[Music] Introduce ‘db/music’ and move code there

All music related functions that do not directly depend on EMMS will now go into
‘db/music’, with the intention that if we in the future replace EMMS with
something else, the API provided by ‘db/music’ will still be valid.  This does
not mean, however, that functions in ‘db/music’ may not use functions from EMMS.

init.el

@@ -2054,8 +2054,7 @@ search commands like `db/helm-shortcuts’."
   :config (require 'emms))
 
 (use-package db-emms
-  :commands (db/play-playlist
-             db/emms-source-file-directory-tree-find
+  :commands (db/emms-source-file-directory-tree-find
              db/emms-track-description
              db/emms-playlist-mode-insert-track
              emms-control/body))
@@ -2070,6 +2069,17 @@ search commands like `db/helm-shortcuts’."
             (require 'emms)
             (require 'helm-adaptive)))
 
+(use-package db-music
+  :commands (db/play-playlist))
+
+(defcustom db/playlist nil
+  "List of songs to include in random playlist."
+  :group 'personal-settings
+  :type '(alist :value-type (choice (const :tag "Undecided" :undecided)
+                                    (const :tag "Include" :include)
+                                    (const :tag "Exclude" :exclude))
+                :key-type file))
+
 
 ;; * Shells and such
 

site-lisp/db-emms.el

@@ -31,30 +31,6 @@
 (declare-function string-remove-prefix "subr-x")
 (declare-function emms-with-inhibit-read-only-t "emms")
 
-
-;; Custom playlist
-
-(defun db/play-playlist ()
-  "Play `db/personal-playlist’ in dedicated EMMS buffer."
-  (interactive)
-  (require 'emms)
-  (save-window-excursion
-    (let ((music-buffer-name "*EMMS Playlist* -- Misc"))
-      (unless (get-buffer music-buffer-name)
-        (emms-playlist-new music-buffer-name))
-      (with-current-buffer (get-buffer music-buffer-name)
-        (emms-stop)
-        (emms-playlist-set-playlist-buffer)
-        (emms-playlist-current-clear)
-        (emms-playlist-current-insert-source
-         'emms-insert-directory-tree
-         (expand-file-name "songs/" emms-source-file-default-directory))
-        (goto-char (point-min))
-        (emms-shuffle)
-        ;; (emms-playlist-sort-by-play-count)
-        (emms-playlist-select-first)
-        (emms-start)))))
-
 
 ;; Custom file finder
 

site-lisp/db-music.el

@@ -0,0 +1,35 @@
+;;; db-music.el -- Music related stuff -*- lexical-binding: t -*-
+
+;;; Commentary:
+
+;;; Code:
+
+
+;; Custom playlist
+
+(defun db/play-playlist ()
+  "Start playing songs from `db/playlist’"
+  (interactive)
+  (require 'emms)
+  (save-window-excursion
+    (let ((music-buffer-name "*EMMS Playlist* -- Personal"))
+      (unless (get-buffer music-buffer-name)
+        (emms-playlist-new music-buffer-name))
+      (with-current-buffer (get-buffer music-buffer-name)
+        (emms-stop)
+        (emms-playlist-set-playlist-buffer)
+        (emms-playlist-current-clear)
+        (dolist (track db/playlist)
+          (when (eq :include (cdr track))
+            (emms-playlist-current-insert-source 'emms-insert-file (car track))))
+        (goto-char (point-min))
+        (emms-shuffle)
+        (emms-playlist-select-first)
+        (emms-start)))))
+
+
+;; End
+
+(provide 'db-music)
+
+;;; db-music ends here