From d430e09a59f6fcabf7d6a73dde50221e32894cdc Mon Sep 17 00:00:00 2001
From: Anna Schumaker <schumaker.anna@gmail.com>
Date: Sun, 26 Jan 2014 13:44:25 -0500
Subject: [PATCH] playqueue: Generic sorting

I don't save the sort order yet.

Signed-off-by: Anna Schumaker <schumaker.anna@gmail.com>
---
 include/callback.h |  1 +
 lib/callback.cpp   |  1 +
 lib/playqueue.cpp  | 20 ++++++++++++++++++++
 3 files changed, 22 insertions(+)

diff --git a/include/callback.h b/include/callback.h
index 505af9f9..8ebb7b5d 100644
--- a/include/callback.h
+++ b/include/callback.h
@@ -24,6 +24,7 @@ struct Callbacks {
 	/* Playqueue callbacks */
 	void (*on_queue_track_add)(Playqueue *, unsigned int);
 	void (*on_queue_track_del)(Playqueue *, unsigned int);
+	void (*on_queue_track_changed)(Playqueue *, unsigned int);
 	void (*on_queue_changed)();
 };
 
diff --git a/lib/callback.cpp b/lib/callback.cpp
index 21683a9c..0ce97be9 100644
--- a/lib/callback.cpp
+++ b/lib/callback.cpp
@@ -25,6 +25,7 @@ static struct Callbacks callbacks = {
 
 	.on_queue_track_add	= no_op,
 	.on_queue_track_del	= no_op,
+	.on_queue_track_changed	= no_op,
 	.on_queue_changed	= no_op,
 };
 
diff --git a/lib/playqueue.cpp b/lib/playqueue.cpp
index f4a9f005..92631cbe 100644
--- a/lib/playqueue.cpp
+++ b/lib/playqueue.cpp
@@ -6,6 +6,7 @@
 #include <playqueue.h>
 
 #include <stdlib.h>
+#include <algorithm>
 #include <sstream>
 
 #define O_MINUTES (60)
@@ -241,12 +242,31 @@ unsigned int Playqueue :: size()
 	return tracks.size();
 }
 
+
+/* Sorting function */
+class SortTracks {
+private:
+	std::list<sort_t> fields;
+public:
+	SortTracks(std::list<sort_t> f) : fields(f) {}
+	bool operator()(unsigned int a, unsigned int b)
+	{
+		library::Song lhs, rhs;
+		library :: lookup(a, &lhs);
+		library :: lookup(b, &rhs);
+		return track_less_than(lhs, rhs, fields);
+	}
+};
+
 void Playqueue :: add_sort(sort_t field)
 {
 	sort_order.remove(field);
 	sort_order.push_back(field);
 	if (sort_order.size() >= 4)
 		sort_order.erase(sort_order.begin());
+	std::stable_sort(tracks.begin(), tracks.end(), SortTracks(sort_order));
+	for (unsigned int i = 0; i < tracks.size(); i++)
+		get_callbacks()->on_queue_track_changed(this, i);
 }
 
 void Playqueue :: reset_sort(sort_t field)