implements the smartstop feature

The smartstop feature is a way to tell mpd to stop playing after
current song.
This patche provides:
- 'state' command returns 'smartstop' state (1 or 0)
- 'smartstop' can activate or not the smartstop state
- when song is terminated, mpd stops playing and smartstop is set to 0

doc/protocol.xml

@@ -216,6 +216,12 @@
                   <returnvalue>0 or 1</returnvalue>
                 </para>
               </listitem>
+              <listitem>
+               <para>
+                <varname>smartstop</varname>:
+                <returnvalue>0 or 1</returnvalue>
+               </para>
+              </listitem>
               <listitem>
                 <para>
                   <varname>playlist</varname>:
@@ -402,6 +408,21 @@
             </para>
           </listitem>
         </varlistentry>
+        <varlistentry id="command_smartstop">
+          <term>
+            <cmdsynopsis>
+              <command>smartstop</command>
+              <arg choice="req"><replaceable>STATE</replaceable></arg>
+            </cmdsynopsis>
+          </term>
+          <listitem>
+            <para>
+              Sets smartstop state to <varname>STATE</varname>,
+              <varname>STATE</varname> should be 0 or 1.
+	      When smartstop is activated, playback is stopped after current song.
+            </para>
+          </listitem>
+        </varlistentry>
         <varlistentry id="command_volume">
           <term>
             <cmdsynopsis>

src/command.c

@@ -59,6 +59,7 @@
 #define COMMAND_STATUS_VOLUME           "volume"
 #define COMMAND_STATUS_STATE            "state"
 #define COMMAND_STATUS_REPEAT           "repeat"
+#define COMMAND_STATUS_SMARTSTOP	"smartstop"
 #define COMMAND_STATUS_RANDOM           "random"
 #define COMMAND_STATUS_PLAYLIST         "playlist"
 #define COMMAND_STATUS_PLAYLIST_LENGTH  "playlistlength"
@@ -469,6 +470,7 @@ handle_status(struct client *client,
 		      COMMAND_STATUS_VOLUME ": %i\n"
 		      COMMAND_STATUS_REPEAT ": %i\n"
 		      COMMAND_STATUS_RANDOM ": %i\n"
+		      COMMAND_STATUS_SMARTSTOP ": %i\n"
 		      COMMAND_STATUS_PLAYLIST ": %li\n"
 		      COMMAND_STATUS_PLAYLIST_LENGTH ": %i\n"
 		      COMMAND_STATUS_CROSSFADE ": %i\n"
@@ -476,6 +478,7 @@ handle_status(struct client *client,
 		      volume_level_get(),
 		      getPlaylistRepeatStatus(&g_playlist),
 		      getPlaylistRandomStatus(&g_playlist),
+		      getPlaylistSmartstopStatus(&g_playlist),
 		      getPlaylistVersion(&g_playlist),
 		      getPlaylistLength(&g_playlist),
 		      (int)(getPlayerCrossFade() + 0.5),
@@ -1092,6 +1095,24 @@ handle_repeat(struct client *client, G_GNUC_UNUSED int argc, char *argv[])
 	return COMMAND_RETURN_OK;
 }
 
+static enum command_return
+handle_smartstop(struct client *client, G_GNUC_UNUSED int argc, char *argv[])
+{
+	int status;
+
+	if (!check_int(client, &status, argv[1], need_integer))
+		return COMMAND_RETURN_ERROR;
+
+	if (status != 0 && status != 1) {
+		command_error(client, ACK_ERROR_ARG,
+			      "\"%i\" is not 0 or 1", status);
+		return COMMAND_RETURN_ERROR;
+	}
+
+	setPlaylistSmartstopStatus(&g_playlist, status);
+	return COMMAND_RETURN_OK;
+}
+
 static enum command_return
 handle_random(struct client *client, G_GNUC_UNUSED int argc, char *argv[])
 {
@@ -1602,6 +1623,7 @@ static const struct command commands[] = {
 	{ "seekid", PERMISSION_CONTROL, 2, 2, handle_seekid },
 	{ "setvol", PERMISSION_CONTROL, 1, 1, handle_setvol },
 	{ "shuffle", PERMISSION_CONTROL, 0, 1, handle_shuffle },
+	{ "smartstop", PERMISSION_CONTROL, 1, 1, handle_smartstop },
 	{ "stats", PERMISSION_READ, 0, 0, handle_stats },
 	{ "status", PERMISSION_READ, 0, 0, handle_status },
 #ifdef ENABLE_SQLITE

src/playlist.c

@@ -261,6 +261,12 @@ getPlaylistRandomStatus(const struct playlist *playlist)
 	return playlist->queue.random;
 }
 
+bool
+getPlaylistSmartstopStatus(const struct playlist *playlist)
+{
+	return playlist->queue.smartstop;
+}
+
 void setPlaylistRepeatStatus(struct playlist *playlist, bool status)
 {
 	if (status == playlist->queue.repeat)
@@ -286,6 +292,18 @@ static void orderPlaylist(struct playlist *playlist)
 	queue_restore_order(&playlist->queue);
 }
 
+void setPlaylistSmartstopStatus(struct playlist *playlist, bool status)
+{
+	playlist->queue.smartstop = status;
+
+	/* if the last song is currently being played, the "next song"
+	   might change when repeat mode is toggled */
+	playlist_update_queued_song(playlist,
+				    playlist_get_queued_song(playlist));
+
+	idle_add(IDLE_OPTIONS);
+}
+
 void setPlaylistRandomStatus(struct playlist *playlist, bool status)
 {
 	const struct song *queued;
@@ -341,6 +359,8 @@ int getPlaylistNextSong(const struct playlist *playlist)
 {
 	if (playlist->current >= 0)
 	{
+		if (playlist->queue.smartstop == 1)
+			return -1;
 		if (playlist->current + 1 < (int)queue_length(&playlist->queue))
 			return queue_order_to_position(&playlist->queue,
 					       playlist->current + 1);

src/playlist.h

@@ -179,6 +179,11 @@ getPlaylistRandomStatus(const struct playlist *playlist);
 
 void setPlaylistRandomStatus(struct playlist *playlist, bool status);
 
+bool
+getPlaylistSmartstopStatus(const struct playlist *playlist);
+
+void setPlaylistSmartstopStatus(struct playlist *playlist, bool status);
+
 int getPlaylistCurrentSong(const struct playlist *playlist);
 
 int getPlaylistNextSong(const struct playlist *playlist);

src/playlist_control.c

@@ -152,6 +152,8 @@ nextSongInPlaylist(struct playlist *playlist)
 
 	next_order = queue_next_order(&playlist->queue, playlist->current);
 	if (next_order < 0) {
+		/* cancel smartstop */
+		playlist->queue.smartstop = false;
 		/* no song after this one: stop playback */
 		stopPlaylist(playlist);
 		return;

src/playlist_state.c

@@ -34,6 +34,7 @@
 #define PLAYLIST_STATE_FILE_STATE		"state: "
 #define PLAYLIST_STATE_FILE_RANDOM		"random: "
 #define PLAYLIST_STATE_FILE_REPEAT		"repeat: "
+#define PLAYLIST_STATE_FILE_SMARTSTOP		"smartstop: "
 #define PLAYLIST_STATE_FILE_CURRENT		"current: "
 #define PLAYLIST_STATE_FILE_TIME		"time: "
 #define PLAYLIST_STATE_FILE_CROSSFADE		"crossfade: "
@@ -71,6 +72,8 @@ playlist_state_save(FILE *fp, const struct playlist *playlist)
 		playlist->queue.random);
 	fprintf(fp, "%s%i\n", PLAYLIST_STATE_FILE_REPEAT,
 		playlist->queue.repeat);
+	fprintf(fp, "%s%i\n", PLAYLIST_STATE_FILE_SMARTSTOP,
+		playlist->queue.smartstop);
 	fprintf(fp, "%s%i\n", PLAYLIST_STATE_FILE_CROSSFADE,
 		(int)(getPlayerCrossFade()));
 	fprintf(fp, "%s\n", PLAYLIST_STATE_FILE_PLAYLIST_BEGIN);
@@ -129,14 +132,20 @@ playlist_state_restore(FILE *fp, struct playlist *playlist)
 		} else if (g_str_has_prefix(buffer, PLAYLIST_STATE_FILE_TIME)) {
 			seek_time =
 			    atoi(&(buffer[strlen(PLAYLIST_STATE_FILE_TIME)]));
-		} else
-		    if (g_str_has_prefix(buffer, PLAYLIST_STATE_FILE_REPEAT)) {
+		} else if (g_str_has_prefix(buffer, PLAYLIST_STATE_FILE_REPEAT)) {
 			if (strcmp
 			    (&(buffer[strlen(PLAYLIST_STATE_FILE_REPEAT)]),
 			     "1") == 0) {
 				setPlaylistRepeatStatus(playlist, true);
 			} else
 				setPlaylistRepeatStatus(playlist, false);
+		} else if (g_str_has_prefix(buffer, PLAYLIST_STATE_FILE_SMARTSTOP)) {
+			if (strcmp
+			    (&(buffer[strlen(PLAYLIST_STATE_FILE_SMARTSTOP)]),
+			     "1") == 0) {
+				setPlaylistSmartstopStatus(playlist, true);
+			} else
+				setPlaylistSmartstopStatus(playlist, false);
 		} else if (g_str_has_prefix(buffer, PLAYLIST_STATE_FILE_CROSSFADE)) {
 			setPlayerCrossFade(atoi
 					   (&

src/queue.c

@@ -40,6 +40,8 @@ queue_next_order(const struct queue *queue, unsigned order)
 {
 	assert(order < queue->length);
 
+	if (queue->smartstop)
+		return -1;
 	if (order + 1 < queue->length)
 		return order + 1;
 	else if (queue->repeat)
@@ -275,6 +277,7 @@ queue_init(struct queue *queue, unsigned max_length)
 	queue->version = 1;
 	queue->repeat = false;
 	queue->random = false;
+	queue->smartstop = false;
 
 	queue->items = g_new(struct queue_item, max_length);
 	queue->order = g_malloc(sizeof(queue->order[0]) *

src/queue.h

@@ -81,6 +81,9 @@ struct queue {
 	    reached? */
 	bool repeat;
 
+	/** stop playing after that song. */
+	bool smartstop;
+
 	/** play back songs in random order? */
 	bool random;