Enable browse-url to buttonize buffers

This patch also moves the internal/external browser logic from
shr to browse-url, where it belongs more naturally.

* doc/misc/eww.texi (Basics): Adjust to browse-url-external-browser.

* doc/misc/gnus.texi (Article Commands): Ditto.

* lisp/gnus/gnus-art.el (gnus-button-url-regexp): Default to
`browse-url-button-regexp', which has taken over the definition
previously enjoyed by this variable.

* lisp/gnus/gnus-sum.el (gnus-summary-browse-url): Adjust usage.

* lisp/net/browse-url.el (browse-url--browser-defcustom-type): New
internal variable...
(browse-url-browser-function, browse-url-external-browser): Used
by these two; the latter of which is a new variable.
(browse-url-botton-regexp): New variable.
(browse-url-button-map): New keymap.
(browse-url-button): New face.
(browse-url-add-buttons): New function to add clickable browse-url
buttons to almost any buffer.
(browse-url-button-open): New command.
(browse-url-button-copy): New command.

* lisp/net/eww.el (eww-browse-with-external-browser)
(eww-follow-link): Adjust usage.

* lisp/net/shr.el (shr-external-browser): Make an obsolete alias
of `browse-url-external-browser'.
(shr-browse-url): Adjust usage.

1 files changed, 10 insertions, 0 deletions

diff --git a/etc/NEWS b/etc/NEWS
index cccb8017bd4..6517f1938c2 100644
--- a/etc/NEWS
+++ b/etc/NEWS
@@ -765,6 +765,12 @@ start of a sentence or at '(point-min)', else '@ref'.
 It now treats the optional 2nd argument to mean that the URL should be
 shown in the currently selected window.
 
+*** A new function, 'browse-url-add-buttons' can be used to add clickable
+links to most ordinary special-mode buffers that display text that
+have URLs embedded.  'browse-url-button-regexp' controls what's
+considered a button.
+
+*** A new variable, 'browse-url-external-browser', has been added.
 ** Comint
 
 +++
@@ -1037,6 +1043,10 @@ has been executed.
 If set, shr will not render tags with attribute 'aria-hidden="true"'.
 This attribute is meant to tell screen readers to ignore a tag.
 
++++
+*** 'shr-external-browser' has been made into an obsolete alias
+of 'browse-url-external-browser'.
+
 ---
 *** 'shr-tag-ol' now respects the ordered list 'start' attribute.