Iterate klass instances in expr and accumulate duration in seconds. Add line break after every total less than or equal to line_duration:
abjad> from abjad.tools import layouttools
abjad> t = Staff(Measure((2, 8), notetools.make_repeated_notes(2)) * 4)
abjad> pitchtools.set_ascending_named_diatonic_pitches_on_nontied_pitched_components_in_expr(t)
abjad> tempo_mark = contexttools.TempoMark(Duration(1, 8), 44, target_context = Staff)(t)
abjad> f(t)
\new Staff {
\tempo 8=44
{
\time 2/8
c'8
d'8
}
{
\time 2/8
e'8
f'8
}
{
\time 2/8
g'8
a'8
}
{
\time 2/8
b'8
c''8
}
}
abjad> layouttools.set_line_breaks_cyclically_by_line_duration_in_seconds_ge(t, Duration(6))
abjad> f(t)
\new Staff {
\tempo 8=44
{
\time 2/8
c'8
d'8
}
{
\time 2/8
e'8
f'8
\break
}
{
\time 2/8
g'8
a'8
}
{
\time 2/8
b'8
c''8
}
}
Set adjust_eol = True to include a magic Scheme incantation to move end-of-line LilyPond TimeSignature and BarLine grobs to the right.
Changed in version 2.0: renamed layout.line_break_every_seconds() to layout.set_line_breaks_cyclically_by_line_duration_in_seconds_ge().