[nongnu] elpa/eldoc-diffstat 0481f4f5a7 3/6: Add minor mode

[ELPA Syncer]

branch: elpa/eldoc-diffstat
commit 0481f4f5a7ca89822faf94bd345161a8f0903f38
Author: Johann Klähn <johann@jklaehn.de>
Commit: Johann Klähn <johann@jklaehn.de>

    Add minor mode
    
    Cf. https://lists.gnu.org/archive/html/emacs-devel/2024-12/msg00589.html
    
    Suggested-by: Stefan Kangas <stefankangas@gmail.com>
---
 NEWS.md           |  6 ++++++
 README.md         | 12 +++---------
 eldoc-diffstat.el | 44 +++++++++++++++++++++++++++++++++++++-------
 3 files changed, 46 insertions(+), 16 deletions(-)

diff --git a/NEWS.md b/NEWS.md
new file mode 100644
index 0000000000..2d69c24cc6
--- /dev/null
+++ b/NEWS.md
@@ -0,0 +1,6 @@
+## unreleased
+
+- `eldoc-diffstat-setup` has been replaced by a minor mode
+  `eldoc-diffstat-mode`; there's also a globalized minor mode
+  `global-eldoc-diffstat-mode` that (by default) will turn on diffstat output 
in
+  all supported major modes.
diff --git a/README.md b/README.md
index 732407ac2b..c438435d67 100644
--- a/README.md
+++ b/README.md
@@ -5,15 +5,9 @@ It supports Git and Mercurial repositories.
 
 ![A screenshot showing diffstat information in the echo area of a magit-log 
buffer.](screenshot.webp "diffstat information is available in the echo area.")
 
-To use, call `eldoc-diffstat-setup` in the desired buffer or mode hook, e.g.:
-
-```elisp
-(add-hook 'git-rebase-mode-hook #'eldoc-diffstat-setup)
-(add-hook 'log-view-mode-hook #'eldoc-diffstat-setup)
-(add-hook 'magit-log-mode-hook #'eldoc-diffstat-setup)
-(add-hook 'magit-status-mode-hook #'eldoc-diffstat-setup)
-(add-hook 'vc-annotate-mode-hook #'eldoc-diffstat-setup)
-```
+To turn on diffstat output in all supported major modes, enable
+`global-eldoc-diffstat-mode`.  You can instead also enable
+`eldoc-diffstat-mode` in individual buffers or via mode hooks.
 
 You might also want to add the following to your config:
 
diff --git a/eldoc-diffstat.el b/eldoc-diffstat.el
index 04636a906c..db2cf864f7 100644
--- a/eldoc-diffstat.el
+++ b/eldoc-diffstat.el
@@ -47,6 +47,11 @@
 ;; These slots are used in git-rebase-action (see git-rebase.el).
 (eieio-declare-slots action-type target)
 
+(defgroup eldoc-diffstat nil
+  "Show VCS diffstat information in echo area."
+  :group 'eldoc
+  :group 'vc)
+
 (defvar eldoc-diffstat--process nil
   "The latest async process used for fetching diffstat information.
 Only one active process at a time; new requests terminate previous ones.
@@ -79,13 +84,38 @@ a property to the process object.")
 Has to match `eldoc-diffstat--commands'.")
 
 ;;;###autoload
-(defun eldoc-diffstat-setup ()
-  "Configure eldoc buffer-locally to display diffstat for revision at point."
-  (interactive)
-  (add-hook 'eldoc-documentation-functions
-            #'eldoc-diffstat--docstring nil 'local)
-  (unless (bound-and-true-p eldoc-mode)
-    (eldoc-mode)))
+(define-obsolete-function-alias 'eldoc-diffstat-setup 'eldoc-diffstat-mode
+  "1.0" "Configure eldoc buffer-locally to display diffstat for revision at 
point.")
+
+;;;###autoload
+(define-minor-mode eldoc-diffstat-mode
+  "Toggle echo area display of VCS diffstat information in the local buffer.
+
+When enabled, diffstat information is shown in supported major modes if
+point is on a revision."
+  :group 'eldoc-diffstat
+  :lighter nil
+  (if eldoc-diffstat-mode
+      (progn
+        (add-hook 'eldoc-documentation-functions
+                  #'eldoc-diffstat--docstring nil 'local)
+        (eldoc-mode))
+    (remove-hook 'eldoc-documentation-functions
+                 #'eldoc-diffstat--docstring 'local)
+    ;; Disable eldoc if diffstat was the only information source.
+    (unless (eldoc--supported-p)
+      (eldoc-mode -1))))
+
+;;;###autoload
+(define-globalized-minor-mode global-eldoc-diffstat-mode
+  eldoc-diffstat-mode eldoc-diffstat-mode
+  :group 'eldoc-diffstat
+  :predicate
+  '(git-rebase-mode
+    log-view-mode
+    magit-log-mode
+    magit-status-mode
+    vc-annotate-mode))
 
 (defun eldoc-diffstat--docstring (callback &rest _ignored)
   "Display diffstat for revision at point by calling CALLBACK.