-

playlist.rkt

@@ -1 +1,110 @@
 #lang racket
+
+(require racket/class
+         "music-library.rkt"
+         racket-sound
+         )
+
+(provide track%
+         playlist%
+         )
+
+(define the-displayln displayln)
+
+(define track%
+  (class object%
+    (init-field
+     [file #f]
+     [title ""]
+     [artist ""]
+     [album ""]
+     [length 0]
+     [number 0]
+     )
+
+    (define/public (displayln)
+      (the-displayln (format "~a - ~a - ~a - ~a"
+                             number
+                             title
+                             album
+                             length)))
+
+    (super-new)
+    (begin
+      (unless (eq? file #f)
+        (let ((tags (id3-tags (format "~a" file))))
+          (set! title (tags-title tags))
+          (set! artist (tags-artist tags))
+          (set! album (tags-album tags))
+          (set! number (tags-track tags))
+          (set! length (tags-length tags))
+          )
+        )
+      )
+    ))
+
+(define list-len length)
+
+(define playlist%
+  (class object%
+    (init-field
+     [start-map #f]
+     [max-tracks 100]
+     )
+    
+    (define tracks '())
+
+    (define (can-add? file)
+      (and (<= (list-len tracks) max-tracks)
+           (is-music-file? file)))
+
+    (define (add-track file)
+      (let  ((track (new track% [file file])))
+        (set! tracks (append tracks (list track)))))
+
+    (define (read-tracks-internal dir)
+      ;(displayln (format "dir = ~a" dir))
+      (if (> (list-len tracks) max-tracks)
+          'done
+          (if (file-exists? dir)
+              (when (can-add? dir)
+                (add-track dir))
+              (if (directory-exists? dir)
+                  (let ((content (directory-list dir)))
+                    (for-each (λ (entry)
+                                (let ((p (build-path dir entry)))
+                                  (if (directory-exists? p)
+                                      (read-tracks-internal p)
+                                      (when (and (file-exists? p) (can-add? p))
+                                        (add-track p)))))
+                              content))
+                  'no-file-or-dir
+                  )
+              )
+          )
+      )
+
+    (define/public (read-tracks)
+      (set! tracks '())
+      (read-tracks-internal start-map)
+      )
+
+    (define/public (length)
+      (list-len tracks))
+
+    (define/public (track i)
+      (list-ref tracks i))
+
+    (define/public (display-tracks)
+      (for-each (λ (track)
+                  (send track displayln))
+                tracks))
+
+    (super-new)
+    (begin
+      (when (eq? start-map #f)
+        (error "Initialize playlist% with a starting map"))
+      )
+    )
+  )
+