Make handling of multiple playlist buffers less error-prone.

darcs-hash:20060531203810-1bfb2-7a5c8ca307d33ea501871a6222ab76ad4ada498d.gz

3 files changed, 83 insertions, 31 deletions

diff --git a/emms-playlist-mode.el b/emms-playlist-mode.el
index 3f673cb..4f6ac2a 100644
--- a/emms-playlist-mode.el
+++ b/emms-playlist-mode.el
@@ -440,7 +440,8 @@ This preserves the current EMMS buffer."
          (type (emms-track-get track 'type)))
     (emms-playlist-select (point))
     (run-hooks 'emms-player-stopped-hook)
-    (switch-to-buffer (setq emms-playlist-buffer (emms-playlist-new)))
+    (switch-to-buffer
+     (emms-playlist-set-playlist-buffer (emms-playlist-new)))
     (emms-add-playlist name)))
 
 ;;; --------------------------------------------------------
diff --git a/emms-streams.el b/emms-streams.el
index bf67b05..10c0d05 100644
--- a/emms-streams.el
+++ b/emms-streams.el
@@ -83,10 +83,8 @@ needed info.")
 (defvar emms-stream-last-stream nil
   "The last stream added/played by EMMS.")
 
-(defvar emms-stream-owns-buffer nil
-  "Indicate whether the current EMMS playlist buffer is owned by
-emms-streams.")
-(make-variable-buffer-local 'emms-stream-owns-buffer)
+(defvar emms-stream-playlist-buffer nil
+  "The EMMS playlist buffer associated with emms-streams.")
 
 ;; Format: (("descriptive name" url feed-number type))
 ;; type could be either url or playlist. If url, then it represents a
@@ -174,9 +172,7 @@ emms-streams.")
   (set-buffer (get-buffer-create emms-stream-buffer-name))
   (erase-buffer)
   (when (string= emms-stream-default-action "play")
-    (save-excursion
-      (with-current-buffer (setq emms-playlist-buffer (emms-playlist-new))
-        (setq emms-stream-owns-buffer t))))
+    (emms-stream-create-playlist))
   (emms-stream-mode)
   (switch-to-buffer emms-stream-buffer-name))
 
@@ -198,6 +194,22 @@ emms-streams.")
   (set-buffer-modified-p nil)
   (message "EMMS Stream Menu"))
 
+(defun emms-stream-create-playlist ()
+  "Create a new EMMS playlist and associate it with emms-streams.
+This is used when `emms-stream-default-action' is \"play\"."
+  (save-excursion
+    (setq emms-stream-playlist-buffer
+          (emms-playlist-set-playlist-buffer (emms-playlist-new)))))
+
+(defun emms-stream-kill-playlist ()
+  "Delete the EMMS playlist associated with emms-streams, if one exists."
+  (when (buffer-live-p emms-stream-playlist-buffer)
+    (save-excursion
+      (if (eq emms-stream-playlist-buffer emms-playlist-buffer)
+          (emms-playlist-current-kill)
+        (kill-buffer emms-stream-playlist-buffer)))
+    (setq emms-stream-playlist-buffer nil)))
+
 (defun emms-stream-popup-revert ()
   "Revert to the window-configuration from before if there is one,
 otherwise just remove the special bindings from the stream menu."
@@ -496,11 +508,7 @@ Don't forget to save your modifications !"
 
 (defun emms-stream-quit ()
   (interactive)
-  (save-excursion
-    (when (and (buffer-live-p emms-playlist-buffer)
-               (with-current-emms-playlist emms-stream-owns-buffer))
-      (emms-stop)
-      (emms-playlist-current-kill)))
+  (emms-stream-kill-playlist)
   (kill-this-buffer)
   (run-hooks 'emms-stream-quit-hook))
 
@@ -508,8 +516,10 @@ Don't forget to save your modifications !"
   (interactive)
   (if (string= emms-stream-default-action "play")
       (progn
+        (emms-stream-kill-playlist)
         (setq emms-stream-default-action "add")
         (message "Default action is now add"))
+    (emms-stream-create-playlist)
     (setq emms-stream-default-action "play")
     (message "Default action is now play")))
 
diff --git a/emms.el b/emms.el
index 0731202..02ce9dd 100644
--- a/emms.el
+++ b/emms.el
@@ -425,6 +425,25 @@ If POS is nil, use current buffer location."
       (match-string-no-properties num string)
     (match-string num string)))
 
+(defun emms-delete-if (predicate seq)
+  "Remove all items satisfying PREDICATE in SEQ.
+This is a destructive function: it reuses the storage of SEQ
+whenever possible."
+  ;; remove from car
+  (while (when (funcall predicate (car seq))
+           (setq seq (cdr seq))))
+  ;; remove from cdr
+  (let ((ptr seq)
+        (next (cdr seq)))
+    (while next
+      (when (funcall predicate (car next))
+        (setcdr ptr (if (consp next)
+                        (cdr next)
+                      nil)))
+      (setq ptr (cdr ptr))
+      (setq next (cdr ptr))))
+  seq)
+
 
 ;;; Tracks
 
@@ -488,6 +507,12 @@ Otherwise, return the type and the name with a colon in between."
 (defvar emms-playlist-buffer nil
   "The current playlist buffer, if any.")
 
+(defvar emms-playlist-buffers nil
+  "The list of EMMS playlist buffers.
+You should use the `emms-playlist-buffer-list' function to
+retrieve a current list of EMMS buffers.  Never use this variable
+for that purpose.")
+
 (defvar emms-playlist-selected-marker nil
   "The marker for the currently selected track.")
 (make-variable-buffer-local 'emms-playlist-selected-marker)
@@ -538,34 +563,50 @@ If called interactively, the new buffer is also selected."
       (when (not (eq major-mode emms-playlist-default-major-mode))
         (funcall emms-playlist-default-major-mode))
       (setq emms-playlist-buffer-p t))
+    (add-to-list 'emms-playlist-buffers buf)
     (when (interactive-p)
       (switch-to-buffer buf))
     buf))
 
 (defun emms-playlist-buffer-list ()
   "Return a list of EMMS playlist buffers.
-The first element will be the most recently-created playlist, and
-so on."
-  (let ((lis nil))
-    (mapc (lambda (buf)
-	    (with-current-buffer buf
-	      (when emms-playlist-buffer-p
-		(setq lis (cons buf lis)))))
-	  (buffer-list))
-    (nreverse lis)))
+The first element is guaranteed to be the current EMMS playlist
+buffer, if it exists, otherwise the slot will be used for the
+other EMMS buffers.  The list will be in newest-first order."
+  ;; prune dead buffers
+  (setq emms-playlist-buffers (emms-delete-if (lambda (buf)
+                                                (not (buffer-live-p buf)))
+                                              emms-playlist-buffers))
+  ;; add new buffers
+  (mapc (lambda (buf)
+          (when (buffer-live-p buf)
+            (with-current-buffer buf
+              (when (and emms-playlist-buffer-p
+                         (not (memq buf emms-playlist-buffers)))
+                (setq emms-playlist-buffers
+                      (cons buf emms-playlist-buffers))))))
+        (buffer-list))
+  ;; force current playlist buffer to head position
+  (when (and (buffer-live-p emms-playlist-buffer)
+             (not (eq (car emms-playlist-buffers) emms-playlist-buffer)))
+    (setq emms-playlist-buffers (cons emms-playlist-buffer
+                                      (delete emms-playlist-buffer
+                                              emms-playlist-buffers))))
+  emms-playlist-buffers)
 
 (defun emms-playlist-current-kill ()
   "Kill the current EMMS playlist buffer and switch to the next one."
   (interactive)
-  (let ((new (cadr (emms-playlist-buffer-list))))
-    (if (buffer-live-p new)
-        (progn
-          (when (buffer-live-p emms-playlist-buffer)
-            (kill-buffer emms-playlist-buffer))
-          (setq emms-playlist-buffer new)
-          (switch-to-buffer emms-playlist-buffer))
-      (with-current-buffer emms-playlist-buffer
-        (bury-buffer)))))
+  (when (buffer-live-p emms-playlist-buffer)
+    (let ((new (cadr (emms-playlist-buffer-list))))
+      (if new
+          (let ((old emms-playlist-buffer))
+            (setq emms-playlist-buffer new
+                  emms-playlist-buffers (cdr emms-playlist-buffers))
+            (kill-buffer old)
+            (switch-to-buffer emms-playlist-buffer))
+        (with-current-buffer emms-playlist-buffer
+          (bury-buffer))))))
 
 (defun emms-playlist-current-clear ()
   "Clear the current playlist.