playqueue: Add a way to delete rows by track_id

This will be used to delete tracks that no longer exist in the library.

Signed-off-by: Anna Schumaker <schumaker.anna@gmail.com>

design/playqueue.txt

@@ -91,6 +91,9 @@ Playqueue: (lib/playqueue.cpp)
 		Erase tracks[playqueue_id] from the tracks vector.
 		length -= track.length.
 
+	void Playqueue :: del_track(unsigned int track_id);
+		Erase all tracks with track id track_id.
+
 	void Playqueue :: set_flag(playqueue_flags flag);
 	void Playqueue :: unset_flag(playqueue_flags flag);
 		Set or unset the given flag.

include/playqueue.h

@@ -36,6 +36,7 @@ public:
 	unsigned int add(unsigned int);
 	unsigned int add_front(unsigned int);
 	void del(unsigned int);
+	void del_track(unsigned int);
 	unsigned int size();
 
 	unsigned int next();

lib/playqueue.cpp

@@ -85,6 +85,17 @@ void Playqueue :: del(unsigned int plist_id)
 	length -= song.track->length;
 }
 
+void Playqueue :: del_track(unsigned int track_id)
+{
+	unsigned int i = 0;
+	while (i < tracks.size()) {
+		if (tracks[i] == track_id)
+			del(i);
+		else
+			i++;
+	}
+}
+
 unsigned int Playqueue :: size()
 {
 	return tracks.size();

tests/playqueue/playqueue.cpp

@@ -181,6 +181,25 @@ void test_6()
 	while (pqueue.size() > 0)
 		print("Selecting id: %u\n", pqueue.next());
 	test_pqueue_status("6b", pqueue);
+	print("\n");
+}
+
+void test_7()
+{
+	char test[] = "7a";
+	Playqueue pqueue(PQ_ENABLED);
+
+	for (unsigned int i = 0; i < 60; i++)
+		pqueue.add(i % 15);
+	test_pqueue_status(test, pqueue);
+
+	for (unsigned int i = 0; i < 15; i++) {
+		pqueue.del_track(i);
+		if ((i + 1) % 3 == 0) {
+			test[1]++;
+			test_pqueue_status(test, pqueue);
+		}
+	}
 }
 
 int main(int argc, char **argv)
@@ -198,5 +217,6 @@ int main(int argc, char **argv)
 	test_4();
 	test_5();
 	test_6();
+	test_7();
 	return 0;
 }

tests/playqueue/playqueue.good

@@ -112,3 +112,10 @@ Selecting id: 12
 Selecting id: 14
 Selecting id: 3
 Test 6b: size: 0, length: 0
+
+Test 7a: size: 60, length: 8572
+Test 7b: size: 48, length: 8288
+Test 7c: size: 36, length: 5608
+Test 7d: size: 24, length: 2964
+Test 7e: size: 12, length: 2644
+Test 7f: size: 0, length: 0