17. Spanners

17.1. Overriding spanners

The symbols below are black with fixed thickness and predetermined spacing:

abjad> staff = Staff("c'4 d'4 e'4 f'4 g'4 a'4 g'2")
abjad> slur_1 = spannertools.SlurSpanner(staff[:2])
abjad> slur_2 = spannertools.SlurSpanner(staff[2:4])
abjad> slur_3 = spannertools.SlurSpanner(staff[4:6])

abjad> f(staff)
\new Staff {
        c'4 (
        d'4 )
        e'4 (
        f'4 )
        g'4 (
        a'4 )
        g'2
}

abjad> show(staff)

But you can override LilyPond grobs to change the look of spanners:

abjad> slur_1.override.slur.color = 'red'
abjad> slur_3.override.slur.color = 'red'

abjad> f(staff)
\new Staff {
        \override Slur #'color = #red
        c'4 (
        d'4 )
        \revert Slur #'color
        e'4 (
        f'4 )
        \override Slur #'color = #red
        g'4 (
        a'4 )
        \revert Slur #'color
        g'2
}

abjad> show(staff)

17.2. Overriding the components to which spanners attach

You can override LilyPond grobs to change spanners’ contents:

abjad> slur_2.override.slur.color = 'blue'
abjad> slur_2.override.note_head.color = 'blue'
abjad> slur_2.override.stem.color = 'blue'

abjad> f(staff)
\new Staff {
        \override Slur #'color = #red
        c'4 (
        d'4 )
        \revert Slur #'color
        \override NoteHead #'color = #blue
        \override Slur #'color = #blue
        \override Stem #'color = #blue
        e'4 (
        f'4 )
        \revert NoteHead #'color
        \revert Slur #'color
        \revert Stem #'color
        \override Slur #'color = #red
        g'4 (
        a'4 )
        \revert Slur #'color
        g'2
}

abjad> show(staff)

17.3. Removing spanner overrides

Delete grob overrides you no longer want:

abjad> del(slur_1.override.slur)
abjad> del(slur_3.override.slur)

abjad> f(staff)
\new Staff {
        c'4 (
        d'4 )
        \override NoteHead #'color = #blue
        \override Slur #'color = #blue
        \override Stem #'color = #blue
        e'4 (
        f'4 )
        \revert NoteHead #'color
        \revert Slur #'color
        \revert Stem #'color
        g'4 (
        a'4 )
        g'2
}

abjad> show(staff)