core/playlist: Add a function for manually rearranging playlists

Signed-off-by: Anna Schumaker <Anna@NoWheyCreamery.com>

core/playlist.c

@@ -208,6 +208,20 @@ bool playlist_sort(struct playlist *playlist, enum compare_t sort)
 	return g_slist_length(playlist->pl_sort) > 0;
 }
 
+bool playlist_rearrange(struct playlist *playlist, unsigned int old_pos,
+			unsigned int new_pos)
+{
+	bool ret;
+
+	if (!playlist || !playlist->pl_ops->pl_rearrange)
+		return false;
+
+	ret = playlist->pl_ops->pl_rearrange(playlist, old_pos, new_pos);
+	if (ret && playlist->pl_type < PL_MAX_TYPE)
+		playlist_types[playlist->pl_type]->pl_save();
+	return ret;
+}
+
 void playlist_set_search(struct playlist *playlist, const gchar *text)
 {
 	gchar **tokens = NULL;

core/playlists/artist.c

@@ -11,6 +11,7 @@ static struct playlist_ops pl_artist_ops = {
 	.pl_can_select = playlist_generic_can_select,
 	.pl_set_random = playlist_generic_set_random,
 	.pl_sort       = playlist_generic_sort,
+	.pl_rearrange  = playlist_generic_rearrange,
 };
 
 

core/playlists/generic.c

@@ -280,6 +280,22 @@ void playlist_generic_resort(struct playlist *playlist)
 	playlist_generic_update(playlist, NULL);
 }
 
+bool playlist_generic_rearrange(struct playlist *playlist, unsigned int old_pos,
+				unsigned int new_pos)
+{
+	GList *nth;
+
+	if (old_pos == new_pos || old_pos >= playlist_size(playlist) ||
+	    new_pos > playlist_size(playlist))
+		return false;
+
+	playlist_clear_sort(playlist);
+	nth = g_queue_pop_nth_link(&playlist->pl_tracks, old_pos);
+	g_queue_push_nth_link(&playlist->pl_tracks, new_pos, nth);
+	playlist_generic_update(playlist, NULL);
+	return true;
+}
+
 struct track *playlist_generic_next(struct playlist *playlist)
 {
 	unsigned int pos, size = playlist_size(playlist);

core/playlists/library.c

@@ -181,6 +181,7 @@ static struct playlist_ops pl_library_ops = {
 	.pl_delete     = pl_library_delete,
 	.pl_set_random = playlist_generic_set_random,
 	.pl_sort       = playlist_generic_sort,
+	.pl_rearrange  = playlist_generic_rearrange,
 };
 
 

core/playlists/system.c

@@ -82,6 +82,7 @@ static struct playlist_ops favorites_ops = {
 	.pl_remove     = playlist_generic_remove,
 	.pl_set_random = playlist_generic_set_random,
 	.pl_sort       = playlist_generic_sort,
+	.pl_rearrange  = playlist_generic_rearrange,
 };
 
 
@@ -132,6 +133,7 @@ static struct playlist_ops hidden_ops = {
 	.pl_remove     = sys_pl_hidden_remove,
 	.pl_set_random = playlist_generic_set_random,
 	.pl_sort       = playlist_generic_sort,
+	.pl_rearrange  = playlist_generic_rearrange,
 };
 
 
@@ -183,6 +185,7 @@ static struct playlist_ops queued_ops = {
 	.pl_remove     = sys_pl_queued_remove,
 	.pl_set_random = playlist_generic_set_random,
 	.pl_sort       = playlist_generic_sort,
+	.pl_rearrange  = playlist_generic_rearrange,
 };
 
 
@@ -207,6 +210,7 @@ static struct playlist_ops collection_ops = {
 	.pl_remove     = sys_pl_hidden_add,
 	.pl_set_random = playlist_generic_set_random,
 	.pl_sort       = playlist_generic_sort,
+	.pl_rearrange  = playlist_generic_rearrange,
 };
 
 
@@ -232,6 +236,7 @@ static struct playlist_ops dynamic_ops = {
 	.pl_can_select = playlist_generic_can_select,
 	.pl_set_random = playlist_generic_set_random,
 	.pl_sort       = playlist_generic_sort,
+	.pl_rearrange  = playlist_generic_rearrange,
 };
 
 

core/playlists/user.c

@@ -82,6 +82,7 @@ static struct playlist_ops user_ops = {
 	.pl_remove     = playlist_generic_remove,
 	.pl_set_random = playlist_generic_set_random,
 	.pl_sort       = playlist_generic_sort,
+	.pl_rearrange  = playlist_generic_rearrange,
 };
 
 

include/core/playlist.h

@@ -71,6 +71,9 @@ void playlist_set_random(struct playlist *, bool);
 /* Called to change the sort order of the playlist. */
 bool playlist_sort(struct playlist *, enum compare_t);
 
+/* Called to manually rearrange the order of the playlist. */
+bool playlist_rearrange(struct playlist *, unsigned int, unsigned int);
+
 
 /* Called to set the playlist's search text  */
 void playlist_set_search(struct playlist *, const gchar *);

include/core/playlists/generic.h

@@ -82,6 +82,9 @@ void playlist_generic_set_random(struct playlist *, bool);
 void playlist_generic_sort(struct playlist *, enum compare_t);
 void playlist_generic_resort(struct playlist *);
 
+/* Generic playlist rearranging operation. */
+bool playlist_generic_rearrange(struct playlist *, unsigned int, unsigned int);
+
 /* Generic playlist next track operation. */
 struct track *playlist_generic_next(struct playlist *);
 

include/core/playlists/playlist.h

@@ -39,6 +39,9 @@ struct playlist_ops {
 
 	/* Called to sort the playlist. */
 	void (*pl_sort)(struct playlist *, enum compare_t);
+
+	/* Called to rearrange the playlist. */
+	bool (*pl_rearrange)(struct playlist *, unsigned int, unsigned int);
 };
 
 

tests/core/playlist.c

@@ -34,6 +34,7 @@ static struct playlist_ops test_ops = {
 	.pl_remove     = playlist_generic_remove,
 	.pl_set_random = playlist_generic_set_random,
 	.pl_sort       = playlist_generic_sort,
+	.pl_rearrange  = playlist_generic_rearrange,
 };
 static struct playlist_callbacks test_cb = {
 	.pl_cb_alloc   = test_pl_alloc,
@@ -76,6 +77,7 @@ static void test_null()
 	g_assert_false(playlist_sort(NULL, COMPARE_TRACK));
 	playlist_generic_resort(NULL);
 	playlist_clear_sort(NULL);
+	g_assert_false(playlist_rearrange(NULL, 0, 0));
 
 	playlist_set_search(NULL, NULL);
 
@@ -280,6 +282,43 @@ static void test_sorting()
 	g_assert_null(p.pl_sort);
 }
 
+static void test_rearranging()
+{
+	struct playlist p = DEFINE_PLAYLIST(PL_MAX_TYPE, "Test", 0, &test_ops);
+	struct track *track;
+	unsigned int i;
+
+	playlist_generic_init(&p, 4, COMPARE_ARTIST, COMPARE_YEAR,
+				     COMPARE_ALBUM,  COMPARE_TRACK);
+	g_assert_cmpuint(g_slist_length(p.pl_sort), ==, 4);
+
+	for (i = 0; i < 13; i++)
+		playlist_add(&p, track_get(i));
+
+	g_assert_false(playlist_rearrange(&p, 42, 4));
+	g_assert_cmpuint(g_slist_length(p.pl_sort), ==, 4);
+	g_assert_false(playlist_rearrange(&p, 4, 42));
+	g_assert_cmpuint(g_slist_length(p.pl_sort), ==, 4);
+	g_assert_false(playlist_rearrange(&p, 4, 4));
+	g_assert_cmpuint(g_slist_length(p.pl_sort), ==, 4);
+	g_assert_true(playlist_rearrange(&p, 12, 0));
+	g_assert_cmpuint(g_slist_length(p.pl_sort), ==, 0);
+	g_assert_true(playlist_rearrange(&p, 1, 12));
+	g_assert_cmpuint(g_slist_length(p.pl_sort), ==, 0);
+
+	for (i = 0; i < 13; i++) {
+		track = playlist_at(&p, i);
+		if (i == 0)
+			g_assert_cmpuint(track->tr_track, ==, 13);
+		else if (i == 12)
+			g_assert_cmpuint(track->tr_track, ==, 1);
+		else
+			g_assert_cmpuint(track->tr_track, ==, i + 1);
+	}
+
+	playlist_generic_deinit(&p);
+}
+
 static void test_next()
 {
 	struct playlist p = DEFINE_PLAYLIST(PL_MAX_TYPE, "Test", 0, &test_ops);
@@ -404,6 +443,7 @@ int main(int argc, char **argv)
 	g_test_add_func("/Core/Playlist/NULL", test_null);
 	g_test_add_func("/Core/Playlists/General", test_playlist);
 	g_test_add_func("/Core/Playlists/Sorting", test_sorting);
+	g_test_add_func("/Core/Playlists/Rearranging", test_rearranging);
 	g_test_add_func("/Core/Playlists/Next Track", test_next);
 	g_test_add_func("/Core/Playlist/Save and Load", test_save_load);
 	ret = g_test_run();

tests/core/playlists/library.c

@@ -76,7 +76,7 @@ void test_library()
 	g_assert_false(playlist->pl_random);
 
 	g_assert_cmpuint(g_slist_length(playlist->pl_sort), ==, 4);
-	playlist_clear_sort(playlist);
+	g_assert_true(playlist_rearrange(playlist, 15, 20));
 	g_assert_cmpuint(g_slist_length(playlist->pl_sort), ==, 0);
 	g_assert_true(playlist_sort(playlist, COMPARE_ARTIST));
 	g_assert_cmpuint(g_slist_length(playlist->pl_sort), ==, 1);