Subject: [PATCH v1 1/1] Support for the truncation of displayed URLs

From: David Edmondson <[email-masked]>
Date: Mon, 15 Oct 2018 11:06:26 +0100

When applying markup to URLs in the buffer, truncate the visible
portion to `rcirc-url-max-length' characters. By default no truncation
is done.
---
 lisp/net/rcirc.el | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/lisp/net/rcirc.el b/lisp/net/rcirc.el
index fe9c71a21c..1c0b540563 100644
--- a/lisp/net/rcirc.el
+++ b/lisp/net/rcirc.el
@@ -168,6 +168,13 @@ rcirc-fill-prefix
 		 (string :tag "Prefix text"))
   :group 'rcirc)
 
+(defcustom rcirc-url-max-length nil
+  "Maximum number of characters in displayed URLs.
+If nil, no maximum is applied."
+  :type '(choice (const :tag "No maximum" nil)
+                 (integer :tag "Number of characters"))
+  :group 'rcirc)
+
 (defvar rcirc-ignore-buffer-activity-flag nil
   "If non-nil, ignore activity in this buffer.")
 (make-variable-buffer-local 'rcirc-ignore-buffer-activity-flag)
@@ -2491,6 +2498,16 @@ rcirc-markup-urls
            (end (match-end 0))
            (url (match-string-no-properties 0))
            (link-text (buffer-substring-no-properties start end)))
+      ;; Truncate the visible part of URLs if required and necessary.
+      (when (and rcirc-url-max-length
+		 (> (- end start) rcirc-url-max-length))
+	(let* ((ellipsis "...")
+               (new-end (- (+ start rcirc-url-max-length)
+                           (length ellipsis))))
+	  (delete-region new-end end)
+	  (goto-char new-end)
+	  (insert ellipsis)
+	  (setq end (point))))
       ;; Add a button for the URL.  Note that we use `make-text-button',
       ;; rather than `make-button', as text-buttons are much faster in
       ;; large buffers.
-- 
2.19.1