[nongnu] elpa/auto-dim-other-buffers 4831cdec23 2/2: Require Emacs 27 to run

[ELPA Syncer]

branch: elpa/auto-dim-other-buffers
commit 4831cdec23f0f9f785d899f7ceb90e4260dac0a0
Author: Michal Nazarewicz <mina86@mina86.com>
Commit: Michal Nazarewicz <mina86@mina86.com>

    Require Emacs 27 to run
    
    Debian old stable (i.e. bullseye) ships with Emacs 27.1 thus it should
    be safe to require that version for adob.  This brings in
    simplification of the code since adow mode can now be assumed.
---
 README.md                 |  17 +++---
 auto-dim-other-buffers.el | 153 ++++++++++++++++------------------------------
 2 files changed, 61 insertions(+), 109 deletions(-)

diff --git a/README.md b/README.md
index a9bc7d464d..a3664de0e9 100644
--- a/README.md
+++ b/README.md
@@ -5,9 +5,8 @@
 
 The `auto-dim-other-buffers-mode` is a global minor mode which makes
 windows without focus less prominent.  With many windows in a frame,
-the idea is that this mode helps recognise which is the selected
-window by providing a non-intrusive but still noticeable visual
-indicator.
+this mode helps recognise which is the selected window by providing
+a non-intrusive but still noticeable visual indicator.
 
 [![Demo](screenshot.gif)](https://www.youtube.com/watch?v=2djOHSWhyD4)
 
@@ -21,7 +20,8 @@ Once installed, enable the mode with:
     M-x auto-dim-other-buffers-mode RET
 
 To make it enabled every time Emacs starts, add the following to Emacs
-initialisation file (typically `~/.emacs` or `~/.emacs.d/init.el`):
+initialisation file (typically `~/.emacs`, `~/.emacs.d/init.el` or
+`~/.config/emacs/init.el`):
 
     (add-hook 'after-init-hook (lambda ()
       (when (fboundp 'auto-dim-other-buffers-mode)
@@ -37,6 +37,9 @@ group which can be accessed with:
 
     M-x customize-group RET auto-dim-other-buffers RET
 
-Note that despite it’s name, since Emacs 27 the mode operates on
-*windows* rather than buffers.  I.e. selected window is highlighted
-and all other windows are dimmed even if they display the same buffer.
+Note that despite it, the mode operates on *windows* rather than
+buffers.  In other words, selected window is highlighted and all other
+windows are dimmed even if they display the same buffer.  The package
+is named `auto-dim-other-buffer` for historical reasons.
+
+Requires Emacs 27 to work.
diff --git a/auto-dim-other-buffers.el b/auto-dim-other-buffers.el
index e0882e2dfa..1dabf8cd63 100644
--- a/auto-dim-other-buffers.el
+++ b/auto-dim-other-buffers.el
@@ -2,6 +2,7 @@
 ;; Author: Michal Nazarewicz <mina86@mina86.com>
 ;; URL: https://github.com/mina86/auto-dim-other-buffers.el
 ;; Version: 2.1.1
+;; Package-Requires: ((emacs "27.1"))
 ;; Keywords: faces
 
 ;; This file is not part of GNU Emacs.
@@ -22,9 +23,9 @@
 ;;; Commentary:
 
 ;; The ‘auto-dim-other-buffers-mode’ is a global minor mode which makes windows
-;; without focus less prominent.  With many windows in a frame, the idea is 
that
-;; this mode helps recognise which is the selected window by providing
-;; a non-intrusive but still noticeable visual indicator.
+;; without focus less prominent.  With many windows in a frame, this mode helps
+;; recognise which is the selected window by providing a non-intrusive but 
still
+;; noticeable visual indicator.
 
 ;; The preferred way to install the mode is by grabbing 
‘auto-dim-other-buffers’
 ;; package form MELPA:
@@ -35,8 +36,8 @@
 ;;
 ;;     M-x auto-dim-other-buffers-mode RET
 
-;; To make the mode enabled every time Emacs starts, add the following
-;; to Emacs initialisation file (~/.emacs or ~/.emacs.d/init.el):
+;; To make the mode enabled every time Emacs starts, add the following to Emacs
+;; initialisation file (see `user-init-file'):
 ;;
 ;;     (add-hook 'after-init-hook (lambda ()
 ;;       (when (fboundp 'auto-dim-other-buffers-mode)
@@ -49,12 +50,10 @@
 ;;
 ;;     M-x customize-group RET auto-dim-other-buffers RET
 
-;; Note that despite it’s name, since Emacs 27 the mode operates on *windows*
-;; rather than buffers.  I.e. selected window is highlighted and all other
-;; windows are dimmed even if they display the same buffer.  In older Emacs
-;; versions the mode falls back to the old behaviour where all windows
-;; displaying selected buffer are highlighted.  This historic behaviour
-;; is where the mode gets its name from.
+;; Note that despite it, the mode operates on *windows* rather than buffers.  
In
+;; other words, selected window is highlighted and all other windows are dimmed
+;; even if they display the same buffer.  The package is named
+;; `auto-dim-other-buffer' for historical reasons.
 
 ;;; Code:
 
@@ -109,13 +108,6 @@ Which faces are actually modified is configured by the
   :group 'auto-dim-other-buffers)
 
 
-(defconst adob--adow-mode (not (version< emacs-version "27.0.90"))
-  "Whether Emacs supports :filtered faces.
-If t, the code will run in ‘auto dim other window’ mode (hence
-‘adow-mode’) which operates on windows rather than buffers.  To
-operate on windows, Emacs must support :filtered face predicate
-which has been added in Emacs 27.")
-
 (defvar adob--last-buffer nil
   "Last selected buffer, i.e. buffer which is currently not dimmed.")
 (defvar adob--last-window nil
@@ -124,12 +116,10 @@ which has been added in Emacs 27.")
 (defun adob--never-dim-p (buffer)
   "Return whether to never dim BUFFER.
 Call ‘auto-dim-other-buffers-never-dim-buffer-functions’ to see
-if any of them return non-nil in which case the BUFFER won’t
-dimmed.  In addition to that, outside of adow-mode (see
-‘adob--adow-mode’), no hidden buffers will be dimmed."
-  (or (and (not adob--adow-mode) (eq ?\s (aref (buffer-name buffer) 0)))
-      (run-hook-with-args-until-success
-       'auto-dim-other-buffers-never-dim-buffer-functions buffer)))
+if any of them return non-nil in which case the BUFFER won’t be
+dimmed."
+  (run-hook-with-args-until-success
+   'auto-dim-other-buffers-never-dim-buffer-functions buffer))
 
 
 (defvar-local adob--face-mode-remapping nil
@@ -139,14 +129,12 @@ dimmed.  In addition to that, outside of adow-mode (see
 (defun adob--remap-add-relative ()
   "Adds all necessary relative face mappings.
 Updates ‘adob--face-mode-remapping’ variable accordingly."
-  (let ((make-face (if adob--adow-mode
-                       (lambda (face) `(:filtered (:window adob--dim t) ,face))
-                     #'identity)))
-    (setq adob--face-mode-remapping
-          (mapcar (lambda (spec)
-                    (face-remap-add-relative (car spec)
-                                             (funcall make-face (cdr spec))))
-                  auto-dim-other-buffers-affected-faces))))
+  (setq adob--face-mode-remapping
+        (mapcar (lambda (spec)
+                  (face-remap-add-relative
+                   (car spec)
+                   `(:filtered (:window adob--dim t) ,(cdr spec))))
+                auto-dim-other-buffers-affected-faces)))
 
 (defun adob--remap-remove-relative ()
   "Remove all relative mappings that we’ve added.
@@ -213,29 +201,26 @@ something we don’t want."
     (adob--remap-add-relative)
     nil))
 
-(defun adob--unmap-face (buffer object)
+(defun adob--unmap-face (buffer)
   "Make sure face remapping is inactive in BUFFER.
 
 Does not preserve current buffer.
 
-If face remapping had to be changed, force update of OBJECT which
-can be a window or a buffer."
+If face remapping had to be changed, forces all windows displaying the
+buffer to be updated on next redisplay."
   (when (buffer-local-value 'adob--face-mode-remapping buffer)
     (set-buffer buffer)
     (adob--remap-remove-relative)
-    (force-window-update object)))
+    (force-window-update buffer)))
 
 (defun adob--dim-buffer (buffer &optional except-in)
   "Dim BUFFER if not already dimmed except in EXCEPT-IN window.
 
 Does not preserve current buffer.
 
-EXCEPT-IN only works if the code is running in adow mode (see
-‘adob--adow-mode’) and it works by deactivating the dimmed face
-in specified window."
+EXCEPT-IN works by deactivating the dimmed face in specified window."
   (when (adob--remap-faces buffer buffer)
-    (dolist (wnd (and adob--adow-mode
-                      (get-buffer-window-list buffer 'n 'visible)))
+    (dolist (wnd (get-buffer-window-list buffer 'n 'visible))
       (set-window-parameter wnd 'adob--dim (not (eq wnd except-in))))))
 
 (defun adob--update ()
@@ -246,11 +231,8 @@ Dim previously selected window if selection has changed."
     (let* ((wnd (selected-window))
            (buf (window-buffer wnd)))
 
-      (cond
-       ((eq wnd adob--last-window))
-       (adob--adow-mode
-        ;; adow-mode is active and window has changed.  Update the adob--dim
-        ;; parameter accordingly.
+      (unless (eq wnd adob--last-window)
+        ;; Window has changed.  Update the adob--dim parameter accordingly.
         (when (and (window-live-p adob--last-window)
                    (not (window-minibuffer-p adob--last-window)))
           (set-window-parameter adob--last-window 'adob--dim t)
@@ -259,21 +241,6 @@ Dim previously selected window if selection has changed."
         (unless (window-minibuffer-p adob--last-window)
           (set-window-parameter adob--last-window 'adob--dim nil)
           (force-window-update adob--last-window)))
-       (t
-        ;; Window has changed but adow-mode is not active.  Make sure buffer
-        ;; displayed in the old window is dimmed.  This is necessary because
-        ;; a command (e.g. ‘quit-window’) could change to a different window
-        ;; while at the same time changing buffer in the old window.  In this
-        ;; scenario, we’re never dimming the buffer in the old window.
-        (and (window-live-p adob--last-window)
-             (not (window-minibuffer-p adob--last-window))
-             (let ((old-buf (window-buffer adob--last-window)))
-               (unless (or (eq old-buf buf)
-                           (eq old-buf adob--last-buffer))
-                 (save-current-buffer
-                   (adob--dim-buffer old-buf))
-                 (force-window-update adob--last-window))))
-        (setq adob--last-window wnd)))
 
       ;; If buffer has changed, update its status.
       (unless (eq buf adob--last-buffer)
@@ -281,9 +248,7 @@ Dim previously selected window if selection has changed."
           (when (buffer-live-p adob--last-buffer)
             (adob--dim-buffer adob--last-buffer wnd))
           (setq adob--last-buffer buf)
-          (if adob--adow-mode
-              (adob--remap-faces buf buf)
-            (adob--unmap-face buf buf)))))))
+          (adob--remap-faces buf buf))))))
 
 (defun adob--rescan-windows ()
   "Rescan all windows in selected frame and dim all non-selected windows."
@@ -292,20 +257,14 @@ Dim previously selected window if selection has changed."
     (save-current-buffer
       (dolist (wnd (window-list nil 'n))
         (let ((buf (window-buffer wnd)))
-          (cond (adob--adow-mode
-                 ;; Update window’s ‘adob--dim’ parameter.  If it changes set
-                 ;; we’ll also later tell Emacs to redisplay the window.
-                 (let ((new (not (eq wnd selected-window))))
-                   (unless (eq new (window-parameter wnd 'adob--dim))
-                     (set-window-parameter wnd 'adob--dim new)
-                     (force-window-update wnd)))
-                 ;; In adow-mode, make sure that the buffer has remapped faces.
-                 (adob--remap-faces buf wnd))
-                ;; Outside of adow-mode, add or remove face remapping depending
-                ;; on whether current buffer selected buffer or not.
-                ((eq buf selected-buffer)
-                 (adob--unmap-face buf wnd))
-                ((adob--remap-faces buf wnd))))))))
+          ;; Update window’s ‘adob--dim’ parameter.  If it changes set
+          ;; we’ll also later tell Emacs to redisplay the window.
+          (let ((new (not (eq wnd selected-window))))
+            (unless (eq new (window-parameter wnd 'adob--dim))
+              (set-window-parameter wnd 'adob--dim new)
+              (force-window-update wnd)))
+          ;; Make sure that the buffer has remapped faces.
+          (adob--remap-faces buf wnd))))))
 
 (defun adob--buffer-list-update-hook ()
   "React to buffer list changes.
@@ -323,13 +282,10 @@ Otherwise, if a new buffer is displayed somewhere, dim 
it."
   "Dim all buffers if `auto-dim-other-buffers-dim-on-focus-out'."
   (when (and auto-dim-other-buffers-dim-on-focus-out
              (buffer-live-p adob--last-buffer))
-    (if adob--adow-mode
-        (when (and (window-live-p adob--last-window)
-                   (not (window-minibuffer-p adob--last-window)))
-          (set-window-parameter adob--last-window 'adob--dim t)
-          (force-window-update adob--last-window))
-      (save-current-buffer
-        (adob--dim-buffer adob--last-buffer)))
+    (when (and (window-live-p adob--last-window)
+               (not (window-minibuffer-p adob--last-window)))
+      (set-window-parameter adob--last-window 'adob--dim t)
+      (force-window-update adob--last-window))
     (setq adob--last-buffer nil
           adob--last-window nil)))
 
@@ -383,15 +339,11 @@ and frame’s doesn’t have focus."
 
 (defun adob--initialize ()
   "Dim all except for the selected buffer."
-  ;; In adow mode, dim current buffer as well except for in selected window.  
If
-  ;; not running in adow mode, don’t dim hidden buffers either (most notably we
-  ;; care about Minibuffer and Echo Area buffers).
+  ;; Dim current buffer as well except in selected window.
   (setq adob--last-window (selected-window)
         adob--last-buffer (window-buffer adob--last-window))
   (dolist (buffer (buffer-list))
-    (when (or adob--adow-mode
-              (not (eq buffer adob--last-buffer)))
-      (adob--dim-buffer buffer adob--last-window))))
+    (adob--dim-buffer buffer adob--last-window)))
 
 ;;;###autoload
 (define-minor-mode auto-dim-other-buffers-mode
@@ -414,16 +366,13 @@ behaviour is where the mode gets its name from."
   (let ((callback (if auto-dim-other-buffers-mode #'add-hook #'remove-hook)))
     (funcall callback 'window-configuration-change-hook #'adob--rescan-windows)
     (funcall callback 'buffer-list-update-hook #'adob--buffer-list-update-hook)
-    ;; Prefer ‘after-focus-change-function’ (which was added in Emacs 27)
-    ;; to ‘focus-out-hook’ and ‘focus-in-hook’.
-    (if (boundp 'after-focus-change-function)
-        (if auto-dim-other-buffers-mode
-            (add-function :after after-focus-change-function
-                          #'adob--focus-change-hook)
-          (remove-function after-focus-change-function
-                           #'adob--focus-change-hook))
-      (funcall callback 'focus-out-hook #'adob--focus-out-hook)
-      (funcall callback 'focus-in-hook #'adob--update)))
+    ;; ‘after-focus-change-function’ has been added in Emacs 27 so we’re safe
+    ;; using it.
+    (if auto-dim-other-buffers-mode
+        (add-function :after after-focus-change-function
+                      #'adob--focus-change-hook)
+      (remove-function after-focus-change-function
+                       #'adob--focus-change-hook)))
 
   ;; Kill focus change timer if present.  If we’re enabling the mode we want to
   ;; start from fresh state.  If we’re disabling the mode, we don’t want the
@@ -451,7 +400,7 @@ behaviour is where the mode gets its name from."
         ;; in the buffer.
         (when (local-variable-p 'adob--face-mode-remapping buffer)
           (set-buffer buffer)
-          (adob--unmap-face buffer buffer)
+          (adob--unmap-face buffer)
           (kill-local-variable 'adob--face-mode-remapping))))))