Add functions for rich clipboard interaction

In order to copy/paste between word processors and Emacs markup modes.
This needs a bit more work (e.g. when copying Org snippets, we need to
siphon some #+ macros and copy any #+SETUPFILEs) but it's a start.

1 files changed, 40 insertions, 0 deletions

diff --git a/.emacs b/.emacs
index c6e5595..7ad2e5c 100644
--- a/.emacs
+++ b/.emacs
@@ -620,4 +620,44 @@
     (save-buffer)
     (kill-buffer buf)))
 
+;; Clipboard interaction.
+(defun my/kill-as-html (text markup)
+  (interactive
+   (list (buffer-substring (region-beginning) (region-end))
+         (or (alist-get major-mode '((markdown-mode . "markdown")
+                                     (org-mode . "org")
+                                     (rst-mode . "rst")))
+             (let ((default "plain"))
+               (read-string (format-prompt "Convert from:" default)
+                            nil nil default)))))
+  ;; TODO: make this a transient to easily (un)set pandoc extensions.
+  (with-temp-buffer
+    (call-process-region text nil "pandoc" nil t nil
+                         "--from" markup "--to" "html")
+    ;; TODO: could gui-set-selection help here?  The docstring makes
+    ;; it sound like passing a value with a 'text/html property set to
+    ;; the HTML string should work, but empirically it doesn't.
+    (call-process-region nil nil "xclip" nil nil nil
+                         "-selection" "clipboard" "-target" "text/html")))
+
+(defun my/yank-from-html (html markup)
+  (interactive
+   (list
+    (gui-get-selection 'CLIPBOARD 'text/html)
+    (or (alist-get major-mode '((markdown-mode . "markdown")
+                                (org-mode . "org")
+                                (rst-mode . "rst")))
+        (let ((default "plain"))
+          (read-string (format-prompt "Convert to:" default)
+                       nil nil default)))))
+  ;; TODO: make this a transient to easily (un)set pandoc extensions.
+  (let* ((disabled-html-extensions '("native_divs" "native_spans"))
+         (html-spec
+          (funcall 'string-join `("html" ,@disabled-html-extensions) "-"))
+         (disabled-markup-extensions '("smart"))
+         (markup-spec
+          (funcall 'string-join `(,markup ,@disabled-markup-extensions) "-")))
+    (call-process-region html nil "pandoc" nil t t
+                         "--from" html-spec "--to" markup-spec)))
+
 ;; TODO: decruftify mode-line (e.g. remove superflous parens)