Set buffer-predicate to spacemacs/useful-buffer-p

Prevent next-buffer, other-buffer, etc. from choosing useless buffers.
No need for spacemacs/next-useful-buffer,
spacemacs/previous-useful-buffer anymore.

Also fix spacemacs/alternate-buffer to respect buffer-predicate.

When spacemacs-layouts is used, buffer-predicate filters useful buffer
that belong to the current layout.

doc/VIMUSERS.org

@@ -233,7 +233,7 @@ built-in =define-key= function is the best way to do that.
 #+begin_src emacs-lisp
   (define-key map new-keybinding function) ; Syntax
   ;; Map H to go to the previous buffer in normal mode
-  (define-key evil-normal-state-map (kbd "H") 'spacemacs/previous-useful-buffer)
+  (define-key evil-normal-state-map (kbd "H") 'previous-buffer)
   ;; Mapping keybinding to another keybinding
   (define-key evil-normal-state-map (kbd "H") (kbd "^")) ; H goes to beginning of the line
 #+end_src

layers/+distributions/spacemacs-base/config.el

@@ -140,6 +140,15 @@ It runs `tabulated-list-revert-hook', then calls `tabulated-list-print'."
 
 (setq ns-use-native-fullscreen (not dotspacemacs-fullscreen-use-non-native))
 
+;; make `next-buffer', `other-buffer', etc. ignore useless buffers (see
+;; `spacemacs/useless-buffer-p')
+(let ((buf-pred-entry (assq 'buffer-predicate default-frame-alist)))
+  (if buf-pred-entry
+      ;; `buffer-predicate' entry exists, modify it
+      (setcdr buf-pred-entry #'spacemacs/useful-buffer-p)
+    ;; `buffer-predicate' entry doesn't exist, create it
+    (push '(buffer-predicate . spacemacs/useful-buffer-p) default-frame-alist)))
+
 ;; ---------------------------------------------------------------------------
 ;; Session
 ;; ---------------------------------------------------------------------------

layers/+distributions/spacemacs-base/funcs.el

@@ -9,6 +9,8 @@
 ;;
 ;;; License: GPLv3
 
+(require 'cl-lib)
+
 ;; add emacs binary helper functions
 (defun spacemacs/emacsbin-path ()
   (interactive)
@@ -217,7 +219,7 @@ automatically applied to."
 
 
 (defun spacemacs/useless-buffer-p (buffer)
-  "Determines if a buffer is useful."
+  "Determines if a buffer is useless."
   (let ((buf-paren-major-mode (get (with-current-buffer buffer
                                      major-mode)
                                    'derived-mode-parent))
@@ -232,6 +234,10 @@ automatically applied to."
                (when (string-match regexp buf-name)
                  (return t))))))
 
+(defun spacemacs/useful-buffer-p (buffer)
+  "Determines if a buffer is useful."
+  (not (spacemacs/useless-buffer-p buffer)))
+
 ;; from magnars modified by ffevotte for dedicated windows support
 (defun spacemacs/rotate-windows (count)
   "Rotate your windows.
@@ -267,24 +273,6 @@ argument takes the kindows rotate backwards."
   (interactive "p")
   (spacemacs/rotate-windows (* -1 count)))
 
-(defun spacemacs/next-useful-buffer ()
-  "Switch to the next buffer and avoid special buffers."
-  (interactive)
-  (let ((start-buffer (current-buffer)))
-    (next-buffer)
-    (while (and (spacemacs/useless-buffer-p (current-buffer))
-                (not (eq (current-buffer) start-buffer)))
-      (next-buffer))))
-
-(defun spacemacs/previous-useful-buffer ()
-  "Switch to the previous buffer and avoid special buffers."
-  (interactive)
-  (let ((start-buffer (current-buffer)))
-    (previous-buffer)
-    (while (and (spacemacs/useless-buffer-p (current-buffer))
-                (not (eq (current-buffer) start-buffer)))
-      (previous-buffer))))
-
 (defun spacemacs/rename-file (filename &optional new-filename)
   "Rename FILENAME to NEW-FILENAME.
 
@@ -706,13 +694,23 @@ The body of the advice is in BODY."
   (load-file (buffer-file-name))
   (ert t))
 
-(defun spacemacs/alternate-buffer ()
+(defun spacemacs/alternate-buffer (&optional window)
   "Switch back and forth between current and last buffer in the
 current window."
   (interactive)
-  (if (evil-alternate-buffer)
-      (switch-to-buffer (car (evil-alternate-buffer)))
-    (switch-to-buffer (other-buffer (current-buffer) t))))
+  (let ((current-buffer (window-buffer window))
+        (buffer-predicate
+         (frame-parameter (window-frame window) 'buffer-predicate)))
+    ;; switch to first buffer previously shown in this window that matches
+    ;; frame-parameter `buffer-predicate'
+    (switch-to-buffer
+     (or (cl-find-if (lambda (buffer)
+                       (and (not (eq buffer current-buffer))
+                            (or (null buffer-predicate)
+                                (funcall buffer-predicate buffer))))
+                     (mapcar #'car (window-prev-buffers window)))
+         ;; `other-buffer' honors `buffer-predicate' so no need to filter
+         (other-buffer current-buffer t)))))
 
 (defun current-line ()
   "Return the line at point as a string."

layers/+distributions/spacemacs-base/keybindings.el

@@ -121,11 +121,11 @@
   "be"  'spacemacs/safe-erase-buffer
   "bh"  'spacemacs/home
   "bk"  'spacemacs/kill-matching-buffers-rudely
-  "bn"  'spacemacs/next-useful-buffer
+  "bn"  'next-buffer
   "bm"  'spacemacs/kill-other-buffers
   "bN"  'spacemacs/new-empty-buffer
   "bP"  'spacemacs/copy-clipboard-to-whole-buffer
-  "bp"  'spacemacs/previous-useful-buffer
+  "bp"  'previous-buffer
   "bR"  'spacemacs/safe-revert-buffer
   "bs"  'spacemacs/switch-to-scratch-buffer
   "bY"  'spacemacs/copy-whole-buffer-to-clipboard
@@ -450,9 +450,9 @@
 (spacemacs|define-transient-state buffer
   :title "Buffer Selection Transient State"
   :bindings
-  ("n" spacemacs/next-useful-buffer "next")
-  ("N" spacemacs/previous-useful-buffer "previous")
-  ("p" spacemacs/previous-useful-buffer "previous")
+  ("n" next-buffer "next")
+  ("N" previous-buffer "previous")
+  ("p" previous-buffer "previous")
   ("K" spacemacs/kill-this-buffer "kill")
   ("q" nil "quit" :exit t))
 (spacemacs/set-leader-keys "b." 'spacemacs/buffer-transient-state/body)

layers/+spacemacs/spacemacs-evil/local/evil-unimpaired/evil-unimpaired.el

@@ -91,8 +91,8 @@
 (define-key evil-visual-state-map (kbd "] e") ":move'>+1")
 ;; (define-key evil-visual-state-map (kbd "[ e") 'move-text-up)
 ;; (define-key evil-visual-state-map (kbd "] e") 'move-text-down)
-(define-key evil-normal-state-map (kbd "[ b") 'spacemacs/previous-useful-buffer)
-(define-key evil-normal-state-map (kbd "] b") 'spacemacs/next-useful-buffer)
+(define-key evil-normal-state-map (kbd "[ b") 'previous-buffer)
+(define-key evil-normal-state-map (kbd "] b") 'next-buffer)
 (define-key evil-normal-state-map (kbd "[ f") 'evil-unimpaired/previous-file)
 (define-key evil-normal-state-map (kbd "] f") 'evil-unimpaired/next-file)
 (define-key evil-normal-state-map (kbd "] l") 'spacemacs/next-error)

layers/+spacemacs/spacemacs-org/local/space-doc/space-doc.el

@@ -77,7 +77,7 @@ This functions is aimed to be used with `spacemacs-space-doc-modificators'."
   ;;FIXME: Need to redesign this.. One day.
   (if flag
       (progn
-        ;; HACK: Hide the original buffer from `spacemacs/previous-useful-buffer'.
+        ;; HACK: Hide the original buffer from `spacemacs/useful-buffer-p'.
         (unless (and (string-prefix-p "*" (buffer-name))
                      (string-suffix-p "*" (buffer-name)))
           (rename-buffer (format "*%s*" (buffer-name))))