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Diffstat (limited to 'emms-playlist-limit.el')
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diff --git a/emms-playlist-limit.el b/emms-playlist-limit.el new file mode 100644 index 0000000..91eff1e --- /dev/null +++ b/emms-playlist-limit.el @@ -0,0 +1,224 @@ +;;; emms-playlist-limit.el --- Limit playlist by various info -*- lexical-binding: t -*- + +;; Copyright (C) 2018 Free Software Foundation, Inc. + +;; Author: William Xu <william.xwl@gmail.com> +;; Author: Fran Burstall <fran.burstall@gmail.com> +;; Keywords: emms, limit + +;; EMMS 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, or (at your option) +;; any later version. + +;; EMMS 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 EMMS; see the file COPYING. If not, write to the +;; Free Software Foundation, Inc., 51 Franklin St, Fifth Floor, +;; Boston, MA 02110-1301, USA. + +;;; Commentary: + +;; This code allows you to "limit" a playlist in the current buffer +;; by creating, and switching to, a derived playlist containing only +;; those tracks with a type (info-artist and the like) matching a +;; regexp. + +;; If the current buffer is the current playlist then the derived +;; playlist is made current. + +;; Usage: +;; ------------------------------------------------------------------ + +;; This code is activated by (emms-all). Otherwise simply do: + +;; (require 'emms-playlist-limit) + +;; Key bindings +;; ------------------------------------------------------------------ + +;; / / emms-playlist-limit-to-all +;; / 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 +;; / t emms-playlist-limit-to-info-title +;; / y emms-playlist-limit-to-info-year + +;;; Code: + +(require 'seq) +(require 'emms-playlist-mode) + +;; User Interfaces + +(defgroup emms-playlist-limit nil + "Playlist limit module for EMMS." + :group 'emms) + +(defcustom emms-playlist-limit-hook nil + "Hooks to run after each limit operation." + :type 'symbol + :group 'emms-playlist-limit) + +(defmacro define-emms-playlist-limit (attribute) + "Macro for defining emms playlist limit to ATTRIBUTE function." + `(defun ,(intern (format "emms-playlist-limit-to-%s" attribute)) (regexp) + ,(format "Switch to a playlist comprising tracks with %s matching REGEXP. + +REGEXP defaults to the value of %s for the track at point. + +When the current buffer is the current playlist, make the derived playlist +the current playlist." attribute attribute) + (interactive + (list + (let* ((curr + (or (emms-playlist-limit-track-get + (or (emms-playlist-track-at) + (emms-playlist-track-at (max 1 (1- (point))))) ; at eol + (quote ,attribute)) + (emms-playlist-limit-track-get + (emms-playlist-selected-track) (quote ,attribute)))) + (attr-name ,(emms-replace-regexp-in-string + "info-" "" (symbol-name attribute))) + (fmt (if curr + (format "Limit to %s (regexp = %s): " attr-name curr) + (format "Limit to %s (regexp): " attr-name)))) + (read-string fmt)))) + (when (string= regexp "") + (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-playlist-limit-track-get + (emms-playlist-selected-track) (quote ,attribute))))) + (if regexp + (emms-playlist-limit-do (quote ,attribute) regexp) + (message "Limit cancelled: no regexp.")))) + +(define-emms-playlist-limit info-artist) +(define-emms-playlist-limit info-composer) +(define-emms-playlist-limit info-performer) +(define-emms-playlist-limit info-title) +(define-emms-playlist-limit info-album) +(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.") + +(defun emms-playlist-limit-to-all () + "Switch to playlist from which this playlist was derived (if it still exists) +and bury this playlist. + +If this playlist is current, make the playlist we switch to current." + (interactive) + (when (and emms-playlist-limit--original-playlist + (buffer-live-p emms-playlist-limit--original-playlist)) + (let* ((old-buf (current-buffer)) + (old-buf-is-current-playlist (eq old-buf emms-playlist-buffer))) + (switch-to-buffer emms-playlist-limit--original-playlist) + (when old-buf-is-current-playlist + (emms-playlist-set-playlist-buffer)) + (bury-buffer old-buf)))) + +(define-key emms-playlist-mode-map (kbd "/ n") 'emms-playlist-limit-to-name) +(define-key emms-playlist-mode-map (kbd "/ a") 'emms-playlist-limit-to-info-artist) +(define-key emms-playlist-mode-map (kbd "/ c") 'emms-playlist-limit-to-info-composer) +(define-key emms-playlist-mode-map (kbd "/ p") 'emms-playlist-limit-to-info-performer) +(define-key emms-playlist-mode-map (kbd "/ t") 'emms-playlist-limit-to-info-title) +(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) + + +;;; Low Level Functions + +(defun emms-playlist-limit-track-get (track type) + "Return the value of TYPE from TRACK. + +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) + (emms-track-get track 'info-date) + (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--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 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. +e.g., + (emms-playlist-limit-do 'info-artist \"Jane Zhang\") + +See `emms-info-mp3find-arguments' for possible options for TYPE." + (emms-playlist-ensure-playlist-buffer) + (let* ((curr (emms-playlist-selected-track)) + (old-buf (current-buffer)) + (old-buf-is-current-playlist (eq old-buf emms-playlist-buffer)) + (buf (emms-playlist-limit--limit-playlist old-buf type regexp))) + (with-current-buffer buf + (if (= (point-min) (point-max)) + (progn + (message "No matching tracks found!") + (kill-buffer)) + (let ((pos (when curr (text-property-any (point-min) (point-max) + 'emms-track curr)))) + (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 + (emms-playlist-set-playlist-buffer)) + (run-hooks 'emms-playlist-limit-hook) + (switch-to-buffer buf))))) + + +(provide 'emms-playlist-limit) + +;;; emms-playlist-limit.el ends here |