From 1c21121f80e7f3d4a76682294c069d77816c4ab9 Mon Sep 17 00:00:00 2001
From: John Olsson <johol@lysator.liu.se>
Date: Wed, 20 May 2026 20:38:46 +0200
Subject: [PATCH] Add cusomizable inline hunk faces

Add two cusomizable faces (four in total)

  - diff-hl-show-hunk-bg
    Background color for changed region when hunk is shown. This face is used
    for creating an overlay that tints the background for the current lines of
    the changed region in the buffer when viewing the hunk.

  - diff-hl-show-hunk-inline-base
    Foreground and background colors for the header and footer when viewing a
    hunk.

  - diff-hl-show-hunk-inline-ul
    Inherits from diff-hl-show-hunk-inline-base and adds an underline to the
    face.

  - diff-hl-show-hunk-inline-ol
    Inherits from diff-hl-show-hunk-inline-base and adds an overline to the
    face.

Modifies diff-hl-show-hunk--click function so mouse clicks toggles showing the
hunk on and off.
---
 diff-hl-show-hunk-inline.el | 22 ++++++++++++++++++++--
 diff-hl-show-hunk.el        | 13 ++++++++++++-
 2 files changed, 32 insertions(+), 3 deletions(-)

diff --git a/diff-hl-show-hunk-inline.el b/diff-hl-show-hunk-inline.el
index 3b5214bb..cd12d0b4 100644
--- a/diff-hl-show-hunk-inline.el
+++ b/diff-hl-show-hunk-inline.el
@@ -74,6 +74,24 @@ the hunk consist only on added lines, then
 `diff-hl-show-hunk--no-lines-removed-message' it is shown."
   :type 'boolean)
 
+(defface diff-hl-show-hunk-inline-base
+  '((((class color) (min-colors 88) (background light))
+     :foreground "black" :background "gray88" :extend t)
+    (((class color) (min-colors 88) (background dark))
+     :foreground "white" :background "#gray13" :extend t))
+  "Face used for background of shown hunk."
+  :group 'diff-hl-show-hunk-inline)
+
+(defface diff-hl-show-hunk-inline-ul
+  '((((class color) (min-colors 88))
+     :inherit diff-hl-show-hunk-inline-base :underline t))
+  "Face used for background of shown hunk with underline.")
+
+(defface diff-hl-show-hunk-inline-ol
+  '((((class color) (min-colors 88))
+     :inherit diff-hl-show-hunk-inline-base :overline t))
+  "Face used for background of shown hunk with overline.")
+
 (defun diff-hl-show-hunk-inline--splice (list offset length)
   "Compute a sublist of LIST starting at OFFSET, of LENGTH."
   (butlast
@@ -115,7 +133,7 @@ Compute it from some WIDTH, and some optional HEADER text."
          (new-width (- width (length header) (length scroll-indicator)))
          (line (propertize (concat (diff-hl-show-hunk-inline--separator new-width)
                                    header scroll-indicator )
-                           'face '(:underline t))))
+                           'face 'diff-hl-show-hunk-inline-ul)))
     (concat line "\n") ))
 
 (defun diff-hl-show-hunk-inline--compute-footer (width &optional footer)
@@ -136,7 +154,7 @@ Compute it from some WIDTH, and some optional FOOTER text."
                                                 'face '(:underline t)))))
          (line (propertize (concat (diff-hl-show-hunk-inline--separator new-width)
                                    footer scroll-indicator)
-                           'face '(:overline t))))
+                           'face 'diff-hl-show-hunk-inline-ol)))
     (concat blank-line "\n" line)))
 
 (defun diff-hl-show-hunk-inline--separator (width &optional sep)
diff --git a/diff-hl-show-hunk.el b/diff-hl-show-hunk.el
index 641683d7..b9eee610 100644
--- a/diff-hl-show-hunk.el
+++ b/diff-hl-show-hunk.el
@@ -61,6 +61,14 @@ corresponding to the clicked line in the original buffer."
           (const :tag "Show inline" diff-hl-show-hunk-inline)
           (const :tag "Show using posframe" diff-hl-show-hunk-posframe)))
 
+(defface diff-hl-show-hunk-bg
+  '((((class color) (min-colors 88) (background light))
+     :background "old lace" :extend t)
+    (((class color) (min-colors 88) (background dark))
+     :background "#555533" :extend t))
+  "Face used for background of shown hunk."
+  :group 'diff-hl-show-hunk)
+
 (defvar diff-hl-show-hunk-mouse-mode-map
   (let ((map (make-sparse-keymap)))
     (define-key map (kbd "<left-margin> <mouse-1>") 'diff-hl-show-hunk--click)
@@ -212,7 +220,9 @@ Returns a list with the buffer and the line number of the clicked line."
   (interactive "e")
   ;; Go the click's position.
   (posn-set-point (event-start event))
-  (diff-hl-show-hunk))
+  (if (and diff-hl-show-hunk--original-window (window-live-p diff-hl-show-hunk--original-window))
+      (diff-hl-show-hunk-hide)
+    (diff-hl-show-hunk)))
 
 (defvar diff-hl-show-hunk-map
   (let ((map (make-sparse-keymap)))
@@ -317,6 +327,7 @@ The backend is determined by `diff-hl-show-hunk-function'."
             (end (overlay-end overlay))
             (type (overlay-get overlay 'diff-hl-hunk-type)))
         (setq diff-hl-show-hunk--original-overlay (make-overlay start end))
+        (overlay-put diff-hl-show-hunk--original-overlay 'face 'diff-hl-show-hunk-bg)
         (overlay-put diff-hl-show-hunk--original-overlay 'diff-hl-hunk-type type)))
 
     (unless overlay