libsaria: Implement playlist iterators

I replace the old queue iterator functions with calls to the queue
playlist object that way I don't need to modify the UI.  This creates a
common iterator that can be used by all playlists.

Signed-off-by: Bryan Schumaker <bjschuma@gmail.com>

include/libsaria/playlist.h

@@ -15,6 +15,7 @@ namespace libsaria
 		private:
 			string filename;
 			list<sid_t> plist;
+			list<sid_t>::iterator it;
 
 		public:
 			Playlist(string);
@@ -22,6 +23,11 @@ namespace libsaria
 
 			void load();
 			void add_ids(list<sid_t> &);
+
+			/* Iterator functions */
+			void iter_reset();
+			Track *iter_next();
+			bool iter_end();
 	};
 
 }; /* Namespace: libsaria */

libsaria/playlist/iter.cpp

@@ -0,0 +1,26 @@
+// Copyright (c) 2012 Bryan Schumaker.
+
+#include <libsaria/library.h>
+#include <libsaria/playlist.h>
+
+namespace libsaria
+{
+
+	void Playlist::iter_reset()
+	{
+		it = plist.begin();
+	}
+
+	Track *Playlist::iter_next()
+	{
+		Track *track = library::get_info(*it);
+		it++;
+		return track;
+	}
+
+	bool Playlist::iter_end()
+	{
+		return it == plist.end();
+	}
+
+}; /* Namespace: libsaria */

libsaria/queue/iter.cpp

@@ -12,19 +12,17 @@ namespace libsaria
 
 		void iter::reset()
 		{
-			it = playqueue.begin();
+			q_queue.iter_reset();
 		}
 
 		libsaria::Track *iter::next()
 		{
-			Track *track = library::get_info(*it);
-			it++;
-			return track;
+			return q_queue.iter_next();
 		}
 
 		bool iter::end()
 		{
-			return it == playqueue.end();
+			return q_queue.iter_end();
 		}
 
 	}; /* Namespace: queue */