new: add outline configurations

Configuring outline-minor-mode, which provides an easy interface to
navigate around codes.  I mainly use this in Emacs Lisp buffers now.

* outline-conf.el (durand-outline-regexp-alist): Each major mode could
have a unique outline heading.

(durand-outline-blocklist, durand-maybe-enable-outline): Don't enable
outline minor mode for derived modes of the major modes in the block
list.

(outline-minor-mode-highlight): I want to highlight the headings.

(outline-minor-mode-cycle): I like the cycling behaviour.

(outline-minor-mode-map): Bind my custom key-bindings.

* view-conf.el (durand-view-map): Bind to my custom map.

1 files changed, 76 insertions, 0 deletions

diff --git a/outline-conf.el b/outline-conf.el
new file mode 100644
index 0000000..e55dafb
--- /dev/null
+++ b/outline-conf.el
@@ -0,0 +1,76 @@
+;;; outline-conf.el --- Configurations for outline   -*- lexical-binding: t; -*-
+
+;; Copyright (C) 2021  李俊緯
+
+;; Author: 李俊緯 <mmemmew@gmail.com>
+;; Keywords: convenience, files, languages, maint, matching, outlines, tools
+
+;; This program is free software; you can redistribute it and/or modify
+;; it under the terms of the GNU General Public License as published by
+;; the Free Software Foundation, either version 3 of the License, or
+;; (at your option) any later version.
+
+;; This program is distributed in the hope that it will be useful,
+;; but WITHOUT ANY WARRANTY; without even the implied warranty of
+;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+;; GNU General Public License for more details.
+
+;; You should have received a copy of the GNU General Public License
+;; along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+;;; Commentary:
+
+;; My configurations for `outline-minor-mode'.
+
+;;; Code:
+
+(require 'outline)
+
+;;;###autoload
+(defvar durand-outline-regexp-alist nil
+  "An alist that associates regular expressions with major modes
+that enable `outline-minor-mode'.")
+
+(setq durand-outline-regexp-alist
+      (list (cons 'emacs-lisp-mode
+                  (rx-to-string
+                   '(seq bol (>= 3 ";") (syntax ?-)) t))))
+
+;;;###autoload
+(defvar durand-outline-blocklist (list 'org-mode 'outline-mode)
+  "The list of major modes in which one should not use
+`outline-minor-mode'.")
+
+;;;###autoload
+(defun durand-maybe-enable-outline ()
+  "Enable `outline-minor-mode' if appropriate."
+  (interactive)
+  (cond
+   ((apply #'derived-mode-p durand-outline-blocklist)
+    (user-error "Should not use `outline-minor-mode' with %S"
+                major-mode))
+   ((null outline-minor-mode)
+    (let ((regexp (cdr-safe (assq major-mode durand-outline-regexp-alist))))
+      (cond
+       (regexp
+        (setq-local outline-regexp regexp))))
+    (outline-minor-mode 1)
+    (message "`outline-minor-mode' enabled"))
+   (t
+    (outline-minor-mode -1)
+    (message "`outline-minor-mode' disabled"))))
+
+(setq outline-minor-mode-highlight 'override)
+(setq outline-minor-mode-cycle t)
+
+(define-key outline-minor-mode-map (vector 3 ?\C-n) #'outline-next-visible-heading)
+(define-key outline-minor-mode-map (vector 3 ?\C-p) #'outline-previous-visible-heading)
+(define-key outline-minor-mode-map (vector 3 ?\C-f) #'outline-forward-same-level)
+(define-key outline-minor-mode-map (vector 3 2) #'outline-backward-same-level)
+(define-key outline-minor-mode-map (vector 3 1) #'outline-show-all)
+(define-key outline-minor-mode-map (vector 3 ?\C-o) #'outline-hide-other)
+(define-key outline-minor-mode-map (vector 3 ?\C-u) #'outline-up-heading)
+
+
+(provide 'outline-conf)
+;;; outline-conf.el ends here