[rhythmbox] shell-player: cancel playlist parsing when stopping (bug #612156)

[Jonathan Matthew <jmatthew src gnome org>]

commit 66db6792c31856dd5bfdcfc2e860bbf43ec7d52c
Author: Jonathan Matthew <jonathan d14n org>
Date:   Sat Oct 9 22:53:51 2010 +1000

    shell-player: cancel playlist parsing when stopping (bug #612156)
    
    If the user tries to stop playback of a radio stream before the playlist
    parser has finished, we need to cancel the parser and ignore any URLs we
    get from it so we don't try to start playback again.  Similarly, if the
    user tries to start playback while the parser is still going, we can just
    ignore that.

 shell/rb-shell-player.c |   52 +++++++++++++++++++++++++++++++++++++++-------
 1 files changed, 44 insertions(+), 8 deletions(-)
---
diff --git a/shell/rb-shell-player.c b/shell/rb-shell-player.c
index a544f5a..a85ea56 100644
--- a/shell/rb-shell-player.c
+++ b/shell/rb-shell-player.c
@@ -255,6 +255,7 @@ struct RBShellPlayerPrivate
 	RBPlayOrder *queue_play_order;
 
 	GQueue *playlist_urls;
+	GCancellable *parser_cancellable;
 
 	RBHeader *header_widget;
 	RBStatusbar *statusbar_widget;
@@ -1514,16 +1515,21 @@ typedef struct {
 	char *location;
 	RhythmDBEntry *entry;
 	RBPlayerPlayType play_type;
+	GCancellable *cancellable;
 } OpenLocationThreadData;
 
 static void
 playlist_entry_cb (TotemPlParser *playlist,
 		   const char *uri,
 		   GHashTable *metadata,
-		   RBShellPlayer *player)
+		   OpenLocationThreadData *data)
 {
-	rb_debug ("adding stream url %s", uri);
-	g_queue_push_tail (player->priv->playlist_urls, g_strdup (uri));
+	if (g_cancellable_is_cancelled (data->cancellable)) {
+		rb_debug ("playlist parser cancelled");
+	} else {
+		rb_debug ("adding stream url %s (%p)", uri, playlist);
+		g_queue_push_tail (data->player->priv->playlist_urls, g_strdup (uri));
+	}
 }
 
 static gpointer
@@ -1534,9 +1540,9 @@ open_location_thread (OpenLocationThreadData *data)
 
 	playlist = totem_pl_parser_new ();
 
-	g_signal_connect_data (G_OBJECT (playlist), "entry-parsed",
+	g_signal_connect_data (playlist, "entry-parsed",
 			       G_CALLBACK (playlist_entry_cb),
-			       data->player, NULL, 0);
+			       data, NULL, 0);
 
 	totem_pl_parser_add_ignored_mimetype (playlist, "x-directory/normal");
 	totem_pl_parser_add_ignored_mimetype (playlist, "inode/directory");
@@ -1544,7 +1550,12 @@ open_location_thread (OpenLocationThreadData *data)
 	playlist_result = totem_pl_parser_parse (playlist, data->location, FALSE);
 	g_object_unref (playlist);
 
-	if (playlist_result == TOTEM_PL_PARSER_RESULT_SUCCESS) {
+	if (g_cancellable_is_cancelled (data->cancellable)) {
+		playlist_result = TOTEM_PL_PARSER_RESULT_CANCELLED;
+	}
+
+	switch (playlist_result) {
+	case TOTEM_PL_PARSER_RESULT_SUCCESS:
 		if (g_queue_is_empty (data->player->priv->playlist_urls)) {
 			GError *error = g_error_new (RB_SHELL_PLAYER_ERROR,
 						     RB_SHELL_PLAYER_ERROR_END_OF_PLAYLIST,
@@ -1557,16 +1568,24 @@ open_location_thread (OpenLocationThreadData *data)
 			char *location;
 
 			location = g_queue_pop_head (data->player->priv->playlist_urls);
-			rb_debug ("playing first stream url %s", data->location);
+			rb_debug ("playing first stream url %s", location);
 			rb_shell_player_open_playlist_url (data->player, location, data->entry, data->play_type);
 			g_free (location);
 		}
-	} else {
+		break;
+
+	case TOTEM_PL_PARSER_RESULT_CANCELLED:
+		rb_debug ("playlist parser was cancelled");
+		break;
+
+	default:
 		/* if we can't parse it as a playlist, just try playing it */
 		rb_debug ("playlist parser failed, playing %s directly", data->location);
 		rb_shell_player_open_playlist_url (data->player, data->location, data->entry, data->play_type);
+		break;
 	}
 
+	g_object_unref (data->cancellable);
 	g_free (data);
 	return NULL;
 }
@@ -1611,6 +1630,11 @@ rb_shell_player_open_location (RBShellPlayer *player,
 		else
 			data->location = g_strconcat ("http://";, location, NULL);
 
+		if (player->priv->parser_cancellable == NULL) {
+			player->priv->parser_cancellable = g_cancellable_new ();
+		}
+		data->cancellable = g_object_ref (player->priv->parser_cancellable);
+
 		g_thread_create ((GThreadFunc)open_location_thread, data, FALSE, NULL);
 	} else {
 		rhythmdb_entry_ref (entry);
@@ -1651,6 +1675,11 @@ rb_shell_player_play (RBShellPlayer *player,
 	if (rb_player_playing (player->priv->mmplayer))
 		return TRUE;
 
+	if (player->priv->parser_cancellable != NULL) {
+		rb_debug ("currently parsing a playlist");
+		return TRUE;
+	}
+
 	/* we're obviously not playing anything, so crossfading is irrelevant */
 	if (!rb_player_play (player->priv->mmplayer, RB_PLAYER_PLAY_REPLACE, 0.0f, error)) {
 		rb_debug ("player doesn't want to");
@@ -3187,6 +3216,13 @@ rb_shell_player_stop (RBShellPlayer *player)
 		g_error_free (error);
 	}
 
+	if (player->priv->parser_cancellable != NULL) {
+		rb_debug ("cancelling playlist parser");
+		g_cancellable_cancel (player->priv->parser_cancellable);
+		g_object_unref (player->priv->parser_cancellable);
+		player->priv->parser_cancellable = NULL;
+	}
+
 	if (player->priv->playing_entry != NULL) {
 		rhythmdb_entry_unref (player->priv->playing_entry);
 		player->priv->playing_entry = NULL;