From: Noboru Ota <me@nobiot.com>
To: ~protesilaos/denote@lists.sr.ht
Cc: Protesilaos Stavrou <info@protesilaos.com>
Subject: Re: [PATCH] Display context of identifier in backlinks buffer with
 xref
In-Reply-To: <87o7tzl1zv.fsf@protesilaos.com>
Date: Wed, 26 Oct 2022 22:01:51 +0200
Message-ID: <86ilk6uzf4.fsf@nobiot.com>
MIME-Version: 1.0
Content-Type: multipart/mixed; boundary="=-=-="

--=-=-=
Content-Type: text/plain

Made patches to make the current version compatible with 27.2.  I have
tested both cases where user option 'denote-backlilnks-show-context' is
on and off for both 27.2 and 28.1.

I have noted this in the commit text: TODO: It is likely that these two
functions can be made into one to be comptabile for both Emacs versions.
Further work is requried to refactor them.

Thanks.
nobiot


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=0001-Fix-denote-retrieve-xrefs-for-Emacs-version-27.2.patch
Content-Description: Patch 1

From 6721b7a437794ff4d5f4237432d6f799986c1c7e Mon Sep 17 00:00:00 2001
From: Noboru Ota <me@nobiot.com>
Date: Wed, 26 Oct 2022 21:28:01 +0200
Subject: [PATCH 1/2] Fix denote--retrieve-xrefs for Emacs version 27.2

'denote--retrieve-xrefs' uses 'xref--alistify', which has changed its
signature between 27.2 and 28.1.  This patch makes the former compatible
with both Emacs versions.
---
 denote.el | 15 +++++++++++----
 1 file changed, 11 insertions(+), 4 deletions(-)

diff --git a/denote.el b/denote.el
index 89d82cd..663c015 100644
--- a/denote.el
+++ b/denote.el
@@ -1146,10 +1146,17 @@ Run `denote-desluggify' on title if the extraction is sucessful."
 (defun denote--retrieve-xrefs (identifier)
   "Return xrefs of IDENTIFIER in variable `denote-directory'.
 The xrefs are returned as an alist."
-  (xref--alistify
-   (xref-matches-in-files identifier (denote-directory-text-only-files))
-   (lambda (x)
-     (xref-location-group (xref-item-location x)))))
+  (cond ((>= emacs-major-version 28)
+         (xref--alistify
+          (xref-matches-in-files identifier (denote-directory-text-only-files))
+          (lambda (x)
+            (xref-location-group (xref-item-location x)))))
+        (t ;; This must only be 27.2 as Denote's prerequisite is 27.2
+         (xref--alistify
+          (xref-matches-in-files identifier (denote-directory-text-only-files))
+          (lambda (x)
+            (xref-location-group (xref-item-location x)))
+          nil))))
 
 (defun denote--retrieve-files-in-xrefs (xrefs-alist)
   "Return sorted file names sans directory from XREFS.
-- 
2.34.1


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=0002-Add-denote-xref-insert-xrefs-27-for-Emacs-version-27.patch
Content-Description: Patch 2

From 8fcead5c27ec28800d9590bcfbe949e368771567 Mon Sep 17 00:00:00 2001
From: Noboru Ota <me@nobiot.com>
Date: Wed, 26 Oct 2022 21:57:56 +0200
Subject: [PATCH 2/2] Add denote-xref--insert-xrefs-27 for Emacs version 27.2

The implementation detail of 'xref--insert-xrefs' has changed between
Emacs 27.2 and 28, which made them incompatible with each other.

As 'denote-xref--insert-xrefs' is based on that function, a new function
has been created.

TODO: It is likely that these two functions can be made into one to be
comptabile for both Emacs versions.  Further work is requried to
refactor them.
---
 denote.el | 44 +++++++++++++++++++++++++++++++++++++++++---
 1 file changed, 41 insertions(+), 3 deletions(-)

diff --git a/denote.el b/denote.el
index 663c015..3768435 100644
--- a/denote.el
+++ b/denote.el
@@ -356,7 +356,7 @@ command."
   :link '(info-link "(denote) The denote-templates option")
   :group 'denote)
 
-(defcustom denote-backlilnks-show-context nil
+(defcustom denote-backlinks-show-context nil
   "When non-nil, the backlinks buffer shows context of identifiers.
 The context is the one line an identifier is found.  This option
 also enables the backlink buffer to show multiple occurrences of an
@@ -2644,8 +2644,11 @@ Use optional TITLE for a prettier heading."
                   (l (length heading)))
         (insert (format "%s\n%s\n\n" heading (make-string l ?-))))
       ;;; We could have a user option to use the current backlink buffer
-      (if denote-backlilnks-show-context
-          (denote-xref--insert-xrefs xrefs-alist)
+      (if denote-backlinks-show-context
+          (cond ((>= emacs-major-version 28)
+                 (denote-xref--insert-xrefs xrefs-alist))
+                (t ;; This can only be Emacs 27.2 as Denote's prequiresite is 27.2
+                 (denote-xref--insert-xrefs-27 xrefs-alist)))
         (mapc (lambda (x)
                 (insert (denote-get-file-name-relative-to-denote-directory (car x)))
                 (make-button (line-beginning-position) (line-end-position) :type 'denote-link-backlink-button)
@@ -2659,6 +2662,41 @@ Use optional TITLE for a prettier heading."
                       (denote-link--prepare-backlinks id xrefs-alist title)))))
     (denote-link--display-buffer buf)))
 
+(defun denote-xref--insert-xrefs-27 (xref-alist)
+  "Insert XREF-ALIST in the current-buffer.
+XREF-ALIST is of the form ((GROUP . (XREF ...)) ...), where
+GROUP is a string for decoration purposes and XREF is an
+`xref-item' object."
+  (require 'compile) ; For the compilation faces.
+  (cl-loop for ((group . xrefs) . more1) on xref-alist
+           for max-line-width =
+           (cl-loop for xref in xrefs
+                    maximize (let ((line (xref-location-line
+                                          (oref xref location))))
+                               (length (and line (format "%d" line)))))
+           for line-format = (and max-line-width
+                                  (format "%%%dd: " max-line-width))
+           do
+           (xref--insert-propertized '(face xref-file-header xref-group t)
+                                     (denote-get-file-name-relative-to-denote-directory group) "\n")
+           (cl-loop for (xref . more2) on xrefs do
+                    (with-slots (summary location) xref
+                      (let* ((line (xref-location-line location))
+                             (prefix
+                              (if line
+                                  (propertize (format line-format line)
+                                              'face 'xref-line-number)
+                                "  ")))
+                        (xref--insert-propertized
+                         (list 'xref-item xref
+                               'mouse-face 'highlight
+                               'keymap xref--button-map
+                               'help-echo
+                               (concat "mouse-2: display in another window, "
+                                       "RET or mouse-1: follow reference"))
+                         prefix summary)))
+                    (insert "\n\n"))))
+
 (defun denote-xref--insert-xrefs (xref-alist)
   "Insert XREF-ALIST in the current buffer.
 XREF-ALIST is of the form ((GROUP . (XREF ...)) ...), where GROUP
-- 
2.34.1


--=-=-=--