libsaria: Add in a simple notification system

Right now it only notifies that an event happened.  I think I should
eventually pass in an additional argument related to the event that
happened.  This will allow me to send out notifications for preferences
or library paths changing.

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

include/libsaria/libsaria.h

@@ -1,6 +1,7 @@
 #ifndef LIBSARIA_H
 #define LIBSARIA_H
 
+#include <libsaria/notify.h>
 #include <libsaria/track.h>
 
 namespace libsaria
@@ -9,6 +10,7 @@ namespace libsaria
 		int argc;
 		char **argv;
 		string name;
+		void (*on_notify)(notify_t);
 	};
 
 	void init(struct initdata *);

include/libsaria/notify.h

@@ -0,0 +1,15 @@
+// Copyright (c) 2012 Bryan Schumaker.
+#ifndef LIBSARIA_NOTIFY_H
+#define LIBSARIA_NOTIFY_H
+
+enum notify_t {
+	TRACK_CHANGED,
+	NOTIFY_SIZE,
+};
+
+namespace libsaria
+{
+	void notify(notify_t);
+}
+
+#endif /* LIBSARIA_NOTIFY_H */

include/ocarina/ocarina.h

@@ -1,6 +1,7 @@
 #ifndef OCARINA_H
 #define OCARINA_H
 
+#include <libsaria/notify.h>
 #include <libsaria/print.h>
 
 #include <gtk/gtk.h>
@@ -10,6 +11,9 @@ using namespace std;
 /* library.cpp */
 void init_library();
 
+/* notify.cpp */
+void on_notify(notify_t);
+
 /* ocarina.cpp */
 string lib_file(const string &);
 GObject *get_object(const string &);
@@ -27,6 +31,7 @@ void init_playlist();
 bool update_idle_bar(int);
 void update_length_label(string &);
 void update_status();
+void update_labels();
 void init_status();
 
 namespace ocarina

libsaria/libsaria.cpp

@@ -1,6 +1,7 @@
 // Copyright (c) 2011 Bryan Schumaker.
 #include <libsaria/libsaria.h>
 #include <libsaria/library.h>
+#include <libsaria/notify.h>
 #include <libsaria/format.h>
 #include <libsaria/prefs.h>
 #include <libsaria/print.h>
@@ -12,12 +13,14 @@
 #include <libsaria/fs.h>
 
 static libsaria::Track outside_track;
+static libsaria::initdata *app_data;
 
 namespace libsaria
 {
 
 	void init(struct initdata *init)
 	{
+		app_data = init;
 		srand( time(NULL) );
 		println("Initializing libsaria");
 
@@ -53,4 +56,10 @@ namespace libsaria
 		outside_track.load(true);
 	}
 
+	void notify(notify_t event)
+	{
+		if (app_data->on_notify)
+			app_data->on_notify(event);
+	}
+
 };

libsaria/track/track.cpp

@@ -1,5 +1,6 @@
 // Copyright (c) 2011 Bryan Schumaker.
 #include <libsaria/library.h>
+#include <libsaria/notify.h>
 #include <libsaria/format.h>
 #include <libsaria/track.h>
 #include <libsaria/audio.h>
@@ -183,6 +184,7 @@ namespace libsaria
 		}
 
 		cur = this;
+		notify(TRACK_CHANGED);
 	}
 
 	void Track::load(bool play)

ocarina/notify.cpp

@@ -0,0 +1,12 @@
+// Copyright (c) 2012 Bryan Schumaker.
+#include <ocarina/ocarina.h>
+
+void on_notify(notify_t event)
+{
+	switch (event) {
+	case TRACK_CHANGED:
+		update_labels();
+	default:
+		break;
+	}
+}

ocarina/ocarina.cpp

@@ -1,6 +1,7 @@
 // Copyright (c) 2011 Bryan Schumaker
 #include <version.h>
 #include <libsaria/libsaria.h>
+#include <libsaria/notify.h>
 #include <libsaria/audio.h>
 #include <libsaria/deck.h>
 #include <libsaria/idle.h>
@@ -175,6 +176,7 @@ int main(int argc, char **argv)
 		argc,
 		argv,
 		"ocarina",	/* app name */
+		on_notify,	/* notification handler */
 	};
 	println("Ocarina " + vers_str());
 	find_lib_path();

ocarina/status.cpp

@@ -32,13 +32,9 @@ static void refresh_widgets()
 	set_label("DurLabel", cur_track->get_lenstr(), "");
 }
 
-static void update_labels()
+void update_labels()
 {
-	libsaria::Track *cur = libsaria::current_track();
-	if (cur == cur_track)
-		return;
-
-	cur_track = cur;
+	cur_track = libsaria::current_track();
 	refresh_widgets();
 	gtk_toggle_button_set_active(GTK_TOGGLE_BUTTON(get_widget("BanButton")),
 				     cur_track->get_banned());
@@ -162,7 +158,6 @@ void update_length_label(string &text)
 
 void update_status()
 {
-	update_labels();
 	update_buttons();
 	update_progress();
 	update_autopause();