/** Return the duration of this staff system. This is the start time
* difference between the first and last measure start time slices in the
* first staff plus the duration of the last measure. (It is assumed that all
* staves in the staff system have the same duration.)
* This is used to compute the screen hotspots of the measure starts.
*/
public Rational getDuration()
{
if (_duration != null)
{
return(_duration);
}
if (getStaffCount() == 0 || getStaff(0).getMeasureStartCount() == 0)
{
// There are no staffs or time slices! This is unexpected. Just return 0.
// DEBUG: maybe this should be handled more gracefully.
_duration = new Rational(0, 1);
return(_duration);
}
Staff staff = getStaff(0);
MeasureStartTimeSlice lastMeasureStart =
staff.getMeasureStart(staff.getMeasureStartCount() - 1);
IntRatio result = new IntRatio(lastMeasureStart.getStartTime());
result.sub(getStartTime());
result.add(lastMeasureStart.getDuration());
_duration = new Rational(result);
return(_duration);
}
/** Creates new Staff from the parentInput's input stream.
* The next object in the input stream must be of this type.
* This also reads all the enclosed MeasureStartTimeSlice objects
* which themselves contain the event TimeSlice and MusicSymbol objects.
*
* @param parentInput the parent RIFF object being used to read the input stream
*/
public static Staff newInstance(Riff parentInput)
{
Riff riffInput = new Riff(parentInput, "LIST");
riffInput.requireFOURCC(RIFF_ID);
Staff staff = new Staff(RiffStaffHeader.newInstance(riffInput));
if (riffInput.getBytesRemaining() <= 0)
// the staff is empty
return staff;
MeasureStartTimeSlice measureStart =
RiffMeasureStartTimeSlice.maybeNew(riffInput);
if (measureStart == null) {
// For some reason, the first chunk in this staff is not a
// measure start time slice. Create a fake one based
// on the previous staff system's end time
// DEBUG: must implement this! For now use start time of 0/1
measureStart = new MeasureStartTimeSlice(new Rational(0, 1), null);
}
while (true) {
if (staff.getMeasureStartCount() > 0 &&
staff.getMeasureStart
(staff.getMeasureStartCount() - 1).getStartTime().Equals
(measureStart.getStartTime()))
// This new measure start time is the same as the last one,
// so just continue using the last one.
// DEBUG: this still doesn't ensure increasing order
// DEBUG: This discards the tags in the newly read measure start
measureStart =
staff.getMeasureStart(staff.getMeasureStartCount() - 1);
else
staff.addMeasureStart(measureStart);
// Read event time slices until the next measure start time slice or
// end of the staff
RiffMeasureStartTimeSlice.addTimeSlices(riffInput, measureStart);
if (riffInput.getBytesRemaining() <= 0)
// reached the end of the staff
break;
// The previous call to readTimeSlices has already
// ensured that the next chunk is a measure start time slice.
measureStart = RiffMeasureStartTimeSlice.newInstance(riffInput);
}
return staff;
}
public int getSymbolCount()
{
if (_symbolPositioner != null)
{
return(_symbolPositioner.getSymbolCount());
}
// Create a new SymbolPositioner and add a position at each quarter note.
_symbolPositioner = new SymbolPositioner();
Rational quarter = new Rational(1, 4);
for (IntRatio r = new IntRatio(0, 1);
r.compareTo(getDuration()) < 0;
r.add(quarter))
{
_symbolPositioner.add(new Rational(r), 0);
}
// Go through the entire staff system and for every measure which
// has the same start time and duration as this, set its
// SymbolPositioner to the new one and call its addToSymbolPositioner
StaffSystem system = getParentStaff().getParentSystem();
for (int staffIndex = 0; staffIndex < system.getStaffCount(); ++staffIndex)
{
Staff staff = system.getStaff(staffIndex);
for (int measureIndex = 0;
measureIndex < staff.getMeasureStartCount();
++measureIndex)
{
MeasureStartTimeSlice measure = staff.getMeasureStart(measureIndex);
if (measure.getStartTime().Equals(getStartTime()) &&
measure.getDuration().Equals(getDuration()))
{
// This is an equivalent measure to this one in another
// staff (or it is this same measure.
measure._symbolPositioner = _symbolPositioner;
measure.addToSymbolPositioner();
// There should not be any more measures in this staff
// with the same start time.
break;
}
}
}
return(_symbolPositioner.getSymbolCount());
}
/** Creates new Staff from the parentInput's input stream.
* The next object in the input stream must be of this type.
* This also reads all the enclosed MeasureStartTimeSlice objects
* which themselves contain the event TimeSlice and MusicSymbol objects.
*
* @param parentInput the parent RIFF object being used to read the input stream
*/
static public Staff newInstance(Riff parentInput)
{
Riff riffInput = new Riff(parentInput, "LIST");
riffInput.requireFOURCC(RIFF_ID);
Staff staff = new Staff(RiffStaffHeader.newInstance(riffInput));
if (riffInput.getBytesRemaining() <= 0)
{
// the staff is empty
return(staff);
}
MeasureStartTimeSlice measureStart =
RiffMeasureStartTimeSlice.maybeNew(riffInput);
if (measureStart == null)
{
// For some reason, the first chunk in this staff is not a
// measure start time slice. Create a fake one based
// on the previous staff system's end time
// DEBUG: must implement this! For now use start time of 0/1
measureStart = new MeasureStartTimeSlice(new Rational(0, 1), null);
}
while (true)
{
if (staff.getMeasureStartCount() > 0 &&
staff.getMeasureStart
(staff.getMeasureStartCount() - 1).getStartTime().Equals
(measureStart.getStartTime()))
{
// This new measure start time is the same as the last one,
// so just continue using the last one.
// DEBUG: this still doesn't ensure increasing order
// DEBUG: This discards the tags in the newly read measure start
measureStart =
staff.getMeasureStart(staff.getMeasureStartCount() - 1);
}
else
{
staff.addMeasureStart(measureStart);
}
// Read event time slices until the next measure start time slice or
// end of the staff
RiffMeasureStartTimeSlice.addTimeSlices(riffInput, measureStart);
if (riffInput.getBytesRemaining() <= 0)
{
// reached the end of the staff
break;
}
// The previous call to readTimeSlices has already
// ensured that the next chunk is a measure start time slice.
measureStart = RiffMeasureStartTimeSlice.newInstance(riffInput);
}
return(staff);
}
