* lisp/emms-playlist-limit.el: limit by track description

1 files changed, 36 insertions, 20 deletions

diff --git a/lisp/emms-playlist-limit.el b/lisp/emms-playlist-limit.el
index 5f0cb28..9fcc74b 100644
--- a/lisp/emms-playlist-limit.el
+++ b/lisp/emms-playlist-limit.el
@@ -45,6 +45,7 @@
 ;;  / a		emms-playlist-limit-to-info-artist
 ;;  / b		emms-playlist-limit-to-info-album
 ;;  / c		emms-playlist-limit-to-info-composer
+;;  / d         emms-playlist-limit-to-description
 ;;  / g		emms-playlist-limit-to-info-genre
 ;;  / n		emms-playlist-limit-to-name
 ;;  / p		emms-playlist-limit-to-info-performer
@@ -79,11 +80,11 @@ the current playlist." attribute)
      (interactive
       (list
        (let* ((curr
-	       (or (emms-track-get
+	       (or (emms-playlist-limit-track-get
 		    (or (emms-playlist-track-at)
 			(emms-playlist-track-at (max 1 (1- (point))))) ; at eol
 		    (quote ,attribute))
-		   (emms-track-get
+		   (emms-playlist-limit-track-get
 		    (emms-playlist-selected-track) (quote ,attribute))))
 	      (attr-name ,(emms-replace-regexp-in-string
 			   "info-" "" (symbol-name attribute)))
@@ -92,11 +93,11 @@ the current playlist." attribute)
 		     (format "Limit to %s (regexp): " attr-name))))
 	 (read-string fmt))))
      (when (string= regexp "")
-       (setq regexp (or (emms-track-get
+       (setq regexp (or (emms-playlist-limit-track-get
 			 (or (emms-playlist-track-at)
 			     (emms-playlist-track-at (max 1 (1- (point))))) ; at eol
 			 (quote ,attribute))
-			(emms-track-get
+			(emms-playlist-limit-track-get
 			 (emms-playlist-selected-track) (quote ,attribute)))))
      (if regexp
 	 (emms-playlist-limit-do (quote ,attribute) regexp)
@@ -110,6 +111,7 @@ the current playlist." attribute)
 (define-emms-playlist-limit info-year)
 (define-emms-playlist-limit info-genre)
 (define-emms-playlist-limit name)
+(define-emms-playlist-limit description)
 
 (defvar-local emms-playlist-limit--original-playlist nil
   "Playlist buffer from which we derive the limited playlist.")
@@ -137,6 +139,7 @@ If this playlist is current, make the playlist we switch to current."
 (define-key emms-playlist-mode-map (kbd "/ b") 'emms-playlist-limit-to-info-album)
 (define-key emms-playlist-mode-map (kbd "/ y") 'emms-playlist-limit-to-info-year)
 (define-key emms-playlist-mode-map (kbd "/ g") 'emms-playlist-limit-to-info-genre)
+(define-key emms-playlist-mode-map (kbd "/ d") 'emms-playlist-limit-to-description)
 (define-key emms-playlist-mode-map (kbd "/ /") 'emms-playlist-limit-to-all)
 
 
@@ -145,9 +148,12 @@ If this playlist is current, make the playlist we switch to current."
 (defun emms-playlist-limit-track-get (track type)
   "Return the value of TYPE from TRACK.
 
-This is a wrapper around `emms-track-get' that also tries
-'info-originalyear, 'info-originaldate and 'info-date to get a
-usable date when TYPE is 'info-year."
+Here TYPE is a field available to `emms-track-get' or
+'description which gives the result of
+`emms-track-description-function'.
+
+When type is 'info-year, also tries 'info-originalyear,
+ 'info-originaldate and 'info-date to get a usable date."
   (cond ((eq type 'info-year)
 	 (let ((date (or (emms-track-get track 'info-originaldate)
 			 (emms-track-get track 'info-originalyear)
@@ -155,26 +161,34 @@ usable date when TYPE is 'info-year."
 			 (emms-track-get track 'info-year))))
 	   (or  (emms-format-date-to-year date)
 		"<unknown year>")))
+	((eq type 'description) (funcall emms-track-description-function track))
 	(t (emms-track-get track type))))
 
-(defun emms-playlist-limit--limit-playlist (playlist type regexp)
-  "Return new playlist containing the tracks of PLAYLIST with TYPE matching REGEXP."
-  (let* ((bufname (concat (buffer-name playlist)
-			  (format "/%s=%s"
-				  (emms-replace-regexp-in-string "info-" "" (symbol-name type)) regexp)))
-	 (tracks (nreverse (with-current-buffer playlist
+(defun emms-playlist-limit--derive-playlist (playlist pred name)
+  "Return a new playlist NAME of tracks in PLAYLIST for which (PRED track)
+is non-nil."
+  (let* ((tracks (nreverse (with-current-buffer playlist
 			     (save-excursion (emms-playlist-tracks-in-region (point-min) (point-max))))))
-	 (filtered-tracks (seq-filter
-			   (lambda (track) (let ((field (emms-playlist-limit-track-get track type)))
-					     (and field (string-match regexp field))))
-			   tracks))
-	 (new-playlist (or (get-buffer bufname)
-			   (emms-playlist-new bufname))))
+	 (filtered-tracks (seq-filter pred tracks))
+	 (new-playlist (or (get-buffer name)
+			   (emms-playlist-new name))))
     (with-current-buffer new-playlist
       (emms-with-inhibit-read-only-t (erase-buffer))
       (mapc #'emms-playlist-insert-track filtered-tracks))
     new-playlist))
 
+(defun emms-playlist-limit--limit-playlist (playlist type regexp)
+  "Return a new playlist of tracks in PLAYLIST with TYPE matching REGEXP."
+  (let* ((bufname (concat (buffer-name playlist)
+			  (format "/%s=%s"
+				  (emms-replace-regexp-in-string "info-" "" (symbol-name type)) regexp))))
+    (emms-playlist-limit--derive-playlist
+     playlist
+     `(lambda (track) (let ((field (emms-playlist-limit-track-get track (quote ,type))))
+		       (and field (string-match ,regexp field))))
+     bufname)))
+
+
 
 (defun emms-playlist-limit-do (type regexp)
   "Switch to a derived playlist containing the tracks with TYPE matching REGEXP.
@@ -194,7 +208,9 @@ See `emms-info-mp3find-arguments' for possible options for TYPE."
 	    (kill-buffer))
 	(let ((pos (when curr (text-property-any (point-min) (point-max)
 						 'emms-track curr))))
-	  (emms-playlist-select (or pos 1)))
+	  (if pos
+	      (emms-playlist-select pos)
+	    (emms-playlist-select-first)))
 	(emms-playlist-mode-center-current)
 	(setq emms-playlist-limit--original-playlist old-buf)
 	(when old-buf-is-current-playlist