toggle (/= 1 toggle-p))
+      (funcall orig-fn))
+
+    (defvar +org-msg-accent-color "#c01c28"
+      "Accent color to use in org-msg's generated CSS.
+Must be set before org-msg is loaded to take effect.")
     (setq org-msg-enforce-css
           (let* ((font-family '(font-family . "-apple-system, BlinkMacSystemFont, \"Segoe UI\", Roboto, Oxygen, Ubuntu, Cantarell,\
         \"Fira Sans\", \"Droid Sans\", \"Helvetica Neue\", Arial, sans-serif, \"Apple Color Emoji\", \"Segoe UI Emoji\", \"Segoe UI Symbol\";"))
@@ -197,12 +218,13 @@ Usefull for affecting HTML export config.")
                  (font-size '(font-size . "11pt"))
                  (font `(,font-family ,font-size))
                  (line-height '(line-height . "1.2"))
-                 (theme-color "#8a0400")
+                 (theme-color +org-msg-accent-color)
                  (bold '(font-weight . "bold"))
                  (color `(color . ,theme-color))
                  (table `((margin-top . "6px") (margin-bottom . "6px")
                           (border-left . "none") (border-right . "none")
-                          (border-top . "2px solid #222222") (border-bottom . "2px solid #222222")
+                          (border-top . "2px solid #222222")
+                          (border-bottom . "2px solid #222222")
                           ))
                  (ftl-number `(,color ,bold (text-align . "left")))
                  (inline-modes '(asl c c++ conf cpp csv diff ditaa emacs-lisp
@@ -234,10 +256,12 @@ Usefull for affecting HTML export config.")
                                   (margin-top . "0px") (margin-left . "30px")
                                   (padding-top . "0px") (padding-left . "5px")))
               (nil signature (,@font (margin-bottom . "20px")))
-              (blockquote nil ((padding . "0px 10px") (margin-left . "10px")
+              (blockquote nil ((padding . "2px 12px") (margin-left . "10px")
-                               (margin-top . "20px") (margin-bottom . "0")
+                               (margin-top . "10px") (margin-bottom . "0")
-                               (border-left . "3px solid #ccc") (font-style . "italic")
+                               (border-left . "3px solid #ccc")
+                               (font-style . "italic")
                                (background . "#f9f9f9")))
+              (p blockquote  ((margin . "0") (padding . "4px 0")))
               (code nil (,font-size ,monospace-font (background . "#f9f9f9")))
               ,@code-src
               (nil linenr ((padding-right . "1em")
@@ -266,10 +290,7 @@ Usefull for affecting HTML export config.")
               (nil org-src-name ,ftl-number)
               (img nil ((vertical-align . "middle")
                         (max-width . "100%")))
-              (img latex-fragment-inline ((transform . ,(format "translateY(-1px) scale(%.3f)"
+              (img latex-fragment-inline ((margin . "0 0.1em")))
-                                                                (/ 1.0 (if (boundp 'preview-scale)
-                                                                           preview-scale 1.4))))
-                                          (margin . "0 -0.35em")))
               (table nil (,@table ,line-height (border-collapse . "collapse")))
               (th nil ((border . "none") (border-bottom . "1px solid #222222")
                        (background-color . "#EDEDED") (font-weight . "500")
@@ -280,8 +301,9 @@ Usefull for affecting HTML export config.")
               (td org-right ((text-align . "right")))
               (td org-center ((text-align . "center")))
               (kbd nil ((border . "1px solid #d1d5da") (border-radius . "3px")
-                        (box-shadow . "inset 0 -1px 0 #d1d5da") (background-color . "#fafbfc")
+                        (box-shadow . "inset 0 -1px 0 #d1d5da")
-                        (color . "#444d56") (padding . "3px 5px") (display . "inline-block")))
+                        (background-color . "#fafbfc") (color . "#444d56")
+                        (padding . "3px 5px") (display . "inline-block")))
               (div outline-text-4 ((margin-left . "15px")))
               (div outline-4 ((margin-left . "10px")))
               (h4 nil ((margin-bottom . "0px") (font-size . "11pt")))
@@ -289,11 +311,11 @@ Usefull for affecting HTML export config.")
                        ,color (font-size . "14pt")))
               (h2 nil ((margin-top . "20px") (margin-bottom . "20px")
                        ,color (font-size . "18pt")))
-              (h1 nil ((margin-top . "20px")
+              (h1 nil ((margin-top . "20px") (margin-bottom . "0px")
-                       (margin-bottom . "0px") ,color (font-size . "24pt")))
+                       ,color (font-size . "24pt")))
-              (p nil ((text-decoration . "none") (margin-bottom . "0px")
+              (p nil ((text-decoration . "none") (line-height . "11pt")
-                      (margin-top . "10px") (line-height . "11pt") ,font-size
+                      (margin-top . "10px") (margin-bottom . "0px")
-                      (max-width . "100ch")))
+                      ,font-size (max-width . "100ch")))
               (b nil ((font-weight . "500") (color . ,theme-color)))
               (div nil (,@font (line-height . "12pt"))))))))