JFugue: Get music string duration

Question

Given the music string Aq Aq Bi Bi Ci Ci is there an object in JFugue that can retrieve its duration (as a double or as a string)?

For example:

double musicStringDuration = new DurationMapper().getDoubleMSDuration("Aq Aq Bi Bi Ci Ci");
System.out.println(musicStringDuration); \\ prints 1.0

Answer 1

JFugue's org.jfugue.tools package contains several tools, including one that will tell you the total duration of a each voice (whether those voices is written as Staccato Strings like you have, or as MIDI channels for music you import, or anything else that JFugue can parse - and it's easy to write new parsers). ComputeDurationForEachTrackTool (and another tool, GetInstrumentsUsedTool) are ParserListeners, and there is a common pattern in JFugue to use a Parser Listener:

*Some*Parser parser = new *Some*Parser();
*Another*ParserListener listener = new *Another*ParserListener();
parser.addParserListener(listener);
parser.parse(*whatever the parser takes*);
*Type* *value* = listener.*method*();

Specifically for your case, you would have:

StaccatoParser parser = new StaccatoParser();
ComputeDurationForEachTrackTool tool = new ComputeDurationForEachTrackTool();
parser.addParserListener(tool);
parser.parse("Aq Aq Bi Bi Ci Ci");
double[] durationsOfEachVoice = tool.getDurations();

While this is longer than the statement you suggested in your question, this is immensely powerful, as it provides a means to connect any parser to any parser listener or tool.

You would find 1.0 in durationsOfEachVoice[0].

Actually, you'll find 2.0 in there, which is unexpected. But I just ran a test on it, and it's returning 0.5 for a quarter note and 0.25 for an eighth note. Sounds like a fix for JFugue version 6! In the meantime, please divide by 2.0 and accept my apologies.