/// <summary>
/// Walk the tree to determine the absolute start and end times of all the elements.
/// the reference times passed in are absolute times, the result of calling this is to set the local start time
/// and end time to absolute times between these two reference times, based on the begin, end and dur attributes
/// and to recursively set all of the children.
/// </summary>
public void ComputeTimeIntervals(TimeContainer context, TimeCode referenceStart, TimeCode referenceEnd)
{
m_startTime = new TimeCode(0d, TimeExpression.CurrentSmpteFrameRate);
m_endTime = new TimeCode(0d, TimeExpression.CurrentSmpteFrameRate);
// compute the beginning of my interval.
TimeCode begin = (Timing.ContainsKey("begin")) ? (TimeCode)Timing["begin"] : new TimeCode(0, TimeExpression.CurrentSmpteFrameRate);
m_startTime = referenceStart + begin;
TimeCode referenceDur, dur, end;
// compute the simple duration of the interval ,
// par children have indefinite default duration, seq children have zero default duration.
// (we dont support indefinite here but truncate to the outer container)
// does end work here? surely it truncates the active duration,
if (!Timing.ContainsKey("dur") && !Timing.ContainsKey("end") && context == TimeContainer.Seq)
{
referenceDur = new TimeCode(0, TimeExpression.CurrentSmpteFrameRate);
}
else
{
if (m_startTime < referenceEnd)
{
referenceDur = referenceEnd - m_startTime;
}
else
{
referenceDur = new TimeCode(0, TimeExpression.CurrentSmpteFrameRate);
}
}
bool containsDur = false;
if (Timing.ContainsKey("dur"))
{
containsDur = true;
dur = (TimeCode)Timing["dur"];
if (dur > referenceDur)
{
dur = referenceDur;
}
}
else
{
dur = referenceDur;
}
m_endTime = m_startTime + dur;
// end can truncate the simple duration.
TimeCode offsetEnd = new TimeCode(0, TimeExpression.CurrentSmpteFrameRate);
offsetEnd += referenceStart;
if (Timing.ContainsKey("end"))
{
end = referenceStart + ((TimeCode)Timing["end"]);
}
else
{
// Original code:
//
// end = referenceEnd;
//
// NOTE: This logic was changed from original TimedText library to properly handle
// Sequential time containers when the duration is indefinite.
if (context == TimeContainer.Par)
{
end = referenceEnd;
}
else
{
end = m_startTime + referenceDur;
}
}
//end = (Timing.ContainsKey("end")) ? (m_startTime.Add((TimeSpan)Timing["end"])) : referenceEnd;
if (!containsDur)
{
m_endTime = end;
}
else
{
m_endTime = (end < m_endTime) ? end : m_endTime;
}
if (TimeSemantics == TimeContainer.Par)
{
foreach (TimeTree <TChildren, TAttribute> child in m_children)
{
child.ComputeTimeIntervals(TimeSemantics, m_startTime, m_endTime);
}
}
else
{
TimeCode s = m_startTime;
foreach (TimeTree <TChildren, TAttribute> child in m_children)
{
child.ComputeTimeIntervals(TimeSemantics, s, m_endTime);
s = child.m_endTime;
}
}
}