libsaria: Randomly pick next song from library

I'll eventually allow more playlists to be stacked, but for now picking
from the library is easy.  I may eventually add in a way to pick
sequentially from a set.

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

include/libsaria/playlist.h

@@ -27,6 +27,8 @@ namespace libsaria
 	class Playlist {
 		private:
 			unsigned int flags;
+			list<Track *>::iterator cur;
+			void incr_iter();
 
 		protected:
 			string name;
@@ -34,17 +36,15 @@ namespace libsaria
 			PlaylistRenderer *renderer;
 			/*bool del_renderer;
 			unsigned int flags;
-			string filename;
-			list<Track *> plist;
-			list<Track *>::iterator cur;
-			PlaylistRenderer *renderer;
+			string filename;*/
 
-			void init_common(string, unsigned int);
+			/*void init_common(string, unsigned int);
 
 			void incr_iter(list<Track *>::iterator &);
 			bool pick_next(list<Track *>::iterator &);
 			void sequential_next();
 			void random_next();*/
+			Track *pick_random();
 			void add_sorted(list<Track *> &);
 
 		public:
@@ -53,6 +53,7 @@ namespace libsaria
 			~Playlist();
 			void set_renderer(PlaylistRenderer *);
 
+			virtual Track *next() = 0;
 			string &get_name();
 			unsigned int get_size();
 
@@ -86,6 +87,7 @@ namespace libsaria
 			Set(string, unsigned int);
 			~Set();
 
+			Track *next();
 			void add_tracks(list<Track *> &);
 	};
 

include/libsaria/stack.h

@@ -13,6 +13,7 @@ namespace libsaria
 	{
 
 		void push(Playlist *);
+		void next();
 
 	};
 
@@ -20,7 +21,6 @@ namespace libsaria
 	//void add_to_playlist(list<sid_t> &);
 	Playlist *stack_top();
 	void stack_top_pop();
-	string next_file();
 	void stack_init();
 
 }; /* Namespace: libsaria */

libsaria/audio/audio.cpp

@@ -4,6 +4,7 @@
 #include <libsaria/print.h>
 #include <libsaria/library.h>
 #include <libsaria/callback.h>
+#include <libsaria/stack.h>
 #include "audio.h"
 
 GstElement *player = NULL;
@@ -38,7 +39,7 @@ static gboolean on_message(GstBus *bus, GstMessage *message, gpointer data)
 		case GST_MESSAGE_ERROR:
 			parse_error(message);
 		case GST_MESSAGE_EOS:
-			/*libsaria::next();*/
+			libsaria::stack::next();
 		default:
 			break;
 	}

libsaria/playlist/next.cpp

@@ -14,17 +14,17 @@ static inline bool choose_randomly(unsigned int flags)
 		return true; //libsaria::prefs::get_bool("random");
 	return (flags & PL_RANDOM) == PL_RANDOM;
 }
-
+*/
 namespace libsaria
 {
 
-	void Playlist::incr_iter(list<Track *>::iterator &it)
+	void Playlist::incr_iter()
 	{
-		it++;
-		if (it == plist.end())
-			it = plist.begin();
+		cur++;
+		if (cur == plist.end())
+			cur = plist.begin();
 	}
-
+/*
 	bool Playlist::pick_next(list<Track *>::iterator &it)
 	{
 		incr_iter(it);
@@ -72,9 +72,23 @@ namespace libsaria
 				}*/
 		/*	}
 		}
+	}*/
+
+	Track *Playlist::pick_random()
+	{
+		unsigned int n, size = get_size();
+
+		if (size == 0)
+			return NULL;
+
+		n = rand() % ((size * 3) / 4);
+		for (unsigned int i = 0; i < n; i++)
+			incr_iter();
+
+		return (*cur);
 	}
 
-	Track *Playlist::next()
+	/*Track *Playlist::next()
 	{
 		int index;
 		Track *track;
@@ -99,6 +113,6 @@ namespace libsaria
 		}
 
 		return track;
-	}
+	}*/
 
-};*/ /* Namespace: libsaria */
+}; /* Namespace: libsaria */

libsaria/playlist/playlist.cpp

@@ -45,6 +45,7 @@ namespace libsaria
 		name = n;
 		flags = f;
 		renderer = NULL;
+		cur = plist.begin();
 	}
 
 	Playlist::~Playlist()

libsaria/playlist/set.cpp

@@ -17,4 +17,9 @@ namespace libsaria
 		add_sorted(tracks);
 	}
 
+	Track *Set::next()
+	{
+		return pick_random();
+	}
+
 }; /* Namespace: libsaria */

libsaria/playlist/stack.cpp

@@ -2,6 +2,7 @@
 #include <libsaria/playlist.h>
 #include <libsaria/callback.h>
 #include <libsaria/stack.h>
+#include <libsaria/track.h>
 
 #include <list>
 #include <sstream>
@@ -22,6 +23,14 @@ namespace libsaria
 		playlist_stack.push_front(plist);
 	}
 
+	void stack::next()
+	{
+		Playlist *plist = playlist_stack.front();
+		Track *track = plist->next();
+		if (track)
+			track->play_now();
+	}
+
 	Playlist *new_playlist(string file, unsigned int flags)
 	{
 		/*Playlist *plist = new Playlist(file, flags);

ocarina/body/footer.cpp

@@ -4,6 +4,7 @@
 #include <ocarina/body.h>
 
 #include <libsaria/audio.h>
+#include <libsaria/stack.h>
 
 static GtkWidget *notebook;
 static GtkWidget *idle_progress;
@@ -13,6 +14,7 @@ static GtkWidget *dur_label;
 static GtkWidget *play_button;
 static GtkWidget *pause_button;
 static GtkWidget *stop_button;
+static GtkWidget *next_button;
 static GstState last_state;
 
 static void add_page(string text, GtkWidget *page)
@@ -64,6 +66,11 @@ static void on_click_stop(GtkWidget *b, GdkEvent *e, gpointer d)
 	libsaria::audio::stop();
 }
 
+static void on_click_next(GtkWidget *b, GdkEvent *e, gpointer d)
+{
+	libsaria::stack::next();
+}
+
 static GtkWidget *make_controls()
 {
 	GtkWidget *box = gtk_hbox_new(FALSE, 0);
@@ -71,6 +78,7 @@ static GtkWidget *make_controls()
 	play_button  = make_button(GTK_STOCK_MEDIA_PLAY, on_click_play, true);
 	pause_button = make_button(GTK_STOCK_MEDIA_PAUSE, on_click_pause, false);
 	stop_button  = make_button(GTK_STOCK_MEDIA_STOP, on_click_stop, true);
+	next_button  = make_button(GTK_STOCK_MEDIA_NEXT, on_click_next, true);
 
 	pos_label = gtk_label_new("");
 	track_progress = gtk_hscale_new_with_range(0, 1, 1000000000);
@@ -87,6 +95,7 @@ static GtkWidget *make_controls()
 	gtk_box_pack_start(GTK_BOX(box), play_button,   FALSE, FALSE, 0);
 	gtk_box_pack_start(GTK_BOX(box), pause_button,  FALSE, FALSE, 0);
 	gtk_box_pack_start(GTK_BOX(box), stop_button,   FALSE, FALSE, 0);
+	gtk_box_pack_start(GTK_BOX(box), next_button,   FALSE, FALSE, 0);
 
 	gtk_widget_show(pos_label);
 	gtk_widget_show(dur_label);